Compact active vibration isolation and tilt stabilization for a portable high-precision atomic gravimeter

TL;DR

This paper presents a compact active vibration and tilt stabilization system for portable atomic gravimeters, significantly improving measurement sensitivity and enabling high-precision gravity measurements in noisy environments.

Contribution

The authors developed a novel compact active feedback system that provides vibration isolation and tilt stabilization for portable atomic gravimeters, enhancing their precision and usability.

Findings

Vertical vibration reduced by up to 300 times in 0.03-10 Hz range

Tilt stabilized within ±1 μrad in noisy environments

Achieved gravity measurement sensitivity of 6.4×10⁻⁸ g/√Hz

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 addresses the two hyperfine ground states of the specific free-falling atomic test mass. We constructed 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 $\pm$ 1 $\mu$rad in the noisy lab environment. This system has enabled high-precision gravity measurements on a portable gravimeter with sensitivity reaching $6.4\times 10^{-8}$ g/$\sqrt{\text{Hz}}$ and resolution of $2.8\times 10^{-9}$ g after an integration time of 4000 s.