Monolithic Integration of InP Wire and SiOx Waveguides on Si Platform

Abstract

We report a low-loss InP wire waveguide monolithically integrated with an SiOx waveguide on an Si platform. By means of directly bonding InP to SiO2, we realized a submicrometer-scale InP wire waveguide with high optical confinement. In addition, a several-micrometer-scale SiOx waveguide with a refractive index difference of ∼3% is integrated on the InP wire waveguide via a spot-size converter (SSC). Experimental results indicate that the InP wire waveguide has a propagation loss of 5 dB/cm and that the InP-SiOx SSC has an insertion loss of 0.7 dB and a reflectance of less than -50 dB. By using the SSC, a low coupling loss of 0.9 dB is achieved between the optical fiber and the InP wire waveguide.