Large-scale high sensitivity laser gyroscopes have important applications for ground-based and space-based gravitational wave detection. We report on the development of a 3 m×3 m heterolithic passive resonant gyroscope (HUST-1) which is installed on the ground of a cave laboratory. We operate the HUST-1 on different longitudinal cavity modes and the rotation sensitivity reaches 1.6×10−9 rad/s/Hz beyond 1 Hz. The drift of the cavity length is one of the major sensitivity limits for our gyroscope in the low frequency regime. By locking cavity length to an ultra-stable reference laser, we achieve a fractional cavity length stability of 5.6×10−9 m/Hz at 0.1 mHz, a four orders of magnitude improvement over the unconstrained cavity in the low frequency regime. We stabilize the cavity length of a large-scale heterolithic passive resonant gyroscope through active feedback and realize long-term operation. The rotation sensitivity reaches 1.7×10−7 rad/s/Hz at 0.1 mHz, a three orders of magnitude improvement, which is no longer limited by the cavity length drift in this frequency range.
@article{arxiv.2003.05310,
title = {3 m$\times$3 m heterolithic passive resonant gyroscope with cavity length stabilization},
author = {Fenglei Zhang and Kui Liu and Zongyang Li and Xiaohua Feng and Ke Li and Yanxia Ye and Yunlong Sun and Leilei He and K. Ulrich Schreiber and Jun Luo and Zehuang Lu and Jie Zhang},
journal= {arXiv preprint arXiv:2003.05310},
year = {2020}
}