title: Tunable diffraction-free array in nonlinear photonic crystal.
abstract: Diffraction-free beams have attracted increasing research interests because of their unique performances and broad applications in various fields. Although many methods have been developed to produce such beams, it is still challenging to realize a tunable non-diffracting beam. Here, we report the generation of a tunable diffraction-free array through second-harmonic generation in a nonlinear photonic crystal, i.e., a 2D periodically-poled LiTaO3crystal. In such a crystal, the second-harmonic wave is engineered by properly designing the domain structure based on the Huygens-Fresnel principle. The characteristics of the generated diffraction-free array including its period, propagation length, and wavelength can be tuned by simply changing the input wavelength. Our observation not only enriches the diffraction-free optics, but also has potential applications for photolithography and imaging.
authors.affiliation: National Laboratory of Solid State Microstructures, College of Engineering and Applied Sciences, and School of Physics, Nanjing University, Nanjing 210093, China.|School of Physics and Telecommunication Engineering, South China Normal University, Guangzhou 510006, China.
authors.forename: Dongmei
authors.initials: D
authors.lastname: Liu
authors.affiliation: National Laboratory of Solid State Microstructures, College of Engineering and Applied Sciences, and 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, and School of Physics, Nanjing University, Nanjing 210093, China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: National Laboratory of Solid State Microstructures, College of Engineering and Applied Sciences, and 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, and School of Physics, Nanjing University, Nanjing 210093, China.
authors.forename: Rui
authors.initials: R
authors.lastname: Ni
authors.affiliation: National Laboratory of Solid State Microstructures, College of Engineering and Applied Sciences, and School of Physics, Nanjing University, Nanjing 210093, China.
authors.forename: Bo
authors.initials: B
authors.lastname: Yang
authors.affiliation: National Laboratory of Solid State Microstructures, College of Engineering and Applied Sciences, and 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, and School of Physics, Nanjing University, Nanjing 210093, China.
authors.forename: Y Q
authors.initials: YQ
authors.lastname: Qin
authors.affiliation: National Laboratory of Solid State Microstructures, College of Engineering and Applied Sciences, and School of Physics, Nanjing University, Nanjing 210093, China.
authors.forename: S N
authors.initials: SN
authors.lastname: Zhu
authors.affiliation: National Laboratory of Solid State Microstructures, College of Engineering and Applied Sciences, and School of Physics, Nanjing University, Nanjing 210093, China.|Department of Physics, University of Arkansas, Fayetteville, Arkansas 72701, USA.
authors.forename: Min
authors.initials: M
authors.lastname: Xiao