Theoretical Research on LIGO Noise Reduction and Advanced Interferometer Configurations

该奖项支持与激光干涉仪引力波天文台（LIGO）相关的理论研究，旨在提高LIGO探测器的灵敏度。在这个项目中进行的研究探索了引力波探测器背后的基本量子和引力物理学，其结果将与更广泛的量子光力学社区广泛相关。该项目将在加州理工学院陈彦北教授的课题组进行；它将成为年轻引力波科学家的训练场，让他们接触到从量子测量理论到经典统计物理学的各种研究课题。陈的研究小组成员将与LIGO实验室的成员以及LIGO科学合作的其他成员密切互动。更具体地说：(A)探索减少LIGO量子噪声的新技术，包括使用主动量子光力学器件，利用多光模式产生的光刚性，以及主动介质的可能应用。对量子测量中所谓的高能量子极限的适用范围将进行批判性的研究。（二）开展先进干涉仪配置研究；特别是，在信号到达时切换干涉仪配置的可行性和优点将进行研究；评估光模缺陷对标定的影响；建立先进LIGO干涉仪升级策略评估框架。(C)对各向异性涂层材料和非平衡低温悬浮液系统的热波动进行理论研究。(D)制定使用宏观测试质量和量子有限测量来测试基本量子和引力物理的策略。

This award supports theoretical research related to the Laser Interferometer Gravitational Wave Observatory (LIGO), with the aim of improving the sensitivity of LIGO detectors. Research carried out during this project explores the fundamental quantum and gravitational physics that underlie gravitational-wave detectors, and the results will be widely relevant to the more general community of quantum optomechanics. This project will be carried out at professor Yanbei Chen's research group at the California Institute of Technology; it will serve as a training ground for young gravitational-wave scientists --- by exposing them to a variety of research topics, ranging from quantum measurement theory to classical statistical physics. Members of Chen's research group will interact closely with members of the LIGO Lab, and the rest of the LIGO Scientific collaboration.More specifically: (A) New techniques of reducing LIGO's quantum noise will be explored, including the use of active quantum optomechanical devices, the employment of optical rigidity generated by multiple optical modes, and the possible application of active medium. The domain of applicability of the so-called Energetic Quantum Limit for quantum measurements will be critically studied. (B) Research on advanced interferometer configurations will be carried out; in particular, the feasibility and merit of switching interferometer configurations during signal arrival will be investigated; the effect of optical-mode imperfection on calibration will be evaluated; a framework for evaluating upgrade strategies for Advanced LIGO interferometers will be established. (C) Theoretical investigations on thermal fluctuations of anistoropic coating materials and non-equilibrium cryogenic suspension systems will be carried out. (D) Strategies of testing fundamental quantum and gravitational physics using macroscopic test masses and quantum-limited measurements will be formulated.