Current-crowded carrier confinement in double-heterostructure lasers

Abstract

The profiles (spatial distributions) of injected carriers and current within a double‐heterostructure stripe‐geometry laser are described theoretically in a one‐dimensional‐flow model. The one‐dimensional model is solved exactly and found to yield comparatively simple analytical expresions even when both radiative (nonlinear) and nonradiative recombination are operative. In the case of a shallow proton bombardment or an oxide stripe, two coupled current components leak from under the stripe—an Ohmic current in the P layer and a diffusion current in the active region. As an example, these wasted leakage currents are evaluated in detail and seen to depend strongly upon the laser design. Features of this work not present in previous analytical studies include incorporation of radiative recombination (Bn²) and a carrier‐concentration‐dependent diffusion coefficient, as well as development of a self‐consistent solution for the two current components.