Generic Heterogeneously Integrated III–V Lasers-on-Chip With Metal-Coated Etched-Mirror

Abstract

In this paper, electrically pumped III–V quantum-well lasers bonded on SiO2 with a metal-coated etched-mirror are reported. There are three key features for the device demonstrated: (i) The metal-coated etched-mirror ensures that the lasers can be used as on-chip light source and provides high reflectance, but requires no additional fabrication steps due to our process design, (ii) the bonded III–V on SiO2 enables high-light confinement in the active region due to high index contrast between III–V and SiO2. Moreover, it promises a flexible choice of host substrate, in which the silicon substrate could also be replaced with other materials, and (iii) the active III–V region is sufficiently close to the SiO2 interlayer, allowing the laser mode to overlap with SiO2. This facilitates effective optical coupling with in-plane passive waveguides, which can be fabricated from thin film of amorphous silicon, silicon nitride or other waveguide materials, to form a subsystem on chip through in-plane integration. The laser devices demonstrated have the lowest threshold of 50 mA, a maximum output power of 9 mW, and a differential quantum efficiency of 27.6%.