Incorporation of strain into a two-dimensional model of quantum-well semiconductor lasers

The effect of strain quantum wells was incorporated into a 2-D semiconductor laser simulator. An anisotropic parabolic band structure was used to approximate the valence band structure obtained from a Lutinger-Kohn k.p theory to facilitate the simulation. It is shown that, with a proper choice of the anisotropic effective masses, a good approximation of the strained band structure can be obtained. This approximation allows the gain, spontaneous emission rate, and the carrier concentration to be modeled in forms usable for the 2-D laser simulator. The usefulness of the 2-D model is demonstrated with an example of a ridge-waveguide strained InGaAs-AlGaAs laser. The simulation shows that for compressive strain, the gain function is enhanced significantly, but so too are the spontaneous emission and the leakage current. The predicted effect of strain on the lasing threshold is in good agreement with experimental results