Optical Interferometers with Reduced Sensitivity to Thermal Noise

TL;DR

This paper proposes optical interferometry schemes that reduce sensitivity to thermal noise by compensating phase shifts caused by surface and bulk strains, thus improving measurement stability.

Contribution

It introduces novel methods for phase shift compensation in optical interferometers to mitigate thermal noise effects.

Findings

Reduced phase sensitivity to thermal fluctuations

Enhanced interferometer stability

Potential for improved measurement precision

Abstract

A fundamental limit to the sensitivity of optical interferometry is thermal noise that drives fluctuations in the positions of the surfaces of the interferometer's mirrors, and thereby in the phase of the intracavity field. Schemes for reducing this thermally driven phase noise are presented in which phase shifts from concomitant strains at the surface and in the bulk of the substrate compensate the phase shift due to the displacement of the surface. Although the position of the physical surface fluctuates, the optical phase upon reflection can have reduced sensitivity to this motion.