Experimental demonstration of broadband reflectionless diffraction-free electromagnetic wave routing

• Main Authors: Zhang, Youming, Gao, Zhen, Gao, Fei, Shi, Xihang, Xu, Hongyi, Luo, Yu, Zhang, Baile
• Other Authors: School of Electrical and Electronic Engineering
• Format: Article
• Language: English
• Published: 2017
• Subjects: Electromagnetic Waves & Oscillations; Dielectric Properties
• Online Access: https://hdl.handle.net/10356/83944; http://hdl.handle.net/10220/42916
• Institution: Nanyang Technological University

Wave diffraction is fundamentally difficult to overcome in the routing and interconnection of photonic signals. Although the phenomenon of reflectionless transport through sharp corners in a routing path has been realized in many previous demonstrations, wave diffraction does not allow them to transport deep-subwavelength information or sub-diffraction-limited images. Recent advances in ɛ -near-zero and anisotropic ɛ -near-infinity metamaterials have provided unique possibilities of achieving reflectionless diffraction-free electromagnetic wave routing, but their designs are fundamentally limited to narrow bandwidths, and they have not been demonstrated in reality. Here we experimentally demonstrate broadband reflectionless diffraction-free routing of electromagnetic waves through two right-angled sharp corners in a bent microwave rectangular waveguide. An image with deep-subwavelength information is transported through the bent waveguide in a broad bandwidth. This Rapid Communication supplements and extends the current studies of metamaterials with extreme permittivities and can be useful for routing and interconnection of subwavelength photonic information.