[16p-A202-1~14] 3.8 Terahertz technologies (formerly 3.9)

▲ [16p-A202-9] Comparison of Topological Valley Photonic Crystal and Unclad Silicon Terahertz Waveguides

〇Ngo Hoai Nguyen¹, Shota Yamamoto¹, Kei Iyoda¹, Yoshiharu Yamada², Yusuke Kondo², Shuichi Murakami², Masayuki Fujita¹, Tadao Nagatsuma¹ (1.Osaka Univ., 2.Osaka Research Inst. of Industrial Science and Technology)

Keywords:terahertz, valley photonic crystal, silicon waveguide

High-speed inter-chip communication is required to support for broad bandwidths with low-loss and low-dispersion despite the routing with several sharp bends. Terahertz communications have a potential to achieve very high throughput. Topological valley photonic crystal (VPC) silicon waveguides have shown near-unity transmission in the photonic band gap for sharp bends. Alternatively, another candidate for low-loss terahertz waveguides, unclad silicon wire waveguides where the terahertz wave is confined by strong total internal reflection between silicon and air, has been developed.
In this work, we compare VPC and unclad silicon waveguides with the same sharp bending structures. Both waveguides consist of eight sharp bends (near zero radii of curvature) with 120 degrees. For reference, we also fabricated straight waveguides with a length of 2 cm.
In conclusion, the VPC waveguide is better at retaining the transmittance than the unclad waveguide for sharp bending structures. VPC also shows its robustness to imperfect fabrication.