Research Towards Future Gravitational-Wave Observatories: Lasers, Optics, Materials, Devices, and Simulations

该奖项支持相对论和相对论天体物理学的研究，并阐述了美国国家科学基金会“宇宙之窗”大构想的优先领域。从2015年9月发现两个黑洞的引力波开始，NSF的激光干涉引力波天文台(LIGO)与处女座合作，开展了引力波观测活动，三次观测报告了90多个致密天体(黑洞和/或中子星)的合并。第四次观测运行将于2023年春季开始，在灵敏度和性能方面都有显著改进。这次A+升级的探测器包括由佛罗里达大学设计和制造的六个低损耗法拉第隔离器。正在进行的研究旨在进一步改进和改进第三代引力波探测器。这项工作将通过佛罗里达大学LIGO小组直接参与LIGO天文台的研究和业务，对国家和国际科学基础设施产生积极影响。这项研究将超越引力波科学。本项目研制的高功率光隔离器已在激光和光学行业得到了商业应用。单频2.1千兆赫可调谐的μm激光器可以影响精密科学的许多领域。佛罗里达小组还通过在各种常设委员会任职，为LIGO-Virgo-KAGRA合作提供服务活动。佛罗里达小组还为学生和博士后科学家提供机会，培养他们在激光和光学、电子学和反馈控制系统、真空和低温以及大规模探测器调试和操作等不同学科中的科学技能。此外，该组织高度重视本科生的教育，每年都有本科生参与研究。高级LIGO的设计旨在将灵敏度提高十倍，并比最初的LIGO具有更好的低频响应。随着挤压和A+升级的引入，敏感度将进一步提高。这些收益需要提高探测器各方面的性能，包括佛罗里达LIGO集团多年来负责的输入光学器件。这项工作将解决高功率光学隔离、改进的激光光束调制，以及改进用于输入光学和核心干涉仪的悬浮的模拟。它还涉及旨在扩大科学覆盖范围的下一代探测器所需的基础研究。这项范围更长的研究包括对波长比目前使用的1064 nm波长更长的调制器和隔离器的研究，完成对硅中杂质的分析(这是一种用于测试低温探测器质量的近乎理想的材料)，以及对工作在2.1μm波长的单频非平面环形振荡器激光器的表征。

This award supports research in relativity and relativistic astrophysics, and it addresses the priority areas of NSF's "Windows on the Universe" Big Idea. Beginning with the September 2015 discovery of gravitational waves from the inspiral of two black holes, NSF's Laser Interferometric Gravitational-Wave Observatory (LIGO), in conjunction with Virgo, have carried out observational campaigns for gravitational waves, with more than 90 mergers of compact objects (black holes and/or neutron stars) reported from three observing runs. A fourth observing run, with significant improvements in sensitivity and performance will begin in Spring 2023. This A+ upgrade of the detectors includes six low-loss Faraday isolators designed and manufactured at the University of Florida. Ongoing research aims at contributing to further improvements as well as to third-generation gravitational-wave detectors. This work will positively influence the national and international scientific infrastructure through the direct participation of the University of Florida LIGO group in research and operations at the LIGO Observatories. The research will go beyond gravitational-wave science. High-power optical isolators developed in this project have commercial applications to the laser and optics industries. A single-frequency 2.1 μm laser, tunable over GHz of frequency, can affect many areas of precision science. The Florida group also contributes service activities to the LIGO-Virgo-KAGRA collaborations by serving on a variety of standing committees. The Florida group also gives students and postdoctoral scientists the opportunity to develop scientific skills from a diverse set of disciplines spanning lasers and optics, electronics and feedback control systems, vacuum and cryogenics, and large-scale detector commissioning and operation. In addition, the group places high value on the education of undergraduate students and each year has involved undergraduates in research.Advanced LIGO was designed for a tenfold sensitivity improvement and much better low-frequency response than initial LIGO. With the introduction of squeezing and the A+ upgrade, the sensitivity will be increased further. These gains require improved performance in all aspects of the detector, including the Input Optics, a responsibility of the Florida LIGO group for many years. Work will address high-power optical isolation, improved modulation of laser beams, and improved simulations of the suspensions used for in the input optics and in the core interferometer. It also addresses basic research needed for next generation detectors aimed at increased science reach. This longer-ranged research includes studies of modulators and isolators at longer wavelengths than the 1064 nm wavelength currently used, completion of analysis of impurities in silicon, a nearly ideal material for the test masses of cryogenic detectors, and the characterization of a single-frequency non-planar ring oscillator laser operating at 2.1 μm wavelength.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.