Devices and Materials for the Instrument Science of Advanced Gravitational-Wave Detectors

引力波是信使，它将告诉我们宇宙中一些能量最高的事件，在这种情况下，非常重的质量经历高加速度的相干运动；如此巨大的质量可以在黑洞、中子星双星系统的合并、超新星和大爆炸的回声中找到。引力波的发现，以及先进的LIGO（美国国家科学基金会为直接探测引力波而建造的激光干涉仪引力波天文台）对引力波源的发现，将成为科学史上的一个重要里程碑。先进的LIGO包含了一系列极其多样化的基础科学和工程学科：例如激光、光学、低噪声电子、控制系统、网格计算、算法开发和处理大型数据集。先进的LIGO干涉仪已经启动，它们的调试大大提高了它们的灵敏度，远远超过了以前的探测器。将灵敏度提高十倍的目标近在眼前。因为搜索量是距离的立方，所以先进的LIGO将在其范围内拥有超过1000倍的源。为了提高灵敏度，除了真空系统之外，基本上所有的东西都被替换了。这包括使用180瓦的激光器、四摆悬挂、40公斤的测试质量、主动地震平台、信号回收干涉仪、稳定的回收腔、输出模式清洁器、直流读出和改进的热补偿。更高的激光功率对佛罗里达大学负责的输入光学提出了挑战。此外，这项研究的影响已经超越了引力波科学。本课题开发的高功率光学器件在激光和光学工业中具有商业应用价值。该项目将解决可能需要的项目，以优化探测器的性能。它还解决了未来升级和下一代探测器所需的基础研究，这将进一步增加天文台的科学覆盖范围以及探测器表征工作。将对干涉仪进行模拟以辅助调试工作。热自适应模式匹配和波束抖动抑制装置的研究。本文将对一种新的定位误差传感方案进行建模和原型设计。热涂层噪声作为温度的函数将被测量。展望未来，将进行实验来测量测试质量的高纯硅中的杂质和自由载流子吸收。法拉第隔离器是未来探测器挤压器的关键部件，今后将投入大量的努力来提高法拉第隔离器的双向通量。

Gravitational waves are the messenger that will tell us about some of the most highly energetic events in the universe, in this case the coherent motion of very heavy masses undergoing high acceleration; such large masses can be found in black holes, the merger of neutron star binary systems, supernovae, and the echoes of the big bang. The discovery of gravitational waves as well as the discovery of these sources with Advanced LIGO, the Laser Interferometer Gravitational Wave Observatory built by the National Science Foundation to make a direct detection of gravitational waves, would be a major milestone in the history of science. Advanced LIGO encompasses an extremely diverse array of underlying scientific and engineering disciplines: examples include lasers, optics, low noise electronics, control systems, grid computing, algorithm development, and handling large data sets. The Advanced LIGO interferometers have turned on and commissioning of them has increased their sensitivity far above previous detectors. The goal of a tenfold sensitivity improvement is in sight. Because the search volume scales as distance cubed, advanced LIGO will have more than 1000 times more sources within its reach. To achieve this improved sensitivity, essentially everything except for the vacuum system has been replaced. This includes the use of a 180 Watt laser, quadruple pendulum suspensions, 40 kilogram test masses, active seismic platforms, a signal-recycled interferometer, stable recycling cavities, an output mode cleaner, DC readout, and improved thermal compensation. The higher laser power presents challenges for the input optics, a responsibility of the University of Florida. Moreover, this research has impacts that go beyond gravitational wave science. High-power optical devices developed in this project have commercial applications in the laser and optics industries.This project will address items that could be needed in order to optimize the performance of the detector. It also addresses basic research needed for future upgrades and next generation detectors, which will further increase the science reach of the observatories as well as work on detector characterization. Simulations of the interferometers will be carried out to aid commissioning work. Work on thermal adaptive mode-matching and devices for beam-jitter suppression will be done. A novel scheme for sensing alignment errors will be modeled and prototyped. Thermal coating noise as a function of temperature will be measured. Looking further into the future, experiments to measure impurities and free carrier absorption in high purity silicon for test masses will be conducted. Considerable effort will be put towards improving the bidirectional throughput of Faraday isolators that are key components of a squeezer for future detectors.