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$\times$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 $1.6\times10^{-9}$ rad/s/$\rm \sqrt{Hz}$ 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 $5.6\times10^{-9}$ m$/\rm \sqrt{Hz}$ 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 $1.7\times10^{-7}$ rad/s/$\sqrt{\rm{Hz}}$ at 0.1 mHz, a three orders of magnitude improvement, which is no longer limited by the cavity length drift in this frequency range.

中文翻译：

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具有腔长稳定功能的 3 m×3 m 异质无源谐振陀螺仪

大尺度高灵敏度激光陀螺在地基和天基引力波探测中具有重要应用。我们报告了安装在洞穴实验室地面上的 300 万美元\乘以 300 万美元的异质无源谐振陀螺仪 (HUST-1) 的开发。我们在不同的纵向腔模式下运行 HUST-1，旋转灵敏度达到 $1.6\times10^{-9}$ rad/s/$\rm \sqrt{Hz}$ 超过 1 Hz。腔长的漂移是我们的陀螺仪在低频范围内的主要灵敏度限制之一。通过将腔长锁定到超稳定的参考激光器，我们在 0.1 mHz 时实现了 $5.6\times10^{-9}$ m$/\rm \sqrt{Hz}$ 的分数腔长稳定性，提高了四个数量级在低频区域的无约束腔上。我们通过主动反馈稳定大型异质无源谐振陀螺的腔长，实现长期运行。旋转灵敏度在 0.1 mHz 时达到 $1.7\times10^{-7}$ rad/s/$\sqrt{\rm{Hz}}$，提高了三个数量级，不再受腔长漂移的限制这个频率范围。