Devices, Materials, and Controls for Future Gravitational-Wave Detectors

2015年9月，两个高级LIGO天文台实现了最初的目标：探测引力波。先进的LIGO的灵敏度提高了10倍，低频响应也更好，现在已经至少三次看到了令人鼓舞的双黑洞。灵敏度的提高来自于更高的激光功率，更好地与地面运动隔离，以及干涉仪本身的变化。更高的激光功率对佛罗里达大学负责的输入光学器件提出了挑战。本研究将从整体上改进干涉仪的输入光学和控制性能。它还解决了下一代探测器的问题，以进一步扩大LIGO的科学范围，从而更好地观测来自黑洞、中子星和其他大型天体物理事件的引力波。这项研究的影响已经超越了引力波科学，因为在这个项目中开发的高功率光学器件已经在激光和光学行业有了商业应用。此外，学生和博士后科学家从不同的学科发展科学技能，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。为了支持近期和长期引力波研究，UF LIGO小组将开展一系列影响未来引力波仪器科学的研究项目。本文将研究一种产生任意调制边带的方法。低损耗法拉第隔离器（计划在不久的将来成为挤压机的关键部件）的工作将完成。研究了现代估计和控制技术在LIGO悬架系统中的应用。本文将研究一种新的准直传感方案和一种新的位置敏感激光束探测器。展望未来，将进行适合低温冷却测试质量的各类高纯硅中杂质和自由载流子吸收的实验。

In September 2015 the two Advanced LIGO observatories reached their initial goal: the detection of gravitational waves. Advanced LIGO, designed for a 10x sensitivity improvement and much better low-frequency response, now has seen inspiraling binary black holes at least three times. The improved sensitivity came from higher laser power, better isolation from ground motion, and changes to the interferometers themselves. The higher laser power presented challenges for the input optics, a responsibility of the University of Florida. This research will address improvements in performance of the input optics and of controls for the interferometer as a whole. It also addresses the next generation of detectors to increaser further the LIGO science reach, enabling better observations of gravitational waves from black holes, neutron stars and other massive astrophysical events. The research has impacts that go beyond gravitational wave science as high-power optical devices developed in this project have commercial applications to the laser and optics industries. In addition, the students and postdoctoral scientists 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 support of near-term and longer-range gravitational-wave research, the UF LIGO group will carry out a number of research projects that impact instrument science for future gravitational-wave. A method for generating arbitrary modulation sidebands will be developed. Work on low-loss Faraday isolators (key components of the squeezer that is planned in the near future) will be completed. Application of modern estimation and control techniques to LIGO suspension systems will be investigated. A novel scheme for alignment sensing as well as a novel position-sensitive laser beam detector will be studied. Looking further into the future, experiments to measure impurities and free carrier absorption in various types of high purity silicon suitable for cryogenically cooled test masses will be conducted.