Design method of high-numerical-aperture super-structure lens and high-numerical-aperture super-structure lens

Abstract

The invention relates to the technical field of optical lenses, in particular to a design method of a high-numerical-aperture super-structure lens and the high-numerical-aperture super-structure lens. A high-deflection-efficiency polarization-insensitive super-structure grating unit is arranged in the super-structure lens; the method comprises the following steps: firstly, performing simulation scanning on geometric parameters of a single super-structure grating unit under each degree of freedom, and then calculating deflection efficiency of the super-structure grating unit under different parameters to obtain a geometric parameter combination with the maximum deflection efficiency under a polarization insensitive condition; and then the superposed super-structure grating units are arranged according to a phase curve rule corresponding to a target wavelength, so that the high-numerical-aperture super-structure lens is obtained, and polarization-insensitive high-focusing-efficiency and high-light-spot-quality focusing can be realized. The invention aims to solve the problems that a traditional super-structure lens cannot realize high focusing efficiency, high light spot quality and polarization-insensitive focusing under a high numerical aperture and cannot perform large-area experimental preparation.

Description

technical field [0001] The invention relates to the technical field of optical lenses, in particular to a design method of a high numerical aperture metalens and a high numerical aperture metalens. Background technique [0002] The metasurface is an artificial material with subwavelength thickness, which mainly modulates the electromagnetic wave through the resonance of the subwavelength periodic structure and the electromagnetic field. Their properties are based on the ability to control the phase and polarization of light using sub-wavelength dielectrics or metallic nanoresonators. Correspondingly, the metasurface can change the phase, polarization, intensity and other properties of the transmitted or reflected beam, and realize various extraordinary optical phenomena such as deflection, retroreflection, polarization conversion, focusing and beam shaping. Metasurfaces used to focus light beams are commonly referred to as metalenses. For beam deflection, through the overa...

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Problems solved by technology

[0009] In order to overcome at least one defect in the above-mentioned prior art, the present invention provides a design method for a high numerical aperture metalens, aiming at solving the problem that traditional metalenses cannot achieve high focusing efficiency, high spot quality, and non-polarization at high numerical apertures. Sensitive focus, and the problem that large-scale experimental preparation cannot be performed

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