ENHANCEMENTS IN MBE-GROWN HIGH-SPEED GAAS AND IN0.35GA0.65AS MQW LASER STRUCTURES USING BINARY SHORT-PERIOD SUPERLATTICES

The luminescence properties of molecular-beam epitaxially grown GaAs/A lGaAs multiple quantum-well laser structures with core and cladding la yers consisting of either binary short-period superlattices (SPSLs) or ternary alloy layers are compared. Photoluminescence enhancements in the SPSL laser structures are attributed to improved gettering of back ground impurities. Low-temperature cathodoluminescence topography reve als regular 1-2 monolayer fluctuations in the QW widths of the ternary alloy laser structures, which are greatly reduced in the SPSL laser s tructures. The SPSL lasers demonstrate lower threshold currents than t he ternary alloy devices. Modulation bandwidths of 16 and 21 GHz have been achieved for 3 X 200 mum2 SPSL lasers containing three GaAS or In 0.35Ga0.65As QWs, respectively, in the active region.