Analysis of perturbations in the lateral far-field of blue InGaN laser diodes

The origin of perturbations in the Gaussian-shaped lateral far-field of blue InGaN laser diodes is explored. Near-field measurements reveal that small stray light intensity peaks beside the ridge waveguide exist. In order to prove quantitatively the impact of this stray light on the far field, an exemplary beam propagation method simulation is performed. Moreover, laser cuts as a chip technological process to block stray light from the out-couple facet are presented. These laser cuts result in a significant improvement of the lateral far-field.