GAIN-CURRENT CHARACTERISTICS OF STRAINED ALGAINP QUANTUM-WELL LASERS

Single quantum well AlGaInP lasers, each having a 65 Angstrom width we ll have been fabricated with GaxIn1-xP well compositions from x=0.43 t o 0.54 grown on substrates orientated 10 degrees off the (100) axis. T he threshold currents have been measured from 120 K to room temperatur e and the samples show a systematic variation with x. At low temperatu re the results are in good agreement with our calculated gain-current curves and we show that at room temperature the rapid increase in thre shold current density with decreasing length is due to a thermally act ivated leakage current rather than gain saturation.