Refractive index sensor based on asymmetric nanostructure perfect absorber, sensing test device and method

Abstract

The invention provides a refractive index sensor based on an asymmetric nanostructure perfect absorber, a sensing test device and a sensing test method. The refractive index sensor comprises a substrate, a gold film, a spacing layer and a nanometer meniscus array, the gold film is evaporated on the substrate and is used for eliminating transmission; the spacing layer is arranged on the gold film and is used for spacing the gold film and the nano meniscus array; the nanometer meniscus array is arranged on the spacing layer, and when light irradiation and the nanometer meniscus array resonate, a local surface plasmon resonance dipole mode or a high-order mode is excited. According to the invention, by controlling and changing the polarization of incident light, different high-order local surface plasmon resonance modes are selectively excited by using the asymmetric nanometer meniscus perfect absorber, and the high-order plasmon resonance modes have relatively small radiation; and due to the perfect absorption property, the refractive index sensor utilizes inevitable loss in daily life, and transmission is reduced, so that the refractive index sensor has relatively high absorption, and the purposes of obtaining a narrow-band spectrum and improving the detection sensitivity of the sensing device are achieved.

Description

technical field [0001] The invention relates to the technical field of micro-nano sensors, in particular, to a refractive index sensor based on an asymmetric nanostructure perfect absorber, a sensing test device and a method. Background technique [0002] With the development of modern information technology, the miniaturization and high integration of devices are the inevitable requirements of this technological progress. However, the interaction between nanostructures and photons based on dielectric materials is difficult to break through the diffraction limit, so how to obtain various nanodevices that break through the diffraction limit is the focus of this research. [0003] Localized surface plasmon (Localized surface plasmon, LSP) is the interaction between free electrons in subwavelength metal structures and the incident electromagnetic field. When free electrons resonate with the light field, localized surface plasmons are generated. The polariton, which exhibits st...

AI Technical Summary

Problems solved by technology

Due to the shortcomings of traditional optical fiber sensors such as low sensing accuracy and poor stability, they cannot meet the actual needs very well. However, based on the advantages of small size, low power consumption, and good stability, plasmonic sensors have attracted people's attention.

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