A folded s-shaped optical fiber sensor and a method for manufacturing the same

Abstract

The present application relates to a kind of to fold S type optical fiber sensor and its preparation method, the preparation method includes: the coating layer at the middle position of optical fiber is stripped, the first optical fiber without coating layer in middle part is obtained and is washed;The first optical fiber after washing is clamped on S type optical fiber processing mould;S type optical fiber is obtained by heating two heating rods and moving two optical fiber clamps;Third heating rod is placed in the part without coating layer in S type optical fiber, third heating rod is perpendicular to the U-shaped side of U-shaped structure, and is located at the middle position of U-shaped side, the part without coating layer is heated by heating third heating rod, and the part without coating layer is folded along the heating position, and the fold S type optical fiber sensor is obtained.The present application method realizes the processing of S type optical fiber using S type optical fiber processing mould, ensures that the prepared S type optical fiber has fixed bending angle, so as to guarantee the consistency of the bending degree of the fold S type optical fiber sensor prepared.

Description

Technical Field

[0001] This invention belongs to the field of fiber optic sensor technology, specifically relating to a folded S-shaped fiber optic sensor and its fabrication method. Background Technology

[0002] Fiber optic sensors have attracted widespread attention due to their advantages such as simple structure, electrical insulation, resistance to electromagnetic interference, and ability to withstand harsh environments. U-shaped fiber optic probes, with their compact structure, high transmission efficiency, and distributed detection capabilities, can be applied in fiber optic sensors for surface plasmon resonance, fluorescence, and Raman spectroscopy, and have broad application prospects in fields such as biomedicine, clinical diagnosis, environmental monitoring, and food safety.

[0003] Currently, common methods for fabricating U-shaped optical fibers often involve first removing the coating and cladding with a sharp blade, then manually bending them after flame heating. However, manual heating and bending means the operator needs to rely on experience or intuition to judge the heating and bending process, making the results relatively uncertain. The operator's skill and experience level can affect the shape and performance of the fabricated U-shaped fiber. Furthermore, manual heating and bending can lead to inconsistencies in bending angles; even the same operator may obtain different results in different operations. This can make it difficult to maintain consistency in large-scale production, resulting in relatively low production efficiency, especially in mass production. Secondly, sensors made from U-shaped optical fibers have a limited number of fixed probe points, preventing simultaneous multi-point detection. Summary of the Invention

[0004] To address the aforementioned problems in the prior art, this invention provides a folded S-shaped fiber optic sensor and its fabrication method. The technical problem to be solved by this invention is achieved through the following technical solution:

[0005] This invention provides a method for fabricating a folded S-shaped fiber optic sensor, comprising:

[0006] Step 1: Strip the coating layer at the middle position of the optical fiber to obtain a first optical fiber with no coating layer in the middle and coating layers at both ends.

[0007] Step 2: Clean the uncoated portion of the first optical fiber;

[0008] Step 3: Clamp the cleaned first optical fiber onto the S-shaped optical fiber processing mold, wherein the two ends of the first optical fiber are clamped onto the two optical fiber clamps of the S-shaped optical fiber processing mold, and the middle part of the first optical fiber is semi-encircled in opposite directions around the two heating rods spaced apart in the S-shaped optical fiber processing mold.

[0009] Step 4: Heat the first optical fiber by heating the two heating rods, move the two optical fiber clamps to draw the heated first optical fiber into an S-shape, and obtain an S-shaped optical fiber after cooling. The uncoated part of the S-shaped optical fiber is in the form of two U-shaped structures with opposite opening directions connected in parallel.

[0010] Step 5: Place the third heating rod in the uncoated part of the S-shaped optical fiber. The third heating rod is perpendicular to the U-shaped side of the U-shaped structure and is located in the middle of the U-shaped side.

[0011] Step 6: Heat the uncoated portion by heating the third heating rod, and fold the uncoated portion along the heating position to obtain a folded S-shaped fiber optic sensor.

[0012] In one embodiment of the present invention, step 2 includes: immersing the uncoated portion of the first optical fiber in a piranha solution for cleaning.

[0013] In one embodiment of the present invention, the S-shaped optical fiber processing mold includes a first optical fiber clamp, a second optical fiber clamp, a first heating rod, a second heating rod, a first guide rail, and a second guide rail; wherein...

[0014] The first guide rail and the second guide rail are arranged parallel to each other at intervals;

[0015] The first fiber optic clamp is mounted on the first end of the first guide rail, and the first fiber optic clamp can slide along the first guide rail;

[0016] The first heating rod is mounted on the first guide rail and is located on the side of the first optical fiber clamp near the second end of the first guide rail. The axis of the first heating rod is perpendicular to the plane of the first guide rail.

[0017] The second fiber optic clamp is mounted on the second end of the second guide rail, and the second fiber optic clamp can slide along the second guide rail;

[0018] The second heating rod is mounted on the second guide rail and is located on the side of the second optical fiber clamp near the first end of the second guide rail. The axis of the second heating rod is perpendicular to the plane of the second guide rail.

[0019] In one embodiment of the present invention, the distance between the first guide rail and the second guide rail is 1-1.5cm.

[0020] In one embodiment of the present invention, a first retaining ring is sleeved on the first heating rod near its top end, and a second retaining ring is sleeved on the second heating rod near its top end; the distance between the first retaining ring and the top end of the first heating rod and the distance between the second retaining ring and the top end of the second heating rod are equal.

[0021] In one embodiment of the present invention, the diameters of the first heating rod and the second heating rod are 7.5-8.5 mm; the ring widths of the first retaining ring and the second retaining ring are 1-1.5 mm; and the distance between the first heating rod and the second heating rod along the guide rail direction is 6-8 cm.

[0022] In one embodiment of the present invention, in step 4, the heating temperature of the two heating rods is 200-600℃, and the bending radius of the U-shaped structure does not exceed 5mm.

[0023] In one embodiment of the present invention, in step 6, the heating temperature of the third heating rod is 200-600°C, and the bending radius of the folded part of the uncoated portion does not exceed 5mm.

[0024] In one embodiment of the present invention, the bend at the fold of the S-shaped fiber optic sensor and the bend at the U-shaped structure serve as fixed points for the probe.

[0025] This invention provides a folded S-shaped fiber optic sensor, which is prepared using the method for preparing a folded S-shaped fiber optic sensor described in any of the above embodiments.

[0026] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0027] 1. The method for fabricating the folded S-shaped fiber optic sensor of the present invention utilizes an S-shaped fiber optic processing mold to fabricate the S-shaped fiber, ensuring that the fabricated S-shaped fiber has a fixed bending angle, thereby guaranteeing the consistency of the bending degree of the fabricated folded S-shaped fiber optic sensor.

[0028] 2. The method for fabricating the folded S-shaped fiber optic sensor of the present invention uses a heating rod to heat the uncoated portion, ensuring uniform heating of the fiber, improving the controllability and consistency of the fabrication process, and avoiding the problem of shape asymmetry or local thermal damage caused by uneven heating of the fiber, which would affect the sensor performance.

[0029] 3. The folded S-shaped fiber optic sensor of the present invention uses the bend at the fold and the bend at the U-shaped structure as fixed points for the probe, providing multiple locations for sensor monitoring. This allows the sensor to perform measurements at multiple points, increasing the coverage and sensitivity of the sensor monitoring.

[0030] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described in detail below with reference to the accompanying drawings. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of a method for fabricating a folded S-shaped fiber optic sensor according to an embodiment of the present invention;

[0032] Figure 2 This is a schematic diagram of the structure of an uncoated multimode optical fiber provided in an embodiment of the present invention;

[0033] Figure 3 This is a schematic diagram of the structure of an S-shaped optical fiber processing mold provided in an embodiment of the present invention;

[0034] Figure 4 This is a schematic diagram of an S-shaped optical fiber provided in an embodiment of the present invention;

[0035] Figure 5 This is a schematic diagram of the bending angle of a U-shaped structure provided in an embodiment of the present invention;

[0036] Figure 6 This is a schematic diagram of the structure of a folded S-shaped fiber optic sensor provided in an embodiment of the present invention.

[0037] icon:

[0038] 1-First fiber optic clamp; 2-Second fiber optic clamp; 3-First heating rod; 4-Second heating rod; 5-First guide rail; 6-Second guide rail; 7-First retaining ring; 8-Second retaining ring. Detailed Implementation

[0039] To further illustrate the technical means and effects adopted by the present invention to achieve the intended purpose, the following detailed description, in conjunction with the accompanying drawings and specific embodiments, provides a detailed explanation of a folded S-shaped fiber optic sensor and its preparation method based on the present invention.

[0040] The foregoing and other technical contents, features, and effects of the present invention will be clearly presented in the following detailed description of specific embodiments in conjunction with the accompanying drawings. Through the description of the specific embodiments, a more in-depth and concrete understanding can be gained of the technical means and effects adopted by the present invention to achieve its intended purpose. However, the accompanying drawings are for reference and illustration only and are not intended to limit the technical solutions of the present invention.

[0041] In a first aspect, embodiments of the present invention provide a method for fabricating a folded S-shaped optical fiber sensor, please refer to [link to relevant documentation]. Figure 1 , Figure 1This is a schematic diagram of a method for fabricating a folded S-shaped fiber optic sensor according to an embodiment of the present invention, as shown below. Figure 1 As shown, the fabrication method of the folded S-shaped fiber optic sensor in this embodiment includes:

[0042] Step 1: Strip the coating layer at the middle position of the optical fiber to obtain the first optical fiber with no coating layer in the middle and coating layers at both ends.

[0043] Alternatively, wire strippers can be used to strip the coating from the optical fiber. This optical fiber is intended to be fabricated into an S-shaped structure and can be multimode fiber, single-mode hollow-core fiber, photonic crystal fiber, or other similar fibers.

[0044] For example, the structure of an uncoated multimode fiber is as follows: Figure 2 As shown, it includes a fiber core and a cladding covering the outside of the fiber core.

[0045] In this embodiment, the parameters of the multimode fiber used are as follows: core diameter: 50 μm, cladding diameter: 125 μm, numerical aperture (NA): 0.2, and transmission mode: supporting the primary mode and several secondary modes.

[0046] Step 2: Clean the uncoated portion of the first optical fiber.

[0047] Optionally, the uncoated portion of the first optical fiber is immersed in a piranha solution for cleaning to remove surface impurities. The piranha solution is a mixture of concentrated sulfuric acid and hydrogen peroxide solution in a 7:3 ratio.

[0048] Step 3: Clamp the cleaned first optical fiber onto the S-shaped optical fiber processing mold. The two ends of the first optical fiber are clamped onto the two optical fiber clamps of the S-shaped optical fiber processing mold, and the middle part of the first optical fiber is semi-encircled in opposite directions around the two heating rods spaced apart in the S-shaped optical fiber processing mold.

[0049] Please see Figure 3 , Figure 3 This is a schematic diagram of the structure of an S-shaped optical fiber processing mold provided in an embodiment of the present invention, as shown below. Figure 3 As shown, the S-shaped optical fiber processing mold in this embodiment includes a first optical fiber clamp 1, a second optical fiber clamp 2, a first heating rod 3, a second heating rod 4, a first guide rail 5, and a second guide rail 6.

[0050] The first guide rail 5 and the second guide rail 6 are arranged parallel to each other at intervals. Optionally, the distance between the first guide rail 5 and the second guide rail 6 is 1-1.5cm. It is understood that, due to the different thicknesses of different types of optical fibers, the distance between the first guide rail 5 and the second guide rail 6 can be adjusted according to the different types of optical fibers. The first optical fiber clamp 1 is installed at the first end of the first guide rail 5 and can slide along the first guide rail 5. The first heating rod 3 is installed on the first guide rail 5, located on the side of the first optical fiber clamp 1 near the second end of the first guide rail 5, and the axis of the first heating rod 3 is perpendicular to the plane of the first guide rail 5. The second optical fiber clamp 2 is installed at the second end of the second guide rail 6 and can slide along the second guide rail 6. The second heating rod 4 is installed on the second guide rail 6, located on the side of the second optical fiber clamp 2 near the first end of the second guide rail 6, and the axis of the second heating rod 4 is perpendicular to the plane of the second guide rail 6.

[0051] In this embodiment, a first retaining ring 7 is fitted on the first heating rod 3 near its top end, and a second retaining ring 8 is fitted on the second heating rod 4 near its top end; the distance between the first retaining ring 7 and the top end of the first heating rod 3 and the distance between the second retaining ring 8 and the top end of the second heating rod 4 are equal.

[0052] In this embodiment, the retaining ring serves as a limiting device to limit the first optical fiber when the middle half of the first optical fiber is partially wrapped around the heating rod, thereby preventing the first optical fiber from moving up and down.

[0053] Furthermore, combined Figure 3 The installation process of the first optical fiber in the S-shaped optical fiber processing mold is described below. First, the first end of the cleaned first optical fiber is clamped in the first optical fiber clamp 1. The remaining part of the first optical fiber is extended along the first guide rail 5 towards the first heating rod 3. After reaching the position of the first heating rod 3, it is wound around the first heating rod 3 counterclockwise for half a turn, and the wrapped part of the first optical fiber is placed on the first retaining ring 7. Then, the remaining part of the first optical fiber is extended towards the side of the second heating rod 4 away from the second optical fiber clamp 2. After reaching the position of the first heating rod 3, it is wound around the second heating rod 4 clockwise for half a turn, and the wrapped part of the first optical fiber is placed on the second retaining ring 8. Finally, the remaining part of the first optical fiber is extended along the second guide rail 6 towards the second optical fiber clamp 2, and the second end of the first optical fiber is clamped in the second optical fiber clamp 2.

[0054] Optionally, the diameter of the first heating rod and the second heating rod is 7.5-8.5 mm; the ring width of the first retaining ring and the second retaining ring is 1-1.5 mm; and the distance between the first heating rod and the second heating rod along the guide rail direction is 6-8 cm.

[0055] Step 4: Heat the first optical fiber by heating two heating rods, move two optical fiber clamps to draw the heated first optical fiber into an S-shape, and obtain an S-shaped optical fiber after cooling. The uncoated part of the S-shaped optical fiber is in the form of two U-shaped structures with opposite opening directions connected in parallel.

[0056] In this embodiment, the heating temperature of the two heating rods is 200-600℃. After the two heating rods heat the first optical fiber surrounding them, the first optical fiber clamp 1 and the second optical fiber clamp 2 are moved along their corresponding guide rails in a direction away from the heating rods, drawing the first optical fiber into an S-shape. The structure of the S-shaped optical fiber obtained after cooling is as follows. Figure 4 The schematic diagram of the S-shaped optical fiber shown is provided. In this embodiment, the bending radius of the U-shaped structure does not exceed 5mm.

[0057] In this embodiment, the S-shaped optical fiber structure fabricated using an S-shaped optical fiber processing mold ensures that the bending angle of each U-shaped structure in the formed S-shaped optical fiber structure is 90°. Figure 5 A schematic diagram showing the bending angle of the U-shaped structure.

[0058] Step 5: Place the third heating rod in the uncoated part of the S-shaped optical fiber. The third heating rod is perpendicular to the U-shaped side of the U-shaped structure and is located in the middle of the U-shaped side.

[0059] Step 6: Heat the uncoated portion by heating the third heating rod, and fold the uncoated portion along the heating position to obtain a folded S-shaped fiber optic sensor.

[0060] In this embodiment, the heating temperature of the third heating rod is 200-600℃, and the bending radius of the folded portion of the uncoated part does not exceed 5mm. Please refer to [reference needed]. Figure 4 and Figure 6 , Figure 4 The dotted line indicates the placement of the third heating rod. After heating with the third heating rod, the fiber optic sensor is folded along the dotted line to obtain a folded S-shaped fiber optic sensor. The structure of the folded S-shaped fiber optic sensor is as follows: Figure 6 As shown in the figure. In this embodiment, the bends at the fold of the S-shaped fiber optic sensor and the bends of the U-shaped structure are used as the fixed points of the probe, namely the five points marked a, b, c, d, and e in the figure.

[0061] The method for fabricating a folded S-shaped fiber optic sensor according to this invention utilizes an S-shaped fiber processing mold to fabricate the S-shaped fiber, ensuring that the fabricated S-shaped fiber has a fixed bending angle, thereby guaranteeing the consistency of the bending degree of the resulting folded S-shaped fiber optic sensor. Heating the uncoated portion using a heating rod ensures uniform heating of the fiber, improving the controllability and consistency of the fabrication process and avoiding problems such as shape asymmetry or localized thermal damage caused by uneven heating of the fiber, which could affect sensor performance. This method for fabricating a folded S-shaped fiber optic sensor also provides a method for developing multi-point monitoring sensors.

[0062] Secondly, embodiments of the present invention provide a folded S-shaped fiber optic sensor, which is prepared using the method for preparing a folded S-shaped fiber optic sensor provided in the first aspect. For details regarding the specific content of the folded S-shaped fiber optic sensor and its corresponding beneficial effects, please refer to the relevant content of the method for preparing a folded S-shaped fiber optic sensor provided in the first aspect, which will not be repeated here.

[0063] In this embodiment of the invention, the folded S-shaped fiber optic sensor has a bend at the fold and a bend at the U-shaped structure as fixed probe points, providing multiple locations for sensor monitoring. This allows the sensor to perform measurements at multiple points, increasing the coverage and sensitivity of the sensor monitoring.

[0064] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations are intended to cover non-exclusive inclusion, such that an article or device comprising a list of elements includes not only those elements but also other elements not expressly listed. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the article or device comprising said element. Terms such as "connected" or "linked" are not limited to physical or mechanical connections but can include electrical connections, whether direct or indirect. The orientations or positional relationships indicated by terms such as "upper," "lower," "left," and "right" are based on the orientations or positional relationships shown in the accompanying drawings and are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as limiting the invention.

[0065] The above description, in conjunction with specific preferred embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of the present invention, and all such modifications and substitutions should be considered within the scope of protection of the present invention.

Claims

1. A method for fabricating a folded S-shaped fiber optic sensor, characterized in that, include: Step 1: Strip the coating layer at the middle position of the optical fiber to obtain a first optical fiber with no coating layer in the middle and coating layers at both ends. Step 2: Clean the uncoated portion of the first optical fiber; Step 3: Clamp the cleaned first optical fiber onto the S-shaped optical fiber processing mold, wherein the two ends of the first optical fiber are clamped onto the two optical fiber clamps of the S-shaped optical fiber processing mold, and the middle part of the first optical fiber is semi-encircled in opposite directions around the two heating rods spaced apart in the S-shaped optical fiber processing mold. Step 4: Heat the first optical fiber by heating the two heating rods, move the two optical fiber clamps to draw the heated first optical fiber into an S-shape, and obtain an S-shaped optical fiber after cooling. The uncoated part of the S-shaped optical fiber is in the form of two U-shaped structures with opposite opening directions connected in parallel. Step 5: Place the third heating rod in the uncoated part of the S-shaped optical fiber. The third heating rod is perpendicular to the U-shaped side of the U-shaped structure and is located in the middle of the U-shaped side. Step 6: Heat the uncoated portion by heating the third heating rod, and fold the uncoated portion along the heating position to obtain a folded S-shaped fiber optic sensor.

2. The method for fabricating a folded S-shaped fiber optic sensor according to claim 1, characterized in that, Step 2 includes immersing the uncoated portion of the first optical fiber in a piranha solution for cleaning.

3. The method for fabricating a folded S-shaped fiber optic sensor according to claim 1, characterized in that, The S-shaped optical fiber processing mold includes a first optical fiber clamp, a second optical fiber clamp, a first heating rod, a second heating rod, a first guide rail, and a second guide rail; wherein... The first guide rail and the second guide rail are arranged parallel to each other at intervals; The first fiber optic clamp is mounted on the first end of the first guide rail, and the first fiber optic clamp can slide along the first guide rail; The first heating rod is mounted on the first guide rail and is located on the side of the first optical fiber clamp near the second end of the first guide rail. The axis of the first heating rod is perpendicular to the plane of the first guide rail. The second fiber optic clamp is mounted on the second end of the second guide rail, and the second fiber optic clamp can slide along the second guide rail; The second heating rod is mounted on the second guide rail and is located on the side of the second optical fiber clamp near the first end of the second guide rail. The axis of the second heating rod is perpendicular to the plane of the second guide rail.

4. The method for fabricating a folded S-shaped fiber optic sensor according to claim 3, characterized in that, The distance between the first guide rail and the second guide rail is 1-1.5cm.

5. The method for fabricating a folded S-shaped fiber optic sensor according to claim 3, characterized in that, A first retaining ring is fitted on the first heating rod near its top end, and a second retaining ring is fitted on the second heating rod near its top end; the distance between the first retaining ring and the top end of the first heating rod and the distance between the second retaining ring and the top end of the second heating rod are equal.

6. The method for fabricating a folded S-shaped fiber optic sensor according to claim 5, characterized in that, The diameters of the first heating rod and the second heating rod are 7.5-8.5 mm; the ring widths of the first retaining ring and the second retaining ring are 1-1.5 mm; and the distance between the first heating rod and the second heating rod along the guide rail direction is 6-8 cm.

7. The method for fabricating a folded S-shaped fiber optic sensor according to claim 1, characterized in that, In step 4, the heating temperature of the two heating rods is 200-600℃, and the bending radius of the U-shaped structure does not exceed 5mm.

8. The method for fabricating a folded S-shaped fiber optic sensor according to claim 1, characterized in that, In step 6, the heating temperature of the third heating rod is 200-600℃, and the bending radius of the folded part of the uncoated portion does not exceed 5mm.

9. The method for fabricating a folded S-shaped fiber optic sensor according to claim 1, characterized in that, The folded section of the S-shaped fiber optic sensor and the bend of the U-shaped structure serve as fixed points for the probe.

10. A folded S-shaped fiber optic sensor, characterized in that, It is prepared using the fabrication method of the folded S-shaped fiber optic sensor according to any one of claims 1-9.

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