Continuous-wave operation of InP laser with etched facet mirrors for photonic integrated circuits

We report the device characteristics of dry-etched facet 1.55 μm FP lasers fabricated using one-time multi-depth etching process. A multi-level mask was utilized during the ICP etching process, yielding vertical and smooth facets with a reflectivity of 18.5%. By employing the SiO₂ passivation layer on both facets, the reflectivity of the front facet was reduced to 9%, whereas the reflectivity of the back facet was effectively enhanced to 97% with the aid of metallic HR coatings. These improvements enable the device performance to be similar to that of lasers with cleaved facets coated with dielectric HR and AR films.