Effects of mirror birefringence and its fluctuations to laser interferometric gravitational wave detectors

Abstract

Crystalline materials are promising candidates as substrates or high-reflective coatings of mirrors to reduce thermal noises in future laser interferometric gravitational wave detectors. However, birefringence of such materials could degrade the sensitivity of gravitational wave detectors, not only because it can introduce optical losses, but also because its fluctuations create extra phase noise in the arm cavity reflected beam. In this paper, we analytically estimate the effects of birefringence and its fluctuations in the mirror substrate and coating for gravitational wave detectors. Our calculations show that the requirements for the birefringence fluctuations in silicon substrate and AlGaAs coating will be on the order of $10^{-8}$ and $10^{-10}$ rad/$\sqrt{\mathrm{Hz}}$ at 100~Hz, respectively, for future gravitational wave detectors. We also point out that optical cavity response needs to be carefully taken into account to estimate optical losses from depolarization.

11 pages, 4 figures

References in corpus (11)

• GW170817: Observation of Gravitational Waves from a Binary Neutron Star Inspiral
• Advanced Virgo: a 2nd generation interferometric gravitational wave detector
• Multi-messenger Observations of a Binary Neutron Star Merger
• Advanced LIGO
• Exploring the Sensitivity of Next Generation Gravitational Wave Detectors
• Prospects for doubling the range of Advanced LIGO
• Frequency-Dependent Responses in 3rd Generation Gravitational-Wave Detectors
• Excess noise and photo-induced effects in highly reflective crystalline mirror coatings
• Axion dark matter search using arm cavity transmitted beams of gravitational wave detectors
• Faraday isolator based on crystalline silicon (c-Si) for 2 micron laser radiation
• Study on electro-optic noise in crystalline coatings toward future gravitational wave detectors

Cited by in corpus (2)

• Development of a polarimetry method toward in-situ substrate birefringence characterization of ground-based gravitational wave detectors
• In situ substrate birefringence characterization in gravitational wave detectors using a heterodyne polarimetry method