Trapezoidal zone plate with quasi-single-stage focusing

Abstract

The invention discloses a trapezoidal wave zone plate with a quasi-single-stage focusing characteristic. The trapezoidal wave zone plate comprises a light-proof substrate and a plurality of ring-shaped wave zones which are sequentially arranged from inside to outside by taking the substrate as a center, wherein each ring-shaped wave zone comprises at least two spiral trapezoidal hole light transmission units which are formed by twisting isosceles-trapezoid-shaped hole light transmission units, and are sequentially connected; the radial light transmittance of the wave zone plate meets a formula shown in the description. Compared with a common Fresnel wave zone plate, the trapezoidal wave zone plate can restrain the diffraction efficiency of a senior focus very well, also can reduce the peak strength of the senior focus. Moreover, when a ratio of the top edge of the original trapezoid to the bottom edge of the original trapezoid is equal to 1 to 5, the trapezoidal wave zone plate further has the effect of eliminating a 3n-level focus, and also restrains the efficiency of a 5-level focus to 0.16% of a 1-level focus (insulating efficiency being 6.93%). Compared with a Gabor wave zone plate, the 1-level focus efficiency is higher than the focusing efficiency of the Gabor wave zone plate, and the trapezoidal wave zone plate is easier to manufacture in comparison with a plurality of binaryzation Gabor wave zone plates.

Description

technical field [0001] The invention relates to the field of diffraction focusing elements, in particular to a trapezoidal zone plate with quasi-single-stage focusing characteristics. Background technique [0002] Like X-ray spectral diagnostic technology, X-ray imaging technology is also an important detection method in laser fusion research, and it is the most intuitive way for real-time diagnosis of deuterium-tritium target ball compression in indirect drive inertial confinement fusion. In the X-ray band, due to the absorption of X-rays by the material and the refractive index close to 1, the optical lens commonly used for focusing imaging is no longer suitable. [0003] In 1871, Rayleigh invented the Fresnel zone plate (FZP), which is composed of a series of concentric ring half-wave bands with alternating light and dark, and relies on diffraction to achieve focusing. It is often used to focus X-rays. However, the low efficiency and multi-focus characteristics of FZP al...

AI Technical Summary

Problems solved by technology

[0006] Most of the existing binary Gabor zone plates have a large number of sectors and a large number of small sharp corners. During production and processing, the randomness and discreteness of the distribution of a large number of primitives makes the work efficiency of the electron beam writing equipment low, and Also not conducive to obtaining zone plate layout data for etching

For the processing of components with too high discrete elements such as random lattice zone plates, a large-area substrate is required, and the substrate will cause a large amount of X-ray absorption, which is not conducive to its application

[0007] In summary, the existing binary Gabor zone plates are not only difficult to achieve self-support, but also difficult to process and manufacture, and most of them are difficult to realize the application in the extreme ultraviolet and X-ray bands

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