RUI: Advancing Gravitational-Wave Optics to Further Explore the Cosmos

RUI：推进引力波光学进一步探索宇宙

• 批准号: 2207998
• 负责人: Joshua Smith
• 金额: $ 35.57万
• 依托单位: CSU Fullerton Auxiliary Services Corporation
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-09-01 至 2025-08-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2207998&HistoricalAwards=false
• 关键词: RUI; Advancing; Gravitational; Wave; Optics

This award supports research in relativity and relativistic astrophysics, and it addresses the priority areas of NSF's "Windows on the Universe" Big Idea. Albert Einstein predicted gravitational waves as a consequence of general relativity in 1916. A century later, the NSF-funded Laser Interferometer Gravitational-Wave Observatory (LIGO) opened a new window on the universe by observing gravitational waves from merging black holes. LIGO and its international partners Virgo and Kagra have since detected gravitational waves from nearly 100 systems. Work is underway to extend the reach of LIGO through the Advanced LIGO+ (A+) upgrades and a potential cryogenic silicon detector, Voyager. A next-generation US observatory, Cosmic Explorer, is also being developed. These detectors will use optical technology to peer deeply into the universe’s dark side and open a wide discovery aperture to the novel and unknown. This project will engage students and faculty at California State University, Fullerton (CSUF) in experimental research aimed at advancing optical technology to further explore the cosmos with gravitational waves. Students and the PI will characterize and develop techniques to reduce the amount of laser light scattered by optical coatings. They will measure the optical scattering of silicon at cryogenic temperatures and estimate its effects on gravitational-wave detector performance. They will map the laser light loss due to birefringence of silicon, at the wavelength and temperature planned for Voyager and possible cryogenic realizations of Cosmic Explorer, for the first time. These studies will help A+ to double the rate of gravitational-wave observations and Voyager and Cosmic Explorer to observe black hole and neutron star collisions to the era of the first stars. This work will additionally contribute to the field of optics and potentially lead to improvements in commercial optics. Conducting this research at CSUF will have a disproportionately positive impact on students from groups traditionally underrepresented in physics.This project will engage students and faculty at California State University, Fullerton (CSUF) in experimental research aimed at advancing optical technology to further explore the cosmos with gravitational waves. To achieve their goals, A+ and Cosmic Explorer require room-temperature optical coatings for 1-micron-wavelength laser light that have improved thermal noise, with still excellent optical properties, including optical scatter. Heat treatment (annealing) of coatings has been shown to decrease both their thermal noise and optical scatter. Students and the PI will employ an annealing scatterometer and an angle-resolved scatterometer to characterize and develop techniques to reduce scattering from the most promising coatings. Voyager technology could extend the reach of LIGO and Cosmic Explorer by reducing thermal noise and thermal aberrations using crystalline silicon optics operated at cryogenic temperatures (123 K, a zero crossing of silicon’s thermal expansion coefficient). The PI and students will use a cryogenic testbed to measure the surface, bulk, and coated optical scattering for high-purity crystalline silicon at cryogenic temperatures and estimate its effects on gravitational-wave detector performance. Optical losses due to birefringence in these transparent crystalline silicon optics could also decrease the astrophysical reach of future detectors. The PI and students will map the birefringence of crystalline silicon at 2-micron-wavelength and 123 K for the first time, using an optical cavity. These studies will help A+ to double the rate of gravitational-wave observations and Voyager and possible cryogenic realizations of Cosmic Explorer to observe black hole and neutron star collisions to the era of the first stars.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

该奖项支持相对论和相对论天体物理学的研究，并解决了NSF“宇宙之窗”大理念的优先领域。阿尔伯特·爱因斯坦在1916年预言引力波是广义相对论的结果。一个世纪后，NSF资助的激光干涉引力波天文台（LIGO）通过观测黑洞合并产生的引力波打开了一扇新的宇宙之窗。LIGO及其国际合作伙伴Virgo和Kagra已经从近100个系统中探测到了引力波。目前正在进行的工作是通过先进的LIGO+（A+）升级和潜在的低温硅探测器Voyager来扩展LIGO的范围。美国的下一代天文台“宇宙探索者”也正在开发中。这些探测器将利用光学技术深入观察宇宙的黑暗面，并为新的和未知的事物打开一个广阔的发现窗口。该项目将吸引加州州立大学富勒顿分校（CSUF）的学生和教师参与旨在推进光学技术的实验研究，以进一步探索宇宙的引力波。学生和PI将表征和开发技术，以减少光学涂层散射的激光量。他们将测量硅在低温下的光学散射，并估计其对引力波探测器性能的影响。他们将首次在旅行者计划的波长和温度以及宇宙探测器可能的低温实现下，绘制由于硅的双折射造成的激光损失。这些研究将帮助A+将引力波观测速率提高一倍，帮助旅行者号和宇宙探测器观测黑洞和中子星星碰撞到第一颗恒星的时代。这项工作还将为光学领域做出贡献，并可能导致商业光学的改进。在CSUF进行这项研究将对物理学传统上代表性不足的学生产生不成比例的积极影响。该项目将吸引加州州立大学富勒顿分校（CSUF）的学生和教师参与旨在推进光学技术的实验研究，以进一步探索宇宙引力波。为了实现他们的目标，A+和Cosmic Explorer需要用于1微米波长激光的室温光学涂层，这些涂层具有改善的热噪声，并且仍然具有优异的光学特性，包括光学散射。涂层的热处理（退火）已被证明可以降低其热噪声和光散射。学生和PI将采用退火散射仪和角分辨散射仪来表征和开发技术，以减少最有前途的涂层的散射。Voyager技术可以通过使用在低温（123 K，硅的热膨胀系数的零交叉）下操作的晶体硅光学器件来减少热噪声和热像差，从而扩展LIGO和Cosmic Explorer的覆盖范围。PI和学生将使用一个低温试验台来测量在低温下高纯晶体硅的表面、体和涂层光学散射，并估计其对引力波探测器性能的影响。由于这些透明晶体硅光学器件中的双折射引起的光学损耗也可能降低未来探测器的天体物理范围。PI和学生将首次使用光学腔绘制2微米波长和123 K晶体硅的双折射。这些研究将帮助A+将引力波观测速率提高一倍，帮助旅行者和宇宙探索者可能的低温实现，以观测黑洞和中子星星碰撞到第一颗恒星的时代。该奖项反映了NSF的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

Imaging scatterometer for observing in situ changes to optical coatings during air annealing

成像散射仪用于观察空气退火过程中光学涂层的原位变化

• DOI: 10.1364/ao.476979
• 发表时间: 2023
• 期刊: Applied Optics
• 影响因子: 1.9
• 作者: Rezac, Michael;Martinez, Daniel;Gleckl, Amy;Smith, Joshua R.
• 通讯作者: Smith, Joshua R.