Dynamical simulation of quantum-well structures

For the design and development of optical semiconductor devices based on qu antum-well structures, the investigation of saturation phenomena is necessa ry for high optical power operation. By applying stationary physical models , nonlinear effects cannot be described adequately; hence, transient models are important for an accurate analysis. By utilizing transient models, sat uration phenomena, signal delays, and distortions can be investigated, For the analysis of integrated optoelectronic devices, such as lasers and modul ators, transient transport or density matrix equations for carriers and pho tons and the Poisson equation have to be solved self-consistently. A transient model which is useful for the investigation of a wide range of optoelectronic applications is presented. Quantum optical phenomena are inc luded by applying the interband density matrix formalism in real-space repr esentation, where the Coulomb singularity is treated exactly in the limits of the discretization. As we focus on electroabsorption modulators, a drift -diffusion model adequately approximates the transport properties. Here, qu antum effects are considered by a quantum correction, the Bohm potential. T he model is applied to investigate transport effects in InP-based waveguide electroabsorption modulators including strained lattices.