title: Design of diffractive phase element for modulating the electric field at the out-of-focus plane in a lens system.
abstract: We demonstrate an efficient method to design the diffractive phase element for modulating the electric field at the out-of-focus plane of a lens system by using an equivalent Fresnel diffraction in free space. In the monochromatic illumination, we show an example to certify the validity of our method experimentally. In the nonmonochromatic illumination, we theoretically display that the spectral beam splitting and highly confined intensity can be obtained simultaneously at the out-of-focus plane, which has the potential in the solar concentrating system and optical encryption.
authors.affiliation: Department of Optics and Optical Engineering, University of Science and Technology of China, Hefei, Anhui, China.
authors.forename: Kun
authors.initials: K
authors.lastname: Huang
authors.forename: Hongfang
authors.initials: H
authors.lastname: Gao
authors.forename: Guowei
authors.initials: G
authors.lastname: Cao
authors.forename: Peng
authors.initials: P
authors.lastname: Shi
authors.forename: Xiaobo
authors.initials: X
authors.lastname: Zhang
authors.forename: Yongping
authors.initials: Y
authors.lastname: Li