Noise spectroscopy of optical microcavity

TL;DR

This paper calculates the intensity noise spectrum of light passing through an optical microcavity, considering thermal thickness fluctuations, revealing acoustic mode peaks and potential for detection with current noise spectroscopy methods.

Contribution

It introduces a theoretical model for noise spectrum in microcavities accounting for thermal fluctuations, highlighting acoustic mode detection capabilities.

Findings

Noise spectrum shows a peak at the acoustic mode frequency.

The noise magnitude is detectable with current spectroscopy techniques.

Spectrum depends on the illuminated area size.

Abstract

The intensity noise spectrum of the light passed through an optical microcavity is calculated with allowance for thermal fluctuations of its thickness. The spectrum thus obtained reveals a peak at the frequency of acoustic mode localized inside the microcavity and depends on the size of the illuminated area. The estimates of the noise magnitude show that it can be detected using the up-to-date noise spectroscopy technique.