Single stage focusing wave zone plate and manufacturing method thereof

Abstract

The invention provides a single stage focusing wave zone plate and a manufacturing method thereof. The single stage focusing wave zone plate comprises a transparent substrate and a plurality of light-proof elements arranged on the transparent substrate, wherein the light-proof element number densities are in cosine distribution and sinusoidal distribution along a radial direction, namely that the light-proof elements are in ring-shaped zonal distribution, and are in random distribution along the ring-shaped zones; the diameter of each ring-shaped zone is rm, wherein rm2 is equal to mf lambda +m2 lambda 2 / 4, lambda is wavelength, f is focal length and m is the number of rings; the shapes of the light-proof elements can be as follows: a hexagon, a round, a sector or any one of other shapes. The single stage focusing wave zone plate provide by the invention only has a pair of conjugated focal points, so that the interference and the error brought by high-order diffraction can be eliminated; and meanwhile, a light transmission region and a light-proof region only exist in a single stage focusing wave zone plate which is in a binaryzation structure, and is easy to manufacture. The single stage focusing wave zone plate provided by the invention has the characteristics of capability of being used as a focal point, an imaging element or a single color device wavelength selective element.

Description

technical field [0001] The present invention relates to zone plate technology, more specifically, to a single-stage focusing zone plate and its manufacturing method. Background technique [0002] In 1871, Rayleigh invented the Fresnel zone plate (Optics, Addison-Wesley, E. Hecht and A. Zajac), which is similar to a lens and has the properties of focusing and imaging. The Fresnel zone plate is composed of concentric annular zones whose linear density gradually increases from the inside to the outside along the radial direction. These concentric circular zones are also called half-wave zones. The areas of each half-wave zone are equal, and adjacent even half The optical path difference between the corresponding part of the wave band or odd half-wave band to the focal point is equal to the wavelength of the incident light. When the electromagnetic wave is incident on the surface of the zone plate, after diffraction, the zone plate will change the amplitude and phase of its ele...

AI Technical Summary

Problems solved by technology

Therefore, the usual practice cannot be used to make Gabor zone plates suitable for X-ray bands

[0004]In 1992, Beynon and KirK et al. proposed a workaround for making X-ray Gabor zone plates (Gabor zone plate with binary transmittance values, Optics Letters, T. D. Beynon, I. Kirk and T. R. Mathews), this method gives the Gabor zone plate the characteristics of the binary optical transfer function, thus greatly reducing the difficulty of making the Gabor zone plate, but the Gabor zone plate designed by this method There are a large number of sharp corners of different sizes in the film, and the existence of a large number of sharp corners directly limits the manufacturing accuracy of the zone plate

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