# Frequency comb generation at 800nm in waveguide array quantum well diode lasers

## TL;DR

This paper presents a theoretical model demonstrating that waveguide arrays in quantum well diode lasers can generate stable frequency combs at 800 nm, offering a compact on-chip solution for comb generation.

## Contribution

It introduces a comprehensive traveling wave model for quantum well diode lasers with waveguide arrays, enabling stable frequency comb generation at 800 nm, which was not feasible with single waveguides.

## Key findings

- Stable frequency combs at 800 nm achieved in GaAs waveguide arrays.
- Optimal waveform generation depends on waveguide coupling, quantum well depth, and input currents.
- Model suggests a compact, efficient on-chip comb source is feasible.

## Abstract

A traveling wave model for a semiconductor diode laser based on quantum wells is presented as well as a comprehensive theoretical model of the lasing dynamics produced by the intensity discrimination of the nonlinear mode-coupling in a waveguide array. By leveraging a recently developed model for the detailed semiconductor gain dynamics, the temporal shaping effects of the nonlinear mode-coupling induced by the waveguide arrays can be characterized. Specifically, the enhanced nonlinear pulse shaping provided by the waveguides are capable of generating stable frequency combs wavelength of 800 nm in a GaAs device, a parameter regime not feasible for stable combline generation using a single waveguide. Extensive numerical simulations showed that stable waveform generation could be achieved and optimized by an appropriate choice of the linear waveguide coupling coefficient, quantum well depth, and the input currents to the first and second waveguides. The model provides a first demonstration that a compact, efficient and robust on-chip comb source can be produced in GaAs.