CN-122015925-A - Four-core optical fiber multi-parameter sensor based on spiral structure and preparation method thereof

CN122015925ACN 122015925 ACN122015925 ACN 122015925ACN-122015925-A

Abstract

The invention relates to a four-core optical fiber multi-parameter sensor based on a spiral structure and a preparation method thereof, wherein the sensor is formed by cascading single-mode optical fibers, four-core optical fibers and single-mode optical fibers, the middle position of each four-core optical fiber is provided with the spiral structure, the integral cascading of the sensor is realized by using a welding machine to carry out discharge welding, different discharge parameters are set for welding different optical fibers, the spiral structure is prepared by using a polarization maintaining optical fiber welding machine, and the spiral structure with different parameters is prepared by adjusting the procedure of the welding machine.

Inventors

FU XINGHU
ZHAO JIANCHENG
ZHANG YONGXIANG
ZU LIJIAO
QIU SHI
JIN WA

Assignees

燕山大学

Dates

Publication Date: 20260512
Application Date: 20260203

Claims (9)

1.A four-core optical fiber multi-parameter sensor based on a spiral structure is characterized by comprising single-mode fibers and four-core optical fibers, wherein the single-mode fibers are respectively cascaded at two ends of the four-core optical fibers, and the middle area of the four-core optical fibers is of the spiral structure.
2. The four-core optical fiber multi-parameter sensor based on the spiral structure of claim 1 is characterized in that the cladding diameter of the single-mode optical fiber is 120-130 microns, the core diameter of the single-mode optical fiber is 8-10 microns, the cladding diameter of the four-core optical fiber is 120-130 microns, and the four cores are distributed in a lattice triangle structure.
3. The four-core optical fiber multi-parameter sensor based on the spiral structure of claim 2, wherein the distance between the middle fiber core and the outer fiber core of the four-core optical fiber is 25-35 μm, the distance between the outer fiber cores is 35-55 μm, the four fiber cores surround the middle fiber core in a regular triangle, and the diameters of the four fiber cores are 8-12 μm.
4. A four-core optical fiber multi-parameter sensor based on a spiral structure according to claim 1, wherein the spiral structure is a non-center offset spiral structure or a center offset spiral structure.
5. The four-core optical fiber multi-parameter sensor based on a spiral structure according to claim 4, wherein the length of the spiral structure part is 5 mm-10 mm, and the spiral angle is 360 DEG-7200 deg.
6. The method for manufacturing the four-core optical fiber multi-parameter sensor based on the spiral structure according to claim 5, wherein the method comprises the following steps: s1, firstly, preparing a required single-mode optical fiber and a four-core optical fiber, removing surface impurities from a coating layer of the optical fiber, and cutting the optical fiber into a required length for later use; s2, placing the single-mode fiber and the lattice four-core fiber at two ends of a fusion splicer, and cascading after fusion splicing to prepare a single-mode fiber-four-core fiber-single-mode fiber cascading structure; s3, placing the single-mode fiber-four-core fiber-single-mode fiber cascade structure in a polarization maintaining fusion splicer to manufacture a spiral structure in the middle of the four-core fiber.
7. The method for manufacturing the four-core optical fiber multi-parameter sensor based on the spiral structure, which is disclosed in claim 6, is characterized in that in the step S2, welding parameters are set to be that the discharge intensity is 100-150 mA, the discharge time is 150-250 ms, the pushing distance is 15-25 mu m, and the number of times of discharge is one.
8. The method for manufacturing the four-core optical fiber multi-parameter sensor based on the spiral structure is characterized in that in the step S3, when the spiral structure is of a spiral structure without center offset, the manufacturing process is as follows, (1) a single-mode optical fiber-four-core optical fiber cascade structure is placed in a polarization maintaining fusion machine, a discharge electrode is located in the middle of the four-core optical fiber and is 5-10 mm right, (2) a sweep motor moves leftwards, the moving speed is 0.5-1.5 mu m/ms, the moving time is 4000-800 ms, (3) the discharge current is set to be 11-14 mA, the sweep motor moves rightwards, the moving speed is 0.01-0.1 mu m/ms, the moving time is 100000-200000 ms, the left motor moves leftwards, the moving speed is 0.01-0.03 mu m/ms, the right motor moves leftwards, the moving speed is 0.05-0.025 mu m/ms, meanwhile, the rotating motor starts to rotate, the rotating speed is 0.03-0.08 DEG/ms, and the rotating time is 100000-200000 ms.
9. The method for manufacturing the four-core optical fiber multi-parameter sensor based on the spiral structure is characterized in that in the step S3, when the spiral structure is of a center-offset spiral structure, the manufacturing process is as follows, (1) a single-mode optical fiber-four-core optical fiber cascade structure is placed in a polarization maintaining fusion machine, a discharge electrode is located in the middle of the four-core optical fiber and is located at the position 5-15 mm far right, (2) a sweep motor moves leftwards, the moving speed is 0.05-0.1 mu m/ms, the moving time is 5000-10000 ms, (3) the discharge current is set to be 11-14 mA, the sweep motor moves rightwards, the moving speed is 0.01-0.1 mu m/ms, the moving time is 100000-200000 ms, the left motor moves leftwards, the moving speed is 0.05-0.025 mu m/ms, the right motor moves leftwards, the moving speed is 0.1-0.03 mu m/ms, meanwhile, the rotating motor starts to rotate, and the rotating speed is 0.03-0.08 DEG/ms, and the rotating time is 100000-2000 ms.

Description

Four-core optical fiber multi-parameter sensor based on spiral structure and preparation method thereof Technical Field The invention relates to the technical field of multi-core optical fiber sensing, in particular to a four-core optical fiber multi-parameter sensor based on a spiral structure and a preparation method thereof. Background Since the 70 s of the last century, fiber optic sensors have attracted attention from numerous researchers with their unique advantages. The optical fiber sensor has the outstanding advantages of high sensitivity, large dynamic range, high response speed, micron size, good biocompatibility, high mechanical strength and low cost. In recent years, optical fiber sensors adopting microcavity structures are widely applied to the fields of industrial production, biomedicine, aerospace and the like, and measurement of physical parameters such as temperature, pressure, strain, refractive index and the like is realized. In the deformation sensing of the artificial intelligent robot, parameters such as torsion and vector bending are very critical parameters, but most optical fiber torsion sensors can only detect the torsion and cannot recognize the torsion direction because the shape of most optical fibers is circularly symmetrical. The pretwisted optical fiber breaks the circular symmetry of the optical fiber, so that the introduction of the spiral twisted chiral structure in the invention increases the torsion sensitivity and the torsion direction identification of the sensor. The chiral spiral multi-core optical fiber shows enhanced coupling between optical fiber cores due to the spiral structure, and the axial non-uniformity of the chiral spiral multi-core optical fiber is superior to the common multi-core optical fiber in the aspects of sensing, OAM mode modulation and the like. The common multi-core optical fiber can be applied to the field of torsion sensing detection, but cannot realize the identification of torsion directions. In the torsion measurement, the pitch length of the chiral helical multicore fiber varies with the direction of torsion. Therefore, the chiral spiral multi-core optical fiber not only can increase the torsion sensitivity, but also can identify the direction of self torsion. Therefore, it is important to conduct research on a spiral multi-core optical fiber sensor. Disclosure of Invention Aiming at the problems, the invention provides a four-core optical fiber multi-parameter sensor based on a spiral structure and a preparation method thereof, which are novel in structure, low in cost, suitable for measuring various parameters, capable of realizing combination of advantages of a multi-core optical fiber and advantages of the spiral optical fiber and improving sensitivity of multi-core optical fiber sensing. The technical scheme adopted by the invention is as follows: The four-core optical fiber multi-parameter sensor based on the spiral structure comprises a single-mode optical fiber and four-core optical fibers, wherein the single-mode optical fibers are respectively cascaded at two ends of the four-core optical fibers, and the middle area of the four-core optical fibers is of the spiral structure. Further, the cladding diameter of the single-mode optical fiber is 120-130 mu m, the core diameter is 8-10 mu m, the cladding diameter of the four-core optical fiber is 120-130 mu m, and the four cores are distributed in a lattice triangle structure. Further, the distance between the middle fiber core and the outer fiber core of the four-core optical fiber is 25-35 mu m, the distance between the outer fiber cores is 35-55 mu m, the four fiber cores surround the middle fiber core in a regular triangle, and the diameters of the four fiber cores are 8-12 mu m. Further, the spiral structure is a non-center offset spiral structure or a center offset spiral structure. Further, the length of the spiral structure part is 5 mm-10 mm, and the spiral angle is 360 degrees-7200 degrees. A method for manufacturing a four-core optical fiber multi-parameter sensor based on a spiral structure, the method comprising the following steps: s1, firstly, preparing a required single-mode optical fiber and a four-core optical fiber, removing surface impurities from a coating layer of the optical fiber, and cutting the optical fiber into a required length for later use; s2, placing the single-mode fiber and the lattice four-core fiber at two ends of a fusion splicer, and cascading after fusion splicing to prepare a single-mode fiber-four-core fiber-single-mode fiber cascading structure; s3, placing the single-mode fiber-four-core fiber-single-mode fiber cascade structure in a polarization maintaining fusion splicer to manufacture a spiral structure in the middle of the four-core fiber. Further, in the step S2, welding parameters are set to be that the discharge intensity is 100-150 mA, the discharge time is 150-250 ms, the pushing distance is 15-25 mu m, and the discharge times are