A two-dimensional nonisothermal finite element simulation of laserdiodes

A fully self-consistent nonisothermal, two-dimensional model of a semiconductor laser device is presented. The model consists of the simultaneous solution of the electrical equations (Poisson's and electron and hole continuity equations), along with the wave equation, photon rate equation, and thermal conduction equation. An analysis is presented for an AlGaAs-GaAs ridge laser diode structure using this model as a representative example. The results agree well with available experimental data. A comparison of the results between isothermal and nonisothermal simulations shows that the nonisothermal case has a higher threshold current and lower quantum efficiency than the idealized isothermal model. The result was found to depend critically on the thermal exchange boundary condition of the simulated device, demonstrating the importance of considering thermal exchange in the design of laser diodes