High-sensitivity SPR refractive index sensor based on plastic optical fiber periodic narrow-groove structure

Abstract

The invention discloses a high-sensitivity SPR refractive index sensor based on a plastic optical fiber periodic narrow-groove structure, and a preparation method and a detection method thereof, and relates to the field of solution refractive index detection. The high-sensitivity SPR refractive index sensor comprises a plastic optical fiber, a row of periodic narrow-groove structures is formed ona section with a certain length on the plastic optical fiber along an axial direction, the periodic narrow-groove structures are equidistant radial semicircular groove-shaped structures, the groove width of a radial semicircular groove-shaped structure is 5-20 microns, the groove depth is 20-100 microns, the distance between the adjacent radial semicircular groove-shaped structures is 400-900 microns, and a layer of gold film is coated on whole surface of the plastic optical fiber. The preparation method comprises the steps of processing the radial semicircular groove-shaped structure on a part with a certain length of the plastic optical fiber at equal intervals by using an ultraviolet laser to form the periodic narrow groove structures, and then sputtering the gold film on the whole surface of the plastic optical fiber by using a magnetron sputtering instrument to complete the processing. The periodic narrow groove structure provided by the invention improves the measurement precision of the refractive index sensor and simplifies the complexity of a test system.

Description

technical field [0001] The invention relates to the field of solution refractive index detection, in particular to a high-sensitivity SPR refractive index sensor based on a plastic optical fiber periodic narrow groove structure. Background technique [0002] When a beam of P-polarized light is incident on the end face of the prism within a certain angle range, surface plasmon waves will be generated at the interface between the prism and the metal film (Au or Ag). When the propagation constant of the incident light wave matches that of the surface plasmon wave, the free electrons in the metal film are caused to resonate, resulting in the surface plasmon resonance—SPR effect. SPR is an optical expertise used to characterize changes in the refractive index of surfaces, and is widely used in biosensing, refractive index detection, etc. Compared with the traditional prism structure, the optical fiber SPR refractive index sensor, on the one hand, makes the structure miniaturized...

AI Technical Summary

Problems solved by technology

[0004] The present invention provides a high-sensitivity SPR refractive index sensor based on a plastic optical fiber periodic narrow groove structure in order to solve the problem that the existing optical fiber SPR refractive index sensor cannot realize precise refractive index detection, and the process is cumbersome and complicated and the production cost is high.

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