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

引力波是一个信使，它将告诉我们宇宙中一些能量最高的事件，在这种情况下，非常重的质量经历了高速加速的相干运动；这样的大质量可以在黑洞、中子星双星系统的合并、超新星和大爆炸的回声中找到。引力波的发现以及高级激光干涉仪引力波天文台(Advanced LIGO)的发现将是科学史上的一个重要里程碑。高级激光干涉仪引力波观测站由美国国家科学基金会建造，用于直接探测引力波。先进的LIGO涵盖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、低噪声电子学、控制系统、网格计算、算法开发和处理大型数据集。先进的LIGO干涉仪已经开启，它们的调试提高了它们的灵敏度，远远超过以前的探测器。敏感度提高10倍的目标指日可待。由于搜索量随着距离的平方而扩大，先进的LIGO将拥有1000多倍于其覆盖范围内的资源。为了实现这种提高的灵敏度，除了真空系统之外，基本上所有的东西都被更换了。这包括使用180瓦激光、四摆悬架、40千克测试质量、活动地震平台、信号回收干涉仪、稳定的回收腔、输出模式清洁器、直流读数和改进的热补偿。更高的激光功率对输入光学提出了挑战，这是佛罗里达大学的责任。此外，这项研究的影响超出了引力波科学。在这个项目中开发的高功率光学设备在激光和光学行业中有商业应用。这个项目将解决可能需要的项目，以优化探测器的性能。它还涉及未来升级和下一代探测器所需的基础研究，这将进一步扩大观测站的科学影响范围以及探测器特性方面的工作。将对干涉仪进行模拟，以帮助调试工作。将开展热自适应模式匹配和光束抖动抑制装置方面的工作。将对一种新的对准误差传感方案进行建模和原型设计。将测量作为温度函数的热涂层噪声。展望未来，将进行用于测试质量的高纯硅中杂质和自由载流子吸收的实验。将作出相当大的努力来提高法拉第隔离器的双向吞吐量，法拉第隔离器是未来探测器的压榨器的关键部件。

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.