Torsion sensor based on asymmetric double core optical fiber

Abstract

The invention provides a torsion sensor based on an asymmetric double core optical fiber. The sensor comprises a wide spectrum light source, single mode optical fibers, the asymmetric double core optical fiber and a spectrum analyzer, wherein the two ends of the asymmetric double core optical fiber are connected with one end of a first single mode optical fiber and one end of a second single modeoptical fiber through optical fiber cones to form an optical fiber Mach-Zehnder interferometer; the other end of the first single mode optical fiber is connected with the wide spectrum light source; and the other end of the second single mode optical fiber is connected with the spectrum analyzer. A sensing arm and a reference arm are integrated into one optical fiber by the asymmetric double coreoptical fiber, so that the sensor has a compact structure, can effectively reduce the influence of a temperature change, and improves the stability of a system; and complicated grating write-in equipment is not needed, so that the sensor is convenient to manufacture and has low cost.

Description

technical field [0001] The invention relates to an optical fiber torsion sensor, in particular to a torsion sensor based on an asymmetric double-core optical fiber. Background technique [0002] The use of torsion sensors to measure the torsion of structures due to external forces has very important applications in scientific research and industry. Traditional torsion sensors are bulky, and it is difficult to embed them in structures to monitor torsion changes inside structures. [0003] Due to its small size and good windability, the fiber optic sensor can be easily embedded inside the structure. Current fiber optic torsion sensors are mainly based on long-period fiber gratings and tilted fiber Bragg gratings, which have disadvantages such as poor mechanical strength, sensitivity to temperature changes, and difficulty in distinguishing the direction of twist. Another fiber-optic torsion sensor is based on dual-mode high-birefringence photonic crystal fibers, but this sens...

AI Technical Summary

Problems solved by technology

The current fiber optic torsion sensors are mainly based on long-period fiber gratings and tilted fiber Bragg gratings, which have disadvantages such as poor mechanical strength, sensitivity to temperature changes, and difficulty in distinguishing the direction of torsion.

Another fiber-optic torsion sensor is based on a dual-mode high-birefringence photonic crystal fiber, but this sensor requires a complex and expensive photonic crystal fiber

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