Nonequilibrium spatiotemporal dynamics of the Wigner distributions in broad-area semiconductor lasers

We investigate the coupled microscopic and macroscopic nonequilibrium spatiotemporal dynamics of broad-area semiconductor lasers. Characteristic nonequilibrium Wigner,distributions of the charge carriers and the interband polarization reveal spatially inhomogeneous field-induced heating and cooling as a consequence of the coupling of the optical field to the carrier and phononic systems. The numerical simulations are performed on the basis of microscopic spatially resolved Maxwell-Bloch equations in which the spatiotemporal variation of thermal properties of the active laser medium are self-consistently included. In particular, the spatiotemporal light-matter interactions are determined by the temporal and spatial transport of the electron-hole plasma, its dependence on carrier-carrier, carrier-phonon, and phonon-phonon scattering processes as well as on the optical properties and macroscopic boundary conditions. In resonantly and nonresonantly excited broad-area semiconductor lasers, the microscopically computed Wigner distributions of the charge carriers and the interband polarization reveal the spatiospectral dependence of the laser gain, the induced refractive index, as well as the electron and hole plasma temperatures. The spatiotemporal nature of these processes explains macroscopic effects such as dynamic thermal lensing and formation of spatiospectral optical structures.