Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published March 13, 2023 | Published
Journal Article Open

Substrate-transferred GaAs/AlGaAs crystalline coatings for gravitational-wave detectors


In this Perspective, we summarize the status of technological development for large-area and low-noise substrate-transferred GaAs/AlGaAs (AlGaAs) crystalline coatings for interferometric gravitational-wave (GW) detectors. These topics were originally presented as part of an AlGaAs Workshop held at American University, Washington, DC, from 15 August to 17 August 2022, bringing together members of the GW community from the laser interferometer gravitational-wave observatory (LIGO), Virgo, and KAGRA collaborations, along with scientists from the precision optical metrology community, and industry partners with extensive expertise in the manufacturing of said coatings. AlGaAs-based crystalline coatings present the possibility of GW observatories having significantly greater range than current systems employing ion-beam sputtered mirrors. Given the low thermal noise of AlGaAs at room temperature, GW detectors could realize these significant sensitivity gains while potentially avoiding cryogenic operation. However, the development of large-area AlGaAs coatings presents unique challenges. Herein, we describe recent research and development efforts relevant to crystalline coatings, covering characterization efforts on novel noise processes as well as optical metrology on large-area (∼10 cm diameter) mirrors. We further explore options to expand the maximum coating diameter to 20 cm and beyond, forging a path to produce low-noise mirrors amenable to future GW detector upgrades, while noting the unique requirements and prospective experimental testbeds for these semiconductor-based coatings.

Additional Information

© 2023 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/). This paper is part of the APL Special Collection on Gravitational Wave Detectors. This research was supported by the National Science Foundation through the following grant awards: American University (Nos. PHYS-2012017 and PHYS-2011787), Caltech (No. PHY-1764464), HWS (Nos. PHY-1912699, PHY-2011688, and PHY-2208079), M.I.T. (No. PHY-1764464), Embry-Riddle Aeronautical University (No. PHY-2110598), and Syracuse University (Nos. PHY-2011723 and PHY-2207640). J. Steinlechner acknowledges the support of ETpathfinder (Interreg Vlaanderen-Nederland), E-TEST (Interreg Euregio Meuse-Rhine), the Province of Limburg, and the NWO Talent Programme Vidi 2020, Project No. VI.Vidi.203.062. D. Kedar and J. Ye acknowledge support from NSF PHY-1734006, NIST, and AFRL. T. Legero, U. Sterr, and J. Yu acknowledge support by the Project 20FUN08 NEXTLASERS, which has received funding from the EMPIR programme co-financed by the Participating States and from the European Union's Horizon 2020 Research and Innovation Programme. A portion of this work was performed in the UCSB Nanofabrication Facility, an open access laboratory. Author Contributions: Garrett David Cole: Writing – review & editing (equal). Thomas Legero: Writing – review & editing (equal). Camille Makarem: Writing – review & editing (equal). Steven Penn: Writing – review & editing (equal). David Reitze: Writing – review & editing (equal). Jessica Steinlechner: Writing – review & editing (equal). Uwe Sterr: Writing – review & editing (equal). Satoshi Tanioka: Writing – review & editing (equal). Gar-Wing Truong: Writing – review & editing (equal). Jun Ye: Writing – review & editing (equal). Jialiang Yu: Writing – review & editing (equal). Stefan Ballmer: Writing – review & editing (equal). GariLynn Billingsley: Writing – review & editing (equal). Seth B. Cataño-Lopez: Writing – review & editing (equal). Martin M. Fejer: Writing – review & editing (equal). Peter Fritschel: Writing – review & editing (equal). Andri M. Gretrasson: Writing – review & editing (equal). Gregory M. Harry: Writing – review & editing (equal). Dhruv Kedar: Writing – review & editing (equal). DATA AVAILABILITY. The data that support the findings of this study are available from the corresponding author upon reasonable request. The authors have no conflicts to disclose.

Attached Files

Published - 110502_1_online.pdf


Files (2.2 MB)
Name Size Download all
2.2 MB Preview Download

Additional details

August 22, 2023
October 18, 2023