title: Diffraction interference induced superfocusing in nonlinear Talbot effect.
abstract: We report a simple, novel subdiffraction method, i.e. diffraction interference induced superfocusing in second-harmonic (SH) Talbot effect, to achieve focusing size of less than λSH/4 (or λpump/8) without involving evanescent waves or subwavelength apertures. By tailoring point spread functions with Fresnel diffraction interference, we observe periodic SH subdiffracted spots over a hundred of micrometers away from the sample. Our demonstration is the first experimental realization of the Toraldo di Francia's proposal pioneered 62 years ago for superresolution imaging.
authors.affiliation: National Laboratory of Solid State Microstructures, College of Engineering and Applied Sciences, School of Physics, Nanjing University, Nanjing 210093, China.
authors.forename: Dongmei
authors.initials: D
authors.lastname: Liu
authors.affiliation: National Laboratory of Solid State Microstructures, College of Engineering and Applied Sciences, School of Physics, Nanjing University, Nanjing 210093, China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Department of Applied Physics, Yale University, New Haven, Connecticut 06511, USA.
authors.forename: Jianming
authors.initials: J
authors.lastname: Wen
authors.affiliation: National Laboratory of Solid State Microstructures, College of Engineering and Applied Sciences, School of Physics, Nanjing University, Nanjing 210093, China.
authors.forename: Zhenhua
authors.initials: Z
authors.lastname: Chen
authors.affiliation: National Laboratory of Solid State Microstructures, College of Engineering and Applied Sciences, School of Physics, Nanjing University, Nanjing 210093, China.
authors.forename: Dunzhao
authors.initials: D
authors.lastname: Wei
authors.affiliation: National Laboratory of Solid State Microstructures, College of Engineering and Applied Sciences, School of Physics, Nanjing University, Nanjing 210093, China.
authors.forename: Xiaopeng
authors.initials: X
authors.lastname: Hu
authors.affiliation: National Laboratory of Solid State Microstructures, College of Engineering and Applied Sciences, School of Physics, Nanjing University, Nanjing 210093, China.
authors.forename: Gang
authors.initials: G
authors.lastname: Zhao
authors.affiliation: National Laboratory of Solid State Microstructures, College of Engineering and Applied Sciences, School of Physics, Nanjing University, Nanjing 210093, China.
authors.forename: S N
authors.initials: SN
authors.lastname: Zhu
authors.affiliation: 1] National Laboratory of Solid State Microstructures, College of Engineering and Applied Sciences, School of Physics, Nanjing University, Nanjing 210093, China [2] Department of Physics, University of Arkansas, Fayetteville, Arkansas 72701, USA.
authors.forename: Min
authors.initials: M
authors.lastname: Xiao