Coherent Perfect Diffraction in Metagratings
Abstract
Metasurfaces are 2D engineered structures with subwavelength granularity, offering a wide range of opportunities to tailor the impinging wavefront. However, fundamental limitations on their efficiency in wave transformation, associated with their deeply subwavelength thickness, challenge their implementation in practical application scenarios. Here, it is shown how the coherent control of metagratings through multiple wave excitations can provide new opportunities to achieve highly reconfigurable broadband metasurfaces with large diffraction efficiency, beyond the limitations of conventional approaches. Remarkably, energy distribution between the 0th and higher diffraction orders can be continuously tuned by changing the relative phase difference between two excitation waves, enabling coherent control, with added benefits of enhanced efficiency and bandwidth. This concept is demonstrated for a thin electric metagrating operating at terahertz frequencies, showing that coherent control can overcome several of the limitations of single‐layer ultrathin metastructures, and extend their feasibility in various practical scenarios.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Jul 23, 2020
- Source ID
- 10.1002/adma.202002341
Entities
People
- Alex Krasnok
- Andrea Alù
- Huifang Zhang
- Jiaguang Han
- Ming Kang
- Quan Xu
- Weili Zhang
- Xi Feng
- Xieyu Chen
- Xueqian Zhang
- Yuehong Xu
- Zhen Tian
- Ziying Zhang
Organizations
- Air Force Office of Scientific Research
- City University of New York
- National Natural Science Foundation of China
- National Science Foundation
- Oklahoma State University–Stillwater
- Simons Foundation
- Tianjin University
- United States Department of Defense
- University of Texas at Austin