Surface plasma enhanced type mixture medium echo wall mode microcavity sensor

Abstract

The invention discloses a surface plasma enhanced type mixture medium echo wall mode microcavity sensor. The surface plasma enhanced type mixture medium echo wall mode microcavity sensor comprises a tunable laser, a polarization controller, a conical optical fiber, a mixed medium microcavity, plasma nanoparticles and a photoelectric detector; laser output by the tunable laser enters the mixed medium microcavity through the conical optical fiber and performs total reflection in the mixed medium microcavity to form echo wall mode resonance; the polarization controller is used for controlling laser polarization state input into the conical optical fiber; the photoelectric detector is used for recording and analyzing an echo wall mode transmission spectrum at the output end of a coupling system consisting of the conical optical fiber and the mixed medium microcavity; the mixed medium microcavity is formed by plating a high-refractive-index film layer on the surface of an optical microcavity; the plasma nanoparticles are attached to the surface of the mixed medium microcavity; the mixed medium microcavity is placed in measured physical quantity. The surface plasma enhanced type mixture medium echo wall mode microcavity sensor has the advantages of compact structure, high sensitivity, high response speed and the like, and has potential application value in the field of biochemical trace real-time detection.

Description

technical field [0001] The invention relates to the technical field of optical fiber sensing, in particular to a surface plasmon-enhanced mixed-medium whispering gallery mode microcavity sensor. Background technique [0002] With the development of modern biochemical industry, there are more and more detection scenarios of extremely small particles, which put forward higher requirements for the sensitivity of optical sensors. [0003] Surface Plasmon Resonance (SPR) biochemical sensor is an optical sensor based on the metal surface plasmon resonance effect, which has the advantages of no need to label the sample to be tested and high sensitivity. The SPR effect is an optical phenomenon. The evanescent wave is incident on the surface of plasmonic nanoparticles, causing a gradient electron concentration distribution on the surface, forming plasma oscillations. When the incident angle or wavelength meets certain conditions, the frequency of the evanescent wave is the same as t...

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Problems solved by technology

However, for ordinary pure dielectric microcavities, adding metal particles on the surface will increase the surface scattering

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