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

We present a comprehensive evaluation of temperature effects on threshold c urrent and slope efficiency of 1.55 mu m Fabry-Perot ridge-waveguide lasers between 20 degrees C and 120 degrees C. Experimental results are analyzed using the commercial laser simulator PICS3D. The software self-consistently combines two-dimensional carrier transport, heat flux, strained quantum-we ll gain computation, and optical waveguiding with a longitudinal mode solve r. All relevant physical mechanisms are considered, including their depende nce on temperature and local carrier density. Careful adjustment of materia l parameters leads to an excellent agreement between simulation and measure ments at all temperatures. At lower temperatures, Auger recombination contr ols the threshold current and the differential internal efficiency. At high temperatures, vertical electron leakage from the separate confinement laye r 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 optica l gain due to wider Fermi spreading of electrons.