Power efficiency of GaSb based 2.0 μm diode lasers

There is an increasing interest in room-temperature diode lasers emitting in the mid infrared wavelength region around 2 μm not only for trace gas analysis, but also for high power applications such as material processing and laser surgery. For the latter application the key issue is a high power conversion efficiency of the diode lasers, which is closely linked to a good thermal management, in order to obtain high output powers. We have realized GaInAsSb/AlGaAsSb QW diode lasers with an emission wavelength between 1.73 and 2.35 μm. The samples were grown by molecular beam epitaxy on (100) GaSb:Te n-type substrates. The active region consists of three compressively strained 10 nm wide GaInAsSb QWs separated by 20 nm wide lattice matched AlGaAsSb barriers. The QW region is surrounded by 400 nm thick AlGaAsSb separate confinement layers, followed by 2 μm thick AlGaAsSb n-doped and p-doped cladding layers. Ridge waveguide lasers made out of these samples were used to derive the standard laser parameters