Different regimes of Purcell Effect in Disordered Photonic Crystals

TL;DR

This paper investigates how disorder in photonic crystals affects spontaneous emission rates, revealing two regimes of the Purcell effect that depend on the disorder level, with implications for lasing and emission enhancement.

Contribution

It identifies and characterizes two distinct regimes of the Purcell effect in disordered photonic crystals, linking disorder levels to emission behavior and potential applications.

Findings

Moderate disorder enhances emission at PBG edges due to edge states.

Higher disorder increases emission within PBG via high-Q states.

Disorder-induced regimes explain observed lasing and emission phenomena.

Abstract

We demonstrate that disorder in photonic crystals could lead to pronounced modification of spontaneous emission rate in the frequency region corresponding to the photonic band gap (PBG). Depending on the amount of disorder, two different regimes of the Purcell effect occurs. For the moderate disorder, an enhancement of spontaneous emission occurs at the edge of PBG due to modification of the properties of the edge state. This effect is responsible for recently observed mirrorless lasing in photonic crystals at the edge of PBG. When the level of disorder increases, the spontaneous emission rate enhances within the PBG due to the appearance of the high quality factor states. This effect is likely responsible for a superlinear dependence of emissions on the pumping observed in synthetic opals.