Multimodal cross polarization filter based on metamaterials

Abstract

The invention provides a multimodal cross polarization filter based on metamaterials. The multimodal cross polarization filter comprises a polarizer, an metamaterial structure and an analyzer which are sequentially arranged; the metamaterial structure comprises a dielectric layer and two metamaterial layers; the two metamaterial layers are respectively positioned on the surfaces of two sides of the dielectric layer, each metamaterial layer consists of metamaterial basic units which are arrayed periodically, structures of the units of the two metamaterial layers are the same, but the units of the two metamaterial layers are perpendicular; each of the structures of the units of the metamaterial layers comprises two metal resonators with different arc lengths, and corresponding central angles include an angle of 140 degrees and an angle of 160 degrees or consists of two other asymmetric angles. The multimodal cross polarization filter can realize cross polarization conversion of a plurality of frequency bands, and a good cross polarization filtering function is realized. Besides, the multimodal cross polarization filter has good tunability and can be used in Terahertz and optical bands.

Description

technical field [0001] The present invention relates to a polarization filter. Background technique [0002] In the 1860s, Henry proposed a very effective polarization spectrum filter (C.H.Henry, Phys.Rev.143,627,1966), mainly relying on the energy exchange between two mutually orthogonal polarization modes in a birefringent crystal To achieve its polarization spectrum filtering, the refractive index of ordinary light and extraordinary light near the filter point is approximately equal, that is, the birefringence disappears, and the function of cross polarization filtering can be realized. If a birefringent crystal is placed between two mutually orthogonal linear polarizers, no light can pass through. However, near the iso-index point of the birefringent crystal, a small perturbation will seriously affect the eigenstate, and the light passing through the crystal will change its own polarization state. Thus, at the point of equal refractive index, a crystal between crossed ...

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Problems solved by technology

However, this patent modulates the cross-polarization output based on the incident light angle, which can only achieve single-peak filtering, which limits its application

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