A symmetrical l-shaped metal metasurface beam splitter and its preparation method

Abstract

The invention discloses a symmetric L-shaped metal metasurface beam splitter, and the beam splitter comprises a metal reflection layer; an SiO2 layer disposed on the metal reflection layer in a coated manner; a metal film formed on the SiO2 layer, wherein the metal film consists of a plurality of periodically distributed beam splitter structure units, and each beam splitter structure unit is formed by the sequential arrangement of n L-shaped structures and n inverted-L-shaped structures in mirror symmetry with the n L-shaped structures. The side length of each L-shaped metal structure is one fifth of a work wavelength, the line width is one fifteenth of the work wavelength and the thickness of the work wavelength is one twentieth of the work wavelength. The side length of the metal films of the L-shaped structures and the inverted-L-shaped structures is 250+ / -10 nm, the line width is 80+ / -10 nm, and the thickness is 60+ / -10 nm. The beam splitter provided by the invention can convert any linearly polarized light into two linearly polarized light beams with the completely equal intensity, phase and polarization at any wide band, and the thickness of the structure is very small.

Description

Technical field [0001] The invention belongs to the technical field of photoelectric information functional devices and material preparation, and particularly relates to a symmetric L-shaped metal superstructure surface beam splitter and a preparation method. Background technique [0002] The beam splitter can split a beam of light into two or more beams, and the equal energy beam splitter has important applications in coherent optics, quantum communication, and computing. In the past, people used methods such as multilayer dielectric films and metal film semi-lenses to achieve partial transmission and partial reflection of light, but it is still difficult to achieve a 50:50 beam splitter that is strictly equal in a wide band. Summary of the invention [0003] In order to solve the above problems, the present invention proposes a symmetric L-shaped metal superstructure surface beam splitter and a preparation method, which can convert polarized light into two polarized lights with ...

AI Technical Summary

Problems solved by technology

In the past, people could use multi-layer dielectric film and metal film semi-mirrors to achieve partial transmission and partial reflection of light, but it is still difficult to achieve a beam splitter with a strictly equal 50:50 in a wide frequency band.

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