title: Super-oscillatory focusing of circularly polarized light by ultra-long focal length planar lens based on binary amplitude-phase modulation.
abstract: In traditional optics, the focal spot size of a conventional lens is restricted to the diffraction limit 0.5λ/NA, where λ is the wavelength in vacuum and NA is the numerical aperture of the lens. Recently, various sub-diffraction focusing optical devices have been demonstrated, but they usually have short focal length and high numerical aperture. Moreover, they always suffer the problem of huge sidelobes near the focal spot and small field of view, especially when the focal spot size is less than the super-oscillation criteria 0.38λ/NA. To address the problem, here, we reported a far-field sub-diffraction point-focusing lens based on binary phase and amplitude modulation with ultra-long focal length 252.8 μm (399.5λ) and small numerical aperture 0.78, and experimentally demonstrated a super-oscillatory focusing of circularly polarized light with spot size 287 nm (0.454λ), smaller than the diffraction limit 0.64λ and the super-oscillation criterion 0.487λ. What's more, on the focal plane, in the measured area within the radius of 142λ, the largest sidelobe intensity is less than 26% of the central lobe intensity. Such ultra-long distance super-oscillatory focusing with small sidelobes and large field of view has great potential applications in far-field super-resolution microscopy, ultra-high-density optical storage and nano-fabrication.
authors.affiliation: Key Laboratory of Optoelectronic Technology and Systems (Chongqing University), Ministry of Education, and Key Disciplines Lab of Novel Micro-nano Devices and System Technology, Chongqing University, 174 Shazheng Street, Shapingba, Chongqing 400044, China.
authors.forename: Gang
authors.initials: G
authors.lastname: Chen
authors.affiliation: Key Laboratory of Optoelectronic Technology and Systems (Chongqing University), Ministry of Education, and Key Disciplines Lab of Novel Micro-nano Devices and System Technology, Chongqing University, 174 Shazheng Street, Shapingba, Chongqing 400044, China.
authors.forename: Yuyan
authors.initials: Y
authors.lastname: Li
authors.affiliation: Key Laboratory of Optoelectronic Technology and Systems (Chongqing University), Ministry of Education, and Key Disciplines Lab of Novel Micro-nano Devices and System Technology, Chongqing University, 174 Shazheng Street, Shapingba, Chongqing 400044, China.
authors.forename: Anping
authors.initials: A
authors.lastname: Yu
authors.affiliation: Key Laboratory of Optoelectronic Technology and Systems (Chongqing University), Ministry of Education, and Key Disciplines Lab of Novel Micro-nano Devices and System Technology, Chongqing University, 174 Shazheng Street, Shapingba, Chongqing 400044, China.
authors.forename: Zhongquan
authors.initials: Z
authors.lastname: Wen
authors.affiliation: National Center for Nanoscience and Technology, No. 11 Zhong Guan CunBei Yi Tiao, Beijing 100190, China.
authors.forename: Luru
authors.initials: L
authors.lastname: Dai
authors.affiliation: Key Laboratory of Optoelectronic Technology and Systems (Chongqing University), Ministry of Education, and Key Disciplines Lab of Novel Micro-nano Devices and System Technology, Chongqing University, 174 Shazheng Street, Shapingba, Chongqing 400044, China.
authors.forename: Li
authors.initials: L
authors.lastname: Chen
authors.affiliation: Key Laboratory of Optoelectronic Technology and Systems (Chongqing University), Ministry of Education, and Key Disciplines Lab of Novel Micro-nano Devices and System Technology, Chongqing University, 174 Shazheng Street, Shapingba, Chongqing 400044, China.
authors.forename: Zhihai
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Optoelectronic Technology and Systems (Chongqing University), Ministry of Education, and Key Disciplines Lab of Novel Micro-nano Devices and System Technology, Chongqing University, 174 Shazheng Street, Shapingba, Chongqing 400044, China.
authors.forename: Senlin
authors.initials: S
authors.lastname: Jiang
authors.affiliation: Key Laboratory of Optoelectronic Technology and Systems (Chongqing University), Ministry of Education, and Key Disciplines Lab of Novel Micro-nano Devices and System Technology, Chongqing University, 174 Shazheng Street, Shapingba, Chongqing 400044, China.|National Center for Nanoscience and Technology, No. 11 Zhong Guan CunBei Yi Tiao, Beijing 100190, China.
authors.forename: Kun
authors.initials: K
authors.lastname: Zhang
authors.affiliation: National Center for Nanoscience and Technology, No. 11 Zhong Guan CunBei Yi Tiao, Beijing 100190, China.
authors.forename: Xianyou
authors.initials: X
authors.lastname: Wang
authors.affiliation: School of Physics, State Key Laboratory for Mesoscopic Physics, Peking University, Beijing 100871, China.
authors.forename: Feng
authors.initials: F
authors.lastname: Lin