Simulation of emission characteristics and optimisation of waveguiding parameters of a ridge semiconductor heterolaser to maximise the emission brightness

Effect of diffusion and fluctuations in the nonequilibrium charge carrier density on the angular distribution of the output intensity for injection lasers based on an InAsSb/InAsSbP heterostructure

“…At the same time, as shown by the results in [6], the "bunched" spatial structure obtained for the distribution of nonequilibrium carriers is very sensitive to variation of the parameters determining the waveguide effects and under certain conditions can become unstable, when the structure of the "bunches" loses axial symmetry relative to the axis of the resonant cavity. The profile of the built-in waveguide is mainly determined by the dependence of the refractive index on the concentration of nonequilibrium carriers.…”

“…As the basis, we took the calculated two-dimensional model described in [5] and supplemented by including diffusional processes, as done by the authors of [6]. As a result, the equation relating the concentration N of nonequilibrium carriers and the components of the radiation intensity u χ ± (x, y) can be written as follows:…”

Calculation of spatial intensity distribution of InAsSb/InAsSbP laser diode emission

“…According to published results [5], it was assumed that the distribution of radiation in the plane perpendicular to the LD active layer was determined only by the geometry and the material composition of the heterostructure layers and remained practically constant for all examined emission modes. Therefore, the propagation of radiation within the LD resonator was given within the framework of a 2D model (Fig.…”

“…Here k 0 = ω χ ⁄ c; n 0 , the effective index of refraction; γ, a coefficient taking into account spontaneous emission into the generation mode (depends on resonator geometry) [6]; r χ , the spectral power of spontaneous emission at frequency ω χ ; c, the group speed of light; changes of the refractive index and the amplification coefficient due to a concentration change were described by the parameter δε N [5]:…”

“…The spectral components were introduced by breaking down a 10-20 nm wavelength range near the maximum of the generation line into M (M ~ 100) components. The following equation was used to describe the evolution of each separate component of the generated emission [5]:…”