Whispering-gallery-mode fiber optic biosensor

Abstract

The invention discloses a whispering-gallery-mode fiber optic biosensor which is provided with at least one optical fiber and at least one micro-resonator. The whispering-gallery-mode fiber optic biosensor can couple the light in the optical fiber to the micro-resonator and excite the whispering gallery mode, the fiber optic biosensor is also provided with a substrate which can be inserted in an object to be measured, the optical fiber is Y-shaped, one branch of the Y-shaped optical fiber is a light incidence end which can be connected with a light source, the other branch is a light emergence end which can be connected with a detector, the lower end of the Y-shaped optical fiber is fixed on the substrate and the tail end is fixedly provided with a reflector, and the micro-resonator is fixed on the substrate and coupled with the lower end of the Y-shaped optical fiber. When the fiber optic biosensor is in use, the light source and the detecting instrument are arranged at the same side of the micro-resonator, thereby being beneficial for detecting and moving and realizing detection for the analyte to be measured in real time without marking the detected object. The substrate of the fiber optic biosensor also can be inserted in the analyte to be measured, therefore the detection is convenient, safe and stable, and outdoor detection can be realized as well. Meanwhile, the technical scheme leads the light wave to be coupled twice in the micro-resonator, thereby further improving the precision and sensitivity of the whispering-gallery-mode sensor.

Description

technical field [0001] The invention relates to an optical fiber sensor, in particular to an optical fiber biosensor using a micro-resonant cavity. Background technique [0002] Such as figure 1 As shown, the fiber optic biosensor in the whispering gallery mode includes an optical fiber and a microresonator that can generate optical resonance, and the microresonator is generally a microsphere, a microdisk or a microring. [0003] Taking the microsphere resonator as an example, the microsphere resonator is a spherical optical resonator with a radius ranging from several microns to hundreds of microns. Through continuous total reflection on the inner surface of the microsphere, the microsphere cavity confines the light near the equatorial plane and orbits along the great circle, which excites a unique whispering gallery mode (WGM or WG for short). Due to the effect of total reflection, the light field outside the sphere is an evanescent field, and this light wave is a non-pr...

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Problems solved by technology

[0006] However, since the microsphere resonant cavity should be set in the middle section of the optical fiber, the two ends of the optical fiber are respectively connected with the light source and the detection instrument. On both sides, it is not conducive to detection and movement. The existing whispering gallery mode sensor cannot be made into a probe shape. Therefore, it cannot be directly inserted into the analyte to be measured, and it is difficult to realize real-time monitoring in the field, and it cannot be directly inserted into a small microcavity. (eg intravascular)

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