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,and susceptible absorption efficiencies.Here...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,and susceptible absorption efficiencies.Here,we propose a new strategy based on Friedrich–Wintgen bound states in the continuum(F–W BICs)to realize a tunable perfect absorber with large dynamic modulation range.For proof of concept,we demonstrate a pentaband ultrahigh absorption system consisting of graphene gratings and graphene sheets through elaborately tuning F–W BIC.The nature of the F–W BIC arises from the destructive interference between Fabry–Perot resonance and guided mode resonance modes in the coherent phase-matching condition.The radiation channels are avoided from crossing.The BIC can be dynamically modulated by engineering the Fermi level of graphene gratings,which breaks the traditional modulation methods with an incidence angle.Remarkably,the perfect absorber with this F–W BIC approach achieves the largest modulation range of up to 3.5 THz.We believe that this work provides a new way to dynamically engineer perfect absorption and stimulates the development of multiband ultracompact devices.展开更多
基金Hunan Provincial Innovation Foundation for Postgraduate(1053320200208)Shanghai Municipal Science and Technology Major Project(2019SHZDZX01)+6 种基金Science and Technology Commission of Shanghai Municipality(20JC1416000,22JC1402900)Shanghai Rising-Star Program(20QA1410400)Natural Science Foundation of Zhejiang Province(LR22F050004)Strategic Priority Research Program of Chinese Academy of Sciences(XDB43010200)Youth Innovation Promotion Association of the Chinese Academy of Sciences(Y2021070)National Natural Science Foundation of China(61865006,61875218,62222514,91850208)National Key Research and Development Program of China(2018YFA0306200)。
文摘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,and susceptible absorption efficiencies.Here,we propose a new strategy based on Friedrich–Wintgen bound states in the continuum(F–W BICs)to realize a tunable perfect absorber with large dynamic modulation range.For proof of concept,we demonstrate a pentaband ultrahigh absorption system consisting of graphene gratings and graphene sheets through elaborately tuning F–W BIC.The nature of the F–W BIC arises from the destructive interference between Fabry–Perot resonance and guided mode resonance modes in the coherent phase-matching condition.The radiation channels are avoided from crossing.The BIC can be dynamically modulated by engineering the Fermi level of graphene gratings,which breaks the traditional modulation methods with an incidence angle.Remarkably,the perfect absorber with this F–W BIC approach achieves the largest modulation range of up to 3.5 THz.We believe that this work provides a new way to dynamically engineer perfect absorption and stimulates the development of multiband ultracompact devices.
