• 文献标题:   Tunable dual-wavelength absorption switch with graphene based on an asymmetric guided-mode resonance structure
  • 文献类型:   Article
  • 作  者:   PARK GC, PARK K
  • 作者关键词:  
  • 出版物名称:   OPTICS EXPRESS
  • ISSN:   1094-4087
  • 通讯作者地址:  
  • 被引频次:   14
  • DOI:   10.1364/OE.416394
  • 出版年:   2021

▎ 摘  要

We propose a tunable dual-wavelength absorption (TDWA) switch based on an asymmetric guided mode resonance (AGMR) structure. A TDWA switch consists of a graphene layer and an AGMR structure sandwiched by cap and slab layers on a buffer/silicon substrate. The AGMR structure adds a smaller grating unit cell next to a larger one, exciting a second resonance close to but distinct from the first resonance. For switching, the TDWA between an absorptive or reflective mode with each on-/off-state, the chemical potential of graphene is tuned from 0.0 eV to 0.6 eV. For the absorptive mode, two absorption peaks of >= 96.2% are separated by 23 nm, both having an on-off ratio of similar to 15.52. For the reflective mode, two reflectance peaks of >= 93.8% are separated by 23 nm, having on-off ratios of 15.56 dB and 18.95 dB. The maximum on-off ratios of 39.98 dB and 34.55 dB are achieved near the reflectance peaks. Both the period of the AGMR and the cap thickness alters the two peak wavelengths linearly, while the grating width of the AGMR varies nonlinearly from 17 nm to 28 nm. The buffer excites a weak Fabry-Perot resonance, which interacts with the TDWA structure, the result of which is the two absorption peaks are varied. Finally, as the incidence angle of light increases up to 5.3 degrees, the distance of the two peak wavelengths is tuned from similar to 22 nm to similar to 77 nm with >= 96% absorption or >= 93% reflectance in each mode. (C) 2021 Optical Society of America under the terms of the OSA Open Access Publishing Agreement