High-power, high-brightness GaInSb/AlGaAsSb quantum-well diode-lasers emitting at 1.9 μm

This study presents results on GaSb-based tapered diode lasers with an emission wavelength of 1.91 μm at 20°C. The active layer of the samples consists of three compressively strained 10 nm wide Ga_0.78In_0.22Sb-QWs, separated by 20 nm wide lattice matched Al_0.29Ga_0.71As_0.02Sb_0.98 barriers. The QW region is surrounded by 400 nm wide Al_0.29Ga_0.71As_0.02Sb_0.98 separate confinement layers, followed by 2 μm thick Al_0.84Ga_0.16As_0.06Sb_0.94 n-doped and p-doped cladding layers. The lateral design is composed of a ridge-waveguide section followed by a trapezoidal amplifier. The rear facet is HR-coated with a reflectivity of 97% while the output facet was AR-coated with a reflectivity of ∼1%. The devices are finally mounted junction side down on copper heat sinks.