文章基本信息

标题：Narrow-frequency sharp-angular filters using all-dielectric cascaded meta-gratings
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作者：Wei-Nan Liu ; Rui Chen ; Wei-Yi Shi 等
期刊名称：Nanophotonics
印刷版ISSN：2192-8606
电子版ISSN：2192-8614
出版年度：2020
卷号：-1
期号：ahead-of-print
页码：1-8
DOI：10.1515/nanoph-2020-0141
出版社：Walter de Gruyter GmbH
摘要：Selective transmission or filtering always responds to either frequency or incident angle, so as hardly to maximize signal-to-noise ratio in communication, detection and sensing. Here, we propose compact meta-filters of narrow-frequency sharp-angular transmission peak along with broad omnidirectional reflection sidebands, in all-dielectric cascaded subwavelength meta-gratings. The inherent collective resonance of waveguide-array modes and thin film approximation of meta-grating are employed as the design strategy. A unity transmission peak, locating at the incident angle of 44.4° and the center wavelength of 1550 nm, is demonstrated in a silicon meta-filter consisting of two-layer silicon rectangular meta-grating. These findings provide possibilities in cascaded meta-gratings spectroscopic design and alternative utilities for high signal-to-noise ratio applications in focus-free spatial filtering and anti-noise systems in telecommunications.
关键词：cascaded meta-gratings ; Fabry-Perot ; spectral and angular selectivity ; subwavelength grating