Parametrically driven inertial sensing in chip-scale optomechanical cavities at the thermodynamical limits with extended dynamic range

TL;DR

This paper presents a theoretical and experimental analysis of a chip-scale optomechanical inertial sensor operating at thermodynamical limits, featuring extended dynamic range and high sensitivity for precise displacement and acceleration measurements.

Contribution

It introduces a novel optomechanical transduction technique with on-chip integration and laser detuning for enhanced dynamic range in inertial sensing.

Findings

Achieved 1.5 mg/Hz acceleration sensitivity

Demonstrated 2.5 fm/Hz^1/2 displacement resolution

Operates at thermodynamical limits with extended dynamic range

Abstract

Recent scientific and technological advances have enabled the detection of gravitational waves, autonomous driving, and the proposal of a communications network on the Moon (Lunar Internet or LunaNet). These efforts are based on the measurement of minute displacements and correspondingly the forces or fields transduction, which translate to acceleration, velocity, and position determination for navigation. State-of-the-art accelerometers use capacitive or piezo resistive techniques, and micro-electromechanical systems (MEMS) via integrated circuit (IC) technologies in order to drive the transducer and convert its output for electric readout. In recent years, laser optomechanical transduction and readout have enabled highly sensitive detection of motional displacement. Here we further examine the theoretical framework for the novel mechanical frequency readout technique of optomechanical transduction when the sensor is driven into oscillation mode [8]. We demonstrate theoretical and physical agreement and characterize the most relevant performance parameters with a device with 1.5mg/Hz acceleration sensitivity, a 2.5 fm/Hz1/2 displacement resolution corresponding to a 17.02 ug/Hz1/2 force-equivalent acceleration, and a 5.91 Hz/nW power sensitivity, at the thermodynamical limits. In addition, we present a novel technique for dynamic range extension while maintaining the precision sensing sensitivity. Our inertial accelerometer is integrated on-chip, and enabled for packaging, with a laser-detuning-enabled approach.