Fiber optic sensor based on edge-hole fiber double Mach zehnder interference vernier effect

Abstract

The invention discloses a fiber optic sensor based on an edge-hole fiber double Mach zehnder interference vernier effect. The fiber optic sensor comprises a broadband light source, a first single-modefiber, a first coreless fiber, a side-hole fiber with at least two air holes and exposed partial holes, a second coreless fiber, a second single-mode fiber, and a spectrometer; energy of a optical field is divided and enters a fiber core of the side-hole fiber, a hole connected with the external environment and a closed hole by the first coreless fiber; the three optical field energies are combined by the second coreless fiber and then output to the spectrometer by the second single-mode fiber; interference occurs between two beams of light from the fiber core of the side-hole fiber and the hole connected with the external environment, Mach zehnder interference is formed, and interference spectrum varies with the external environment; the Mach zehnder interference also occurs in the two beams of light from the fiber core and the enclosed hole, and an interference spectrum is not affected by change of the external environment; and the two Mach zehnder interferences are in parallel to form the vernier effect, and thus the sensor has 44084.1 nm / RIU ultra-high sensitivity.

Description

technical field [0001] The invention relates to an optical fiber sensor, in particular to an optical fiber sensor based on the dual Mach-Zehnder interference vernier effect of side-hole optical fiber, and belongs to the technical field of photobiochemical sensing. Background technique [0002] The detection of refractive index has been playing an important role in biomedicine, physics, chemistry, industry and other fields. Among many refractive index sensors, optical fiber sensors have the advantages of fast response, no electromagnetic interference, explosion-proof and flame-proof, easy remote telemetry, good confidentiality, light weight, high mechanical strength, etc., and have great application prospects in optical sensors . However, a common problem encountered by fiber optic sensors is that the energy of the light field in the fiber is in contact with the external environment through the evanescent field, the light-matter interaction is weak, and the sensitivity is ve...

AI Technical Summary

Problems solved by technology

The above structure undoubtedly successfully improves the sensitivity of the optical fiber sensor by using the vernier effect, but the optical path is complicated and the structure is quite complicated, which is inconvenient for actual use

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