Huddle test of optical inertial sensors combined with slightly damped mechanics

摘要

Precise seismic measurements and active isolation in the low-frequency domain are more and more required. In order to meet the requirements, an optical inertial sensor is developed, where a lightly damped mechanical structure (high Q factor) is employed. The sensor consists of two parts. The first part is a homemade interferometric readout which has a resolution below 1 pm/√Hz at 1 Hz, and the other one is a mechanical part which has a low resonance frequency and a high Q factor. For the developed sensor at hand, the mechanical structure of STS-1 vertical seismometer is used and adapted for hosting the interferometric readout. The sensor is then placed inside a vacuum chamber to be immune from the ambient noise. The sensor resolution is experimentally examined using huddle tests.