Calculation of laser interference quantum noise in gravitational wave detection

Quantum noise is one of the main noises that affect laser interference gravitational wave detection. To cope with quantum noise and further improve detection sensitivity, this paper applies the quantum transfer function method to rederive the source attribution of quantum noise in traditional Michelson interferometers. The results show that for two types of quantum noise, radiation pressure noise and shot noise, radiation pressure noise can be directly attributed to the amplitude quadrature fluctuations of vacuum fluctuations at the unused port of the interferometer, while shot noise can only be completely attributed to the phase quadrature fluctuations at the unused port under certain conditions. Under the premise of clearly knowing the source attribution of quantum noise, squeezed light technology can improve the sensitivity of detectors. However, when adopting unequal arm interference detection schemes, attention must be paid to the length difference between the two unequal arm lengths. Finally, this article also mentions the issues that may need to be considered when promoting the application of squeezed light technology in space gravitational wave detection, including the impact of weak light lock-in amplification technology, the relationship between different interferometers, the impact of data post-processing, and the generation of squeezed light.