Terahertz Band Data Communications using Dielectric Rod Waveguide Muhsin Ali 1* , Jonas Tebart 2 , Alejandro Rivera-Lavado 1,3 , Dmitri Lioubtchenko 4,5 , Luis Enrique Garcia- Muñoz 1 , Andreas Stöhr 2 and Guillermo Carpintero 1 1 Universidad Carlos III de Madrid, Avenida de la Universidad 30, 28911 Leganes, Madrid, Spain 2 ZHO / Optoelectronics, University of Duisburg-Essen, Lotharstr. 55, 47057 Duisburg, Germany 3 Yebes Observatory, Dirección General del Instituto Geográfico Nacional, Yebes, Spain 4 KTH Royal Institute of Technology, Department of Micro and Nano Systems, Stockholm, Sweden 5 Institute of High-Pressure Physics, CENTERA Laboratories, Warsaw, Poland Author e-mail address: muali@ing.uc3m.es Abstract: A terahertz data link is presented using dielectric rod waveguide (DRW) at 300 GHz and complex modulations for speeds up to 120 Gbps. Performance comparison with WR-3 rectangular waveguide validates the low-dispersion behaviour of DRW. © 2022 The Authors. 1. Introduction Terahertz (THz) frequencies (100 GHz – 10 THz) have received increased interest in recent years as the need to boost the capacity of communication systems continues to rise due to growing data traffic [1]. While the research on THz wireless communications is already ongoing, chip-scale data links are gaining attention [2, 3]. It involves routing or transport of large amounts of data in the order of Tbps between the chips, e.g. graphics processors, in a small area, providing ultra-fast interconnections. With the increasing number of chips and amount of data, the traditional interconnections reach their limits. Recently, Webber et al. [4] reported a photonic crystal based waveguide for 100 Gbps THz link, with a limited relative RF bandwidth. In this paper, we report dielectric rod waveguide (DRW) technology providing broad frequency coverage, realising the low dispersion ultra-broadband interconnections for high-speed data communications. The performance of DRW is validated in a THz data link at 300 GHz using three different complex modulations, achieving peak bitrate of 80 Gbps with envelope detection (ED). The proposed system is scalable to different frequency bands. 2. Dielectric Rod Waveguide The DRW is fabricated from a high-resistivity (> 10 kΩ) silicon (Si) wafer with a dielectric permittivity ε r and loss tangent of 11.9 and 0.0001, respectively. The sketch and geometry of DRW used in this work are shown in Fig. 1(a). It consists of three sections. A rectangular slab, with length L slab , width W rod , thickness T rod , through which the THz wave propagates and a matching taper with length L taper on both sides of the slab. The purpose of this taper is to provide matching between the rod and hollow metallic waveguides to launch the wave into DRW. One of the primary advantages of DRW is its ultra-broadband functionality. With a proper matching taper design, it can be coupled with different rectangular waveguides [5] while keeping the single mode operation. Fig. 1(b) shows the simulated S-parameters of DRW. One can notice that the transmission |S21| of more than -0.5 dB is maintained throughout the entire frequency band. While the reflections are better than -10 dB, indicating a good matching. Such performance makes it attractive for establishing communication links with wide signal bandwidth. (a) (b) Fig. 1. (a) Sketch of a DRW with matching tapers fed by WR-3 rectangular waveguides and (b) simulated reflection coefficient and transmission over WR-3 frequency band. WR-3 L taper L slab Wrod Trod W1H.5 OFC 2022 © Optica Publishing Group 2022 Disclaimer: Preliminary paper, subject to publisher revision Authorized licensed use limited to: UNIVERSIDAD CARLOS III MADRID. Downloaded on April 20,2022 at 09:50:58 UTC from IEEE Xplore. Restrictions apply.