Achromatic optical metasurface focusing element

Abstract

The invention provides an achromatic optical metasurface focusing element. The achromatic optical metasurface focusing element comprises a substrate and a plurality of cuboid nanorods generated on thesubstrate, wherein the nanorods are divided into a first size, a second size and a third size and correspond to a first wavelength lambda 1, a second wavelength lambda 2 and a third wavelength lambda3; the nanorods of the first size, the second size and the third size are alternately arranged in a regular hexagon array at intervals; the length and the width of the nanorods are coupled with the wavelength of an incident light beam, and rotation angles of the nanorods are coupled with the wavelength, the focal length, an additional phase modulation value and a position of the incident light beam, so that the focal lengths of the element to parallel incident light with three wavelengths are the same. According to the achromatic optical metasurface focusing element, the achromatic adaptationof incident beams with various wavelengths can be realized by adjusting the length, width and rotation angle of the nanorod, and the universality of the design scheme is greatly higher than that of the existing scheme.

Description

technical field [0001] The invention belongs to the field of optical devices, in particular to an achromatic optical metasurface focusing element. Background technique [0002] Metasurface is a new type of two-dimensional optical material developed in recent years. Its basic unit is composed of sub-wavelength structure, which has ultra-light and ultra-thin properties. A kind of electromagnetic regulation, the metasurface device based on this can easily realize special functions that are difficult or even impossible to achieve with traditional optical devices. Its advantages in resolution and miniaturization are welcomed by market users. However, most metasurface components have strict requirements on the wavelength used. Usually, a design scheme can only be used at a specific wavelength, which greatly reduces its practicability. Contents of the invention [0003] In order to overcome the defects and deficiencies of the existing technology, the present invention proposes ...

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Problems solved by technology

However, most metasurface components have strict requirements on the wavelength used. Usually, a

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