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

TL;DR

This paper presents a new in-situ polarimetry method for measuring substrate birefringence in gravitational wave detectors, aiming to improve detector sensitivity by enabling better diagnostics of mirror birefringence.

Contribution

The paper introduces a novel in-situ birefringence measurement technique demonstrated with a tabletop setup, suitable for large-scale gravitational wave detectors.

Findings

Successful demonstration of the in-situ birefringence measurement method

Potential for integration as a diagnostic tool in gravitational wave detectors

Discussion of technological developments for future implementation

Abstract

Improving the sensitivity of gravitational wave detectors is necessary to enrich scientific outcome of gravitational wave astronomy. Birefringence in test mass mirrors of gravitational wave detectors can become an important factor for both current and next-generation gravitational wave detectors to achieve improved performance. In-situ birefringence characterization can become an essential diagnostic tool for detector performance, and needs to be established. We report a possible in-situ birefringence characterization method and its experimental results with a tabletop setup. The scheme proposed and demonstrated in this paper can be used as a diagnostic tool in large-scale gravitational wave detectors. We also discuss possible technological developments toward implementation in future gravitational wave detectors.