Researches on hybrid integration of III-V semiconductor light sources and detectors on silicon circuits using optofluidic microbubble manipulation

Abstract

Hybrid integration of III-V compound semiconductor on silicon has been investigated using optofluidic manipulation. By taking advantages of microbubble manipulation based on photothermocapillary convective flows induced by focused laser beam, the microscale semiconductor block can be trapped on the microbubble surface and precisely assembled on a desired position. Optically and electrically pumped III-V light sources and photodetectors heterogeneously integrated on silicon waveguides are successfully realized, and their characterizations are also discussed. In addition, to complement high silicon material losses at visible wavelengths, simple laser-induced photothermal oxidation of Ti layer for in-situ formation of rutile TiO2-based optical waveguides and microring resonators on silicon is demonstrated. The localized photothermal heating can convert the absorptive metal to the large-bandgap dielectric material through selective oxidation. In the last section, in case that subwavelength-scale lasers will be heterogeneously integrated on silicon in future, an efficient waveguide coupling interface for metallo-dielectric nanopatch lasers using metal slot waveguide is proposed and theoretically investigated. I believe the heterogeneously integrated active optical device would be useful for various applications such as bio-, medical-, and chemical-sensors and integrated optical interconnection applications in silicon photonics platforms.