Modeling of the performance of high-power diode amplifier systems with an optothermal microscopic spatio-temporal theory

We present a detailed theoretical analysis of the dependence of spatio-temporal carrier and light field dynamics of high-power diode amplifier systems on their geometry and facet reflectivities as well as on the spatial and spectral characteristics of the optical input beam. The basis of the numerical modeling is the Maxwell-Bloch equations for spatially inhomogeneous semiconductor lasers which are self-consistently coupled to the nonequilibrium temperature dynamics of the electron-hole plasma. They microscopically describe the interaction between the optical fields, the charge carriers, and the interband polarization. Our numerical modeling allows an identification of the influence of dynamic internal laser effects such as diffraction, self-focusing, scattering, carrier diffusion, and heating on the performance of broad-area or tapered amplifiers (e.g., far field, near field). It thus provides a means of optimizing the epitaxial structure and geometry of high-power diode amplifier systems.