Designing and understanding directional emission from spiral microlasers

TL;DR

This paper investigates how spiral-shaped microcavities can produce highly directional laser emission by analyzing the effects of pumping methods and geometry, providing insights for designing advanced microlasers.

Contribution

It introduces a systematic study of spiral microlasers' far-field emission, identifying conditions for optimal directionality and explaining previous experimental findings.

Findings

Directional emission achieved with boundary pumping and specific geometries

Identification of an optimal regime for emission directionality

Consistent explanation of prior experimental results

Abstract

The availability of microlasers with highly directional far-field characteristics is crucial for future applications. To this end we study the far-field emission of active microcavities with spiral shape using the Schroedinger-Bloch model. We find that they can provide directional emission under the conditions of (i) pumping along the resonator boundary and (ii) for specific resonator geometries. We systematically study the far-field characteristics under variation of the pumped area and the cavity geometry, and identify an directionality-optimized regime. Our results consistently explain previously obtained experimental results.