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.
© 2012 Optical Society of America
Diffraction and Gratings
Original Manuscript: March 22, 2012
Revised Manuscript: June 10, 2012
Manuscript Accepted: June 15, 2012
Published: July 16, 2012
Kun Huang, Hongfang Gao, Guowei Cao, Peng Shi, Xiaobo Zhang, and Yongping Li, "Design of diffractive phase element for modulating the electric field at the out-of-focus plane in a lens system," Appl. Opt. 51, 5149-5153 (2012)