Metasurfaces have become a new photonic structure for providing potential applications to develop integrated devices with small thickness, because they can introduce an abrupt phase change by arrays of scatterers. To ...Metasurfaces have become a new photonic structure for providing potential applications to develop integrated devices with small thickness, because they can introduce an abrupt phase change by arrays of scatterers. To be applied more widely, active metasurface devices are highly desired. Here, a tunable terahertz meta-lens whose focal length is able to be electrically tuned by ～4.45λ is demonstrated experimentally. The lens consists of a metallic metasurface and a monolayer graphene. Due to the dependence of the abrupt phase change of the metasurface on the graphene chemical potential, which can be modulated using an applied gate voltage, the focal length is changed from 10.46 to 12.24 mm when the gate voltage increases from 0 to 2.0 V. Experimental results are in good agreement with the theoretical hypothesis. This type of electrically controlled meta-lens could widen the application of terahertz technology.展开更多
One new species of the genus Brithura Edwards, 1916, B. triprocessa Men & Liu sp. nov. from China is described and illustrated. The morphological description of the internal reproductive system for both sexes of t...One new species of the genus Brithura Edwards, 1916, B. triprocessa Men & Liu sp. nov. from China is described and illustrated. The morphological description of the internal reproductive system for both sexes of the new species is provided, which represents the first concern of the internal reproductive system in this genus.展开更多
基金National Key R&D Program of China(2017YFB1002900)973 Program of China(2013CBA01702)+1 种基金National Natural Science Foundation of China(NSFC)(11404224,1174243,11774246,61405012,61420106014)Excellent Young Scholars Research Fund of Beijing Institute of Technology(BIT)
文摘Metasurfaces have become a new photonic structure for providing potential applications to develop integrated devices with small thickness, because they can introduce an abrupt phase change by arrays of scatterers. To be applied more widely, active metasurface devices are highly desired. Here, a tunable terahertz meta-lens whose focal length is able to be electrically tuned by ～4.45λ is demonstrated experimentally. The lens consists of a metallic metasurface and a monolayer graphene. Due to the dependence of the abrupt phase change of the metasurface on the graphene chemical potential, which can be modulated using an applied gate voltage, the focal length is changed from 10.46 to 12.24 mm when the gate voltage increases from 0 to 2.0 V. Experimental results are in good agreement with the theoretical hypothesis. This type of electrically controlled meta-lens could widen the application of terahertz technology.
基金supported by grants from the National Natural Science Foundation of China(41501058,31300551)the Anhui Outstanding Young Talent Support Program(gxfx2017059)the Foundation of the Education Department of Anhui Province(KJ2017A360)
文摘One new species of the genus Brithura Edwards, 1916, B. triprocessa Men & Liu sp. nov. from China is described and illustrated. The morphological description of the internal reproductive system for both sexes of the new species is provided, which represents the first concern of the internal reproductive system in this genus.
