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

The results of simulation of the emission characteristics of high-power ridge lasers at pump currents much higher than the threshold current are presented. The nonlinear interaction of carriers and the field in the laser cavity taking into account their distributions along the cavity axis and the influence of the inhomogeneous heating of the laser on the waveguiding effect are considered in the simulation. The dependence of the maximum single-mode output power on the ridge width W and the built-in δn_b of the refractive index is studied. It is shown that a set of values of W and δn_b can be divided into four regions, each of which is characterised by its own type of the upset of lateral-single-mode operation. The calculated values of the threshold current, differential effici-ency and the far-field intensity distribution of laser emission agree well with the experiment.