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</div> <div class="control"> <button class="button is-small is-link">Go</button> </div> </div> </form> </div> </div> <ol class="breathe-horizontal" start="1"> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2408.02804">arXiv:2408.02804</a> <span> [<a href="https://arxiv.org/pdf/2408.02804">pdf</a>, <a href="https://arxiv.org/format/2408.02804">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Instrumentation and Methods for Astrophysics">astro-ph.IM</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Instrumentation and Detectors">physics.ins-det</span> </div> </div> <p class="title is-5 mathjax"> GEO600 beam splitter thermal compensation system: new design and commissioning </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Nadji%2C+S">S茅verin Nadji</a>, <a href="/search/physics?searchtype=author&query=Wittel%2C+H">Holger Wittel</a>, <a href="/search/physics?searchtype=author&query=Mukund%2C+N">Nikhil Mukund</a>, <a href="/search/physics?searchtype=author&query=Lough%2C+J">James Lough</a>, <a href="/search/physics?searchtype=author&query=Affeldt%2C+C">Christoph Affeldt</a>, <a href="/search/physics?searchtype=author&query=Bergamin%2C+F">Fabio Bergamin</a>, <a href="/search/physics?searchtype=author&query=Brinkmann%2C+M">Marc Brinkmann</a>, <a href="/search/physics?searchtype=author&query=Kringel%2C+V">Volker Kringel</a>, <a href="/search/physics?searchtype=author&query=L%C3%BCck%2C+H">Harald L眉ck</a>, <a href="/search/physics?searchtype=author&query=Weinert%2C+M">Michael Weinert</a>, <a href="/search/physics?searchtype=author&query=Danzmann%2C+K">Karsten Danzmann</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2408.02804v1-abstract-short" style="display: inline;"> Gravitational waves have revolutionised the field of astronomy by providing scientists with a new way to observe the universe and gain a better understanding of exotic objects like black holes. Several large-scale laser interferometric gravitational wave detectors (GWDs) have been constructed worldwide, with a focus on achieving the best sensitivity possible. However, in order for a detector to op… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2408.02804v1-abstract-full').style.display = 'inline'; document.getElementById('2408.02804v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2408.02804v1-abstract-full" style="display: none;"> Gravitational waves have revolutionised the field of astronomy by providing scientists with a new way to observe the universe and gain a better understanding of exotic objects like black holes. Several large-scale laser interferometric gravitational wave detectors (GWDs) have been constructed worldwide, with a focus on achieving the best sensitivity possible. However, in order for a detector to operate at its intended sensitivity, its optics must be free from imperfections such as thermal lensing effects. In the GEO\,600 gravitational wave detector, the beam splitter (BS) experiences a significant thermal lensing effect due to the high power build-up in the Power Recycling Cavity (PRC) combined with a very small beam waist. This causes the fundamental mode to be converted into higher order modes (HOMs), subsequently impacting the detector's performance. To address this issue, the GEO\,600 detector is equipped with a thermal compensation system (TCS) applied to the BS. This involves projecting a spatially tunable heating pattern through an optical system onto the beam splitter. The main objective of the TCS is to counteract the thermal lens at the BS and restore the detector to its ideal operating condition. This paper presents the new beam splitter TCS in GEO\,600, its commissioning, and its effect on strain sensitivity. It also outlines the planned upgrade to further enhance the performance of the TCS. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2408.02804v1-abstract-full').style.display = 'none'; document.getElementById('2408.02804v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 5 August, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">14 pages, 10 figures</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2305.18284">arXiv:2305.18284</a> <span> [<a href="https://arxiv.org/pdf/2305.18284">pdf</a>, <a href="https://arxiv.org/format/2305.18284">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Optics">physics.optics</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Instrumentation and Methods for Astrophysics">astro-ph.IM</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Instrumentation and Detectors">physics.ins-det</span> </div> </div> <p class="title is-5 mathjax"> Characterization and evasion of backscattered light in the squeezed-light enhanced gravitational wave interferometer GEO 600 </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Bergamin%2C+F">Fabio Bergamin</a>, <a href="/search/physics?searchtype=author&query=Lough%2C+J">James Lough</a>, <a href="/search/physics?searchtype=author&query=Schreiber%2C+E">Emil Schreiber</a>, <a href="/search/physics?searchtype=author&query=Grote%2C+H">Hartmut Grote</a>, <a href="/search/physics?searchtype=author&query=Mehmet%2C+M">Moritz Mehmet</a>, <a href="/search/physics?searchtype=author&query=Vahlbruch%2C+H">Henning Vahlbruch</a>, <a href="/search/physics?searchtype=author&query=Affeldt%2C+C">Christoph Affeldt</a>, <a href="/search/physics?searchtype=author&query=Andric%2C+T">Tomislav Andric</a>, <a href="/search/physics?searchtype=author&query=Bisht%2C+A">Aparna Bisht</a>, <a href="/search/physics?searchtype=author&query=Bringmann%2C+M">Marc Bringmann</a>, <a href="/search/physics?searchtype=author&query=Kringel%2C+V">Volker Kringel</a>, <a href="/search/physics?searchtype=author&query=L%C3%BCck%2C+H">Harald L眉ck</a>, <a href="/search/physics?searchtype=author&query=Mukund%2C+N">Nikhil Mukund</a>, <a href="/search/physics?searchtype=author&query=Nadji%2C+S">Severin Nadji</a>, <a href="/search/physics?searchtype=author&query=Sorazu%2C+B">Borja Sorazu</a>, <a href="/search/physics?searchtype=author&query=Strain%2C+K">Kenneth Strain</a>, <a href="/search/physics?searchtype=author&query=Weinert%2C+M">Michael Weinert</a>, <a href="/search/physics?searchtype=author&query=Danzmann%2C+K">Karsten Danzmann</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2305.18284v1-abstract-short" style="display: inline;"> Squeezed light is injected into the dark port of gravitational wave interferometers, in order to reduce the quantum noise. A fraction of the interferometer output light can reach the OPO due to sub-optimal isolation of the squeezing injection path. This backscattered light interacts with squeezed light generation process, introducing additional measurement noise. We present a theoretical descripti… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2305.18284v1-abstract-full').style.display = 'inline'; document.getElementById('2305.18284v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2305.18284v1-abstract-full" style="display: none;"> Squeezed light is injected into the dark port of gravitational wave interferometers, in order to reduce the quantum noise. A fraction of the interferometer output light can reach the OPO due to sub-optimal isolation of the squeezing injection path. This backscattered light interacts with squeezed light generation process, introducing additional measurement noise. We present a theoretical description of the noise coupling mechanism. We propose a control scheme to achieve a de-amplification of the backscattered light inside the OPO with a consequent reduction of the noise caused by it. The scheme was implemented at the GEO 600 detector and has proven to be crucial in maintaining a good level of quantum noise reduction of the interferometer for high parametric gain of the OPO. In particular, the mitigation of the backscattered light noise helped in reaching 6dB of quantum noise reduction [Phys. Rev. Lett. 126, 041102 (2021)]. The impact of backscattered-light-induced noise on the squeezing performance is phenomenologically equivalent to increased phase noise of the squeezing angle control. The results discussed in this paper provide a way for a more accurate estimation of the residual phase noise of the squeezed light field. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2305.18284v1-abstract-full').style.display = 'none'; document.getElementById('2305.18284v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 29 May, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">14 pages, 6 figures</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2301.06221">arXiv:2301.06221</a> <span> [<a href="https://arxiv.org/pdf/2301.06221">pdf</a>, <a href="https://arxiv.org/format/2301.06221">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Instrumentation and Detectors">physics.ins-det</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Instrumentation and Methods for Astrophysics">astro-ph.IM</span> </div> </div> <p class="title is-5 mathjax"> First demonstration of neural sensing and control in a kilometer-scale gravitational wave observatory </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Mukund%2C+N">Nikhil Mukund</a>, <a href="/search/physics?searchtype=author&query=Lough%2C+J">James Lough</a>, <a href="/search/physics?searchtype=author&query=Bisht%2C+A">Aparna Bisht</a>, <a href="/search/physics?searchtype=author&query=Wittel%2C+H">Holger Wittel</a>, <a href="/search/physics?searchtype=author&query=Nadji%2C+S+L">S茅verin Landry Nadji</a>, <a href="/search/physics?searchtype=author&query=Affeldt%2C+C">Christoph Affeldt</a>, <a href="/search/physics?searchtype=author&query=Bergamin%2C+F">Fabio Bergamin</a>, <a href="/search/physics?searchtype=author&query=Brinkmann%2C+M">Marc Brinkmann</a>, <a href="/search/physics?searchtype=author&query=Kringel%2C+V">Volker Kringel</a>, <a href="/search/physics?searchtype=author&query=L%C3%BCck%2C+H">Harald L眉ck</a>, <a href="/search/physics?searchtype=author&query=Weinert%2C+M">Michael Weinert</a>, <a href="/search/physics?searchtype=author&query=Danzmann%2C+K">Karsten Danzmann</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2301.06221v2-abstract-short" style="display: inline;"> Suspended optics in gravitational wave (GW) observatories are susceptible to alignment perturbations, particularly slow drifts over time, due to variations in temperature and seismic levels. Such misalignments affect the coupling of the incident laser beam into the optical cavities, degrade both circulating power and optomechanical photon squeezing and thus decrease the astrophysical sensitivity t… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2301.06221v2-abstract-full').style.display = 'inline'; document.getElementById('2301.06221v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2301.06221v2-abstract-full" style="display: none;"> Suspended optics in gravitational wave (GW) observatories are susceptible to alignment perturbations, particularly slow drifts over time, due to variations in temperature and seismic levels. Such misalignments affect the coupling of the incident laser beam into the optical cavities, degrade both circulating power and optomechanical photon squeezing and thus decrease the astrophysical sensitivity to merging binaries. Traditional alignment techniques involve differential wavefront sensing using multiple quadrant photodiodes but are often restricted in bandwidth and are limited by the sensing noise. We present the first-ever successful implementation of neural network-based sensing and control at a gravitational wave observatory and demonstrate low-frequency control of the signal recycling mirror at the GEO 600 detector. Alignment information for three critical optics is simultaneously extracted from the interferometric dark port camera images via a CNN-LSTM network architecture and is then used for MIMO control using soft actor-critic-based deep reinforcement learning. Overall sensitivity improvement achieved using our scheme demonstrates deep learning's capabilities as a viable tool for real-time sensing and control for current and next-generation GW interferometers. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2301.06221v2-abstract-full').style.display = 'none'; document.getElementById('2301.06221v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 24 April, 2023; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 15 January, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">12 pages, 8 figures</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2208.09320">arXiv:2208.09320</a> <span> [<a href="https://arxiv.org/pdf/2208.09320">pdf</a>, <a href="https://arxiv.org/format/2208.09320">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Instrumentation and Detectors">physics.ins-det</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1088/1361-6382/aca45b">10.1088/1361-6382/aca45b <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> A vertical inertial sensor with interferometric readout </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Kranzhoff%2C+S+L">S. L. Kranzhoff</a>, <a href="/search/physics?searchtype=author&query=Lehmann%2C+J">J. Lehmann</a>, <a href="/search/physics?searchtype=author&query=Kirchhoff%2C+R">R. Kirchhoff</a>, <a href="/search/physics?searchtype=author&query=Carlassara%2C+M">M. Carlassara</a>, <a href="/search/physics?searchtype=author&query=Cooper%2C+S+J">S. J. Cooper</a>, <a href="/search/physics?searchtype=author&query=Koch%2C+P">P. Koch</a>, <a href="/search/physics?searchtype=author&query=Leavey%2C+S">S. Leavey</a>, <a href="/search/physics?searchtype=author&query=Lueck%2C+H">H. Lueck</a>, <a href="/search/physics?searchtype=author&query=Mow-Lowry%2C+C+M">C. M. Mow-Lowry</a>, <a href="/search/physics?searchtype=author&query=Woehler%2C+J">J. Woehler</a>, <a href="/search/physics?searchtype=author&query=von+Wrangel%2C+J">J. von Wrangel</a>, <a href="/search/physics?searchtype=author&query=Wu%2C+D+S">D. S. Wu</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2208.09320v1-abstract-short" style="display: inline;"> High precision interferometers such as gravitational-wave detectors require complex seismic isolation systems in order to decouple the experiment from unwanted ground motion. Improved inertial sensors for active isolation potentially enhance the sensitivity of existing and future gravitational-wave detectors, especially below 30 Hz, and thereby increase the range of detectable astrophysical signal… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2208.09320v1-abstract-full').style.display = 'inline'; document.getElementById('2208.09320v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2208.09320v1-abstract-full" style="display: none;"> High precision interferometers such as gravitational-wave detectors require complex seismic isolation systems in order to decouple the experiment from unwanted ground motion. Improved inertial sensors for active isolation potentially enhance the sensitivity of existing and future gravitational-wave detectors, especially below 30 Hz, and thereby increase the range of detectable astrophysical signals. This paper presents a vertical inertial sensor which senses the relative motion between an inertial test mass suspended by a blade spring and a seismically isolated platform. An interferometric readout was used which introduces low sensing noise, and preserves a large dynamic range due to fringe-counting. The expected sensitivity is comparable to other state-of-the-art interferometric inertial sensors and reaches values of $10^{-10}\,\text{m}/\sqrt{\text{Hz}}$ at 100 mHz and $10^{-12}\,\text{m}/\sqrt{\text{Hz}}$ at 1 Hz. The potential sensitivity improvement compared to commercial L-4C geophones is shown to be about two orders of magnitude at 10 mHz and 100 mHz and one order of magnitude at 1 Hz. The noise performance is expected to be limited by thermal noise of the inertial test mass suspension below 10 Hz. Further performance limitations of the sensor, such as tilt-to-vertical coupling from a non-perfect levelling of the test mass and nonlinearities in the interferometric readout, are also quantified and discussed. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2208.09320v1-abstract-full').style.display = 'none'; document.getElementById('2208.09320v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 19 August, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 2022. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2206.04905">arXiv:2206.04905</a> <span> [<a href="https://arxiv.org/pdf/2206.04905">pdf</a>, <a href="https://arxiv.org/format/2206.04905">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Instrumentation and Methods for Astrophysics">astro-ph.IM</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="General Relativity and Quantum Cosmology">gr-qc</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Instrumentation and Detectors">physics.ins-det</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1088/1361-6382/ac8fdb">10.1088/1361-6382/ac8fdb <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> ETpathfinder: a cryogenic testbed for interferometric gravitational-wave detectors </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Utina%2C+A">A. Utina</a>, <a href="/search/physics?searchtype=author&query=Amato%2C+A">A. Amato</a>, <a href="/search/physics?searchtype=author&query=Arends%2C+J">J. Arends</a>, <a href="/search/physics?searchtype=author&query=Arina%2C+C">C. Arina</a>, <a href="/search/physics?searchtype=author&query=de+Baar%2C+M">M. de Baar</a>, <a href="/search/physics?searchtype=author&query=Baars%2C+M">M. Baars</a>, <a href="/search/physics?searchtype=author&query=Baer%2C+P">P. Baer</a>, <a href="/search/physics?searchtype=author&query=van+Bakel%2C+N">N. van Bakel</a>, <a href="/search/physics?searchtype=author&query=Beaumont%2C+W">W. Beaumont</a>, <a href="/search/physics?searchtype=author&query=Bertolini%2C+A">A. Bertolini</a>, <a href="/search/physics?searchtype=author&query=van+Beuzekom%2C+M">M. van Beuzekom</a>, <a href="/search/physics?searchtype=author&query=Biersteker%2C+S">S. Biersteker</a>, <a href="/search/physics?searchtype=author&query=Binetti%2C+A">A. Binetti</a>, <a href="/search/physics?searchtype=author&query=ter+Brake%2C+H+J+M">H. J. M. ter Brake</a>, <a href="/search/physics?searchtype=author&query=Bruno%2C+G">G. Bruno</a>, <a href="/search/physics?searchtype=author&query=Bryant%2C+J">J. Bryant</a>, <a href="/search/physics?searchtype=author&query=Bulten%2C+H+J">H. J. Bulten</a>, <a href="/search/physics?searchtype=author&query=Busch%2C+L">L. Busch</a>, <a href="/search/physics?searchtype=author&query=Cebeci%2C+P">P. Cebeci</a>, <a href="/search/physics?searchtype=author&query=Collette%2C+C">C. Collette</a>, <a href="/search/physics?searchtype=author&query=Cooper%2C+S">S. Cooper</a>, <a href="/search/physics?searchtype=author&query=Cornelissen%2C+R">R. Cornelissen</a>, <a href="/search/physics?searchtype=author&query=Cuijpers%2C+P">P. Cuijpers</a>, <a href="/search/physics?searchtype=author&query=van+Dael%2C+M">M. van Dael</a>, <a href="/search/physics?searchtype=author&query=Danilishin%2C+S">S. Danilishin</a> , et al. (90 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2206.04905v1-abstract-short" style="display: inline;"> The third-generation of gravitational wave observatories, such as the Einstein Telescope (ET) and Cosmic Explorer (CE), aim for an improvement in sensitivity of at least a factor of ten over a wide frequency range compared to the current advanced detectors. In order to inform the design of the third-generation detectors and to develop and qualify their subsystems, dedicated test facilities are req… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2206.04905v1-abstract-full').style.display = 'inline'; document.getElementById('2206.04905v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2206.04905v1-abstract-full" style="display: none;"> The third-generation of gravitational wave observatories, such as the Einstein Telescope (ET) and Cosmic Explorer (CE), aim for an improvement in sensitivity of at least a factor of ten over a wide frequency range compared to the current advanced detectors. In order to inform the design of the third-generation detectors and to develop and qualify their subsystems, dedicated test facilities are required. ETpathfinder prototype uses full interferometer configurations and aims to provide a high sensitivity facility in a similar environment as ET. Along with the interferometry at 1550 nm and silicon test masses, ETpathfinder will focus on cryogenic technologies, lasers and optics at 2090 nm and advanced quantum-noise reduction schemes. This paper analyses the underpinning noise contributions and combines them into full noise budgets of the two initially targeted configurations: 1) operating with 1550 nm laser light and at a temperature of 18 K and 2) operating at 2090 nm wavelength and a temperature of 123 K. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2206.04905v1-abstract-full').style.display = 'none'; document.getElementById('2206.04905v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 10 June, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2022. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2203.10815">arXiv:2203.10815</a> <span> [<a href="https://arxiv.org/pdf/2203.10815">pdf</a>, <a href="https://arxiv.org/format/2203.10815">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Instrumentation and Detectors">physics.ins-det</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="High Energy Physics - Experiment">hep-ex</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Quantum Physics">quant-ph</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1103/PhysRevD.105.082003">10.1103/PhysRevD.105.082003 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Improving the stability of frequency dependent squeezing with bichromatic control of filter cavity length, alignment and incident beam pointing </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Zhao%2C+Y">Yuhang Zhao</a>, <a href="/search/physics?searchtype=author&query=Capocasa%2C+E">Eleonora Capocasa</a>, <a href="/search/physics?searchtype=author&query=Eisenmann%2C+M">Marc Eisenmann</a>, <a href="/search/physics?searchtype=author&query=Aritomi%2C+N">Naoki Aritomi</a>, <a href="/search/physics?searchtype=author&query=Page%2C+M">Michael Page</a>, <a href="/search/physics?searchtype=author&query=Guo%2C+Y">Yuefan Guo</a>, <a href="/search/physics?searchtype=author&query=Polini%2C+E">Eleonora Polini</a>, <a href="/search/physics?searchtype=author&query=Arai%2C+K">Koji Arai</a>, <a href="/search/physics?searchtype=author&query=Aso%2C+Y">Yoichi Aso</a>, <a href="/search/physics?searchtype=author&query=van+Beuzekom%2C+M">Martin van Beuzekom</a>, <a href="/search/physics?searchtype=author&query=Huang%2C+Y">Yao-Chin Huang</a>, <a href="/search/physics?searchtype=author&query=Lee%2C+R">Ray-Kuang Lee</a>, <a href="/search/physics?searchtype=author&query=L%C3%BCck%2C+H">Harald L眉ck</a>, <a href="/search/physics?searchtype=author&query=Miyakawa%2C+O">Osamu Miyakawa</a>, <a href="/search/physics?searchtype=author&query=Prat%2C+P">Pierre Prat</a>, <a href="/search/physics?searchtype=author&query=Shoda%2C+A">Ayaka Shoda</a>, <a href="/search/physics?searchtype=author&query=Tacca%2C+M">Matteo Tacca</a>, <a href="/search/physics?searchtype=author&query=Takahashi%2C+R">Ryutaro Takahashi</a>, <a href="/search/physics?searchtype=author&query=Vahlbruch%2C+H">Henning Vahlbruch</a>, <a href="/search/physics?searchtype=author&query=Vardaro%2C+M">Marco Vardaro</a>, <a href="/search/physics?searchtype=author&query=Wu%2C+C">Chien-Ming Wu</a>, <a href="/search/physics?searchtype=author&query=Leonardi%2C+M">Matteo Leonardi</a>, <a href="/search/physics?searchtype=author&query=Barsuglia%2C+M">Matteo Barsuglia</a>, <a href="/search/physics?searchtype=author&query=Flaminio%2C+R">Raffaele Flaminio</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2203.10815v1-abstract-short" style="display: inline;"> Frequency dependent squeezing is the main upgrade for achieving broadband quantum noise reduction in upcoming observation runs of gravitational wave detectors. The proper frequency dependence of the squeezed quadrature is obtained by reflecting squeezed vacuum from a Fabry-Perot filter cavity detuned by half of its linewidth. However, since the squeezed vacuum contains no classical amplitude, co-p… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2203.10815v1-abstract-full').style.display = 'inline'; document.getElementById('2203.10815v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2203.10815v1-abstract-full" style="display: none;"> Frequency dependent squeezing is the main upgrade for achieving broadband quantum noise reduction in upcoming observation runs of gravitational wave detectors. The proper frequency dependence of the squeezed quadrature is obtained by reflecting squeezed vacuum from a Fabry-Perot filter cavity detuned by half of its linewidth. However, since the squeezed vacuum contains no classical amplitude, co-propagating auxiliary control beams are required to achieve the filter cavity's length, alignment, and incident beam pointing stability. In our frequency dependent squeezing experiment at the National Astronomical Observatory of Japan, we used a control beam at a harmonic of squeezed vacuum wavelength and found visible detuning variation related to the suspended mirrors angular drift. These variations can degrade interferometer quantum noise reduction. We investigated various mechanisms that can cause the filter cavity detuning variation. The detuning drift is found to be mitigated sufficiently by fixing the incident beam pointing and applying filter cavity automatic alignment. It was also found that there is an optimal position of the beam on the filter cavity mirror that helps to reduce the detuning fluctuations. Here we report a stabilized filter cavity detuning variation of less than 10$\,$Hz compared to the 113$\,$Hz cavity linewidth. Compared to previously published results [Phys. Rev. Lett. 124, 171101 (2020)], such detuning stability would be sufficient to make filter cavity detuning drift induced gravitational wave detector detection range fluctuation reduce from $11\%$ to within $2\%$. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2203.10815v1-abstract-full').style.display = 'none'; document.getElementById('2203.10815v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 21 March, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 2022. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Accepted by PRD</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2005.10292">arXiv:2005.10292</a> <span> [<a href="https://arxiv.org/pdf/2005.10292">pdf</a>, <a href="https://arxiv.org/format/2005.10292">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Instrumentation and Detectors">physics.ins-det</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1103/PhysRevLett.126.041102">10.1103/PhysRevLett.126.041102 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> First demonstration of 6 dB quantum noise reduction in a kilometer scale gravitational wave observatory </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Lough%2C+J">James Lough</a>, <a href="/search/physics?searchtype=author&query=Schreiber%2C+E">Emil Schreiber</a>, <a href="/search/physics?searchtype=author&query=Bergamin%2C+F">Fabio Bergamin</a>, <a href="/search/physics?searchtype=author&query=Grote%2C+H">Hartmut Grote</a>, <a href="/search/physics?searchtype=author&query=Mehmet%2C+M">Moritz Mehmet</a>, <a href="/search/physics?searchtype=author&query=Vahlbruch%2C+H">Henning Vahlbruch</a>, <a href="/search/physics?searchtype=author&query=Affeldt%2C+C">Christoph Affeldt</a>, <a href="/search/physics?searchtype=author&query=Brinkmann%2C+M">Marc Brinkmann</a>, <a href="/search/physics?searchtype=author&query=Bisht%2C+A">Aparna Bisht</a>, <a href="/search/physics?searchtype=author&query=Kringel%2C+V">Volker Kringel</a>, <a href="/search/physics?searchtype=author&query=L%C3%BCck%2C+H">Harald L眉ck</a>, <a href="/search/physics?searchtype=author&query=Mukund%2C+N">Nikhil Mukund</a>, <a href="/search/physics?searchtype=author&query=Nadji%2C+S">S茅verin Nadji</a>, <a href="/search/physics?searchtype=author&query=Sorazu%2C+B">Borja Sorazu</a>, <a href="/search/physics?searchtype=author&query=Strain%2C+K">Kenneth Strain</a>, <a href="/search/physics?searchtype=author&query=Weinert%2C+M">Michael Weinert</a>, <a href="/search/physics?searchtype=author&query=Danzmann%2C+K">Karsten Danzmann</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2005.10292v1-abstract-short" style="display: inline;"> Photon shot noise, arising from the quantum-mechanical nature of the light, currently limits the sensitivity of all the gravitational wave observatories at frequencies above one kilohertz. We report a successful application of squeezed vacuum states of light at the GEO\,600 observatory and demonstrate for the first time a reduction of quantum noise up to $6.03 \pm 0.02$ dB in a kilometer-scale int… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2005.10292v1-abstract-full').style.display = 'inline'; document.getElementById('2005.10292v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2005.10292v1-abstract-full" style="display: none;"> Photon shot noise, arising from the quantum-mechanical nature of the light, currently limits the sensitivity of all the gravitational wave observatories at frequencies above one kilohertz. We report a successful application of squeezed vacuum states of light at the GEO\,600 observatory and demonstrate for the first time a reduction of quantum noise up to $6.03 \pm 0.02$ dB in a kilometer-scale interferometer. This is equivalent at high frequencies to increasing the laser power circulating in the interferometer by a factor of four. Achieving this milestone, a key goal for the upgrades of the advanced detectors, required a better understanding of the noise sources and losses, and implementation of robust control schemes to mitigate their contributions. In particular, we address the optical losses from beam propagation, phase noise from the squeezing ellipse, and backscattered light from the squeezed light source. The expertise gained from this work carried out at GEO 600 provides insight towards the implementation of 10 dB of squeezing envisioned for third-generation gravitational wave detectors. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2005.10292v1-abstract-full').style.display = 'none'; document.getElementById('2005.10292v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 20 May, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 2020. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Phys. Rev. Lett. 126, 041102 (2021) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2003.10672">arXiv:2003.10672</a> <span> [<a href="https://arxiv.org/pdf/2003.10672">pdf</a>, <a href="https://arxiv.org/format/2003.10672">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Instrumentation and Methods for Astrophysics">astro-ph.IM</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Instrumentation and Detectors">physics.ins-det</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1103/PhysRevLett.124.171101">10.1103/PhysRevLett.124.171101 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Frequency-Dependent Squeezed Vacuum Source for Broadband Quantum Noise Reduction in Advanced Gravitational-Wave Detectors </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Zhao%2C+Y">Yuhang Zhao</a>, <a href="/search/physics?searchtype=author&query=Aritomi%2C+N">Naoki Aritomi</a>, <a href="/search/physics?searchtype=author&query=Capocasa%2C+E">Eleonora Capocasa</a>, <a href="/search/physics?searchtype=author&query=Leonardi%2C+M">Matteo Leonardi</a>, <a href="/search/physics?searchtype=author&query=Eisenmann%2C+M">Marc Eisenmann</a>, <a href="/search/physics?searchtype=author&query=Guo%2C+Y">Yuefan Guo</a>, <a href="/search/physics?searchtype=author&query=Polini%2C+E">Eleonora Polini</a>, <a href="/search/physics?searchtype=author&query=Tomura%2C+A">Akihiro Tomura</a>, <a href="/search/physics?searchtype=author&query=Arai%2C+K">Koji Arai</a>, <a href="/search/physics?searchtype=author&query=Aso%2C+Y">Yoichi Aso</a>, <a href="/search/physics?searchtype=author&query=Huang%2C+Y">Yao-Chin Huang</a>, <a href="/search/physics?searchtype=author&query=Lee%2C+R">Ray-Kuang Lee</a>, <a href="/search/physics?searchtype=author&query=L%C3%BCck%2C+H">Harald L眉ck</a>, <a href="/search/physics?searchtype=author&query=Miyakawa%2C+O">Osamu Miyakawa</a>, <a href="/search/physics?searchtype=author&query=Prat%2C+P">Pierre Prat</a>, <a href="/search/physics?searchtype=author&query=Shoda%2C+A">Ayaka Shoda</a>, <a href="/search/physics?searchtype=author&query=Tacca%2C+M">Matteo Tacca</a>, <a href="/search/physics?searchtype=author&query=Takahashi%2C+R">Ryutaro Takahashi</a>, <a href="/search/physics?searchtype=author&query=Vahlbruch%2C+H">Henning Vahlbruch</a>, <a href="/search/physics?searchtype=author&query=Vardaro%2C+M">Marco Vardaro</a>, <a href="/search/physics?searchtype=author&query=Wu%2C+C">Chien-Ming Wu</a>, <a href="/search/physics?searchtype=author&query=Barsuglia%2C+M">Matteo Barsuglia</a>, <a href="/search/physics?searchtype=author&query=Flaminio%2C+R">Raffaele Flaminio</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2003.10672v2-abstract-short" style="display: inline;"> The astrophysical reach of current and future ground-based gravitational-wave detectors is mostly limited by quantum noise, induced by vacuum fluctuations entering the detector output port. The replacement of this ordinary vacuum field with a squeezed vacuum field has proven to be an effective strategy to mitigate such quantum noise and it is currently used in advanced detectors. However, current… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2003.10672v2-abstract-full').style.display = 'inline'; document.getElementById('2003.10672v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2003.10672v2-abstract-full" style="display: none;"> The astrophysical reach of current and future ground-based gravitational-wave detectors is mostly limited by quantum noise, induced by vacuum fluctuations entering the detector output port. The replacement of this ordinary vacuum field with a squeezed vacuum field has proven to be an effective strategy to mitigate such quantum noise and it is currently used in advanced detectors. However, current squeezing cannot improve the noise across the whole spectrum because of the Heisenberg uncertainty principle: when shot noise at high frequencies is reduced, radiation pressure at low frequencies is increased. A broadband quantum noise reduction is possible by using a more complex squeezing source, obtained by reflecting the squeezed vacuum off a Fabry-Perot cavity, known as filter cavity. Here we report the first demonstration of a frequency-dependent squeezed vacuum source able to reduce quantum noise of advanced gravitational-wave detectors in their whole observation bandwidth. The experiment uses a suspended 300-m-long filter cavity, similar to the one planned for KAGRA, Advanced Virgo and Advanced LIGO, and capable of inducing a rotation of the squeezing ellipse below 100 Hz. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2003.10672v2-abstract-full').style.display = 'none'; document.getElementById('2003.10672v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 28 April, 2020; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 24 March, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 2020. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Phys. Rev. Lett. 124, 171101 (2020) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2001.00242">arXiv:2001.00242</a> <span> [<a href="https://arxiv.org/pdf/2001.00242">pdf</a>, <a href="https://arxiv.org/format/2001.00242">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="General Relativity and Quantum Cosmology">gr-qc</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Instrumentation and Methods for Astrophysics">astro-ph.IM</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Instrumentation and Detectors">physics.ins-det</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1103/PhysRevD.101.102006">10.1103/PhysRevD.101.102006 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Bilinear noise subtraction at the GEO 600 observatory </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Mukund%2C+N">Nikhil Mukund</a>, <a href="/search/physics?searchtype=author&query=Lough%2C+J">James Lough</a>, <a href="/search/physics?searchtype=author&query=Affeldt%2C+C">Christoph Affeldt</a>, <a href="/search/physics?searchtype=author&query=Bergamin%2C+F">Fabio Bergamin</a>, <a href="/search/physics?searchtype=author&query=Bisht%2C+A">Aparna Bisht</a>, <a href="/search/physics?searchtype=author&query=Brinkmann%2C+M">Marc Brinkmann</a>, <a href="/search/physics?searchtype=author&query=Kringel%2C+V">Volker Kringel</a>, <a href="/search/physics?searchtype=author&query=L%C3%BCck%2C+H">Harald L眉ck</a>, <a href="/search/physics?searchtype=author&query=Nadji%2C+S+L">S茅verin Landry Nadji</a>, <a href="/search/physics?searchtype=author&query=Weinert%2C+M">Michael Weinert</a>, <a href="/search/physics?searchtype=author&query=Danzmann%2C+K">Karsten Danzmann</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2001.00242v2-abstract-short" style="display: inline;"> Longitudinal control signals used to keep gravitational wave detectors at a stable operating point are often affected by modulations from test mass misalignments leading to an elevated noise floor ranging from 50 to 500 Hz. Nonstationary noise of this kind results in modulation sidebands and increases the number of glitches observed in the calibrated strain data. These artifacts ultimately affect… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2001.00242v2-abstract-full').style.display = 'inline'; document.getElementById('2001.00242v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2001.00242v2-abstract-full" style="display: none;"> Longitudinal control signals used to keep gravitational wave detectors at a stable operating point are often affected by modulations from test mass misalignments leading to an elevated noise floor ranging from 50 to 500 Hz. Nonstationary noise of this kind results in modulation sidebands and increases the number of glitches observed in the calibrated strain data. These artifacts ultimately affect the data quality and decrease the efficiency of the data analysis pipelines looking for astrophysical signals from continuous waves as well as the transient events. In this work, we develop a scheme to subtract one such bilinear noise from the gravitational wave strain data and demonstrate it at the GEO 600 observatory. We estimate the coupling by making use of narrow-band signal injections that are already in place for noise projection purposes and construct a coherent bilinear signal by a two-stage system identification process. We improve upon the existing filter design techniques by employing a Bayesian adaptive directed search strategy that optimizes across the several key parameters that affect the accuracy of the estimated model. The scheme takes into account the possible nonstationarities in the coupling by periodically updating the involved filter coefficients. The resulting postoffline subtraction leads to a suppression of modulation sidebands around the calibration lines along with a broadband reduction of the midfrequency noise floor. The observed increase in the astrophysical range and a reduction in the occurrence of nonastrophysical transients suggest that the above method is a viable data cleaning technique for current and future generation gravitational wave observatories. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2001.00242v2-abstract-full').style.display = 'none'; document.getElementById('2001.00242v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 28 May, 2020; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 1 January, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2020. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">9 pages, 9 figures; matches published version</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Phys. Rev. D 101, 102006 (2020) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1711.05439">arXiv:1711.05439</a> <span> [<a href="https://arxiv.org/pdf/1711.05439">pdf</a>, <a href="https://arxiv.org/ps/1711.05439">ps</a>, <a href="https://arxiv.org/format/1711.05439">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Instrumentation and Detectors">physics.ins-det</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Geophysics">physics.geo-ph</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1063/1.5000592">10.1063/1.5000592 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Huddle test measurement of a near Johnson noise limited geophone </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Kirchhoff%2C+R">R. Kirchhoff</a>, <a href="/search/physics?searchtype=author&query=Mow-Lowry%2C+C+M">C. M. Mow-Lowry</a>, <a href="/search/physics?searchtype=author&query=Adya%2C+V+B">V. B. Adya</a>, <a href="/search/physics?searchtype=author&query=Bergmann%2C+G">G. Bergmann</a>, <a href="/search/physics?searchtype=author&query=Cooper%2C+S">S. Cooper</a>, <a href="/search/physics?searchtype=author&query=Hanke%2C+M+M">M. M. Hanke</a>, <a href="/search/physics?searchtype=author&query=Koch%2C+P">P. Koch</a>, <a href="/search/physics?searchtype=author&query=Koehlenbeck%2C+S+M">S. M. Koehlenbeck</a>, <a href="/search/physics?searchtype=author&query=Lehmann%2C+J">J. Lehmann</a>, <a href="/search/physics?searchtype=author&query=Oppermann%2C+P">P. Oppermann</a>, <a href="/search/physics?searchtype=author&query=Woehler%2C+J">J. Woehler</a>, <a href="/search/physics?searchtype=author&query=Wu%2C+D+S">D. S. Wu</a>, <a href="/search/physics?searchtype=author&query=Lueck%2C+H">H. Lueck</a>, <a href="/search/physics?searchtype=author&query=Strain%2C+K+A">K. A. Strain</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1711.05439v1-abstract-short" style="display: inline;"> In this paper the sensor noise of two geophone configurations (L-22D and L-4C geophones from Sercel with custom built amplifiers) was measured by performing two huddle tests. It is shown that the accuracy of the results can be significantly improved by performing the huddle test in a seismically quiet environment and by using a large number of reference sensors to remove the seismic foreground sig… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1711.05439v1-abstract-full').style.display = 'inline'; document.getElementById('1711.05439v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1711.05439v1-abstract-full" style="display: none;"> In this paper the sensor noise of two geophone configurations (L-22D and L-4C geophones from Sercel with custom built amplifiers) was measured by performing two huddle tests. It is shown that the accuracy of the results can be significantly improved by performing the huddle test in a seismically quiet environment and by using a large number of reference sensors to remove the seismic foreground signal from the data. Using these two techniques, the measured sensor noise of the two geophone configurations matched calculated predictions remarkably well in the bandwidth of interest (0.01 Hz to 100 Hz). Low noise operational amplifiers OPA188 were utilized to amplify the L-4C geophone to give a sensor that was characterized to be near Johnson noise limited in the bandwidth of interest with a noise value of $10^{-11} \text{m}/\sqrt{\text{Hz}}$ at 1 Hz. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1711.05439v1-abstract-full').style.display = 'none'; document.getElementById('1711.05439v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 15 November, 2017; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> November 2017. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">7 pages, 2 supplementary materials, 8 figures plus 2 supplementary material figures, accepted for publication in Review of Scientific Instruments</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1707.02903">arXiv:1707.02903</a> <span> [<a href="https://arxiv.org/pdf/1707.02903">pdf</a>, <a href="https://arxiv.org/format/1707.02903">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Instrumentation and Detectors">physics.ins-det</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1088/1361-6382/aa5e1f">10.1088/1361-6382/aa5e1f <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Passive-performance, analysis, and upgrades of a 1-ton seismic attenuation system </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Bergmann%2C+G">G Bergmann</a>, <a href="/search/physics?searchtype=author&query=Mow-Lowry%2C+C+M">C M Mow-Lowry</a>, <a href="/search/physics?searchtype=author&query=Adya%2C+V+B">V B Adya</a>, <a href="/search/physics?searchtype=author&query=Bertolini%2C+A">A Bertolini</a>, <a href="/search/physics?searchtype=author&query=Hanke%2C+M+M">M M Hanke</a>, <a href="/search/physics?searchtype=author&query=Kirchhoff%2C+R">R Kirchhoff</a>, <a href="/search/physics?searchtype=author&query=K%C3%B6hlenbeck%2C+S+M">S M K枚hlenbeck</a>, <a href="/search/physics?searchtype=author&query=K%C3%BChn%2C+G">G K眉hn</a>, <a href="/search/physics?searchtype=author&query=Oppermann%2C+P">P Oppermann</a>, <a href="/search/physics?searchtype=author&query=Wanner%2C+A">A Wanner</a>, <a href="/search/physics?searchtype=author&query=Westphal%2C+T">T Westphal</a>, <a href="/search/physics?searchtype=author&query=W%C3%B6hler%2C+J">J W枚hler</a>, <a href="/search/physics?searchtype=author&query=Wu%2C+D+S">D S Wu</a>, <a href="/search/physics?searchtype=author&query=L%C3%BCck%2C+H">H L眉ck</a>, <a href="/search/physics?searchtype=author&query=Strain%2C+K+A">K A Strain</a>, <a href="/search/physics?searchtype=author&query=Danzmann%2C+K">K Danzmann</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1707.02903v1-abstract-short" style="display: inline;"> The 10m Prototype facility at the Albert-Einstein-Institute (AEI) in Hanover, Germany, employs three large seismic attenuation systems to reduce mechanical motion. The AEI Seismic-Attenuation-System (AEI-SAS) uses mechanical anti-springs in order to achieve resonance frequencies below 0.5Hz. This system provides passive isolation from ground motion by a factor of about 400 in the horizontal direct… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1707.02903v1-abstract-full').style.display = 'inline'; document.getElementById('1707.02903v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1707.02903v1-abstract-full" style="display: none;"> The 10m Prototype facility at the Albert-Einstein-Institute (AEI) in Hanover, Germany, employs three large seismic attenuation systems to reduce mechanical motion. The AEI Seismic-Attenuation-System (AEI-SAS) uses mechanical anti-springs in order to achieve resonance frequencies below 0.5Hz. This system provides passive isolation from ground motion by a factor of about 400 in the horizontal direction at 4Hz and in the vertical direction at 9Hz. The presented isolation performance is measured under vacuum conditions using a combination of commercial and custom-made inertial sensors. Detailed analysis of this performance led to the design and implementation of tuned dampers to mitigate the effect of the unavoidable higher order modes of the system. These dampers reduce RMS motion substantially in the frequency range between 10 and 100Hz in 6 degrees of freedom. The results presented here demonstrate that the AEI-SAS provides substantial passive isolation at all the fundamental mirror-suspension resonances. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1707.02903v1-abstract-full').style.display = 'none'; document.getElementById('1707.02903v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 10 July, 2017; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> July 2017. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Classical and Quantum Gravity 34.6 (2017): 065002 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1602.03845">arXiv:1602.03845</a> <span> [<a href="https://arxiv.org/pdf/1602.03845">pdf</a>, <a href="https://arxiv.org/ps/1602.03845">ps</a>, <a href="https://arxiv.org/format/1602.03845">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="General Relativity and Quantum Cosmology">gr-qc</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Instrumentation and Methods for Astrophysics">astro-ph.IM</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Instrumentation and Detectors">physics.ins-det</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1103/PhysRevD.95.062003">10.1103/PhysRevD.95.062003 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Calibration of the Advanced LIGO detectors for the discovery of the binary black-hole merger GW150914 </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=The+LIGO+Scientific+Collaboration"> The LIGO Scientific Collaboration</a>, <a href="/search/physics?searchtype=author&query=Abbott%2C+B+P">B. P. Abbott</a>, <a href="/search/physics?searchtype=author&query=Abbott%2C+R">R. Abbott</a>, <a href="/search/physics?searchtype=author&query=Abbott%2C+T+D">T. D. Abbott</a>, <a href="/search/physics?searchtype=author&query=Abernathy%2C+M+R">M. R. Abernathy</a>, <a href="/search/physics?searchtype=author&query=Ackley%2C+K">K. Ackley</a>, <a href="/search/physics?searchtype=author&query=Adams%2C+C">C. Adams</a>, <a href="/search/physics?searchtype=author&query=Addesso%2C+P">P. Addesso</a>, <a href="/search/physics?searchtype=author&query=Adhikari%2C+R+X">R. X. Adhikari</a>, <a href="/search/physics?searchtype=author&query=Adya%2C+V+B">V. B. Adya</a>, <a href="/search/physics?searchtype=author&query=Affeldt%2C+C">C. Affeldt</a>, <a href="/search/physics?searchtype=author&query=Aggarwal%2C+N">N. Aggarwal</a>, <a href="/search/physics?searchtype=author&query=Aguiar%2C+O+D">O. D. Aguiar</a>, <a href="/search/physics?searchtype=author&query=Ain%2C+A">A. Ain</a>, <a href="/search/physics?searchtype=author&query=Ajith%2C+P">P. Ajith</a>, <a href="/search/physics?searchtype=author&query=Allen%2C+B">B. Allen</a>, <a href="/search/physics?searchtype=author&query=Altin%2C+P+A">P. A. Altin</a>, <a href="/search/physics?searchtype=author&query=Amariutei%2C+D+V">D. V. Amariutei</a>, <a href="/search/physics?searchtype=author&query=Anderson%2C+S+B">S. B. Anderson</a>, <a href="/search/physics?searchtype=author&query=Anderson%2C+W+G">W. G. Anderson</a>, <a href="/search/physics?searchtype=author&query=Arai%2C+K">K. Arai</a>, <a href="/search/physics?searchtype=author&query=Araya%2C+M+C">M. C. Araya</a>, <a href="/search/physics?searchtype=author&query=Arceneaux%2C+C+C">C. C. Arceneaux</a>, <a href="/search/physics?searchtype=author&query=Areeda%2C+J+S">J. S. Areeda</a>, <a href="/search/physics?searchtype=author&query=Arun%2C+K+G">K. G. Arun</a> , et al. (702 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1602.03845v2-abstract-short" style="display: inline;"> In Advanced LIGO, detection and astrophysical source parameter estimation of the binary black hole merger GW150914 requires a calibrated estimate of the gravitational-wave strain sensed by the detectors. Producing an estimate from each detector's differential arm length control loop readout signals requires applying time domain filters, which are designed from a frequency domain model of the detec… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1602.03845v2-abstract-full').style.display = 'inline'; document.getElementById('1602.03845v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1602.03845v2-abstract-full" style="display: none;"> In Advanced LIGO, detection and astrophysical source parameter estimation of the binary black hole merger GW150914 requires a calibrated estimate of the gravitational-wave strain sensed by the detectors. Producing an estimate from each detector's differential arm length control loop readout signals requires applying time domain filters, which are designed from a frequency domain model of the detector's gravitational-wave response. The gravitational-wave response model is determined by the detector's opto-mechanical response and the properties of its feedback control system. The measurements used to validate the model and characterize its uncertainty are derived primarily from a dedicated photon radiation pressure actuator, with cross-checks provided by optical and radio frequency references. We describe how the gravitational-wave readout signal is calibrated into equivalent gravitational-wave-induced strain and how the statistical uncertainties and systematic errors are assessed. Detector data collected over 38 calendar days, from September 12 to October 20, 2015, contain the event GW150914 and approximately 16 of coincident data used to estimate the event false alarm probability. The calibration uncertainty is less than 10% in magnitude and 10 degrees in phase across the relevant frequency band 20 Hz to 1 kHz. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1602.03845v2-abstract-full').style.display = 'none'; document.getElementById('1602.03845v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 28 February, 2017; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 11 February, 2016; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> February 2016. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">15 pages, 10 figures</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Phys. Rev. D 95, 062003 (2017) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1510.00317">arXiv:1510.00317</a> <span> [<a href="https://arxiv.org/pdf/1510.00317">pdf</a>, <a href="https://arxiv.org/format/1510.00317">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Instrumentation and Detectors">physics.ins-det</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1088/0264-9381/33/7/075009">10.1088/0264-9381/33/7/075009 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> GEO 600 and the GEO-HF upgrade program: successes and challenges </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Dooley%2C+K+L">K. L. Dooley</a>, <a href="/search/physics?searchtype=author&query=Leong%2C+J+R">J. R. Leong</a>, <a href="/search/physics?searchtype=author&query=Adams%2C+T">T. Adams</a>, <a href="/search/physics?searchtype=author&query=Affeldt%2C+C">C. Affeldt</a>, <a href="/search/physics?searchtype=author&query=Bisht%2C+A">A. Bisht</a>, <a href="/search/physics?searchtype=author&query=Bogan%2C+C">C. Bogan</a>, <a href="/search/physics?searchtype=author&query=Degallaix%2C+J">J. Degallaix</a>, <a href="/search/physics?searchtype=author&query=Gr%C3%A4f%2C+C">C. Gr盲f</a>, <a href="/search/physics?searchtype=author&query=Hild%2C+S">S. Hild</a>, <a href="/search/physics?searchtype=author&query=Hough%2C+J">J. Hough</a>, <a href="/search/physics?searchtype=author&query=Khalaidovski%2C+A">A. Khalaidovski</a>, <a href="/search/physics?searchtype=author&query=Lastzka%2C+N">N. Lastzka</a>, <a href="/search/physics?searchtype=author&query=Lough%2C+J">J. Lough</a>, <a href="/search/physics?searchtype=author&query=L%C3%BCck%2C+H">H. L眉ck</a>, <a href="/search/physics?searchtype=author&query=Macleod%2C+D">D. Macleod</a>, <a href="/search/physics?searchtype=author&query=Nuttall%2C+L">L. Nuttall</a>, <a href="/search/physics?searchtype=author&query=Prijatelj%2C+M">M. Prijatelj</a>, <a href="/search/physics?searchtype=author&query=Schnabel%2C+R">R. Schnabel</a>, <a href="/search/physics?searchtype=author&query=Schreiber%2C+E">E. Schreiber</a>, <a href="/search/physics?searchtype=author&query=Slutsky%2C+J">J. Slutsky</a>, <a href="/search/physics?searchtype=author&query=Sorazu%2C+B">B. Sorazu</a>, <a href="/search/physics?searchtype=author&query=Strain%2C+K+A">K. A. Strain</a>, <a href="/search/physics?searchtype=author&query=Vahlbruch%2C+H">H. Vahlbruch</a>, <a href="/search/physics?searchtype=author&query=Was%2C+M">M. Was</a>, <a href="/search/physics?searchtype=author&query=Willke%2C+B">B. Willke</a> , et al. (3 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1510.00317v2-abstract-short" style="display: inline;"> The German-British laser-interferometric gravitational wave detector GEO 600 is in its 14th year of operation since its first lock in 2001. After GEO 600 participated in science runs with other first-generation detectors, a program known as GEO-HF began in 2009. The goal was to improve the detector sensitivity at high frequencies, around 1 kHz and above, with technologically advanced yet minimally… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1510.00317v2-abstract-full').style.display = 'inline'; document.getElementById('1510.00317v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1510.00317v2-abstract-full" style="display: none;"> The German-British laser-interferometric gravitational wave detector GEO 600 is in its 14th year of operation since its first lock in 2001. After GEO 600 participated in science runs with other first-generation detectors, a program known as GEO-HF began in 2009. The goal was to improve the detector sensitivity at high frequencies, around 1 kHz and above, with technologically advanced yet minimally invasive upgrades. Simultaneously, the detector would record science quality data in between commissioning activities. As of early 2014, all of the planned upgrades have been carried out and sensitivity improvements of up to a factor of four at the high-frequency end of the observation band have been achieved. Besides science data collection, an experimental program is ongoing with the goal to further improve the sensitivity and evaluate future detector technologies. We summarize the results of the GEO-HF program to date and discuss its successes and challenges. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1510.00317v2-abstract-full').style.display = 'none'; document.getElementById('1510.00317v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 19 January, 2016; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 1 October, 2015; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2015. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1504.06503">arXiv:1504.06503</a> <span> [<a href="https://arxiv.org/pdf/1504.06503">pdf</a>, <a href="https://arxiv.org/ps/1504.06503">ps</a>, <a href="https://arxiv.org/format/1504.06503">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Optics">physics.optics</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1088/0264-9381/33/1/015012">10.1088/0264-9381/33/1/015012 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Birefringence Measurements on Crystalline Silicon </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Kr%C3%BCger%2C+C">Christoph Kr眉ger</a>, <a href="/search/physics?searchtype=author&query=Heinert%2C+D">Daniel Heinert</a>, <a href="/search/physics?searchtype=author&query=Khalaidovski%2C+A">Alexander Khalaidovski</a>, <a href="/search/physics?searchtype=author&query=Steinlechner%2C+J">Jessica Steinlechner</a>, <a href="/search/physics?searchtype=author&query=Nawrodt%2C+R">Ronny Nawrodt</a>, <a href="/search/physics?searchtype=author&query=Schnabel%2C+R">Roman Schnabel</a>, <a href="/search/physics?searchtype=author&query=L%C3%BCck%2C+H">Harald L眉ck</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1504.06503v1-abstract-short" style="display: inline;"> Crystalline silicon has been proposed as a new test mass material in third generation gravitational wave detectors such as the Einstein Telescope (ET). Birefringence can reduce the interferometric contrast and can produce dynamical disturbances in interferometers. In this work we use the method of polarisation-dependent resonance frequency analysis of Fabry-Perot-cavities containing silicon as a b… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1504.06503v1-abstract-full').style.display = 'inline'; document.getElementById('1504.06503v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1504.06503v1-abstract-full" style="display: none;"> Crystalline silicon has been proposed as a new test mass material in third generation gravitational wave detectors such as the Einstein Telescope (ET). Birefringence can reduce the interferometric contrast and can produce dynamical disturbances in interferometers. In this work we use the method of polarisation-dependent resonance frequency analysis of Fabry-Perot-cavities containing silicon as a birefringent medium. Our measurements show a birefringence of silicon along the (111) axis of the order of $螖\, n \approx 10^{-7}$ at a laser wavelength of 1550nm and room temperature. A model is presented that explains the results of different settings of our measurements as a superposition of elastic strains caused by external stresses in the sample and plastic strains possibly generated during the production process. An application of our theory on the proposed ET test mass geometry suggests no critical effect on birefringence due to elastic strains. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1504.06503v1-abstract-full').style.display = 'none'; document.getElementById('1504.06503v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 24 April, 2015; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 2015. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">19 pages, 6 figures, 2 tables</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1405.2783">arXiv:1405.2783</a> <span> [<a href="https://arxiv.org/pdf/1405.2783">pdf</a>, <a href="https://arxiv.org/ps/1405.2783">ps</a>, <a href="https://arxiv.org/format/1405.2783">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="General Relativity and Quantum Cosmology">gr-qc</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Optics">physics.optics</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Quantum Physics">quant-ph</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1088/0264-9381/31/21/215009">10.1088/0264-9381/31/21/215009 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Design of a speed meter interferometer proof-of-principle experiment </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Gr%C3%A4f%2C+C">C. Gr盲f</a>, <a href="/search/physics?searchtype=author&query=Barr%2C+B+W">B. W. Barr</a>, <a href="/search/physics?searchtype=author&query=Bell%2C+A+S">A. S. Bell</a>, <a href="/search/physics?searchtype=author&query=Campbell%2C+F">F. Campbell</a>, <a href="/search/physics?searchtype=author&query=Cumming%2C+A+V">A. V. Cumming</a>, <a href="/search/physics?searchtype=author&query=Danilishin%2C+S+L">S. L. Danilishin</a>, <a href="/search/physics?searchtype=author&query=Gordon%2C+N+A">N. A. Gordon</a>, <a href="/search/physics?searchtype=author&query=Hammond%2C+G+D">G. D. Hammond</a>, <a href="/search/physics?searchtype=author&query=Hennig%2C+J">J. Hennig</a>, <a href="/search/physics?searchtype=author&query=Houston%2C+E+A">E. A. Houston</a>, <a href="/search/physics?searchtype=author&query=Huttner%2C+S+H">S. H. Huttner</a>, <a href="/search/physics?searchtype=author&query=Jones%2C+R+A">R. A. Jones</a>, <a href="/search/physics?searchtype=author&query=Leavey%2C+S+S">S. S. Leavey</a>, <a href="/search/physics?searchtype=author&query=L%C3%BCck%2C+H">H. L眉ck</a>, <a href="/search/physics?searchtype=author&query=Macarthur%2C+J">J. Macarthur</a>, <a href="/search/physics?searchtype=author&query=Marwick%2C+M">M. Marwick</a>, <a href="/search/physics?searchtype=author&query=Rigby%2C+S">S. Rigby</a>, <a href="/search/physics?searchtype=author&query=Schilling%2C+R">R. Schilling</a>, <a href="/search/physics?searchtype=author&query=Sorazu%2C+B">B. Sorazu</a>, <a href="/search/physics?searchtype=author&query=Spencer%2C+A">A. Spencer</a>, <a href="/search/physics?searchtype=author&query=Steinlechner%2C+S">S. Steinlechner</a>, <a href="/search/physics?searchtype=author&query=Strain%2C+K+A">K. A. Strain</a>, <a href="/search/physics?searchtype=author&query=Hild%2C+S">S. Hild</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1405.2783v2-abstract-short" style="display: inline;"> The second generation of large scale interferometric gravitational wave detectors will be limited by quantum noise over a wide frequency range in their detection band. Further sensitivity improvements for future upgrades or new detectors beyond the second generation motivate the development of measurement schemes to mitigate the impact of quantum noise in these instruments. Two strands of develo… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1405.2783v2-abstract-full').style.display = 'inline'; document.getElementById('1405.2783v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1405.2783v2-abstract-full" style="display: none;"> The second generation of large scale interferometric gravitational wave detectors will be limited by quantum noise over a wide frequency range in their detection band. Further sensitivity improvements for future upgrades or new detectors beyond the second generation motivate the development of measurement schemes to mitigate the impact of quantum noise in these instruments. Two strands of development are being pursued to reach this goal, focusing both on modifications of the well-established Michelson detector configuration and development of different detector topologies. In this paper, we present the design of the world's first Sagnac speed meter interferometer which is currently being constructed at the University of Glasgow. With this proof-of-principle experiment we aim to demonstrate the theoretically predicted lower quantum noise in a Sagnac interferometer compared to an equivalent Michelson interferometer, to qualify Sagnac speed meters for further research towards an implementation in a future generation large scale gravitational wave detector, such as the planned Einstein Telescope observatory. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1405.2783v2-abstract-full').style.display = 'none'; document.getElementById('1405.2783v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 11 September, 2014; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 12 May, 2014; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 2014. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Revised version: 16 pages, 6 figures</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Class. Quantum Grav. 31 215009 (2014) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1311.5367">arXiv:1311.5367</a> <span> [<a href="https://arxiv.org/pdf/1311.5367">pdf</a>, <a href="https://arxiv.org/format/1311.5367">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Instrumentation and Detectors">physics.ins-det</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Optics">physics.optics</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1088/0264-9381/31/6/065008">10.1088/0264-9381/31/6/065008 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Thermal Correction of Astigmatism in the Gravitational Wave Observatory GEO 600 </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Wittel%2C+H">Holger Wittel</a>, <a href="/search/physics?searchtype=author&query=L%C3%BCck%2C+H">Harald L眉ck</a>, <a href="/search/physics?searchtype=author&query=Affeldt%2C+C">Christoph Affeldt</a>, <a href="/search/physics?searchtype=author&query=Dooley%2C+K+L">Katherine L Dooley</a>, <a href="/search/physics?searchtype=author&query=Grote%2C+H">Hartmut Grote</a>, <a href="/search/physics?searchtype=author&query=Leong%2C+J+R">Jonathan R Leong</a>, <a href="/search/physics?searchtype=author&query=Prijatelj%2C+M">Mirko Prijatelj</a>, <a href="/search/physics?searchtype=author&query=Schreiber%2C+E">Emil Schreiber</a>, <a href="/search/physics?searchtype=author&query=Slutsky%2C+J">Jacob Slutsky</a>, <a href="/search/physics?searchtype=author&query=Strain%2C+K+A">Kenneth A. Strain</a>, <a href="/search/physics?searchtype=author&query=Was%2C+M">Michal Was</a>, <a href="/search/physics?searchtype=author&query=Willke%2C+B">Benno Willke</a>, <a href="/search/physics?searchtype=author&query=Danzmann%2C+K">Karsten Danzmann</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1311.5367v1-abstract-short" style="display: inline;"> The output port of GEO 600 is dominated by unwanted high order modes (HOMs). The current thermal actuation system, a ring heater behind one of the folding mirrors, causes a significant amount of astigmatism, which produces HOMs. We have built and installed an astigmatism correction system, based on heating this folding mirror at the sides (laterally). With these side heaters and the ring heater be… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1311.5367v1-abstract-full').style.display = 'inline'; document.getElementById('1311.5367v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1311.5367v1-abstract-full" style="display: none;"> The output port of GEO 600 is dominated by unwanted high order modes (HOMs). The current thermal actuation system, a ring heater behind one of the folding mirrors, causes a significant amount of astigmatism, which produces HOMs. We have built and installed an astigmatism correction system, based on heating this folding mirror at the sides (laterally). With these side heaters and the ring heater behind the mirror, it is possible to tune its radius of curvature in the horizontal and the vertical degree of freedom. We use this system to match the mirrors in the two arms of GEO 600 to each other, thereby reducing the contrast defect. The use of the side heaters reduces the power of the HOMs at the output of GEO 600 by approximately 37%. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1311.5367v1-abstract-full').style.display = 'none'; document.getElementById('1311.5367v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 21 November, 2013; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> November 2013. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1112.1804">arXiv:1112.1804</a> <span> [<a href="https://arxiv.org/pdf/1112.1804">pdf</a>, <a href="https://arxiv.org/ps/1112.1804">ps</a>, <a href="https://arxiv.org/format/1112.1804">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Optics">physics.optics</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Instrumentation and Detectors">physics.ins-det</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Quantum Physics">quant-ph</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1088/0264-9381/29/7/075003">10.1088/0264-9381/29/7/075003 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Optical layout for a 10m Fabry-P茅rot Michelson interferometer with tunable stability </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Gr%C3%A4f%2C+C">Christian Gr盲f</a>, <a href="/search/physics?searchtype=author&query=Hild%2C+S">Stefan Hild</a>, <a href="/search/physics?searchtype=author&query=L%C3%BCck%2C+H">Harald L眉ck</a>, <a href="/search/physics?searchtype=author&query=Willke%2C+B">Benno Willke</a>, <a href="/search/physics?searchtype=author&query=Strain%2C+K+A">Kenneth A. Strain</a>, <a href="/search/physics?searchtype=author&query=Go%C3%9Fler%2C+S">Stefan Go脽ler</a>, <a href="/search/physics?searchtype=author&query=Danzmann%2C+K">Karsten Danzmann</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1112.1804v1-abstract-short" style="display: inline;"> The sensitivity of high-precision interferometric measurements can be limited by Brownian noise within dielectric mirror coatings. This occurs, for instance, in the optical resonators of gravitational wave detectors where the noise can be reduced by increasing the laser beam size. However, the stability of the resonator and its optical performance often impose a limit on the maximally feasible bea… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1112.1804v1-abstract-full').style.display = 'inline'; document.getElementById('1112.1804v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1112.1804v1-abstract-full" style="display: none;"> The sensitivity of high-precision interferometric measurements can be limited by Brownian noise within dielectric mirror coatings. This occurs, for instance, in the optical resonators of gravitational wave detectors where the noise can be reduced by increasing the laser beam size. However, the stability of the resonator and its optical performance often impose a limit on the maximally feasible beam size. In this article we describe the optical design of a 10\,m Fabry-P茅rot Michelson interferometer with tunable stability. Our design will allow us to carry out initial commissioning with arm cavities of high stability, while afterwards the arm cavity length can be increased stepwise towards the final, marginally stable configuration. Requiring only minimal hardware changes, with respect to a comparable "static" layout, the proposed technique will not only enable us to explore the stability limits of an optical resonator with realistic mirrors exhibiting inevitable surface imperfections, but also the opportunity to measure coating Brownian noise at frequencies as low as a few hundred Hertz. A detailed optical design of the tunable interferometer is presented and requirements for the optical elements are derived from robustness evaluations. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1112.1804v1-abstract-full').style.display = 'none'; document.getElementById('1112.1804v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 8 December, 2011; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> December 2011. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Class. Quantum Grav. 29 (2012) 075003 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1112.0198">arXiv:1112.0198</a> <span> [<a href="https://arxiv.org/pdf/1112.0198">pdf</a>, <a href="https://arxiv.org/format/1112.0198">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Quantum Physics">quant-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Optics">physics.optics</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1088/1742-6596/363/1/012013">10.1088/1742-6596/363/1/012013 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Status of the GEO 600 squeezed-light laser </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Khalaidovski%2C+A">Alexander Khalaidovski</a>, <a href="/search/physics?searchtype=author&query=Vahlbruch%2C+H">Henning Vahlbruch</a>, <a href="/search/physics?searchtype=author&query=Lastzka%2C+N">Nico Lastzka</a>, <a href="/search/physics?searchtype=author&query=Graef%2C+C">Christian Graef</a>, <a href="/search/physics?searchtype=author&query=Lueck%2C+H">Harald Lueck</a>, <a href="/search/physics?searchtype=author&query=Danzmann%2C+K">Karsten Danzmann</a>, <a href="/search/physics?searchtype=author&query=Grote%2C+H">Hartmut Grote</a>, <a href="/search/physics?searchtype=author&query=Schnabel%2C+R">Roman Schnabel</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1112.0198v1-abstract-short" style="display: inline;"> In the course of the high-frequency upgrade of GEO 600, its optical configuration was extended by a squeezed-light laser [1]. Recently, a non-classically enhanced measurement sensitivity of GEO 600 was reported [2]. In this paper, a characterization of the squeezed-light laser is presented. Thereupon, the status of the integration into GEO 600 is reviewed, focussing on the sources of optical loss… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1112.0198v1-abstract-full').style.display = 'inline'; document.getElementById('1112.0198v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1112.0198v1-abstract-full" style="display: none;"> In the course of the high-frequency upgrade of GEO 600, its optical configuration was extended by a squeezed-light laser [1]. Recently, a non-classically enhanced measurement sensitivity of GEO 600 was reported [2]. In this paper, a characterization of the squeezed-light laser is presented. Thereupon, the status of the integration into GEO 600 is reviewed, focussing on the sources of optical loss limiting the shot noise reduction by squeezing at the moment. Finally, the possibilities for a future loss reduction are discussed. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1112.0198v1-abstract-full').style.display = 'none'; document.getElementById('1112.0198v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 1 December, 2011; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> December 2011. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Proceeding of the 9th Edoardo Amaldi Conference on Gravitational Waves</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1111.7252">arXiv:1111.7252</a> <span> [<a href="https://arxiv.org/pdf/1111.7252">pdf</a>, <a href="https://arxiv.org/format/1111.7252">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Optics">physics.optics</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Instrumentation and Detectors">physics.ins-det</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Quantum Physics">quant-ph</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1007/s00340-012-4878-z">10.1007/s00340-012-4878-z <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> The 10m AEI prototype facility A brief overview </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Westphal%2C+T">Tobias Westphal</a>, <a href="/search/physics?searchtype=author&query=Bergmann%2C+G">Gerald Bergmann</a>, <a href="/search/physics?searchtype=author&query=Bertolini%2C+A">Alessandro Bertolini</a>, <a href="/search/physics?searchtype=author&query=Born%2C+M">Michael Born</a>, <a href="/search/physics?searchtype=author&query=Chen%2C+Y">Yanbei Chen</a>, <a href="/search/physics?searchtype=author&query=Cumming%2C+A+V">Alan V Cumming</a>, <a href="/search/physics?searchtype=author&query=Cunningham%2C+L">Liam Cunningham</a>, <a href="/search/physics?searchtype=author&query=Dahl%2C+K">Katrin Dahl</a>, <a href="/search/physics?searchtype=author&query=Graef%2C+C">Christian Graef</a>, <a href="/search/physics?searchtype=author&query=Hammond%2C+G">Giles Hammond</a>, <a href="/search/physics?searchtype=author&query=Heinzel%2C+G">Gerhard Heinzel</a>, <a href="/search/physics?searchtype=author&query=Hild%2C+S">Stefan Hild</a>, <a href="/search/physics?searchtype=author&query=Huttner%2C+S">Sabina Huttner</a>, <a href="/search/physics?searchtype=author&query=Jones%2C+R">Russel Jones</a>, <a href="/search/physics?searchtype=author&query=Kawazoe%2C+F">Fumiko Kawazoe</a>, <a href="/search/physics?searchtype=author&query=Koehlenbeck%2C+S">Sina Koehlenbeck</a>, <a href="/search/physics?searchtype=author&query=Kuehn%2C+G">Gerrit Kuehn</a>, <a href="/search/physics?searchtype=author&query=Lueck%2C+H">Harald Lueck</a>, <a href="/search/physics?searchtype=author&query=Mossavi%2C+K">Kasem Mossavi</a>, <a href="/search/physics?searchtype=author&query=Poeld%2C+J+H">Jan H Poeld</a>, <a href="/search/physics?searchtype=author&query=Somiya%2C+K">Kentaro Somiya</a>, <a href="/search/physics?searchtype=author&query=van+Veggel%2C+M">Marielle van Veggel</a>, <a href="/search/physics?searchtype=author&query=Wanner%2C+A">Alexander Wanner</a>, <a href="/search/physics?searchtype=author&query=Willke%2C+B">Benno Willke</a>, <a href="/search/physics?searchtype=author&query=Strain%2C+K+A">Ken A Strain</a> , et al. (2 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1111.7252v2-abstract-short" style="display: inline;"> The AEI 10 m prototype interferometer facility is currently being constructed at the Albert Einstein Institute in Hannover, Germany. It aims to perform experiments for future gravitational wave detectors using advanced techniques. Seismically isolated benches are planned to be interferometrically interconnected and stabilized, forming a low-noise testbed inside a 100 m^3 ultra-high vacuum system.… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1111.7252v2-abstract-full').style.display = 'inline'; document.getElementById('1111.7252v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1111.7252v2-abstract-full" style="display: none;"> The AEI 10 m prototype interferometer facility is currently being constructed at the Albert Einstein Institute in Hannover, Germany. It aims to perform experiments for future gravitational wave detectors using advanced techniques. Seismically isolated benches are planned to be interferometrically interconnected and stabilized, forming a low-noise testbed inside a 100 m^3 ultra-high vacuum system. A well-stabilized high power laser will perform differential position readout of 100 g test masses in a 10 m suspended arm-cavity enhanced Michelson interferometer at the crossover of measurement (shot) noise and backaction (quantum radiation pressure) noise, the so-called Standard Quantum Limit (SQL). Such a sensitivity enables experiments in the highly topical field of macroscopic quantum mechanics. In this article we introduce the experimental facility and describe the methods employed, technical details of subsystems will be covered in future papers. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1111.7252v2-abstract-full').style.display = 'none'; document.getElementById('1111.7252v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 28 December, 2011; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 30 November, 2011; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> November 2011. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1010.5677">arXiv:1010.5677</a> <span> [<a href="https://arxiv.org/pdf/1010.5677">pdf</a>, <a href="https://arxiv.org/ps/1010.5677">ps</a>, <a href="https://arxiv.org/format/1010.5677">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Optics">physics.optics</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1088/2040-8978/13/5/055504">10.1088/2040-8978/13/5/055504 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Eigenmode in a misaligned triangular optical cavity </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Kawazoe%2C+F">Fumiko Kawazoe</a>, <a href="/search/physics?searchtype=author&query=Schilling%2C+R">Roland Schilling</a>, <a href="/search/physics?searchtype=author&query=Lueck%2C+H">Harald Lueck</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1010.5677v1-abstract-short" style="display: inline;"> We derive relationships between various types of small misalignments on a triangular Fabry-Perot cavity and associated geometrical eigenmode changes. We focus on the changes of beam spot positions on cavity mirrors, the beam waist position, and its angle. A comparison of analytical and numerical results shows excellent agreement. The results are applicable to any triangular cavity close to an isos… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1010.5677v1-abstract-full').style.display = 'inline'; document.getElementById('1010.5677v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1010.5677v1-abstract-full" style="display: none;"> We derive relationships between various types of small misalignments on a triangular Fabry-Perot cavity and associated geometrical eigenmode changes. We focus on the changes of beam spot positions on cavity mirrors, the beam waist position, and its angle. A comparison of analytical and numerical results shows excellent agreement. The results are applicable to any triangular cavity close to an isosceles triangle, with the lengths of two sides much bigger than the other, consisting of a curved mirror and two flat mirrors yielding a waist equally separated from the two flat mirrors. This cavity shape is most commonly used in laser interferometry. The analysis presented here can easily be extended to more generic cavity shapes. The geometrical analysis not only serves as a method of checking a simulation result, but also gives an intuitive and handy tool to visualize the eigenmode of a misaligned triangular cavity. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1010.5677v1-abstract-full').style.display = 'none'; document.getElementById('1010.5677v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 27 October, 2010; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2010. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">17 pages, 21 figures</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/0912.3164">arXiv:0912.3164</a> <span> [<a href="https://arxiv.org/pdf/0912.3164">pdf</a>, <a href="https://arxiv.org/ps/0912.3164">ps</a>, <a href="https://arxiv.org/format/0912.3164">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Instrumentation and Detectors">physics.ins-det</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="General Relativity and Quantum Cosmology">gr-qc</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Quantum Physics">quant-ph</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1088/1742-6596/228/1/012029">10.1088/1742-6596/228/1/012029 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Building blocks for future detectors: Silicon test masses and 1550 nm laser light </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Schnabel%2C+R">R. Schnabel</a>, <a href="/search/physics?searchtype=author&query=Britzger%2C+M">M. Britzger</a>, <a href="/search/physics?searchtype=author&query=Br%C3%BCckner%2C+F">F. Br眉ckner</a>, <a href="/search/physics?searchtype=author&query=Burmeister%2C+O">O. Burmeister</a>, <a href="/search/physics?searchtype=author&query=Danzmann%2C+K">K. Danzmann</a>, <a href="/search/physics?searchtype=author&query=D%C3%BCck%2C+J">J. D眉ck</a>, <a href="/search/physics?searchtype=author&query=Eberle%2C+T">T. Eberle</a>, <a href="/search/physics?searchtype=author&query=Friedrich%2C+D">D. Friedrich</a>, <a href="/search/physics?searchtype=author&query=L%C3%BCck%2C+H">H. L眉ck</a>, <a href="/search/physics?searchtype=author&query=Mehmet%2C+M">M. Mehmet</a>, <a href="/search/physics?searchtype=author&query=Nawrodt%2C+R">R. Nawrodt</a>, <a href="/search/physics?searchtype=author&query=Steinlechner%2C+S">S. Steinlechner</a>, <a href="/search/physics?searchtype=author&query=Willke%2C+B">B. Willke</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="0912.3164v1-abstract-short" style="display: inline;"> Current interferometric gravitational wave detectors use the combination of quasi-monochromatic, continuous-wave laser light at 1064 nm and fused silica test masses at room temperature. Detectors of the third generation, such as the Einstein-Telescope, will involve a considerable sensitivity increase. The combination of 1550 nm laser radiation and crystalline silicon test masses at low temperatu… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('0912.3164v1-abstract-full').style.display = 'inline'; document.getElementById('0912.3164v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="0912.3164v1-abstract-full" style="display: none;"> Current interferometric gravitational wave detectors use the combination of quasi-monochromatic, continuous-wave laser light at 1064 nm and fused silica test masses at room temperature. Detectors of the third generation, such as the Einstein-Telescope, will involve a considerable sensitivity increase. The combination of 1550 nm laser radiation and crystalline silicon test masses at low temperatures might be important ingredients in order to achieve the sensitivity goal. Here we compare some properties of the fused silica and silicon test mass materials relevant for decreasing the thermal noise in future detectors as well as the recent technology achievements in the preparation of laser radiation at 1064 nm and 1550 nm relevant for decreasing the quantum noise. We conclude that silicon test masses and 1550 nm laser light have the potential to form the future building blocks of gravitational wave detection. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('0912.3164v1-abstract-full').style.display = 'none'; document.getElementById('0912.3164v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 16 December, 2009; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> December 2009. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> J.Phys.Conf.Ser.228:012029,2010 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/0707.0231">arXiv:0707.0231</a> <span> [<a href="https://arxiv.org/pdf/0707.0231">pdf</a>, <a href="https://arxiv.org/ps/0707.0231">ps</a>, <a href="https://arxiv.org/format/0707.0231">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Optics">physics.optics</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Instrumentation and Detectors">physics.ins-det</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1103/PhysRevE.72.066615">10.1103/PhysRevE.72.066615 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Analysis of a four-mirror cavity enhanced Michelson interferometer </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Thuering%2C+A">Andre Thuering</a>, <a href="/search/physics?searchtype=author&query=Lueck%2C+H">Harald Lueck</a>, <a href="/search/physics?searchtype=author&query=Danzmann%2C+K">Karsten Danzmann</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="0707.0231v1-abstract-short" style="display: inline;"> We investigate the shot noise limited sensitivity of a four-mirror cavity enhanced Michelson interferometer. The intention of this interferometer topology is the reduction of thermal lensing and the impact of the interferometers contrast although transmissive optics are used with high circulating powers. The analytical expressions describing the light fields and the frequency response are derive… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('0707.0231v1-abstract-full').style.display = 'inline'; document.getElementById('0707.0231v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="0707.0231v1-abstract-full" style="display: none;"> We investigate the shot noise limited sensitivity of a four-mirror cavity enhanced Michelson interferometer. The intention of this interferometer topology is the reduction of thermal lensing and the impact of the interferometers contrast although transmissive optics are used with high circulating powers. The analytical expressions describing the light fields and the frequency response are derived. Although the parameter space has 11 dimensions, a detailed analysis of the resonance feature gives boundary conditions allowing systematic parameter studies. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('0707.0231v1-abstract-full').style.display = 'none'; document.getElementById('0707.0231v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 2 July, 2007; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> July 2007. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Phys.Rev.E72:066615,2005 </p> </li> </ol> <div class="is-hidden-tablet">  <span class="help" style="display: inline-block;"><a href="https://github.com/arXiv/arxiv-search/releases">Search v0.5.6 released 2020-02-24</a>  </span> </div> </div> </main> <footer> <div class="columns 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