title: Three-dimensional Dammann array.
abstract: We demonstrate a scheme that can produce a three-dimensional (3D) focus spot array in a 3D lattice structure, called a 3D Dammann array, in focal region of an objective. This 3D Dammann array is generated by using two separate micro-optical elements, a Dammann zone plate (DZP) that produces a series of coaxial focus spots and a conventional two-dimensional (2D) Dammann grating (DG). A simple, fast, and clear method is presented to design this binary pure-phase (0,π) DZP in vectorial Debye theory regime. Based on this kind of DZP, one can always obtain a 3D Dammann array both for low and high numerical aperture (NA) focusing objectives. For experimental demonstration, an arrangement combining a DZP, a 2D DG, and a pair of opposing lenses is proposed to generate a 5×5×5 Dammann array in focal region of an objective with NA=0.127 and another 6×6×7 Dammann array for an objective of NA=0.66. It is shown that this arrangement makes it possible to achieve 3D Dammann arrays with micrometer-sized focus spots and focus spacings of tens of micrometers for various practical applications, such as 3D parallel micro- and nanomachining, 3D simultaneous optical manipulation, 3D optical data storage, and multifocal fluorescence microscope, etc.
authors.affiliation: Lab of Information Optics and Optoelectronics Techniques, Shanghai Institute of Optics and Fine Mechanics, Academia Sinica, Shanghai, China.
authors.forename: Junjie
authors.initials: J
authors.lastname: Yu
authors.forename: Changhe
authors.initials: C
authors.lastname: Zhou
authors.forename: Wei
authors.initials: W
authors.lastname: Jia
authors.forename: Wugang
authors.initials: W
authors.lastname: Cao
authors.forename: Shaoqing
authors.initials: S
authors.lastname: Wang
authors.forename: Jianyong
authors.initials: J
authors.lastname: Ma
authors.forename: Hongchao
authors.initials: H
authors.lastname: Cao