Assessing Plasma-Etched InP Laser Facet Quality

This work presents an approach to assess the quality of etched laser facets, considering factors such as roughness, inclination, and non-uniform light emission. Broad area InP lasers, using plasma etched facets, operating at 1550 nm are manufactured with varying facet quality on five 100 mm wafers. Comparison of the threshold current density of lasers of different length was used to derive relative facet reflectivity and demonstrated the relationship between the reflectivity and the optical mode weighted facet roughness and facet inclination.