Lasing in localized modes of a slow light photonic crystal waveguide

TL;DR

This paper demonstrates lasing in disordered GaAs photonic crystal waveguides with quantum dots, showing localization effects and the influence of structural disorder on lasing modes within the slow light regime.

Contribution

It reports the first observation of lasing in localized modes of a disordered photonic crystal waveguide with quantum dots as gain medium.

Findings

Lasing occurs at random locations within the waveguide.

Lasing frequencies are within the slow light regime.

Out-of-plane scattering is the main loss channel.

Abstract

We demonstrate lasing in GaAs photonic crystal waveguides with InAs quantum dots as gain medium. Structural disorder is present due to fabrication imperfection and causes multiple scat- tering of light and localization of light. Lasing modes with varying spatial extend are observed at random locations along the guide. Lasing frequencies are determined by the local structure and occur within a narrow frequency band which coincides with the slow light regime of the waveguide mode. The three-dimensional numerical simulation reveals that the main loss channel for lasing modes located away from the waveguide end is out-of-plane scattering by structural disorder.