Chiral metasurfaces have been proven to possess great potential in chiroptical applications.However,the multiband chiral metasurface with near-perfect circular dichroism has not been well studied.Also,the widely used ...Chiral metasurfaces have been proven to possess great potential in chiroptical applications.However,the multiband chiral metasurface with near-perfect circular dichroism has not been well studied.Also,the widely used bilayer metasurface usually suffers from the interlayer alignment and weak resonance.Here,we propose a twisted Moirémetasurface which can support three chiral bands with near-unity circular dichroism.The Moirémetasurface can remove the restriction of interlayer alignment,while maintaining a strong monolayer resonance.The two chiral bands in the forward direction can be described by two coupled-oscillator models.The third chiral band is achieved by tuning the interlayer chiral mode on resonance with the intralayer mode,to eliminate the parallel and converted components simultaneously.Finally,we study the robustness and tunability of the triple-layer Moirémetasurface in momentum space.This work provides a universal method to achieve three near-unity circular dichroism bands in one metasurface,which can promote applications of chiral metasurfaces in multiband optical communication,chiral drug separation,sensing,optical encryption,chiral laser,nonlinear and quantum optics,etc.展开更多
The wavelength variation of a laser-dye-type random laser is observed experimentally.It is found that the emitting wavelength of a random laser changes with the change of concentration of the gain material.Also,the ac...The wavelength variation of a laser-dye-type random laser is observed experimentally.It is found that the emitting wavelength of a random laser changes with the change of concentration of the gain material.Also,the actual radiation wavelength is influenced by the pumping rate of the source,the cavity competition and the concentration of scatterers.展开更多
We propose a scheme for carpet anti-cloak based on the transformation optics. An anti-cloak layer is designed, which can make the external electromagnetic waves break the carpet cloak shielding. The external electroma...We propose a scheme for carpet anti-cloak based on the transformation optics. An anti-cloak layer is designed, which can make the external electromagnetic waves break the carpet cloak shielding. The external electromagnetic waves can be detected under the carpet cloak, while not affecting the role of carpet cloak of stealth. The Jacobian transformation tensor is calculated by numerically solving the Laplace equations with proper boundary condition. Thus, it is possible to design tile anti-cloak layer of irregular shape. The simulation results demonstrate the feasibilities and flexibilities of the structure. Design details and full-wave simulation results are provided.展开更多
基金the National Natural Science Foundation of China(Grant Nos.12174031,91950108,and 11774035)。
文摘Chiral metasurfaces have been proven to possess great potential in chiroptical applications.However,the multiband chiral metasurface with near-perfect circular dichroism has not been well studied.Also,the widely used bilayer metasurface usually suffers from the interlayer alignment and weak resonance.Here,we propose a twisted Moirémetasurface which can support three chiral bands with near-unity circular dichroism.The Moirémetasurface can remove the restriction of interlayer alignment,while maintaining a strong monolayer resonance.The two chiral bands in the forward direction can be described by two coupled-oscillator models.The third chiral band is achieved by tuning the interlayer chiral mode on resonance with the intralayer mode,to eliminate the parallel and converted components simultaneously.Finally,we study the robustness and tunability of the triple-layer Moirémetasurface in momentum space.This work provides a universal method to achieve three near-unity circular dichroism bands in one metasurface,which can promote applications of chiral metasurfaces in multiband optical communication,chiral drug separation,sensing,optical encryption,chiral laser,nonlinear and quantum optics,etc.
基金Supported by the National Natural Science Foundation of China under Grant Nos.60677006 and 11074024.
文摘The wavelength variation of a laser-dye-type random laser is observed experimentally.It is found that the emitting wavelength of a random laser changes with the change of concentration of the gain material.Also,the actual radiation wavelength is influenced by the pumping rate of the source,the cavity competition and the concentration of scatterers.
基金Supported by the National Natural Science Foundation of China under Grant Nos 10574016, 60778049, 60677006 and 10904003 and the National Hight-Technology Research and Development Program of China under Grant 2009AA09Z101.
基金Supported by the National Natural Science Foundation of China under Grant Nos 10574016, 60778049, 60677006 and 10904003, and the National High-Technology Research and Development Program of China under Grant No 2009AA09Z101.
基金financially supported by the National Natural Science Foundation of China under Grant No.61275130
文摘We propose a scheme for carpet anti-cloak based on the transformation optics. An anti-cloak layer is designed, which can make the external electromagnetic waves break the carpet cloak shielding. The external electromagnetic waves can be detected under the carpet cloak, while not affecting the role of carpet cloak of stealth. The Jacobian transformation tensor is calculated by numerically solving the Laplace equations with proper boundary condition. Thus, it is possible to design tile anti-cloak layer of irregular shape. The simulation results demonstrate the feasibilities and flexibilities of the structure. Design details and full-wave simulation results are provided.
