Optically levitated gyroscopes with a MHz rotating micro-rotor

TL;DR

This paper introduces the world's smallest optically levitated rotor gyroscope operating at MHz speeds, demonstrating its ability to measure angular velocity with high stability and potential for quantum applications.

Contribution

It proposes and experimentally demonstrates a novel high-speed levitated rotor gyroscope with unprecedented small size and bias stability, advancing optomechanical gyroscopic technology.

Findings

Achieved rotation at MHz speeds with a levitated vaterite particle.

Measured an angular rate bias instability of 0.08°/s.

Theoretically possible to improve bias stability to 10^{-9}°/h.

Abstract

The optically levitated particles have been driven to rotate at an ultra-high speed of GHz, and the gyroscopic application of these levitated particles to measure angular motion have long been explored. However, this gyroscope has not been proven either theoretically or experimentally. Here, a rotor gyroscope based on optically levitated high-speed rotating particles is proposed. In vacuum, an ellipsoidal vaterite particle with 3.58 $\mu$m average diameter is driven to rotate at MHz, and the optical axis orientation of the particle is measured by the particle rotational signal. The external inputted angular velocity makes the optical axis deviate from the initial position, which changes the frequency and amplitude of the rotational signal. The inputted angular velocity is hence detected by the rotational signal, and the angular rate bias instability of the prototype is measured to be $0.08^o/s$. It is the smallest rotor gyroscope in the world, and the bias instability can be further improved up to $10^{-9o}/h$ theoretically by cooling the motion and increasing the angular moment of the levitated particle. Our work opens a new application paradigm of the levitated optomechanical systems and possibly bring the rotor gyroscope to the quantum realm.