Microcavity resonance condition, quality factor, and mode volume are determined by different penetration depths

TL;DR

This paper clarifies how three different penetration depths influence the resonance, quality factor, and mode volume of DBR-based microcavities, correcting previous incomplete models and providing experimental validation.

Contribution

It introduces a comprehensive analysis involving three penetration depths and experimentally verifies their roles in microcavity properties.

Findings

Three distinct penetration depths are crucial for accurate microcavity modeling.

Experimental results match theoretical predictions for penetration depths.

Corrected equations improve the understanding of DBR-based microcavities.

Abstract

The penetration depth in a Distributed Bragg Reflector (DBR) co-determines the resonance condition, quality factor, and mode volume of DBR-based microcavities. Recent studies have used an incomplete description of the penetration depth and incorrect equations. We present a complete analysis that involves three different penetration depths. We also present a series of experiments on microcavities to accurately determine the frequency and modal penetration depth of our DBRs and compare these results with theoretical predictions. The obtained results are relevant for anyone who models a DBR as an effective hard mirror if lengths of the order of the wavelength are relevant, as is the case for microcavities.