Excess quantum noise due to mode nonorthogonality in dielectric microresonators

TL;DR

This paper develops a theoretical framework for understanding the frequency-specific light emission in complex dielectric microresonators, highlighting the impact of mode nonorthogonality and providing improved relations for laser threshold predictions.

Contribution

It introduces a generalized Petermann factor and a refined relation between resonance lifetime and laser threshold for non-paraxial, non-uniform dielectric microresonators.

Findings

Lorentzian intensity profiles characterized by a generalized Petermann factor.

Renormalized peak positions and resonance lifetimes derived.

Improved laser threshold relations for complex microresonator geometries.

Abstract

This work presents a theory of the frequency-resolved light emission of active two-dimensional dielectric microresonators, which are characterized by a highly non-paraxial mode structure and frequently feature a position-dependent dielectric constant and non-uniform gain. The Lorentzian intensity profile is characterized by an appropriately generalized Petermann factor, a renormalized peak position, and the cold-cavity resonance lifetime Gamma. The theory also delivers a relation of Gamma to the laser threshold that improves earlier phenomenological expressions even for the case of a homogeneous medium.