Dielectric waveguide interconnects for hybrid mm-Waves and terahertz system integration

In this work, we propose interconnection structures for substrateless all-silicon dielectric waveguides, a platform for terahertz (THz) hybrid integration that currently relies on traditional tapered interfaces. We demonstrate two dielectric waveguide-to-waveguide interconnect approaches: a truncated termination and a quarter-wave-matched (QWM) slot termination. Both designs maintain a confined coupling point, enabling consistent coupling. Experimental results show maximum interconnection coupling losses of 5 dB 5\,dB 5 d B and 2.5 dB 2.5\,dB 2.5 d B for the truncated and QWM-slot terminations, respectively, across the 220–330 GHz band. The QWM-slot transmission coefficient remains above minus 3 dB -3\,dB − 3 d B with a misalignment tolerance up to 100 mu m 100\, 100 μ m , representing a 2.5 times 2.5× 2.5 × improvement over the truncated design. Offset characterization along three axes reveals smooth decoupling behavior over a 1 mm range, validating the potential for broadband, contactless interconnects between dielectric waveguide interfaces. These results establish a compact THz interconnect concept with substantially relaxed translational alignment tolerances, making it well-suited for deployment in scalable 6G multi-chip arrays and THz sensing modules.