Analysis of Segmented Tapered Rib-Waveguide Semiconductor Optical Amplifiers

A single stripe semiconductor laser typically produces about 10mW of output power. This figure can be increased to about 50-60 mW by using some complicated fabrications techniques, but the goal of achieving higher powers and maintaining single mode operation has proved elusive. When the drive current to a single stripe laser is increased two effects may occur to limit the output power: the inversion population starts to saturate, and Catastrophic Optical Damage, (COD), starts to destroy the facets. Several approaches to these problems have been tried, eg., increased active area, and laser arrays, and have generally been found to be unsatisfactory. Increasing the active area does indeed result in increased output power but at the expense of the far-field pattern; and, unfortunately, increasing the active area generally leads to multi-mode operation, and hence a poor far-field.