3-D modeling of current spreading and carrier diffusion in semiconductor DH laser with stripe discontinuities

This paper presents a three-dimensional (3-D) numerical modeling of semiconductor double heterostructure (DH) single- and double-stripe lasers with stripe discontinuities along the longitudinal direction. Asymmetric step discontinuities in the biasing stripes or gradually varying stripe dimensions can contribute to eliminate undesirable two-lobed far-field pattern in strongly-coupled stripe arrays. Thus accurate 3-D modeling of the stripe geometry is important in the design of high-power laser arrays. Using an iterative finite difference method, a self-consistent solution for the nonlinear semiconductor device equations is presented showing the lateral current and carrier density distributions along the active layer for singleand double-stripe DH lasers with step discontinuities. The influence of different stripe geometries and biasing on carrier distribution is discussed.