Encoding generalized phase functions on Dammann gratings

Opt Lett. 2010 May 15;35(10):1536-8. doi: 10.1364/OL.35.001536.

Abstract

We extend the Dammann encoding concept to more general phase functions, i.e., to encode a phase pattern so that a number of diffracted orders have the same intensity. We demonstrate a Dammann vortex grating that generates different vortex patterns in the different diffracted orders. We also show a Fresnel lens that creates seven transverse focal spots in each of seven axial planes.