Quasi-periodic optical metasurface imaging element

Abstract

The invention provides a quasi-periodic optical metasurface imaging element. The quasi-periodic optical metasurface imaging element comprises a substrate and a plurality of cuboid nanorods generated on the substrate, the nanorods are divided into a first size and a second size which respectively correspond to a first wavelength lambda 1 and a second wavelength lambda 2; the first size of nanorodsand the second size of nanorods are alternately arranged in a gold spiral shape at intervals; the length and the width of the nanorod are coupled with the wavelength of an incident light beam; and therotation angle of the nanorod is coupled with the wavelength, focal length, additional phase modulation value and position of the incident light beam, so that the focal length of the element to the parallel incident light with two wavelengths is the same. By adjusting the length, the width and the rotation angle of the nanorod, adaptation to incident beams with various wavelengths can be achieved, the incident beams are focused at the same point and have the quasi-periodic characteristic, and the universality of the design scheme is greatly higher than that of an existing scheme.

Description

technical field [0001] The invention belongs to the field of optical devices, in particular to a quasi-periodic optical metasurface imaging 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 propose...

AI Technical Summary

Problems solved by technology

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.

Images