Single-stage focusing spiral wave zone plate

• Main Authors: WANG XIAOXIA, MIAO ZHUANGLEI, WANG MENGGUANG, ZANG HUAPING
• Format: Patent
• Language: Chinese; English
• Published: 08.01.2021
• Subjects: OPTICAL ELEMENTS, SYSTEMS, OR APPARATUS; OPTICS; PHYSICS

The invention provides a single-stage focusing spiral wave zone plate. The wave zone plate comprises a transparent substrate and a plurality of lightproof elements formed on the transparent substrate;the number density of the lightproof elements is in cosine or sine distribution along the radial direction, i.e., the lightproof elements are distributed annularly and are randomly distributed alongrings; the transmittance function of the zone plate is described in the descriptions of the invention; in the transmittance function, l is a topological charge number, phi is an argument, n is the number of rings, ri is the radius of the nth ring, r1 is equal to lambda f, wherein lambda is the wavelength, and f is the focal length. The single-stage focusing spiral wave zone plate is only provided with a pair of conjugated first-stage focuses, so that interference and errors caused by high-stage diffraction can be eliminated, and vortex light beams can be generated; meanwhile, the structureof the single-stage focusing s