Electrothermal Analysis of CW High-Power Broad-Area Laser Diodes: A Comparison Between 2-D and 3-D Modeling

We present a self-consistent electrothermal analysis for continuous wave (CW) high-power broad-area laser diodes using the finite-element method (FEM). A comparison between conventional 2D (lateral and longitudinal) and 3D models indicates that a 2D model not only overestimates the junction temperature but can also be inappropriate for evaluating the temperature profile in the active layer of large-aperture devices. Current spreading and facet heating make the active layer temperature distribution inherently 3D. Thus, a 2D model deviates even further from the 3D result as the injection current increases. We report here for the first time a full steady-state 3D electrothermal model including facet heating, and point out the importance of such an analysis for investigating the lateral mode behavior in high-power broad-area laser diodes.