InGaAsP Grating Couplers Fabricated Using Complementary-Metal–Oxide–Semiconductor-Compatible III–V-on-Insulator on Si

We have demonstrated InGaAsP grating couplers using the III–V-on-insulator (III–V-OI) on a Si wafer. The direct bonding of an InGaAsP/InP wafer and a thermally oxidized SiO 2 /Si wafer allows us to fabricate the grating couplers through the standard complementary metal–oxide–semiconductor (CMOS)-compatible process. The grating coupler, which was designed by the time-domain beam-propagation method (TD-BPM), exhibited a coupling efficiency of 38%, the 3 dB bandwidth of 37 nm, and the 1 dB lateral alignment tolerance of ±2.5 µm for the c-band wavelength, making it suitable for the III–V CMOS photonics platform.