Metal metamaterial wave plate

Abstract

The invention provides a metal metamaterial wave plate. The metal metamaterial wave plate comprises a medium substrate, a metal metamaterial layer and a medium wrapping layer, wherein the metal metamaterial layer is arranged on the medium substrate and comprises metal particles periodically arrayed; the medium wrapping layer is arranged on the metal metamaterial layer and used for providing impedance matching; the metal particles periodically arrayed are distributed in a rectangular array; each metal particle of the metal particles periodically arrayed comprises at least one pair of smooth plane side walls in parallel, and a Fabry-Perot resonant cavity is formed between adjacent metal particles in the direction perpendicular to the smooth plane side walls. The metal metamaterial wave plate has the advantages that the conversion efficiency is high, the working wave band is wide, integration is easy and preparation is easy.

Description

Technical field [0001] The present invention relates to the field of optical devices, and in particular to a metal metamaterial wave plate. Background technique [0002] Polarization is a fundamental property of electromagnetic waves. The information carried by the polarization state is of great value in signal transmission and sensing measurement. Applications involving polarization control technology have penetrated into every aspect of our daily lives and science. The wave plate is the most common polarization control device, which can realize the mutual conversion between linear polarization, circular polarization, and elliptical polarization, as well as the rotation of the polarization direction of linear polarization. Traditional wave plates are mostly prepared from optical crystals with birefringent characteristics. They use the characteristics of birefringent crystals to have different refractive indexes for light components in different polarization directions to ...

AI Technical Summary

Problems solved by technology

However, most dielectric metamaterial waveplates use silicon as the working medium. Due to the limited band gap of silicon, this type of waveplate cannot maintain high efficiency in the band above 300 terahertz.

Although some devices using wide-bandgap dielectric materials such as titanium oxide can adapt to wider bands, their structural aspect ratio is too large, making preparation extremely difficult and costly, making it difficult to popularize

Wave plates based on metal metamaterials can flexibly adjust the working band of the device through the structural design of the material, but this type of wave plate uses the surface plasmon resonance of metal materials, so the loss will be relatively high

At the same time, using a single-layer metal nanostructure wave plate with a thickness smaller than the wavelength cannot effectively control the reflection loss, so the efficiency of metal metamaterial wave plates in the optical band is generally low

The use of coupling between multilayer metal metamaterials to simultaneously generate electrical resonance and magnetic resonance to form a Huygens metasurface can improve the efficiency of metal metamaterial wave plates, but the efficiency of metal metamaterial Huygens metasurfaces is still at present. Less than 50%, and its structure is complex and difficult to prepare

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