Stable planar mesoscopic photonic crystal cavities

TL;DR

This paper introduces a novel high-Q mesoscopic photonic crystal cavity using self-collimation and planar mirrors, achieving high confinement and energy storage with improved reflectivity over traditional designs.

Contribution

It presents a new cavity design leveraging mesoscopic self-collimation in photonic crystals, resulting in high-Q factors and enhanced confinement compared to standard methods.

Findings

Achieved Q factor > 10^4 in optimized cavity

Demonstrated improved reflectivity over distributed Bragg reflectors

Enhanced energy storage and field confinement

Abstract

Mesoscopic self-collimation in mesoscopic photonic crystals with high reflectivity is exploited to realize a novel high-Q factor cavity by means of mesoscopic PhC planar mirrors. These mirrors efficiently confine a mode inside a planar Fabry-Perot-like cavity, due to a beam focusing effect that stabilises the cavity even for small beam sizes, resembling the focusing behaviour of curved mirrors. Moreover, they show an improved reflectivity with respect to their standard distributed Bragg reflector counterparts that allows higher compactness. A Q factor higher than 10^4 has been achieved for an optimized 5-period-long mirror cavity. The optimization of the Q factor and the performances in terms of energy storage, field enhancement and confinement are detailed.