Optical fiber dislocation temperature sensor and preparation method thereof

Abstract

The invention discloses an optical fiber dislocation temperature sensor and a preparation method thereof. The optical fiber dislocation temperature sensor comprises a dislocation optical fiber integrated with a photoresist film layer. The staggered optical fiber integrated with the photoresist film layer comprises a staggered optical fiber and a photoresist film layer covering a staggered area of the staggered optical fiber; the dislocation optical fiber is composed of a first multi-mode optical fiber, a second multi-mode optical fiber and a third multi-mode optical fiber which is welded between the first multi-mode optical fiber and the second multi-mode optical fiber in a dislocation mode. The staggered optical fiber is prepared through the optical fiber melting technology, the staggered area of the staggered optical fiber is coated with the SU-8 photoresist with the high thermo-optical coefficient and the high thermal expansion coefficient to form the photoresist film layer, high-sensitivity temperature sensing detection is achieved, the size is small, the preparation process is simple, and the sensor is suitable for biomedical treatment, medical treatment and the like. Wide application prospects are realized in the fields of aerospace, industry and agriculture and the like.

Description

Technical Field

[0001] The present invention belongs to the technical field of optical fiber sensors, and in particular relates to an optical fiber misalignment temperature sensor and a preparation method thereof. Background Art

[0002] Temperature plays a crucial role in fields such as biomedicine, aerospace, and agriculture and industry. For example, during cell culture, the temperature must be precisely maintained near a relatively stable value to ensure normal cell growth and metabolic activity. Generally, the temperature deviation must be controlled within ±0.5°C. Therefore, accurate temperature measurement and control are particularly important. Currently, researchers have developed various types of temperature sensors, including thermocouples, semiconductors, infrared, and fiber optics. Fiber optic temperature sensors offer many advantages, including immunity to electromagnetic interference, distributed remote measurement capabilities, and durability in harsh environments, making them widely used in various fields.

[0003] Currently, all-fiber Mach-Zehnder sensors have a strong evanescent field and are sensitive to temperature parameters, making them popular among researchers. This type of temperature sensor is achieved by preparing the optical fiber into a cone-sphere, micropore, D-type, or dislocation. Different cladding modes are excited and interfere with the core mode, obtaining a Mach-Zehnder interference spectrum. However, the cladding film and core mode transmission medium are usually silicon or air. Since the thermo-optical effect and thermal expansion effect of these two media are not very obvious, when the temperature changes, the effective refractive index difference and effective interference length of the sensor do not change much, so its temperature sensing sensitivity is not high enough. Recently, some polymer materials with high thermo-optic coefficients and high thermal expansion coefficients have been integrated with MZI to achieve highly sensitive temperature sensing detection. For example, in 2019, Chu et al. (doi:10.1109 / LPT.2019.2901720) combined a suspended hollow-core fiber with a single-mode fiber, and used a CO2 laser to etch two microholes on the sidewall of the suspended hollow-core fiber to construct a microfluidic channel. The rGO / ethanol suspension was then injected into the suspended hollow-core fiber to make an MZI temperature sensor, which significantly improved the sensitivity. However, the preparation process is too complicated and the manufacturing cost is high. In 2024, Tian et al. (doi:10.1016 / j.sna.2024.115526) proposed an MZI structure for capturing optical signals. The structure was prepared by forming three cavities through six consecutive offset fusions and adsorbing PMMA microspheres into the cavities. Although highly sensitive temperature detection was achieved, the sensor required multiple delicate operation steps to cascade multiple dislocation structures, was large in size (4.75 mm), had a narrow temperature measurement range, and a complex preparation process. Summary of the Invention

[0004] Based on the above technical problems, the present invention provides an optical fiber dislocation temperature sensor and a preparation method thereof. The dislocation optical fiber is prepared by optical fiber fusion technology, and SU-8 photoresist with a high thermo-optical coefficient and a high thermal expansion coefficient is coated on the dislocation area of ​​the dislocation optical fiber to form a photoresist film layer, thereby achieving highly sensitive temperature sensing detection. The sensor has a small size and a simple preparation process, and has broad application prospects in biomedicine, aerospace, industry and agriculture and other fields.

[0005] The present invention proposes an optical fiber misalignment temperature sensor, comprising a misaligned optical fiber integrated with a photoresist film layer;

[0006] The dislocated optical fiber with integrated photoresist film layer comprises a dislocated optical fiber and a photoresist film layer covering the dislocated area of ​​the dislocated optical fiber;

[0007] The staggered optical fiber is composed of a first multimode optical fiber, a second multimode optical fiber, and a third multimode optical fiber staggered and fused between the first multimode optical fiber and the second multimode optical fiber.

[0008] Preferably, the misalignment directions between the first multimode optical fiber and the third multimode optical fiber, and the misalignment distances between the second multimode optical fiber and the third multimode optical fiber are the same.

[0009] Preferably, the offset distance is 1 / 3 of the diameter of the first multimode optical fiber, the second multimode optical fiber or the third multimode optical fiber.

[0010] Preferably, the cladding diameter of the first multimode optical fiber, the second multimode optical fiber or the third multimode optical fiber is 100-150 μm, and the core diameter is 60-70 μm.

[0011] Preferably, the length of the third multimode optical fiber, ie, the offset length, is 600-800 μm, preferably 700 μm.

[0012] Preferably, the photoresist film layer is formed by curing SU-8 photoresist.

[0013] Preferably, the sensor further comprises a broadband light source and a spectrum analyzer; the broadband light source and the spectrum analyzer are respectively connected to two ends of the offset optical fiber of the integrated photoresist film layer.

[0014] In the present invention, when the misalignment distance between the first multimode optical fiber and the third multimode optical fiber and between the second multimode optical fiber and the third multimode optical fiber is 1 / 3 of the diameter of the multimode optical fiber, the length of the third multimode optical fiber, i.e., the misalignment region, is 700 μm, and the photoresist film layer is formed by curing SU-8 photoresist, the temperature sensitivity of the interference peak near 1300 nm in the interference spectrum of the misaligned optical fiber corresponding to the integrated photoresist film layer reaches 0.70012 nm / °C.

[0015] The present invention also provides a method for preparing the above-mentioned optical fiber misalignment temperature sensor, comprising the following steps:

[0016] S1. Align two sections of multimode optical fiber on the central axis, stagger them vertically for a certain distance, and then fuse them for the first time to form a first staggered welding point, thereby obtaining a preliminary staggered optical fiber product;

[0017] S2, cutting the misaligned optical fiber into two sections away from the first misaligned fusion splice point, aligning them again on the central axis, and then fusing them a second time after being misaligned up and down by the same distance to form a second misaligned fusion splice point, thereby obtaining a misaligned optical fiber;

[0018] S3. Coating SU-8 photoresist on the dislocated area between the first dislocated fusion point and the second dislocated fusion point on the dislocated optical fiber, and forming a photoresist film layer after light curing to obtain the dislocated optical fiber with integrated photoresist film layer.

[0019] Preferably, in step S1, the discharge intensity of the first welding and the second welding is 30-50 bits, and the discharge time is 2500-3000 ms.

[0020] Preferably, in step S2, the light curing time is 10-30s.

[0021] The specific working principle of the sensor of the present invention is as follows:

[0022] According to the Mach-Zehnder principle, the incident light signal is transmitted in the core of a multimode optical fiber and is split into two beams at the offset structure. One beam continues to propagate along the offset fiber with an intensity of I1, while the other beam propagates along the photoresist with an intensity of I2. These two beams are coupled into the multimode optical fiber at the other end of the offset structure. Since the refractive index of the multimode optical fiber is 1.47 and the refractive index of the SU-8 photoresist is 1.5, the optical path lengths of the two beams are different during transmission. After superposition within the multimode optical fiber, a Mach-Zehnder interference spectrum is obtained. The intensity distribution of the interference spectrum is I out As shown in the following formula (1):

[0023]

[0024] In formula (1), φ is the phase difference between the two beams I1 and I2. The phase difference of this structure is shown in the following formula (2):

[0025]

[0026] In formula (2), Δn eff is the effective refractive index difference between the multimode fiber and the SU-8 photoresist, L is the interference length of the staggered structure, and λ is the wavelength of the incident light. When the phase difference satisfies an odd multiple of π, the center wavelength position of the interference peak and valley can be obtained as shown in the following formula (3):

[0027]

[0028] λ k is the center wavelength of the k-th order interference peak and valley; according to formula (3), when the offset optical fiber with integrated photoresist film layer is used to detect the ambient temperature, due to the high thermal expansion and thermo-optical coefficients of the optical fiber and photoresist, the effective refractive index difference and effective interference length L of the structure will change with temperature, and thus the center wavelength of the trough of the interference peak will change with temperature. By monitoring the movement of the interference peak and valley in the interference spectrum of the offset optical fiber with integrated photoresist film layer, the temperature response characteristics of the structure can be obtained. Then the change of the value of the center wavelength of the interference peak and valley with temperature is specifically shown in the following formula (4):

[0029]

[0030] In addition, according to formula (4), it can be seen that the length of the dislocation structure is different, and the interference peak in the interference spectrum changes differently with temperature.

[0031] The present invention provides an optical fiber misalignment temperature sensor, which is essentially a highly sensitive misaligned optical fiber Mach-Zehnder temperature sensor with a compact size and a simple preparation process. The sensor first uses optical fiber fusion technology to prepare a misaligned pure optical fiber Mach-Zehnder interferometer. The misalignment area of ​​the sensing unit can be one-third of the optical fiber diameter, and the length of the misaligned optical fiber can be 700 μm. Then, SU-8 photoresist is coated on the misalignment and completely fills the cavity in the misaligned area. The SU-8 photoresist is cured in the microcavity using ultraviolet exposure technology. Incident light is split into two beams at the misalignment of the sensor. One beam is transmitted forward along the SU-8 photoresist, and the other beam is transmitted forward along the misaligned optical fiber. At the other end of the misalignment structure, it is coupled into a multimode optical fiber. The two beams of transmitted light interfere and superimpose to obtain a transmission interference spectrum of the Mach-Zehnder interferometer. The refractive index of SU-8 photoresist is 1.58, while the refractive index of silicon is 1.47. Because SU-8 photoresist has both a high thermo-optic coefficient and a high thermal expansion coefficient, with the thermo-optic coefficient of SU-8 photoresist being negative and the thermo-optic coefficient of silicon being positive, the effective refractive index difference varies significantly with temperature. Furthermore, the high thermal expansion coefficient of SU-8 photoresist increases the effective interference length of the structure as the temperature rises. This significantly improves the sensitivity of the sensor's staggered structure while also eliminating the need for an excessively long sensing area. In practical applications, the proposed sensor achieves a temperature sensitivity of 0.70012 nm / °C within a temperature range of 30°C to 60°C. Therefore, the proposed sensor is compact, highly sensitive, and simple to manufacture, promising broad applications in biomedicine, aerospace, industry, and agriculture. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1Schematic diagram of the preparation process of the staggered optical fiber with integrated photoresist film layer according to the present invention;

[0033] Figure 2 These are optical images and transmission interference spectra of different misalignment lengths (third multimode fiber lengths) in the misaligned optical fiber of the present invention: (a) is a misaligned optical fiber with a misalignment length of 600 μm, (b) is a misaligned optical fiber with a misalignment length of 700 μm, (c) is a misaligned optical fiber with a misalignment length of 800 μm, (d) is a transmission interference spectrum with a misalignment length of 600 μm, and (e) is a transmission interference spectrum with a misalignment length of 700 μm.

[0034] (f) is the transmission interference spectrum with a dislocation length of 800 μm;

[0035] Figure 3 The optical image and transmission interference spectrum of the dislocated optical fiber with integrated photoresist film layer of the present invention: (a) is the optical image, (b) is the transmission interference spectrum;

[0036] Figure 4 This is a diagram of the temperature monitoring system of the optical fiber misalignment temperature sensor of the present invention;

[0037] Figure 5 This is the transmission interference diagram of the optical fiber misalignment temperature sensor of the present invention when used for temperature detection:

[0038] (a) is the transmission interference pattern at different temperatures, and (b) is the linear fitting curve of the interference peak near 1300nm. DETAILED DESCRIPTION

[0039] Hereinafter, the present invention will describe the technical solution in detail through specific embodiments. However, it should be clearly stated that these embodiments are provided for illustration only and are not to be construed as limiting the scope of the present invention.

[0040] Example

[0041] This embodiment provides an optical fiber misalignment temperature sensor, comprising a misaligned optical fiber integrated with a photoresist film layer;

[0042] The dislocated optical fiber with integrated photoresist film layer comprises a dislocated optical fiber and a photoresist film layer covering the dislocated area of ​​the dislocated optical fiber;

[0043] The staggered optical fiber is composed of a first multimode optical fiber, a second multimode optical fiber, and a third multimode optical fiber staggered and fused between the first multimode optical fiber and the second multimode optical fiber.

[0044] The above-mentioned optical fiber misalignment temperature sensor is prepared by the following method:

[0045] (1)Reference Figure 1a. Take two sections of multimode optical fiber (core diameter of 62.5μm, cladding diameter of 125μm) about 30cm long from the optical fiber reel; use Miller pliers to remove the coating layer at one end of the multimode optical fiber, use lens cleaning paper dipped in 75% alcohol to wipe off the coating residue, and use an optical fiber cleaver to cut the end face of the removed coating layer flat; fix the two cut multimode optical fibers in the pressure plates at both ends of the optical fiber fusion splicer (KL-300T0), pay attention to the ends of the optical fibers close to the discharge electrodes, but not more than the position where the two discharge electrode pointers are facing each other, and cover the windproof cover; select the left optical fiber through the manual fusion splicing program of the fusion splicer, and adjust its position so that it is misaligned with the right optical fiber. The misalignment distance of the two multimode optical fibers is about one-third of the optical fiber diameter. Then set the discharge intensity of the fusion splicer to 40bit and the discharge time to 2750ms, and weld the two misaligned optical fibers together. After the fusion is completed, manually supplement the discharge 2-3 times to make the misaligned optical fiber welding more secure;

[0046] (2)Reference Figure 1 b. Open the windproof cover, take out the optical fiber, and fix the dislocated optical fiber obtained in step (1) under the precision cutting system (XDC-10A-530HS). Place the two-dimensional mobile platform and the cutting knife side by side under the precision cutting system, and the dislocated optical fiber is fixed in the clamp of the cutting knife and the two-dimensional mobile platform; turn the reflector to adjust the field of view to the brightest without shadow, turn the coarse and fine screw knobs so that the optical fiber dislocation structure can be clearly seen, adjust the two-dimensional mobile platform to adjust the dislocation structure to the center of the field of view and near the blade of the optical fiber cutting knife, accurately control the position of the cutting point through the two-dimensional mobile platform, and reserve the blade distance, and cut the optical fiber cantilever structure on one side of the dislocated optical fiber fusion point;

[0047] (3)Reference Figure 1 c. Place the optical fiber staggered cantilever structure obtained in step (2) on one side of the optical fiber fusion splicer and fix it. Place another multimode optical fiber with a smooth end face cut on the other side of the optical fiber fusion splicer and fix it, and align it with the multimode optical fiber on one side of the cantilever; use the same fusion splicing parameters as in step (1) to fuse it with the optical fiber staggered cantilever structure to form a staggered convex structure, namely the staggered optical fiber;

[0048] (4) placing the dislocated optical fiber with the dislocated convex structure obtained in step (3) above a bracket with a hollow center, so that the dislocated portion of the optical fiber is exactly located in the center of the hollow bracket, which is convenient for coating SU-8 photoresist on the dislocated convex structure; placing the bracket below the precision cutting system, adjusting the objective lens and the bracket while slightly rotating the dislocated convex structure of the optical fiber until the dislocated structure is clearly seen in the center of the field of view;

[0049] (5)Reference Figure 1d. Take an appropriate amount of SU-8 photoresist on a glass slide and let it stand for 5 minutes to allow the solvent in the photoresist to evaporate completely and increase the viscosity of the photoresist; then use a syringe needle to dip a small amount of SU-8 photoresist, slowly move the needle tip to the dislocation area of ​​the convex structure of the optical fiber, and monitor the needle position in real time under the precision cutting system to ensure that the photoresist is accurately applied to the dislocation area. The speed should be fast and the force should be light when applying to ensure the uniformity and consistency of the coating; since the photoresist has a self-leveling function, the applied photoresist forms a uniform photoresist film layer in the concave dislocation area, and then an ultraviolet light source (XP104) is used to accurately expose the coated area for 20 seconds. After exposure, an acid is generated in the SU-8 photoresist. This acid acts as a catalyst at a certain temperature to cross-link and solidify the photoresist, thereby cross-linking with the optical fiber to form an optical fiber dislocation sensing structure, that is, a dislocation optical fiber with an integrated photoresist film layer.

[0050] In this application, three misaligned optical fibers with misalignment lengths of 600 μm, 700 μm, and 800 μm were obtained using the same preparation method, and their optical images are shown in FIG. Figure 2 As shown in Figures 2a, 2b, and 2c. From the optical images, we can see that the shape of the dislocation structure is regular, the dislocation length increases successively, and the size of the dislocation fiber deviating from the center of the structure is about 42μm. The three dislocation fibers are connected to a broadband light source (YSL, SC-5-FC) and a spectrometer (YOKOGAWA, AQ63700D) respectively. The transmission interference spectra are Figure 2 d, 2e, and 2f. From the three interference spectra, we can see that when the misalignment length is 600μm, 700μm, and 800μm, the loss of the misaligned fiber interference spectrum is -21.89dBm, -25.6dBm, and -52.34dBm, respectively. It can be seen that as the length of the misaligned structure increases, the insertion loss of the misaligned fiber also gradually increases. However, according to interference theory, the longer the interference length, the higher the temperature sensitivity of the misaligned fiber. Therefore, in order to ensure the sensitivity of the misaligned fiber while minimizing its insertion loss, we select a misaligned fiber with an interference length of 700μm for further research and provide its detailed temperature response characteristics.

[0051] In order to further improve the temperature response characteristics of the dislocated optical fiber, SU-8 photoresist is applied to the dislocated part of the dislocated optical fiber to improve its temperature response characteristics. The optical picture of the dislocated optical fiber with integrated photoresist film layer obtained after coating the photoresist is shown in the figure. Figure 3 As shown in a. Figure 3 As can be seen from a, the photoresist completely covers the dislocation area. Since the photoresist has a positive thermal expansion coefficient, it effectively enhances the temperature sensitivity of the dislocation fiber. In addition, due to the coverage of the photoresist, the mechanical strength of the dislocation fiber is significantly improved. We conducted a spectral test on the optical fiber after coating with photoresist, and the results are shown in Figure 3b. From Figure 3 It can be observed in b that there are multiple characteristic peaks within the test range.

[0052] In order to test the temperature sensing characteristics of the obtained offset optical fiber with integrated photoresist film layer in detail, we used Figure 4 The temperature monitoring system shown in FIG. Figure 4 It can be seen that the system is mainly composed of several key components, including a broadband light source that can provide an incident light with a wavelength range of 600nm to 1700nm. In addition, the system also includes a spectrometer with a resolution of 0.02nm. In order to accurately control the temperature environment, the system is also equipped with a temperature control box (CK-80G). First, the offset optical fiber with integrated photoresist film layer is connected to the broadband light source and spectrometer through a pigtail. After the connection is completed, the offset optical fiber with integrated photoresist film layer is placed in the temperature control box to calibrate the temperature response characteristics of the structure.

[0053] Figure 5 a shows the transmission interference spectrum of the offset optical fiber with integrated photoresist film layer at different temperatures. The temperature detection range is from 30℃ to 60℃, and the data is recorded every 5℃. After the temperature of the temperature control box reaches the preset value, wait for 1 minute and then record the transmission interference spectrum of the structure to avoid the influence of ambient temperature fluctuation on the measurement results. A total of seven sets of data are recorded. Figure 5 As can be seen from a, there are multiple interference peaks in the transmission interference spectrum of the offset optical fiber with integrated photoresist film layer. The contrast of the interference peak near 1300nm is the largest, so the temperature response characteristics of the interference peak are given in detail here. Figure 5 It can also be seen in Figure a that as the temperature gradually increases, the central wavelength of the interference peak gradually shifts from 1305.63nm to 1327.30nm, a total redshift of 21.67nm. This is because when the temperature rises, both the photoresist and the optical fiber experience thermo-optical and thermal expansion effects. Since the thermal expansion coefficients of both the optical fiber and the photoresist are positive, as the temperature rises, the effective interference length of the optical fiber staggered structure increases, causing the central wavelength of the interference peak to redshift. At the same time, the optical fiber and the photoresist have positive and negative thermo-optic coefficients, respectively, which reduces the effective refractive index difference of the staggered optical fiber with an integrated photoresist film layer, resulting in a blueshift of the corresponding central wavelength of the interference peak. According to the experimental results, the thermal expansion effects of the optical fiber and the photoresist play a major role in the staggered optical fiber with an integrated photoresist film layer.

[0054] Here, the central wavelength of the interference peak around 1300nm is tested in detail as it changes with temperature. The central wavelength positions of the interference peaks at 30℃, 35℃, 40℃, 45℃, 50℃, 55℃ and 60℃ are all Figure 5These data points are linearly fitted, as shown in Figure 2 (b), with a slope and correlation coefficient of 0.70012 nm / °C and 0.93339, respectively. Based on the fitting results, the temperature sensitivity is approximately 0.70012 nm / °C within the detection range of 30°C to 60°C. The experimental results demonstrate that the dislocation structure has high sensitivity and good linear response characteristics within the measured temperature range.

[0055] This paper proposes a fiber-optic misalignment Mach-Zehnder temperature sensor with simple fabrication, low cost, and excellent temperature sensitivity. Fiber melting and UV curing techniques were used to fabricate the fiber-optic misalignment sensor. By analyzing the spectra of three misalignment structures of varying lengths, a fiber structure with a misalignment length of 700 μm and a misalignment area approximately one-third of the fiber diameter was selected for further investigation of its temperature characteristics. Experimental results demonstrate that the temperature sensitivity of the fiber-optic temperature sensing structure, coated with SU-8 photoresist, reached 0.70012 nm / °C. This sensor has broad application prospects in biomedicine, aerospace, industry, and agriculture.

[0056] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solution and inventive concept of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. An optical fiber misalignment temperature sensor, characterized in that: A dislocated optical fiber including an integrated photoresist film layer; The dislocated optical fiber with integrated photoresist film layer comprises a dislocated optical fiber and a photoresist film layer covering the dislocated area of ​​the dislocated optical fiber; The staggered optical fiber is composed of a first multimode optical fiber, a second multimode optical fiber, and a third multimode optical fiber staggered and fused between the first multimode optical fiber and the second multimode optical fiber.

2. The optical fiber misalignment temperature sensor according to claim 1, characterized in that: The first multimode optical fiber and the third multimode optical fiber, as well as the second multimode optical fiber and the third multimode optical fiber, have the same misalignment direction and the same misalignment distance.

3. The optical fiber misalignment temperature sensor according to claim 2, characterized in that: The misalignment distance is 1 / 3 of the diameter of the first multimode optical fiber, the second multimode optical fiber or the third multimode optical fiber.

4. The optical fiber misalignment temperature sensor according to claim 2 or 3, characterized in that: The cladding diameter of the first multimode optical fiber, the second multimode optical fiber or the third multimode optical fiber is 100-150 μm, and the core diameter is 60-70 μm.

5. The optical fiber misalignment temperature sensor according to any one of claims 2 to 4, characterized in that: The length of the third multimode optical fiber is 600-800 μm, preferably 700 μm.

6. The optical fiber misalignment temperature sensor according to any one of claims 1 to 5, characterized in that: The photoresist film layer is formed by curing SU-8 photoresist.

7. The optical fiber misalignment temperature sensor according to any one of claims 1 to 6, characterized in that: The sensor further comprises a broadband light source and a spectrum analyzer; the broadband light source and the spectrum analyzer are respectively connected to two ends of the dislocated optical fiber of the integrated photoresist film layer.

8. A method for preparing the optical fiber misalignment temperature sensor according to any one of claims 1 to 7, characterized in that: The steps include: S1. Align two sections of multimode optical fiber on the central axis, stagger them vertically for a certain distance, and then fuse them for the first time to form a first staggered welding point, thereby obtaining a preliminary staggered optical fiber product; S2, cutting the misaligned optical fiber into two sections away from the first misaligned fusion splice point, aligning them again on the central axis, and then fusing them a second time after being misaligned up and down by the same distance to form a second misaligned fusion splice point, thereby obtaining a misaligned optical fiber; S3. Coating SU-8 photoresist on the dislocated area between the first dislocated fusion point and the second dislocated fusion point on the dislocated optical fiber, and forming a photoresist film layer after light curing to obtain the dislocated optical fiber with integrated photoresist film layer.

9. The method for preparing the optical fiber misalignment temperature sensor according to claim 8, characterized in that: In step S1, the discharge intensity of the first welding and the second welding is 30-50 bits, and the discharge time is 2500-3000 ms.

10. The method for preparing the optical fiber misalignment temperature sensor according to claim 8 or 9, characterized in that: In step S2, the light curing time is 10-30s.

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