Impact and Mitigation of Wavefront Distortions in Precision Interferometry

超稳定激光干涉测量已成为精密计量的基石。了解高阶光学模式是激光干涉引力波（GW）探测社区特别感兴趣的。最近的研究表明，模式失配是压缩损耗的主要原因，压缩损耗的大小会影响探测器的探测范围。本课题的目的是研究一种直接获取激光模式结构的新技术。我们将提高该技术的动态范围，优化设计折衷，并确定与GW检测相关的频率范围内的主要噪声源。这种装置可以在精密计量装置的调试期间使用以改善设置的信噪比，在LIGO的情况下，这可以改善诸如双星中子星的高频源的检测率和信噪比。光学时钟和GW检测器共享共同的限制噪声源，镜面涂层布朗噪声。通过将询问光切换到更高阶空间模式，可以减少这种情况。我们将研究这种技术中的损失，并发现对失配的敏感性增加。模式分析器技术，我们调查将提供有价值的洞察光束和失配。这种技术可能成为一种使能技术，用于绘制布朗噪声减少光学时钟和GW检测器。

Ultra-stable laser interferometry has become a cornerstone of precision metrology. Understanding higher-order optical modes is of particular interest to the Laser Interferometric Gravitational Wave (GW) detection community. Recent research at detectors shows that mode mismatches account for a significant amount of the squeezing loss, which reduces the range of the detector.The aim of this project is to investigate a novel technique which directly access the mode structure of a laser beam. We will improve the dynamic range of the technique, characterise the design tradeoff's and determine predominant noise sources across the frequency range relevant to GW detection. Such a device could be used during the commissioning of precision metrology devices to improve signal to noise of the setup, in the case of LIGO this can improve the detection rate and signal to noise ratio of high frequency sources such as Binary Neutron Stars.Optical Clocks and GW detectors share a common limiting noise source, mirror coating brownian noise. By switching the interrogation light to a higher order spatial mode, this may be reduced. We will investigate losses in this technique and find that the sensitive to mismatches increases. The mode analyser technique we investigate will provide valuable insight into the beam and mismatches. This technique may become an enabling technology for charting brownian noise reduction in optical clocks and GW detectors.