A modified multiplexed vortex helico-conical petal-like zone plate

Abstract

A modified multiplexed vortex helico-conical petal-like zone plate (MMVHPZP) is proposed to generate a polygon-like beam or light-arm beam with an adjustable opening. The MMVHPZP consists of the modified helico-conical petal-like zone plate (MHPZP) with the topological charge l and exponent n, and the multiplexed vortex spiral phase plate (MVSPP) with the inner topological charge l 1 and outer topological charge l 2. Moreover, when l 1 is equal or unequal to l 2, the MMVHPZP has the adjustable polygon-like beam or light-arm beam, respectively. In addition, when n is small or large, the number of arms is equal to the absolute difference between l 1 and l 2 or the sum of one and the absolute difference between l 1 and l 2, respectively. Furthermore, for the different l 1 or l 2, the opening is constant. With the increase of the n or l, the opening is larger. When l 1 is greater or less than l 2, the rotation direction of arms is the anticlockwise or clockwise direction, respectively.