Gyroscope as quantum angular speed meter

TL;DR

This paper investigates the quantum limits of optical gyroscopes, revealing fundamental sensitivity bounds and proposing a measurement strategy to evade quantum back action, highlighting differences between integrating and rate gyroscopes.

Contribution

It demonstrates the quantum-limited sensitivity of optical gyroscopes and introduces a measurement approach to evade quantum back action, emphasizing the fundamental differences between integrating and rate gyroscopes.

Findings

Quantum sensitivity limit due to ponderomotive action.

Uncorrelated quantum fluctuations cause power-dependent uncertainty.

Feasibility of quantum back action evading measurement of angular momentum.

Abstract

We found that the measurement sensitivity of an optical integrating gyroscope is fundamentally limited due to ponderomotive action of the light leading to the standard quantum limit of the rotation angle detection. The uncorrelated quantum fluctuations of power of clockwise and counterclockwise electromagnetic waves result in optical power-dependent uncertainty of the angular gyroscope position. We also show that, on the other hand, a quantum back action evading measurement of angular momentum of a gyroscope becomes feasible if proper measurement strategy is selected. The angle is perturbed in this case. This observation hints on fundamental inequivalency of integrating and rate gyroscopes.