Temperature sensitivity of high power GaSb based 2 µm diode lasers

We have realized strained triple-quantum-well, large-optical-cavity GaInSb/AlGaAsSb/GaSb diode lasers emitting in the 2 µm wavelength range. In order to optimize these devices for power applications, we investigate samples at 2.2 µm wavelength with different Al-content in the barrier and seperate confinement layers, and thus different quantum-well barrier heights. Devices with 40 % Al revealed the highest value for the characteristic temperature T0, which is attributed to a reduction in the heterobarrier leakage. On the other hand, the lasers with 20 % Al yielded the best power efficiency eta rho with a maximum value of 30 %, reducing the thermal load generated in the active region and making this device structure well suited for power applications.