Ultrawide dynamic modulation of perfect absorption with a Friedrich–Wintgen BIC

• DOI: 10.1364/prj.481020
• Publication Date: 2023-01-05T19:00:51Z
• Authors: Enduo Gao; Rong Jin; Zhenchu Fu; Guangtao Cao; Yan Deng; Jian Chen; Guanhai Li; Xiaoshuang Chen; Hongjian Li
• Keywords: Modulation (music); Coupled mode theory

Dynamical control of perfect absorption plays an indispensable role in optical switch and modulators. However, it always suffers from the limited modulation range, small depth, susceptible efficiencies. Here, we propose a new strategy based on Friedrich–Wintgen bound states continuum (F–W BICs) to realize tunable absorber with large dynamic range. For proof concept, demonstrate pentaband ultrahigh system consisting graphene gratings sheets through elaborately tuning F–W BIC. The nature BIC arises destructive interference between Fabry–Perot resonance guided mode modes coherent phase-matching condition. radiation channels are avoided crossing. can be dynamically modulated by engineering Fermi level gratings, which breaks traditional methods incidence angle. Remarkably, this approach achieves largest range up 3.5 THz. We believe that work provides way engineer stimulates development multiband ultracompact devices.