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，它解决了NSF“宇宙之窗”大构想的优先领域。从2015年9月发现来自两个黑洞的引力波开始，美国国家科学基金会的激光干涉引力波天文台（LIGO）与处女座一起开展了引力波观测活动，在三次观测运行中报告了90多个紧凑物体（黑洞和/或中子星）的合并。第四次观测将于2023年春季开始，灵敏度和性能将有显著提高。这个探测器的A+升级包括六个由佛罗里达大学设计和制造的低损耗法拉第隔离器。正在进行的研究旨在进一步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天文台的研究和运作，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在激光和光学工业中具有商业应用价值。单频2.1 μm激光，可调频率超过GHz，可以影响许多领域的精密科学。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了从不同学科发展科学技能的机会，包括激光和光学，电子和反馈控制系统，真空和低温，以及大型探测器的调试和操作。此外，该集团非常重视本科生的教育，每年都有本科生参与研究。与最初的LIGO相比，先进的LIGO的灵敏度提高了十倍，低频响应也大大改善。随着挤压功能的引入和A+的升级，灵敏度将进一步提高。这些增益需要探测器各方面的性能改进，包括输入光学，这是佛罗里达LIGO团队多年来的职责。工作将解决高功率光学隔离，改进激光光束的调制，以及改进用于输入光学和核心干涉仪的悬架的模拟。它还涉及下一代探测器所需的基础研究，旨在扩大科学覆盖范围。这项更长期的研究包括研究比目前使用的1064nm波长更长的波长的调制器和隔离器，完成对硅中杂质的分析，硅是一种近乎理想的低温探测器测试质量材料，以及工作在2.1 μm波长的单频非平面环形振荡器激光器的表征。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

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.