Robust Unclad Terahertz Waveguides and Integrated Components Enabled by Multimode Effects and Matched Slot Couplers
Year: 2025
Type: article
Abstract: We address critical physical fragility issues associated with terahertz integrated all-silicon substrateless devices. This is necessary because, although the current state-of-the-art offers excellent electromagnetic performance, real-world deployment is currently held back by physical fragility. One such structural weakness is the input coupler, which has so-far exclusively taken the form of an exposed matching taper that reduces core dimensions over several wavelengths, and hence is vulnerable to breakage. This is replaced with a subwavelength slot-waveguide coupler, which is an emerging compact alternative that exploits reflection-cancellation as opposed to a progressive transition. The other key structural weakness is the in-plane integrated support that physically suspends the substrateless waveguide’s core, and this is addressed with multi-mode effects that localize a field null to the point of contact with a solid supporting beam. The resultant robust waveguide platform exhibits around thirty percent relative bandwidth, which is sufficient for terahertz communications in standard allocated bands. In addition to physical support, multimode effects are also exploited to realize an integrated two-by-two splitter, which is incidentally the first demonstration of an integrated dielectric multimode interferometer splitter in the terahertz range.
Authors: Daniel Headland, Guillermo Carpintero
Institution: Universidad Carlos III de Madrid
Language: English
Topic: Photonic and Optical Devices
Subfield: Electrical and Electronic Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $2,645
OpenAlex ID: W4411725674