Giant Gain Enhancement in Photonic Crystals with a Degenerate Band Edge

TL;DR

This paper introduces a novel photonic crystal design with a degenerate band edge that significantly enhances gain and reduces lasing thresholds by leveraging slow wave resonance and increased photon lifetime.

Contribution

It presents a new approach utilizing degenerate band edges in photonic crystals to achieve giant gain enhancement and low-threshold lasing, surpassing standard designs.

Findings

Gain enhancement is several orders of magnitude higher at DBE.

DBE-based cavities enable low-threshold lasing.

Enhanced photon lifetime and local density of states at DBE.

Abstract

We propose a new approach leading to giant gain enhancement. It is based on unconventional slow wave resonance associated to a degenerate band edge (DBE) in the dispersion diagram for a special class of photonic crystals supporting two modes at each frequency. We show that the gain enhancement in a Fabry-Perot cavity (FPC) when operating at the DBE is several orders of magnitude stronger when compared to a cavity of the same length made of a standard photonic crystal with a regular band edge (RBE). The giant gain condition is explained by a significant increase in the photon lifetime and in the local density of states. We have demonstrated the existence of DBE operated special cavities that provide for superior gain conditions for solid-state lasers, quantum cascade lasers, traveling wave tubes, and distributed solid state amplifiers. We also report the possibility to achieve low-threshold lasing in FPC with DBE compared to RBE-based lasers.