Construction method of modified single-focus fractal zone plate and zone plate thereof

Abstract

The invention discloses a construction method of a modified single-focus fractal zone plate and a zone plate thereof. The method comprises a step of determining a total number M of spiral high-transmittance bands on a corrected single-focus fractal zone plate based on the element number of a Cantor sequence of an Sth level and carrying out fractal on the modified single-focus fractal zone plate according to the Cantor sequence of the Sth level, a step of determining an alpha1 value of the modified single-focus fractal zone plate capable of generating a single main focus with a plurality of secondary focuses or determining an alpha2 value of the modified single-focus fractal zone plate capable of generating two equal-intensity main focuses with a plurality of secondary focuses, and a step of constructing the corresponding modified single-focus fractal zone plate based on the obtained alpha1 value or alpha2 value and an internal and external radius formula of the spiral light-transmittance bands of the modified single-focus fractal zone plate. The zone plate designed by the invention can only generate a first-stage focus or first-stage and second-stage focuses in an axial direction,so that a low-chromatic-aberration image can be generated, the multi-plane simultaneous imaging, particle capturing and photoetching are realized.

Description

technical field [0001] The invention belongs to the field of optoelectronic technology, and in particular relates to a construction method of a modified single-focus fractal zone plate and the zone plate. Background technique [0002] The sub-focus can be used in different fields. For example, the sub-focus near the main focus can be used to extend the focal depth. Therefore, the sub-focus can be used to reduce image chromatic aberration, generate a series of optical vortices, and realize multi-plane lithography. It can also be used for Capture particles in multiple planes simultaneously or generate multiple images. [0003] Some existing zone plates can produce a single main focus with multiple sub-focus points, such as fractal zone plates and fractal zone plates with missing structures can produce a single main focus with multiple sub-focus points, wherein, The fractional fractal zone plate can produce a designable main focus; the composite fractional fractal zone plate c...

AI Technical Summary

Problems solved by technology

However, the high-order subfocals of these photonic sieves still have low intensity, and these photonic sieves cannot produce only the first-order focus or the first-order and second-order foci in the axial direction.

Although the new monofocal x-ray zone plates and monofocal photon sieves can produce only one primary focus, these zone plates cannot produce a single main focus with many subfoci and two isointense main foci with many subfoci

[0006] Therefore, there is a lack in the prior art that can produce a single main focus with multiple sub-focuses or two equal-intensity main focuses with multiple sub-focuses, and at the same time, only produce a primary focus or a primary and secondary focus in the axial direction focal zone plate

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