For low volume applications, hybrid integration is a less challenging way for integrating a laser with passive photonic integrated circuits. The idea is simply

For low volume applications, hybrid integration is a less challenging way for integrating a laser with passive photonic integrated circuits. The idea is simply place a laser die and the passive die next to each other during packaging, and the laser power is transferred between the dies by butt-coupling (or photonic wire bonding). The R&D cost can be much lower but the tedious (and usually required to be active) alignment procedure prevents mass-production.