Minimizing Quantum Decoherence in Gravitational-Wave Detectors

该奖项支持旨在扩展引力波探测器的天体物理范围的仪器的开发。自2015年先进LIGO首次探测到引力波以来，引力波为宇宙打开了一扇新的观测窗口。这些遥远时空中的微弱扰动为望远镜观测到的光带来了新的补充信息。在未来的十年里，引力波探测将揭示对极端重力、中子星内部超致密物质状态和黑洞本质的新见解。LIGO探测器使用距离超过4公里的高功率激光束来测量通过的引力波。该项目将开发新型自适应光学系统，能够显著减少LIGO和未来探测器内部的光学损耗，实现更高的激光功率和对引力波的更高灵敏度。除了对天体物理学的影响外，这项新技术还将提供一种在复杂激光系统中实现更低损耗的通用方法，并有可能加速许多领域的发现，包括原子、分子、光学物理和光量子计算。量子噪声限制了引力波探测器在高频上的灵敏度，而在高频上，一些最引人注目的观测——黑洞环降和双中子星合并——将会发生。使用压缩相干光态和更高的激光功率直接减少了这种噪音，扩展了探测器的天体物理范围。为了支持更高水平的压缩和激光功率，该项目将开发新的低噪声自适应光学器件，用于在更高的空间频率下动态控制激光波前，赋予引力波探测器关键的新校正能力。高阶光学像差导致压缩态退相干，降低了激光腔的光学增益，目前限制了先进LIGO的工作功率。通过光学损耗的降低，这项新技术旨在使量子噪声降低系数达到1.7，达到750千瓦的先进时代设计功率，以及更大的压缩光增强。这将扩大探测器的天体物理范围，提高探测率，并使对单个波形的高精度测量成为可能。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 the development of instrumentation aimed at extending the astrophysical reach of gravitational-wave detectors. Since their first detection by Advanced LIGO in 2015, gravitational waves have opened a new observational window on the Universe. These faint disturbances in distant space-time carry new and complementary information to the light observed by telescopes. In the coming decade, gravitational-wave detections will reveal new insights into extreme gravity, ultra-dense states of matter inside neutron stars, and the nature of black holes. The LIGO detectors employ high-power laser beams over 4-kilometer distances to measure passing gravitational waves. This project will develop novel adaptive optics capable of significantly reducing the optical losses inside LIGO and future detectors, enabling higher laser power and greater sensitivity to gravitational waves. In addition to its astrophysical impact, this new technology will provide a general means of achieving lower loss in complex laser systems, with potential to accelerate discoveries in many fields including atomic, molecular, and optical physics and optical quantum computing.Quantum noise limits the sensitivity of gravitational-wave detectors at high frequencies, where some of the most compelling observations—black hole ringdowns and binary neutron star mergers—stand to be made. The use of squeezed coherent states of light and higher laser power directly reduce this noise, extending the astrophysical reach of the detectors. To support higher levels of squeezing and laser power, this project will develop novel low-noise adaptive optics for dynamic control of the laser wavefront at higher spatial-frequencies, endowing gravitational-wave detectors with critical new corrective capabilities. Higher-order optical aberrations induce decoherence of the squeezed state and degrade the optical gain of the laser cavities—and currently limit the operating power of Advanced LIGO. Through the optical loss reduction it will afford, this new technology seeks to enable a quantum noise reduction factor of 1.7 from reaching the 750 kW Advanced-era design power, as well as greater squeezed-light enhancement. This will both extend the astrophysical range of the detectors, increasing detection rates, and enable higher-precision measurements of individual waveforms.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.