Optical fiber defect detection device and optical fiber defect detection method

Abstract

The invention provides an optical fiber defect detection device and an optical fiber defect detection method.The optical fiber defect detection device comprises a laser source, an optical fiber fixing assembly used for fixing a to-be-detected single-cladding erbium-doped optical fiber and an optical focusing imaging assembly located on the side, away from the laser source, of the optical fiber fixing assembly and tightly attached to the optical fiber fixing assembly; the optical focusing imaging assembly is used for capturing infrared light scattered by the side face of the single-cladding erbium-doped fiber and outputting defect information of the single-cladding erbium-doped fiber. According to the optical fiber defect detection device, the laser source is matched with the optical focusing imaging assembly to capture the infrared light scattered by the side surface of the single-cladding erbium-doped optical fiber, so that the detection process avoids the limitation that the cladding of the optical fiber cannot guide light and the problem that a fiber core absorbs visible light; meanwhile, the stability of the detection process is ensured by means of the optical fiber fixing assembly so as to improve the accuracy of defect identification, and finally a reliable and practical technical means is provided for quality management and control of the optical fibers.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of optical fiber testing, in particular to an optical fiber defect detection device and an optical fiber defect detection method. BACKGROUND

[0002] Erbium-doped optical fiber is widely used in various fiber amplifiers in communication systems due to its large bandwidth, low noise, high power and other characteristics. During the manufacturing process of the erbium-doped optical fiber, other elements need to be co-doped to provide a coordination field environment for erbium ions to improve the luminescence characteristics of the erbium ions. However, a large stress will be generated in the core. If the stress is not properly released during the preparation process, it will cause bubbles, cracks and defects in the core, which will seriously affect the quality of the optical fiber.

[0003] Since the quality of the optical fiber determines its reliability, special optical fibers need to be tested before they are shipped. The utility model patent CN222618520U is an optical fiber end face defect observation and detection device, which has compact structure and high detection precision. However, it can only observe the defects on the end face of the optical fiber and cannot effectively detect the defects in the long optical fiber distance. Moreover, the detection method is destructive and is not convenient for optical fiber shipment detection application. The patent CN115100200B is an optical fiber defect detection method and system based on optical means, which obtains the visible light image of the optical fiber segment to be detected, compares the image lines and judges the defect type of the optical fiber. However, this method is limited by the accuracy of the visible light image of the optical fiber and can only detect larger defects, with low detection accuracy. It is difficult to detect defects below microns in the optical fiber. Especially in single-clad erbium-doped optical fiber, the erbium-doped optical fiber has absorption in the commonly used visible light (red or green light), so it cannot be detected by visible light. Defect inspection is very important for the shipment detection of optical fiber.

[0004] Therefore, there is an urgent need for an optical fiber defect detection device and an optical fiber defect detection method to solve the above technical problems. SUMMARY

[0005] The present application aims to provide an optical fiber defect detection device and an optical fiber defect detection method to solve the technical problem that the existing single-clad erbium-doped optical fiber cannot be effectively detected due to the fact that the cladding cannot guide light and the core has absorption in the visible light band.

[0006] To solve the above technical problems, the present application first provides an optical fiber defect detection device, comprising: a laser source; an optical fiber fixing assembly for fixing the single-clad erbium-doped optical fiber to be tested; An optical focusing imaging component is arranged on the side of the optical fiber fixing component away from the laser source and is closely arranged on the optical fiber fixing component, and is used for capturing the infrared light scattered by the single-clad erbium-doped optical fiber and outputting the defect information of the single-clad erbium-doped optical fiber.

[0007] Preferably, the laser emitted by the laser source is continuous laser, the wavelength is 1054-1074 nm, and the emission power is 3-15 W.

[0008] Preferably, the optical fiber fixing component further comprises an optical fiber disc with a barrel wall and a fixing clamp for fixing the optical fiber disc, and the fixing clamp is clamped and connected with both ends of the optical fiber disc.

[0009] Preferably, the single-clad erbium-doped optical fiber is uniformly wound on the barrel wall and is fused with the output tail fiber of the laser source.

[0010] Preferably, the length of the single-clad erbium-doped optical fiber is 100-5000 m.

[0011] Preferably, the optical focusing imaging component comprises an infrared mirror and an optical imaging member, and the infrared mirror is arranged between the optical fiber fixing component and the optical imaging member. The infrared mirror is used for collecting the infrared light scattered by the single-clad erbium-doped optical fiber and focusing the infrared light on the optical imaging member, and the optical imaging member is used for generating the defect information of the single-clad erbium-doped optical fiber according to the imaging result of the infrared mirror.

[0012] Preferably, when the imaging result of the infrared mirror is a low-noise high-gray-scale image, the single-clad erbium-doped optical fiber is a defect-free optical fiber; and when part of the imaging result of the infrared mirror is a high-brightness image, the single-clad erbium-doped optical fiber is an optical fiber containing bubbles or bright spots.

[0013] Correspondingly, the application further provides a fiber defect detection method applied to the fiber defect detection device of any one of the above, and the method comprises the following steps: S10, fixing the single-clad erbium-doped optical fiber to be detected on the optical fiber fixing component in the defect detection device and fusing the single-clad erbium-doped optical fiber with the output tail fiber of the laser source; S20, turning on the laser source and adjusting the position of the single-clad erbium-doped optical fiber, so that the optical focusing imaging component captures the infrared light scattered by the single-clad erbium-doped optical fiber and outputs the defect information of the single-clad erbium-doped optical fiber.

[0014] Preferably, the laser emitted by the laser source in the defect detection device is continuous laser, the wavelength is 1054-1074 nm, and the emission power is 3-15 W.

[0015] Preferably, the length of the single-clad erbium-doped optical fiber is 100-5000 m.

[0016] The beneficial effect of the present application is that: unlike the prior art, the present application provides a fiber defect detection device and a fiber defect detection method, the fiber defect detection device comprises a laser source, a fiber fixing assembly for fixing a single-clad erbium-doped optical fiber to be tested, and an optical focusing imaging assembly located on the side of the fiber fixing assembly away from the laser source and closely arranged with the fiber fixing assembly, the optical focusing imaging assembly is used for capturing infrared light scattered by the side of the single-clad erbium-doped optical fiber, and outputting defect information of the single-clad erbium-doped optical fiber. The fiber defect detection device captures the infrared light scattered by the side of the single-clad erbium-doped optical fiber through the cooperation of the laser source and the optical focusing imaging assembly, so that the detection process avoids the limitation that the cladding of such optical fiber cannot guide light and the problem of absorption of visible light by the core, thereby solving the technical bottleneck that the prior art cannot effectively detect it, and then ensuring the stability of the detection process by means of the fiber fixing assembly to improve the accuracy of defect identification, further filling the technical gap in the field of single-clad erbium-doped optical fiber defect detection, and finally providing a reliable and practical technical means for the quality control of such optical fiber. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 The overall architecture schematic diagram of the fiber defect detection device provided by the embodiment of the present application is shown in the figure. Figure 2 The method flow chart of the fiber defect detection method provided by the embodiment of the present application is shown in the figure. Figure 3 The fiber information image collected in the fiber defect detection device provided by the embodiment 1 of the present application is shown in the figure. In the description of the drawings: 10-fiber defect detection device; 11-laser source; 12-fiber fixing assembly; 121-fiber disc; 122-fixing clamp; 13-optical focusing imaging assembly; 131-infrared mirror; 132-optical imaging member; 20-single-clad erbium-doped optical fiber. DETAILED DESCRIPTION

[0018] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0019] The purpose of the present application is to overcome the defects of the prior art, and to provide a fiber defect detection device and a fiber defect detection method, which captures infrared light scattered by the side of a single-clad erbium-doped optical fiber through the cooperation of a laser source and an optical focusing imaging assembly, so that the detection process avoids the limitation that the cladding of such optical fiber cannot guide light and the problem of absorption of visible light by the core. Please refer to Figure 1 , Figure 1The overall architecture schematic diagram of the optical fiber defect detection device provided by the embodiment of the present application is shown in the figure. Figure 1 It can be seen that the optical fiber defect detection device 10 comprises a laser source 11, an optical fiber fixing assembly 12 for fixing a single-clad erbium-doped optical fiber 20 to be detected, and an optical focusing imaging assembly 13 located on the side of the optical fiber fixing assembly 12 away from the laser source 11 and closely arranged with the optical fiber fixing assembly 12, the optical focusing imaging assembly 13 being used for capturing infrared light scattered by the side of the single-clad erbium-doped optical fiber 20 and outputting defect information of the single-clad erbium-doped optical fiber 20.

[0020] In the embodiment, the laser source 11 is connected with the single-clad erbium-doped optical fiber 20 to be detected through optical fiber fusion, and the laser emitted by the laser source 11 is coupled into the core of the single-clad erbium-doped optical fiber 20; wherein the low-loss connection with the single-clad erbium-doped optical fiber 20 can be realized through optical fiber fusion, so that the laser energy can be efficiently transmitted into the core of the single-clad erbium-doped optical fiber 20 to be detected, thereby avoiding the influence of laser power attenuation caused by connection loss on the detection signal strength, and further ensuring that the scattered light signal generated by the interaction of the laser in the core with the defect is sufficient, further providing a stable light source basis for the optical focusing imaging assembly 13 to accurately capture the defect information, and finally improving the recognition sensitivity and detection reliability of the entire detection device to the optical fiber defect.

[0021] Specifically, the laser emitted by the laser source 11 is continuous laser with a wavelength of 1064nm±10nm, which avoids the absorption wavelength band of the single-clad erbium-doped optical fiber 20 and avoids the situation that the detection light is excessively absorbed by the core without light output; the emission power of the laser source 11 is 3~15W, on the one hand, the power cannot be too low, otherwise the entire single-clad erbium-doped optical fiber 20 to be detected cannot be illuminated, on the other hand, the power cannot be too high, otherwise the optical fiber damage caused by phenomena such as optical fiber nonlinear effect will occur.

[0022] In the embodiment, the optical fiber fixing assembly 12 further comprises an optical fiber disc 121 having a barrel wall and a fixing clamp 122 for fixing the optical fiber disc 121, the fixing clamp 122 being clamped and connected with both ends of the optical fiber disc 121, and the single-clad erbium-doped optical fiber 20 being uniformly wound on the barrel wall and fused at an optical fiber fusion point 21 with the output tail fiber of the laser source 11.

[0023] Specifically, the fixing clamp 122 is clamped to both ends of the fiber optic disk 121 to keep the fiber optic disk 121 stable during the detection process and avoid fiber displacement due to shaking; the single-clad erbium-doped fiber 20 is uniformly wound on the cylinder wall to reduce additional scattering interference caused by uneven bending or stress concentration of the fiber, and ensure the stability of laser transmission within the fiber; at the same time, the fiber and the output pigtail of the laser source 11 are fused together and wound to fix it, thereby ensuring the robustness and low loss characteristics of the optical path connection and reducing signal fluctuations caused by loose connection; further, it provides a stable and uniform scattered light signal source for the optical focusing imaging component 13; ultimately improving the stability and accuracy of defect detection results.

[0024] In this embodiment, the optical focusing imaging component 13 includes an infrared mirror 131 and an optical imaging component 132. The infrared mirror 131 is located between the fiber fixing component 12 and the optical imaging component 132. The infrared mirror 131 is used to collect infrared light scattered from the side of the single-clad erbium-doped fiber 20 and focus it onto the optical imaging component 132. The optical imaging component 132 is used to generate defect information of the single-clad erbium-doped fiber 20 based on the imaging result of the infrared mirror 131.

[0025] Specifically, an infrared mirror 131 is used to collect infrared light scattered from the side of a single-clad erbium-doped fiber 20, enabling the detection signal to accurately lock onto the characteristic light signal generated by defects in this type of fiber (avoiding its absorption interference with visible light). At the same time, the focusing effect enhances the intensity and concentration of the light signal. The optical imaging component 132 generates defect information based on the clear image after focusing, thereby effectively converting the scattered light signal into identifiable defect data and avoiding information distortion caused by signal blurring or stray light interference. This achieves targeted capture and accurate conversion of defect signals, solving the problem that this type of fiber is difficult to image and identify due to its special optical characteristics. It further improves the clarity and completeness of defect information, ultimately ensuring the specificity and accuracy of defect detection and providing a reliable basis for fiber quality assessment.

[0026] In this embodiment, the optical imaging component 132 analyzes the abnormal imaging through the acquired images: defect-free optical fibers exhibit low noise and high grayscale (without a clear numerical value, but can be clearly distinguished by comparing the acquired images); optical fibers containing bubbles or bright spots, due to Mie scattering, will have the defective part exhibit a characteristic of brightness in the imaging area that is significantly higher than the corresponding brightness of the surrounding defect-free part, thus identifying the optical fiber defect.

[0027] Specifically, the aforementioned design of the optical imaging component 132 analyzes abnormal imaging based on image features (low noise and high grayscale of defect-free optical fibers and high brightness of optical fibers containing bubbles / bright spots due to Mie scattering), so that defects and normal areas form clearly distinguishable visual features. This allows for accurate identification of optical fiber defects by utilizing differences in optical properties, avoiding misjudgment or missed detection of defects caused by interference from the optical properties of the single-clad erbium-doped fiber 20 itself. Furthermore, it transforms abstract differences in optical signals into intuitive image feature comparisons, lowering the technical threshold for defect identification. This further enhances the objectivity and consistency of defect judgment (unaffected by subjective experience), ultimately ensuring high sensitivity and high accuracy in detecting optical fiber defects (such as bubbles and bright spots), providing a clear and reliable basis for optical fiber quality assessment.

[0028] Please see Figure 2 The present invention also provides a fiber optic defect detection method, applied to the fiber optic defect detection device 10 as described in any of the above claims, the method comprising: S10, the single-clad erbium-doped fiber 20 to be tested is fixed on the fiber fixing assembly 12 in the defect detection device and fused with the output pigtail of the laser source 11. S20, turn on the laser source 11 and adjust the position of the single-clad erbium-doped fiber 20 so that the optical focusing imaging component 13 captures the infrared light scattered from the side of the single-clad erbium-doped fiber 20 and outputs the defect information of the single-clad erbium-doped fiber 20.

[0029] Specifically, the laser source 11 in the defect detection device emits a continuous laser with a wavelength of 1054~1074nm and an emission power of 3~15W.

[0030] Specifically, the length of the single-clad erbium-doped fiber 20 is 100~5000m.

[0031] The technical solution of the present invention will now be described in conjunction with specific embodiments.

[0032] Example 1: like Figure 1 As shown, this embodiment 1 provides an optical fiber defect detection device 10, which mainly includes: an optical focusing imaging component 13 (imaging area) composed of an optical imaging component 132 and an infrared mirror 131; a sample area composed of a fixing clamp 122, an optical fiber disk 121 and a single-clad erbium-doped fiber 20 to be tested; and a light source area composed of the output pigtail of a laser source 11, the fiber melting point of the single-clad erbium-doped fiber 20 to be tested, and the laser source 11.

[0033] The laser source 11 has a center wavelength of 1064nm and a continuous output power of 10W. The output pigtail of the laser source 11 is directly fused with the fiber to be tested, so as to realize the coupling of the 1064nm laser from the laser source 11 to the core of the single-clad erbium-doped fiber 20 to be tested.

[0034] Specifically, the cylindrical portion of the fiber optic disk 121 is 200 mm high and 160 mm in diameter. The fixing clamp 122 fixes the fiber optic disk 121 in the sample area. The length of the single-clad erbium-doped fiber 20 to be tested is 1000 m.

[0035] Please see Figure 3 , Figure 3 The image shows optical fiber information acquired by the optical fiber defect detection device 10 provided in Embodiment 1 of the present invention; Figure 3 It can be seen that the infrared mirror 131 collects the infrared light scattered from the side of the single-clad erbium-doped fiber 20 to be inspected and focuses it onto the optical imaging component 132. The optical imaging component 132 generates defect information of the single-clad erbium-doped fiber 20 to be inspected based on the imaging results of the infrared mirror 131. Figure 3 Most of the area exhibits low-noise, high-grayscale image characteristics, while a small portion (micrometer level) shows high-brightness image characteristics, thus identifying this part as a defect (bubble or bright spot) in the single-clad erbium-doped fiber 20.

[0036] Unlike existing technologies, the optical fiber defect detection device 10 and optical fiber defect detection method provided by this invention have the following advantages: First, this application specifically overcomes the detection limitations of single-clad erbium-doped fiber 20. By adopting infrared light (avoiding visible light absorption in the fiber core) and capturing side-scattered light (without the need for cladding light guiding), it solves the problem of ineffective detection caused by the special optical characteristics of this type of fiber, filling a technological gap. Second, the structural design of the fiber defect detection device 10 provided in this application takes into account both stability and efficiency. The fusion splicing of the laser source 11 and the optical fiber ensures low-loss light transmission. The cooperation between the fiber disk 121 and the fixing clamp 122 reduces fiber stress interference. The infrared mirror 131 focuses and enhances the signal. The multiple designs together ensure the stability and sufficiency of the detection signal, laying the foundation for accurate detection. Third, the fiber optic defect detection device 10 provided in this application analyzes image features (low noise and high grayscale in normal areas vs. high brightness in defect areas) through optical imaging component 132, and uses Mie scattering characteristics to clearly distinguish between defective and normal areas, reducing the risk of subjective misjudgment, improving the sensitivity and consistency of detection, and providing a reliable basis for fiber optic quality control.

[0037] It should be noted that all the above embodiments belong to the same inventive concept, and the descriptions of each embodiment have different focuses. Where the description in a particular embodiment is not detailed, please refer to the description in other embodiments.

[0038] The above embodiments merely illustrate implementation methods of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A fiber optic defect detection device, characterized in that, include: Laser source; Fiber optic fixing assembly, used to fix the single-clad erbium-doped fiber to be tested; An optical focusing imaging component is located on the side of the fiber fixing component away from the laser source and is disposed close to the fiber fixing component. It is used to capture infrared light scattered from the side of the single-clad erbium-doped fiber and output defect information of the single-clad erbium-doped fiber.

2. The optical fiber defect detection device according to claim 1, characterized in that, The laser source emits a continuous laser with a wavelength of 1054~1074nm and an emission power of 3~15W.

3. The optical fiber defect detection device according to claim 1, characterized in that, The optical fiber fixing assembly further includes an optical fiber disk with a cylindrical wall and a fixing clamp for fixing the optical fiber disk, the fixing clamp being clamped and connected to both ends of the optical fiber disk.

4. The optical fiber defect detection device according to claim 3, characterized in that, The single-clad erbium-doped optical fiber is uniformly wound around the cylinder wall and fused to the output pigtail of the laser source.

5. The optical fiber defect detection device according to claim 4, characterized in that, The length of the single-clad erbium-doped fiber is 100~5000m.

6. The optical fiber defect detection device according to claim 1, characterized in that, The optical focusing imaging assembly includes an infrared mirror and an optical imaging component, wherein the infrared mirror is located between the fiber optic fixing assembly and the optical imaging component; The infrared mirror is used to collect infrared light scattered from the side of the single-clad erbium-doped fiber and focus it onto the optical imaging component; the optical imaging component is used to generate defect information of the single-clad erbium-doped fiber based on the imaging result of the infrared mirror.

7. The optical fiber defect detection device according to claim 6, characterized in that, When the imaging result of the infrared mirror is a low-noise, high-grayscale image, the single-clad erbium-doped fiber is a defect-free fiber; when part of the imaging result of the infrared mirror is a high-brightness image, the single-clad erbium-doped fiber contains bubbles or bright spots.

8. A method for detecting optical fiber defects, applied to the optical fiber defect detection device as described in any one of claims 1 to 7, characterized in that, The method includes: S10, the single-clad erbium-doped fiber to be tested is fixed on the fiber fixing assembly in the defect detection device and fused with the output pigtail of the laser source; S20, turn on the laser source and adjust the position of the single-clad erbium-doped fiber so that the optical focusing imaging component captures the infrared light scattered from the side of the single-clad erbium-doped fiber and outputs the defect information of the single-clad erbium-doped fiber.

9. The optical fiber defect detection method according to claim 8, characterized in that, The laser source in the defect detection device emits a continuous laser with a wavelength of 1054~1074nm and an emission power of 3~15W.

10. The optical fiber defect detection method according to claim 8, characterized in that, The length of the single-clad erbium-doped fiber is 100~5000m.

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