Difference between penetration and damping lengths in photonic crystal mirrors

TL;DR

This paper investigates the relationship between penetration and damping lengths in photonic crystal mirrors, revealing that their usual trade-off can be overcome with specific designs, leading to improved optical properties.

Contribution

It demonstrates that in photonic crystal heterostructure mirrors, penetration length and damping length are not necessarily correlated, challenging classical assumptions.

Findings

Penetration length is not correlated with damping length in heterostructure mirrors.

Designs can break the classical trade-off between damping and penetration lengths.

Photonic crystal structures can be optimized for better mirror performance.

Abstract

Different mirror geometries in two-dimensional photonic crystal slabs are studied with fully-vectorial calculations. We compare their optical properties and, in particular, we show that, for heterostructure mirrors, the penetration length associated with the delay induced by distributed reflection is not correlated to the characteristic damping length of the electromagnetic energy distribution in the mirror. This unexpected result evidences that the usual trade-off between short damping lengths and large penetration lengths that is classically encountered in distributed Bragg reflectors can be overcome with carefully designed photonic crystal structures.