Modeling and optimization of transverse modes in vertical-external-cavity surface-emitting lasers

We present a system-oriented model to simulate the dynamics of transverse modes in vertical-external-cavity surface-emitting lasers. An analytical expression for the gain as a function of carrier density and temperature is derived from a simulation of the full-structure reflectivity, while the field propagation in the cavity is computed with a generalized Huygens–Fresnel integral. The laser rate equations are employed to calculate the field and gain dynamics until a steady state is reached. The optimal cavity mode size for highest output power and brightness is extracted for two of the most commonly employed pump beam shapes. The effect of pump power and output coupler on the steady-state solution and mode size optimum are discussed.