Experimental Test of a Two-dimensional Approximation for Dielectric Microcavities

TL;DR

This paper experimentally tests the accuracy of a two-dimensional approximation model for dielectric microcavities used in microlasers, revealing significant deviations and limitations of the model in real three-dimensional resonators.

Contribution

The study provides an experimental validation showing the two-dimensional approximation often fails to accurately predict resonance properties of three-dimensional dielectric resonators.

Findings

Significant deviations between measurements and model predictions

The two-dimensional approximation generally fails for three-dimensional dielectric resonators

Experimental data highlight the need for more accurate modeling approaches

Abstract

Open dielectric resonators of different shapes are widely used for the manufacture of microlasers. A precise determination of their resonance frequencies and widths is crucial for their design. Most microlasers have a flat cylindrical geometry, and a two-dimensional approximation, the so-called method of the effective index of refraction, is commonly employed for numerical calculations. Our aim has been an experimental test of the precision and applicability of a model based on this approximation. We performed very thorough and accurate measurements of the resonance frequencies and widths of two passive circular dielectric microwave resonators and found significant deviations from the model predictions. From this we conclude that the model generally fails in the quantitative description of three-dimensional dielectric resonators.