Marginally Unstable Periodic Orbits in Semiclassical Mushroom Billiards

TL;DR

This paper investigates marginally unstable periodic orbits in optical mushroom billiards, revealing their robustness and influence on emission patterns, with implications for microcavity laser design.

Contribution

It demonstrates the effects of cavity openness on far-field emission and the robustness of marginally unstable orbits against shape perturbations.

Findings

Directional emission influenced by marginally unstable orbits

Robustness of orbits despite shape perturbations

Potential applications in microcavity laser design

Abstract

Optical mushroom shaped billiards offer a unique opportunity to isolate and study non-dispersive, marginally unstable periodic orbits. Here we show that the openness of the cavity to external fields presents unanticipated consequences for the far-field distribution, including directional emission. This is mediated by interactions of marginally unstable periodic orbits with chaotic modes and is potentially relevant for the design of microcavity lasers. We also show that such orbits are robust against perturbations to the shape of the cavity, despite the non-generic character of the classical counterpart and the lack of structural stability of the corresponding classical orbits.