Abstract

InAs/GaInSb broken-gap superlattices (bgsls) are attractive candidates for MWIR laser active regions because they possess sufficient degrees of freedom to permit tailoring of the valence-band structure while the strain is kept low enough to prevent the formation of misfit dislocations. The valence-band structure can be optimized to suppress Auger recombination and to reduce the density of states at k = 0, thereby reducing laser threshold. Here we report what we believe to be the first MWIR MQW laser diodes with InAs/Ga_0.75In_0.25Sb BGSL quantum wells. The laser structures employ Ga_0.75In_0.25- As_0.22Sb_0.78 barrier layers and InAs/AlSb superlattice cladding layers with an AlSb blocking layer deposited directly on top of the p-type superlattice clad for enhanced electron confinement.

© 1995 Optical Society of America