A dual-channel narrow-band absorber based on oblique incidence mode of te-polarized light

Abstract

The purpose of the present invention is to provide a dual-channel narrow-band absorber based on the oblique incidence mode of TE polarized light, providing higher sensitivity and quality factor of comprehensive response sensitivity, including infrared graphene-based narrow-band absorption units, infrared graphene-based narrow-band absorption units The unit includes a top-to-bottom dielectric layer, a buffer dielectric layer, a graphene film, a high-refractive-index nanocavity metasurface, and a metal substrate. The upper end of the high-refractive index nanocavity metasurface is provided with a hole downward, and the hole is filled with The same dielectric layer as the dielectric layer, because the reflection spectrum width of the structure is 0.5 nm, and the absorption rate at the resonance position is as high as 97%, so the structure is helpful to design a high-sensitivity refractive index sensor, in which the top dielectric layer is used as the first channel, high refractive index The nanometer deep hole array on the supersurface of the nanocavity is used as the second channel, and the results show that the sensitivity of the sensor can reach 500 nm / RIU, and the quality factor of the comprehensive response sensitivity is as high as 1000 / RIU, which is superior to the existing technology.

Description

technical field [0001] The invention belongs to the technical field of surface plasmons, and in particular relates to a dual-channel narrow-band absorber based on the oblique incidence mode of TE polarized light. Background technique [0002] Surface plasmon is a special electromagnetic wave that appears on the medium and the metal surface under certain conditions when light is irradiated on the metal surface. It propagates along the interface between the metal and the medium in the horizontal direction and in the direction perpendicular to the metal surface. The above is exponentially decreasing. Different from general electromagnetic waves, surface plasmons are highly localized and can generate many new phenomena and new applications. For example: transmission-enhancing properties of light irradiated onto a metal film engraved with subwavelength periodic array holes. Surface plasmons can break through the diffraction limit, which is beneficial to the further development ...

AI Technical Summary

Problems solved by technology

[0003] For the refractive index sensor, its sensitivity largely depends on the narrow bandwidth of the absorption spectrum. Narrower bandwidth means higher sensitivity. Most of the existing plasmonic structures use the normal incidence mode of TM polarized light. The sensitivity , the quality factor of the comprehensive response sensitivity is not high

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