Threshold current of ridge waveguide laser in gain and index guiding regimes including end facet reflectivity

In the paper we present the results of an efficient computer code that allows us to evaluate the ridge waveguide laser threshold current for quasi-TE and quasi-TM modes, including the effects of refractive index variation, produced by carriers, and end facet reflectivity. These two effects are taken into account in a new formulation, suitable to be integrated efficiently in the same computer code. Results for the threshold current in index and gain guided structures are presented, and compared within the framework of possible approximations.