1.
Opt Lett
; 35(6): 880-2, 2010 Mar 15.
Article
in English
| MEDLINE
| ID: mdl-20237630
ABSTRACT
We describe the design, fabrication, and experimental demonstration of a circular Dammann grating element generating a point-spread function of two concentric rings with equal intensity. The element was fabricated using grayscale lithography, providing a smooth and accurate phase profile. As a result, we obtained high diffraction efficiency and good uniformity between the two rings.