Fresnel filtering of Gaussian beams in microcavities

TL;DR

This paper investigates how Gaussian beams behave in microcavities, revealing deviations from Snell's law near the critical angle due to Fresnel filtering, supported by experimental data and theoretical analysis.

Contribution

It provides the first experimental evidence of Fresnel filtering effects in Gaussian beams within microcavities and compares the results with theoretical predictions.

Findings

Deviations from Snell's law observed near the critical angle.

Fresnel filtering effect confirmed experimentally.

Qualitative agreement between theory and experiment.

Abstract

We study the output from the modes described by the superposition of Gaussian beams confined in the quasi-stadium microcavities. We experimentally observe the deviation from Snell's law in the output when the incident angle of the Gaussian beam at the cavity interface is near the critical angle for total internal reflection, providing direct experimental evidence on the Fresnel filtering. The theory of the Fresnel filtering for a planar interface qualitatively reproduces experimental data, and a discussion is given on small deviation between the measured data and the theory.