Optomechanical accelerometers for geodesy

TL;DR

This paper introduces a new optomechanical inertial sensor designed for low-frequency geodesy applications, demonstrating high sensitivity, low noise, and robustness, with experimental validation against commercial seismometers.

Contribution

The paper presents a novel optomechanical accelerometer with high quality factor and low noise floor, suitable for geodesy, along with data analysis algorithms for noise correction.

Findings

Successfully detected low-frequency seismic noise.

Achieved a noise floor of approximately 5E-11 m s-2 per root-Hz at 1Hz.

Demonstrated robustness against environmental variables.

Abstract

We present a novel optomechanical inertial sensor for low frequency applications and corresponding acceleration measurements. This sensor has a resonant frequency of 4.7Hz, a mechanical quality factor of 476k, a test mass of 2.6 gram, and a projected noise floor of approximately 5E-11 m s-2. per root-Hz at 1Hz. Such performance, together with its small size, low weight, reduced power consumption, and low susceptibility to environmental variables such as magnetic field or drag conditions makes it an attractive technology for future geodesy missions. In this paper, we present an experimental demonstration of low-frequency ground seismic noise detection by direct comparison with a commercial seismometer, anda data analysis algorithms for the identification, characterization, and correction of several noise sources.