Mode reflectivity of tilted mirrors in semiconductor lasers with etched facets

Mode reflectivity at nonvertical facets of 2-D dielectric waveguides has been calculated, and its dependence on the facet shape is discussed in order to estimate the reflectivity of the facets of semiconductor lasers fabricated by an etching technique. It has been made clear that an optimum range of core thickness exists which gives the minimum dependence of the tilt angle on reflectivity and that even a small deformation of a facet near the core deteriorates reflectivity. Some numerical examples are given for Ga(x) In(1-x)As(y) P(1-y)/InP double heterostructure lasers with etched mirrors.