For a conventional cascaded metasurface,the combination channel and each single channel are mutually dependent because the phase modulation of a cascaded metasurface is the sum of each single one.Here we propose a cas...For a conventional cascaded metasurface,the combination channel and each single channel are mutually dependent because the phase modulation of a cascaded metasurface is the sum of each single one.Here we propose a cascaded metasurface that can independently encode information into multiple channels.Based on the orientation degeneracy of anisotropic metasurfaces,each single metasurface can produce a quick-response(QR)image in the near field,governed by the Malus law,while the combined channel can produce a holographic image in the far field,governed by geometric phase.The independent and physically separated trichannel design makes information encryption safer.展开更多
The design of a conventional zoom lens is always challenging because it requires not only sophisticated optical design strategy, but also complex and precise mechanical structures for system adjustment. Here, we propo...The design of a conventional zoom lens is always challenging because it requires not only sophisticated optical design strategy, but also complex and precise mechanical structures for system adjustment. Here, we propose a continuous-zoom lens consisting of two chiral geometric metasurfaces with dielectric nanobrick arrays sitting on a transparent substrate. The metalens can continuously vary the focal length by rotating either of the two metasurfaces around its optical axis without changing any other conditions. Due to the polarization dependence of the geometric metasurface, the positive and negative polarities are interchangeable in one identical metalens only by changing the handedness of the incident circularly polarized light, which can generate varying focal lengths ranging from-∞ to +∞ in principle.展开更多
Hyperlenses based on metamaterials can be applied to subwavelength imaging in the lightwave band. In this letter, we demonstrate both through simulations and experimentally verified results that our proposed half- cyl...Hyperlenses based on metamaterials can be applied to subwavelength imaging in the lightwave band. In this letter, we demonstrate both through simulations and experimentally verified results that our proposed half- cylindrical shaped hyperlens can be used for super-resolution microwave focusing in a TE mode. Based on split ring resonators, the hyperlens satisfies a hyperbolic dispersion relationship. Simulations demonstrate that the focused spot size and position are insensitive to the rotation angle of the hyperlens around its geometric center. Experimental results show that a focused spot size 1/3 of the vacuum wavelength is achieved in the microwave band.展开更多
基金supported by the National Key Research and Development Program of China(No.2021YFE0205800)the National Natural Science Foundation of China(Nos.12174292,11904267,and 91950110)the Fundamental Research Funds for the Central Universities(Nos.2042022kf1013,2042022kf0024,and 2042021kf0018)。
文摘For a conventional cascaded metasurface,the combination channel and each single channel are mutually dependent because the phase modulation of a cascaded metasurface is the sum of each single one.Here we propose a cascaded metasurface that can independently encode information into multiple channels.Based on the orientation degeneracy of anisotropic metasurfaces,each single metasurface can produce a quick-response(QR)image in the near field,governed by the Malus law,while the combined channel can produce a holographic image in the far field,governed by geometric phase.The independent and physically separated trichannel design makes information encryption safer.
基金supported by the National Natural Science Foundation of China(Nos.11774273,11574240,61640409,and 61805184)the Outstanding Youth Funds of Hubei Province(No.2016CFA034)+2 种基金the Open Foundation of State Key Laboratory of Optical Communication Technologies and Networks,Wuhan Research Institute of Posts and Telecommunications(No.OCTN-201605)the Postdoctoral Innovation Talent Support Program of China(No.BX20180221)the Natural Science Foundation of Guangxi(No.2017GXNSFAA198048)
文摘The design of a conventional zoom lens is always challenging because it requires not only sophisticated optical design strategy, but also complex and precise mechanical structures for system adjustment. Here, we propose a continuous-zoom lens consisting of two chiral geometric metasurfaces with dielectric nanobrick arrays sitting on a transparent substrate. The metalens can continuously vary the focal length by rotating either of the two metasurfaces around its optical axis without changing any other conditions. Due to the polarization dependence of the geometric metasurface, the positive and negative polarities are interchangeable in one identical metalens only by changing the handedness of the incident circularly polarized light, which can generate varying focal lengths ranging from-∞ to +∞ in principle.
基金the National Natural Science Foundation of China under Grants Nos.11374235,61271150,61007024,and 10904118
文摘Hyperlenses based on metamaterials can be applied to subwavelength imaging in the lightwave band. In this letter, we demonstrate both through simulations and experimentally verified results that our proposed half- cylindrical shaped hyperlens can be used for super-resolution microwave focusing in a TE mode. Based on split ring resonators, the hyperlens satisfies a hyperbolic dispersion relationship. Simulations demonstrate that the focused spot size and position are insensitive to the rotation angle of the hyperlens around its geometric center. Experimental results show that a focused spot size 1/3 of the vacuum wavelength is achieved in the microwave band.
