Terahertz Communications Using Effective-Medium-Slot Waveguides

Nguyen H. Ngo; Weijie Gao; Guillaume Ducournau; Hadjer Nihel Khelil; Rita Younes; Pascal Szriftgiser; Hidemasa Yamane; Yoshiharu Yamada; Shuichi Murakami; Withawat Withayachumnankul; Masayuki Fujita

arXiv · 2601.08261

Terahertz Communications Using Effective-Medium-Slot Waveguides

Nguyen H. Ngo·Weijie Gao·Guillaume Ducournau·Hadjer Nihel Khelil·Rita Younes·Pascal Szriftgiser·Hidemasa Yamane·Yoshiharu Yamada·Shuichi Murakami·Withawat Withayachumnankul·Masayuki Fujita

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Abstract

All-dielectric effective-medium-clad waveguides have been widely exploited in terahertz communications owing to their extremely low loss, low dispersion, and broad bandwidth. In this work, we propose a substrateless effective-medium-slot waveguide. Additionally, we introduce a taper-free interface that allows terahertz waves to directly couple from a metallic hollow waveguide without requiring dielectric insertion. By engineering slot couplers with an effectivemedium channel for impedance and modal matching, the waveguide achieves a fractional 3-dB bandwidth of 40% with a maximum coupling efficiency of 90% in the WR-2.2 band (330-500 GHz). By employing a broadband uni-traveling-carrier photodiode transmitter and sub-harmonic mixer receivers, we achieve an aggregated data rate of 0.8 Tbit/s with quadrature amplitude modulation schemes across 14 channels from 330-600 GHz. The effective-medium-slot waveguide platform yields robust broadband coupling with enhanced mechanical protection, offering reliable interconnects for ultra-high-speed terahertz integrated systems.

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Nguyen H. Ngo, Weijie Gao, Guillaume Ducournau, Hadjer Nihel Khelil, Rita Younes, Pascal Szriftgiser, Hidemasa Yamane, Yoshiharu Yamada, Shuichi Murakami, Withawat Withayachumnankul, Masayuki Fujita. 2026-04-15. Terahertz Communications Using Effective-Medium-Slot Waveguides. https://arxiv.org/abs/2601.08261

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