Room-temperature operation of 3.26μm GaSb-based type-I lasers with quinternary AlGaInAsSb barriers

TLDR

The GaSb‑based type‑I laser structures, comprising three compressively strained GaInAsSb quantum wells with AlGaInAsSb barriers and waveguides, exhibit high structural and optical quality and enable 3.26 µm emission that aligns with a strong CH₄ absorption line for gas sensing. The study introduces quinternary AlGaInAsSb as a novel barrier material for GaSb‑based type‑I laser diodes. The new barrier material enhances the valence‑band offset for wavelengths beyond 3 µm, enabling 3.26 µm pulsed ridge‑waveguide laser emission up to 50 °C.

Abstract

Quinternary AlGaInAsSb is introduced as a new barrier material for GaSb-based type-I laser diodes. For wavelengths beyond 3μm, this material improves the valence-band offset between GaInAsSb quantum wells and barriers as compared to standard GaInAsSb∕AlGaAsSb structures. The laser structures, which comprise three compressively strained GaInAsSb quantum wells and AlGaInAsSb barriers and waveguides, show good structural and optical quality. 3.26μm emission has been achieved with ridge waveguide lasers working in pulsed operation up to 50°C. With this emission wavelength, a strong absorption line of CH4 is accessible for gas absorption measurements.