Microscopic design of GaInNAs quantum well laser diodes on ternary substrates for high-speed and high-temperature operations

Material properties of highly strained GaInNAs quantum wells grown on GaInAs or quasi-GaInAs substrates are investigated by using microscopic theory together with a band structure calculation based on ten-band k⋅p theory specially formulated for highly strained materials. It is shown that the material gain of GaInNAs quantum wells is reduced by incorporating N into a well layer although the strain in the well layer becomes small. The reduction can be compensated by properly choosing barrier materials. The performance of laser diodes, such as characteristic temperatures T0 and differential gains, is also investigated, and the present results show that very high T0(≃140K) and differential gain with moderate strain (≃1.6%) can be achieved by carefully designing quantum well structures, indicating the applicability of these lasers for high-temperature and high-speed operation.