An electron vortex beam(EVB) carrying orbital angular momentum(OAM) plays a key role in a series of fundamental scientific researches, such as chiral energy-loss spectroscopy and magnetic dichroism spectroscopy. So fa...An electron vortex beam(EVB) carrying orbital angular momentum(OAM) plays a key role in a series of fundamental scientific researches, such as chiral energy-loss spectroscopy and magnetic dichroism spectroscopy. So far, almost all the experimentally created EVBs manifest isotropic doughnut intensity patterns. Here, based on the correlation between local divergence angle of electron beam and phase gradient along azimuthal direction, we show that free electrons can be tailored to EVBs with customizable intensity patterns independent of the carried OAM. As proof-of-concept, by using computer generated hologram and designing phase masks to shape the incident free electrons in the transmission electron microscope, three structured EVBs carrying identical OAM are tailored to exhibit completely different intensity patterns. Furthermore, through the modal decomposition, we quantitatively investigate their OAM spectral distributions and reveal that structured EVBs present a superposition of a series of different eigenstates induced by the locally varied geometries. These results not only generalize the concept of EVB, but also demonstrate an extra highly controllable degree of freedom for electron beam manipulation in addition to OAM.展开更多
Interfacial solar steam generation(ISSG)is a novel and potential solution to global freshwater crisis.Here,based on a facile sol-gel fabrication process,we demonstrate a highly scalable Janus aramid nanofiber aerogel(...Interfacial solar steam generation(ISSG)is a novel and potential solution to global freshwater crisis.Here,based on a facile sol-gel fabrication process,we demonstrate a highly scalable Janus aramid nanofiber aerogel(JANA)as a high-efficiency ISSG device.JANA performs near-perfect broadband optical absorption,rapid photothermal conversion and effective water transportation.Owning to these features,efficient desalination of salty water and purification of municipal sewage are successfully demonstrated using JANA.In addition,benefiting from the mechanical property and chemical stability of constituent aramid nanofibers,JANA not only possesses outstanding flexibility and fire-resistance properties,but its solar steaming efficiency is also free from the influences of elastic deformations and fire treatments.We envision JANA provides a promising platform for mass-production of high-efficiency ISSG devices with supplementary capabilities of convenient transportation and long-term storage,which could further promote the realistic applications of ISSG technology.展开更多
Monochromatic light can be characterized by its three fun dame ntal properties:amplitude,phase,and polarization.In this work,we propose a versatile,transmission-mode all-dielectric metasurface platform that can indepe...Monochromatic light can be characterized by its three fun dame ntal properties:amplitude,phase,and polarization.In this work,we propose a versatile,transmission-mode all-dielectric metasurface platform that can independently manipulate the phase and amplitude for two orthogonal states of polarization in the visible frequency range.For proof-o仁concept experimental demonstration,various single-layer metasurfaces composed of subwavelength-spaced titanium-dioxide nanopillars are designed,fabricated,and characterized to exhibit the ability of polarization-switchable multidimensional light-field manipulation,including polarization-switchable grayscale nanoprinting,nonuniform cylindrical lensing,and complex-amplitude holography.We envision the metasurface platform dem on strated here to open new possibilities toward creating compact multifunctional optical devices for applications in polarization optics,information encoding,optical data storage,and security.展开更多
基金This work is supported in part by the Key Research and Development Program from Ministry of Science and Technology of China(2022YFA1205000)National Natural Science Foundation of China(12274217 and 62105142)+1 种基金Natural Science Foundation of Jiangsu Province(BK20220068 and BK20212004)Fundamental Research Funds for Central Universities.
文摘An electron vortex beam(EVB) carrying orbital angular momentum(OAM) plays a key role in a series of fundamental scientific researches, such as chiral energy-loss spectroscopy and magnetic dichroism spectroscopy. So far, almost all the experimentally created EVBs manifest isotropic doughnut intensity patterns. Here, based on the correlation between local divergence angle of electron beam and phase gradient along azimuthal direction, we show that free electrons can be tailored to EVBs with customizable intensity patterns independent of the carried OAM. As proof-of-concept, by using computer generated hologram and designing phase masks to shape the incident free electrons in the transmission electron microscope, three structured EVBs carrying identical OAM are tailored to exhibit completely different intensity patterns. Furthermore, through the modal decomposition, we quantitatively investigate their OAM spectral distributions and reveal that structured EVBs present a superposition of a series of different eigenstates induced by the locally varied geometries. These results not only generalize the concept of EVB, but also demonstrate an extra highly controllable degree of freedom for electron beam manipulation in addition to OAM.
基金jointly supported by the National Natural Science Foundation of China (no. 62105142)Natural Science Foundation of Jiangsu Province (BK20220068)+1 种基金the Center Fundamental Research Funds for the Central UniversitiesEntrepreneurship and Innovation Program of Jiangsu Province (JSSCBS20210002)。
文摘Interfacial solar steam generation(ISSG)is a novel and potential solution to global freshwater crisis.Here,based on a facile sol-gel fabrication process,we demonstrate a highly scalable Janus aramid nanofiber aerogel(JANA)as a high-efficiency ISSG device.JANA performs near-perfect broadband optical absorption,rapid photothermal conversion and effective water transportation.Owning to these features,efficient desalination of salty water and purification of municipal sewage are successfully demonstrated using JANA.In addition,benefiting from the mechanical property and chemical stability of constituent aramid nanofibers,JANA not only possesses outstanding flexibility and fire-resistance properties,but its solar steaming efficiency is also free from the influences of elastic deformations and fire treatments.We envision JANA provides a promising platform for mass-production of high-efficiency ISSG devices with supplementary capabilities of convenient transportation and long-term storage,which could further promote the realistic applications of ISSG technology.
基金the Key Research and Development Program from Ministry of Science and Technology of China(2017YFA0303700 and 2016YFA0202100)National Natural Science Foundation of China(11774163)+1 种基金Fundamental Research Funds for the Central Universities(0213-14380194).M.L.and T.Xu ack no wledge tech nical support from micro-fabricati on and in teg rati on technology center from Nanji ng Un iversity.W.Z.L.C.and A.A.acknowledge support under the Cooperative Research Agreement between the University of Maryland and the National Institute of Standards and Technology,Award#70-NANB14H209,through the University of Maryland.M.L.,W.Z.and P.H.contributed equally to this work.
文摘Monochromatic light can be characterized by its three fun dame ntal properties:amplitude,phase,and polarization.In this work,we propose a versatile,transmission-mode all-dielectric metasurface platform that can independently manipulate the phase and amplitude for two orthogonal states of polarization in the visible frequency range.For proof-o仁concept experimental demonstration,various single-layer metasurfaces composed of subwavelength-spaced titanium-dioxide nanopillars are designed,fabricated,and characterized to exhibit the ability of polarization-switchable multidimensional light-field manipulation,including polarization-switchable grayscale nanoprinting,nonuniform cylindrical lensing,and complex-amplitude holography.We envision the metasurface platform dem on strated here to open new possibilities toward creating compact multifunctional optical devices for applications in polarization optics,information encoding,optical data storage,and security.
