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

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.