Buried heterostructure vertical-cavity surface-emitting laser with semiconductor mirrors

TL;DR

This paper presents a buried heterostructure VCSEL with high quality factor and low lasing threshold, fabricated via epitaxial regrowth over an InGaAs quantum well, demonstrating effective microscale confinement and spectral overlap at low temperatures.

Contribution

The work introduces a novel epitaxial regrowth technique for buried heterostructure VCSELs that enhances confinement and reduces parasitic effects, achieving low-threshold lasing at 40 K.

Findings

High cavity Q factor (~4000) maintained

Lasing achieved at 40 K with 10 mW incident power

Laser linewidth approximately 3 GHz at 5 times threshold

Abstract

We report a buried heterostructure vertical-cavity surface-emitting laser fabricated by epitaxial regrowth over an InGaAs quantum well gain medium. The regrowth technique enables microscale lateral confinement that preserves a high cavity quality factor (loaded $Q\approx$ 4000) and eliminates parasitic charging effects found in existing approaches. Under optimal spectral overlap between gain medium and cavity mode (achieved here at $T$ = 40 K) lasing was obtained with an incident optical power as low as $P_{\rm th}$ = 10 mW ($\lambda_{\rm p}$ = 808 nm). The laser linewidth was found to be $\approx$3 GHz at $P_{\rm p}\approx$ 5 $P_{\rm th}$.