Fabrication and characterization of a binary diffractive lens for controlling focal distribution

We fabricated a binary diffractive lens to control focal distribution, such as intensity distribution, by controlling the focal length and depth of focus. The results revealed changes in the focal length and depth of focus as a function of changes in the ring zone interval ΔR_M at the end of the lens. Similar results were obtained from experiments. The peak position on the optical axis shifts further away from the lens. The half-width in the propagation direction increases with the ΔR_M. These results demonstrate the possibility of controlling the focal distribution using single flat lenses by changing the periodic structure.