All-dielectric super-lens for shaping Gaussian light into top-hat light and preparation method of all-dielectric super-lens

Abstract

The invention discloses an all-dielectric super-lens for shaping Gaussian light into top-hat light and a preparation method thereof, and belongs to the field of laser beam shaping. The all-dielectric super-lens comprises a dielectric substrate layer and a metasurface structure, wherein the metasurface structure is located on the surface of one side of the dielectric substrate layer and comprises a plurality of metasurface columnar structure units, the metasurface columnar structure units are arranged in a tetragonal lattice periodic array mode, and the metasurface columnar structure units are the same in height. According to the invention, based on Gaussian light, target top-hat light electric field intensity amplitude distribution and electric field intensity distribution of the input surface and the output surface of an all-dielectric super lens, optimization design is performed on a super lens phase, and the super-lens is designed and prepared according to the optimally designed phase; and a metasurface structure greatly reduces the size of a beam shaping device, the thickness of the device can be reduced to the hundred-micron dimension, other elements do not need to be added, the beam shaping device is simplified, the assembly precision requirement is reduced, and the super-lens has the advantage of being high in phase regulation and control precision and can achieve continuous phase regulation and control.

Description

technical field [0001] The invention belongs to the field of laser beam shaping, and more particularly relates to an all-dielectric superlens for shaping Gaussian light into flat top light and a preparation method thereof. Background technique [0002] The energy of the laser beam generally obeys the Gaussian distribution, and the non-uniformity of its energy will cause the local temperature to rise and destroy the material. In many laser application fields, this non-uniformity will limit its application. Therefore, the Gaussian beam needs to be shaped. A flat-top beam with good uniformity is obtained. Flat-top beam refers to a laser beam with uniform energy density in the cross section of the beam transmission direction. Due to its uniform energy distribution, it has important applications in the fields of laser welding, laser drilling, laser cautery, laser medical treatment, and laser display. Applications. The uniform light spot allows uniform laser treatment of the wor...

AI Technical Summary

Problems solved by technology

The beam shaping system of the aspheric lens method is designed according to the principle of geometric optics. The system contains one or more aspheric lenses. The disadvantages are large volume, complex structure, heavy weight and high cost.

The beam shaping system of the diffractive optical element method is designed according to the principle of diffractive optics. The system usually includes a diffractive optical element and a focusing lens close to the diffractive optical element. The manufacturing process of the diffractive optical element is complicated, and it is difficult to integrate with the refractive lens and reduce the volume. , high cost and other disadvantages. At the same time, due to the immaturity of multiple photolithography processes, the phase distribution needs to be quantitatively designed, and it is difficult to achieve continuous phase change control to achieve more accurate wavefront control.

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