Coupled type single mode optical fiber fadeout wave sensor

Abstract

The invention relates to a novel coupled high-sensitivity single-mode optical fiber evanescent wave sensor, which belongs to the technical field of optical fibers and sensors. A coupled single-mode optical fiber evanescent wave sensor of the present invention is mainly composed of a light source, an optical fiber, an optical fiber evanescent wave sensing element, a detector, a signal processing unit, and a container containing a side medium; it is characterized in that the optical The micro is a single-mode optical fiber; the optical fiber evanescent wave sensing element is a fused-cone single-mode fiber coupler probe; the fused-cone single-mode fiber coupler probe is packaged in a matrix, and there is a sensing single-mode fiber cone in the matrix There is a single-mode optical fiber lead-in end of a single-mode optical fiber coupler for sensing at both ends, which fixes the optical fiber on the substrate by fixing glue; there is still a hole near the optical fiber taper area to allow the measured gas or liquid to pass through and surround the optical fiber. The hollow access groove in the cone area; the probe or sensing element of the fused cone single-mode fiber coupler is placed in a container containing the measured medium and is surrounded by the measured medium. The sensor of the present invention has the advantages of simple structure, high sensitivity, good selectivity, strong anti-interference ability, real-time detection, no need for sampling measurement, convenient networking, etc., and its minimum detection limit reaches ppb-ppm level.

Description

Technical field: [0001] The invention relates to a novel coupled single-mode optical fiber evanescent wave sensor, which belongs to the technical field of optical fibers and sensors. Background technique: [0002] Optical fiber evanescent wave sensing technology is to change the intensity, phase or frequency of the transmitted light in the optical fiber through the interaction of the evanescent wave penetrating the optical fiber waveguide and the measured object, and measure these changes to obtain the concentration of the measured object, The method of parameters such as refractive index and pH value. When used in the fields of environment, biology, chemistry, etc., the parameters to be tested are very small, such as the content of substances, changes in refractive index, etc., such as drinking water quality measurement, DNA measurement, biological immunity measurement, etc. How to improve the sensitivity of the optical fiber evanescent wave sensor, reduce the noise, and m...

AI Technical Summary

Problems solved by technology

[0006] Researchers have adopted different methods to improve the sensitivity of optical fiber evanescent wave sensors and reduce noise, and a lot of manpower and material resources have been spent on this topic.

However, so far, it is still an unsolved problem to measure multiple parameters online with label-free (non-fluorescent) high-sensitivity evanescent wave sensors.

Images