Compact Active Vibration Isolation and Tilt Stabilization for a Portable High-Precision Atomic Gravimeter
F. E. Oon, Rainer Dumke
Abstract
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 $\ifmmode\pm\else\textpm\fi{}1\phantom{\rule{0.2em}{0ex}}\ensuremath{\mu}\mathrm{rad}$ in a noisy laboratory environment. This system enables high-precision gravity measurements on a portable gravimeter with sensitivity reaching $6.4\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}8}g/\sqrt{\mathrm{Hz}}$ and resolution of $2.8\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}9}g$ after an integration time of 4000 s.