# Supersymmetric Single-Lateral-Mode GaN-Based Ridge-Waveguide Edge-Emitting Lasers

## TL;DR

This paper introduces a new laser design using supersymmetry to achieve high-power single-mode operation in nitride-based lasers.

## Contribution

The study proposes a supersymmetry approach to suppress higher-order modes in nitride lasers using multi-ridge waveguide structures.

## Key findings

- Triple-ridge waveguides show a mode separation ratio more than twice that of double-ridge waveguides.
- Both configurations achieve strong mode discrimination with improved ridge-width tolerance.
- The design enables high-power single-mode operation with low-divergence Gaussian beams.

## Abstract

High-power nitride-based edge-emitting lasers with low-divergence Gaussian beams are useful for applications including laser surgery, material processing, and 3D printing. Fundamental lateral mode operation is typically achieved using narrow or shallow ridges. However, narrow ridges limit the active region, while shallow ridges can allow higher-order mode lasing. To address these challenges, this study applies a supersymmetry approach using optical coupling between neighbouring ridges to confine the fundamental mode while suppressing higher-order modes. Two nitride-based edge-emitting laser configurations—double-ridge and triple-ridge waveguides—are analysed, with a focus on ridge-width tolerances and the effects of gain and absorption. Both configurations achieve strong mode discrimination. However, the triple-ridge waveguide structure exhibits a mode separation ratio more than twice that of the double-ridge waveguide, making it promising for high-power single-mode operation. The results of this study provide a basis for further study of supersymmetry effects in nitride lasers.