Optical fiber sensor of plasma resonance microstructure

Abstract

The invention discloses a plasma resonance microstructure fiber sensor which comprises a light source, two ordinary single mode fibers, a microstructure fiber and a photoelectric detector, wherein, the light source, the first ordinary single mode fiber, the microstructure fiber, the second ordinary single mode fiber and the photoelectric detector are connected sequentially; the microstructure fiber is formed by photonic crystal fiber taper which has paralleled hexagon cross section and two-dimensional periodic structure; a metal membrane and a protein polymer membrane are coated on the surface of the tapered section from inside to outside sequentially; and the periodic structure consists of a background medium and dielectric rods which are distributed and arranged in the background medium periodically. As the usage of a microstructure fiber cladding light guiding mechanism, the fiber sensor can not only educe a guided mode without peeling cladding, but also realize high coupling efficiency of optical power of incident wave entering surface plasma resonance wave without a buffer layer. The invention has the advantages of simple process, compact structure, high measuring accuracy, strong anti-interference ability, being capable of being operated in harsh environment, and the like.

Description

technical field [0001] The invention relates to a microstructure optical fiber sensor, in particular to a plasma resonance microstructure optical fiber sensor capable of real-time on-line measurement of the concentration of a target substance in a water sample. Background technique [0002] The surface plasmon resonance (SPR, Surface plasmon resonance) sensor detects the refractive index change of the sample at the sensing interface by exciting the surface plasmon resonance wave (SPW, Surface plasmon wave). When the resonance condition is met, a resonance absorption peak is generated due to attenuated total reflection (ATR, Attenuated Total Reflection), passing through the resonance angle θ SPR or resonance wavelength λ SPR Calibration is used to determine the concentration of the target substance in the solution and monitor the quality of the sample. SPR sensing technology is a new type of analytical technology based on physical optical properties that has developed rapid...

AI Technical Summary

Problems solved by technology

At present, the typical SPR sensor adopts the Kretchmann prism structure, which has the obvious disadvantages of being bulky and difficult to detect in real time, especially the angle modulation requires a precise stepping motor to drive the angle adjustment device, and the angle resolution requires very precise

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