Unclad microphotonics for terahertz waveguides and systems

A practical approach to realize substrateless, unclad, micro-scale intrinsic silicon waveguides for the terahertz range is presented. The waveguides are monolithically integrated within a supporting silicon frame, with which they are fabricated together from the same silicon wafer in a single-mask etching process. This establishes an integration platform to house many diverse components and facilitates packaging. Effective medium techniques are deployed to prevent the frame from interfering with the waveguide's functionality. Straight waveguides of this sort are experimentally found to be efficient and broadband. Elementary components including Y-junctions and evanescent couplers are developed, and deployed in demonstrations of applications for terahertz waves including sensing and communications. This is a promising pathway to realize future microphotonic devices for diverse applications of terahertz waves.Daniel Headland, Withawat Withayachumnankul, Xiongbin Yu, Masayuki Fujita, and Tadao Nagatsum