Square-shaped beam generated by phase shifted bounded square zone plate

A novel diffractive element is presented which is made through lateral phase shifted square zone plate bounded along horizontal and vertical axes via two perpendicular rectangle windows, respectively. We demonstrate that under a given condition the element is able to produce a square light beam at the focal plane. We have also elaborated that the produced square beam can be simply manipulated by an appropriate combination of the phase shifting parameter and bounded width. Experimental works verify the simulation results.