Compact Active Vibration Isolation and Tilt Stabilization for a Portable High-Precision Atomic Gravimeter

In high-precision atomic gravimeters, a rest mass is needed to provide a gravity reference, which is typically the retro-reflecting mirror of the Raman laser beams that address the two hyperfine ground states of the specific free-falling atomic test mass. We construct a compact active feedback control system for the retro-reflecting mirror that provides vibration isolation in the vertical axis as well as two-rotation stabilization in the horizontal plane. The active feedback control provides vertical vibration reduction of up to a factor of 300 in the frequency range of 0.03 to 10 Hz and tilt stabilization of approximately ±1μrad in a noisy laboratory environment. This system enables high-precision gravity measurements on a portable gravimeter with sensitivity reaching 6.4×10-8g/Hz and resolution of 2.8×10-9g after an integration time of 4000 s. © 2022 American Physical Society.