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

In this paper, electrically pumped III-V quantum-well lasers bonded on SiO
₂
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 SiO
₂
enables high-light confinement in the active region due to high index contrast between III-V and SiO
₂
. 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 SiO
₂
interlayer, allowing the laser mode to overlap with SiO
₂
. 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%.