Self-consistent analysis of high-temperature effects on strained-layer multiquantum-well InGaAsP-InP lasers

We present a comprehensive evaluation of the temperature effects on the threshold current and the slope efficiency of 1.55 /spl mu/m Fabry-Perot ridge-waveguide lasers between 20/spl deg/C and 120/spl deg/C. Experimental results are analyzed using the commercial laser simulator PICS3D. The software self-consistently combines two-dimensional carrier transport, heat flux, strained quantum-well gain computation, and optical waveguiding with a longitudinal mode solver. All relevant physical mechanisms are considered, including their dependence on temperature and local carrier density. Careful adjustment of material parameters leads to an excellent agreement between simulation and measurements at all temperatures. At lower temperatures, Auger recombination controls the threshold current and the differential internal efficiency. At high temperatures, the vertical electron leakage from the separate confinement layer mainly limits the laser performance. The increase of internal absorption is less important. However, all these carrier and photon loss enhancements with higher temperature are mainly triggered by the reduction of the optical gain due to wider Fermi spreading of electrons.