# Three-dimensional micro-billiard lasers: the square pyramid

## TL;DR

This paper reports the discovery of three-dimensional lasing modes in pyramidal microlasers, revealing complex mode structures beyond previous planar confinement, with implications for quantum chaos and laser stability.

## Contribution

It demonstrates the existence of genuine 3D periodic orbit modes in pyramidal microlasers, expanding understanding of mode localization in non-symmetric resonators.

## Key findings

- Lasing modes are localized on 3D periodic orbits.
- Mode structures differ from previously observed planar modes.
- Implications for laser stability and polarization are discussed.

## Abstract

Microlasers are of ample interest for advancing quantum chaos studies at the intersection of wave dynamics and geometric optics in resonators. However, the mode structures of three-dimensional microlasers without rotational symmetry remain largely unexplored due to fabrication limitations. Previous studies of such cavities revealed lasing modes localized on periodic orbits exclusively confined to a single plane. In this work, we report on the characterization of pyramidal, polymer-based microlasers and demonstrate that the lasing modes are localized on a genuine three-dimensional periodic orbit. The consequences on the laser features are further discussed, in particular stability and polarization issues.