Enhancement of the optical gain in GaAs nanocylinders for nanophotonic applications

TL;DR

This paper investigates how p-type doping and compressive strain can significantly enhance optical gain in GaAs nanocylinders, potentially enabling low-threshold, high-speed nanolasers for integrated photonics.

Contribution

It demonstrates that combining p-type doping with compressive strain in GaAs nanocylinders greatly improves optical gain and reduces lasing threshold, advancing nanolaser development.

Findings

100x increase in optical gain

Approximately 5-fold increase in modulation bandwidth

Lowered lasing threshold through optimized doping and strain

Abstract

Semiconductor nanolasers based on micro disks, photonic crystal cavities, and metallo-dielectric nanocavities have been studied during the last decade for on-chip light source applications. However, practical realization of low threshold, room temperature operation of semiconductor nanolasers is still a challenge due to the large surface-to-volume ratio of the nanostructures, which results in low optical gain and hence higher lasing threshold. Also, the gain in nanostructures is an important parameter for designing all-dielectric metamaterial-based active applications. Here, we investigate the impact of p-type doping, compressive strain, and surface recombination on the gain spectrum and the spatial distribution of carriers in GaAs nanocylinders. Our analysis reveals that the lasing threshold can be lowered by choosing the right doping concentration in the active III-V material combined with compressive strain. This combination of strain and p-type doping shows 100x improvement in gain and ~5 times increase in modulation bandwidth for high-speed operation.