Bistable operation and nonuniform output in an injection heterostructure laser

Spontaneous transition to nonuniform lasing with hot spots attaching to arbitrarily slight inhomogeneities is studied as the cause of the nonuniform spatial distribution of the output intensity of heterostructure injection lasers. A mechanism for instability involving a nonlinear waveguide effect is examined for the case of steady-state, single-mode lasing. The optical properties of the active layer, the profile of the dielectric function along the z-coordinate, the boundary conditions on the electromagnetic wave, the amplitude of the steady-state, single-mode output, and the dimensionless intensity of the electromagnetic field are presented. Bistability in the fixed-voltage case is discussed, as is the physical cause of the bistability in a heterostructure injection laser.