title: Programmable Bidirectional Folding of Metallic Thin Films for 3D Chiral Optical Antennas.
abstract: 3D structures with characteristic lengths ranging from nanometer to micrometer scale often exhibit extraordinary optical properties, and have been becoming an extensively explored field for building new generation nanophotonic devices. Albeit a few methods have been developed for fabricating 3D optical structures, constructing 3D structures with nanometer accuracy, diversified materials, and perfect morphology is an extremely challenging task. This study presents a general 3D nanofabrication technique, the focused ion beam stress induced deformation process, which allows a programmable and accurate bidirectional folding (-70°-+90°) of various metal and dielectric thin films. Using this method, 3D helical optical antennas with different handedness, improved surface smoothness, and tunable geometries are fabricated, and the strong optical rotation effects of single helical antennas are demonstrated.
authors.affiliation: National Key Laboratory of Science and Technology on Micro/Nano Fabrication, Institute of Microelectronics, Peking University, Beijing, 100871, P. R. China.
authors.forename: Yifei
authors.initials: Y
authors.lastname: Mao
authors.affiliation: College of Engineering and Applied Sciences, National Laboratory of Solid State Microstructures, and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, Jiangsu, 210093, P. R. China.
authors.forename: Yun
authors.initials: Y
authors.lastname: Zheng
authors.affiliation: National Key Laboratory of Science and Technology on Micro/Nano Fabrication, Institute of Microelectronics, Peking University, Beijing, 100871, P. R. China.
authors.forename: Can
authors.initials: C
authors.lastname: Li
authors.affiliation: Key Laboratory of Broadband Wireless Communication and Sensor Network Technology of Ministry of Education, College of Internet of Things, Nanjing University of Posts and Telecommunications, Nanjing, Jiangsu, 210096, P. R. China.
authors.forename: Lin
authors.initials: L
authors.lastname: Guo
authors.affiliation: National Key Laboratory of Science and Technology on Micro/Nano Fabrication, Institute of Microelectronics, Peking University, Beijing, 100871, P. R. China.
authors.forename: Yini
authors.initials: Y
authors.lastname: Pan
authors.affiliation: Electron Microscopy Laboratory, Peking University, Beijing, 100871, P. R. China.
authors.forename: Rui
authors.initials: R
authors.lastname: Zhu
authors.affiliation: Electron Microscopy Laboratory, Peking University, Beijing, 100871, P. R. China.
authors.forename: Jun
authors.initials: J
authors.lastname: Xu
authors.affiliation: College of Engineering and Applied Sciences, National Laboratory of Solid State Microstructures, and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, Jiangsu, 210093, P. R. China.
authors.forename: Weihua
authors.initials: W
authors.lastname: Zhang
authors.affiliation: National Key Laboratory of Science and Technology on Micro/Nano Fabrication, Institute of Microelectronics, Peking University, Beijing, 100871, P. R. China.|Innovation Center for MicroNanoelectronics and Integrated System, Beijing, 100871, P. R. China.
authors.forename: Wengang
authors.initials: W
authors.lastname: Wu
keywords: chiral optical antennas; focused ion beam; nanofabrication; optical rotation; programmable folding