Optical fiber defect detection system and method

Abstract

The invention provides an optical fiber defect detection system and method, and the system comprises an optical fiber fixing groove which is used for fixing the two ends of a to-be-detected optical fiber after the to-be-detected optical fiber passes through refractive index matching oil in an optical amplification device; the broadband light source is arranged on the light inlet side of the optical amplification device and is used for emitting detection light to the optical amplification device; the visible light source is connected with one end of the to-be-measured fiber and used for emitting visible light to the to-be-measured fiber; the optical amplification device is used for moving along the axis direction of the optical fiber to be detected and amplifying the detection light; after the detection light passes through the refractive index matching oil in the optical amplification device, the detection light is emitted to the optical imaging device from the light emitting side of the optical amplification device; and the optical imaging device is used for generating a corresponding optical imaging result according to the detection light emitted by the light emitting side of the optical amplification device and the visible light passing through the to-be-detected optical fiber so as to obtain defect detection information of the to-be-detected optical fiber. According to the invention, the accuracy and efficiency of optical fiber defect detection are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of special optical fiber testing, and particularly to an optical fiber defect detection system and method. Background Art

[0002] During the manufacturing and application processes of special optical fibers, the detection of internal defects in optical fibers is crucial. These defects include impurities, bubbles, and cracks in the core and cladding, which seriously affect the performance and reliability of optical fibers.

[0003] Figure 1 For a schematic radial end view of an existing special optical fiber with a complex structure, reference can be made to Figure 1 As shown, the special optical fiber includes 1 core layer and 2 cladding layers. Existing optical fiber defect detection methods usually rely on microscope observation or complex optical testing equipment. These methods are not only cumbersome and time-consuming to operate, but also often difficult to achieve high-precision defect detection for such special optical fibers with complex structures.

[0004] Therefore, there is an urgent need for an optical fiber defect detection system and method to solve the above problems. Summary of the Invention

[0005] In view of the problems existing in the prior art, the present invention provides an optical fiber defect detection system and method.

[0006] The present invention provides an optical fiber defect detection system, including an optical fiber fixing groove, a broadband light source, a visible light source, an optical amplification device, and an optical imaging device, wherein: The optical fiber fixing groove is used to fix both ends of the optical fiber to be tested after the optical fiber to be tested passes through the refractive index matching oil in the optical amplification device. Among them, the broadband light source and the optical amplification device are on the same optical axis, the axis direction of the optical fiber to be tested is perpendicular to the optical axis, and the part of the optical fiber to be tested in the refractive index matching oil is the cladding part; The broadband light source is arranged on the light incident side of the optical amplification device and is used to emit detection light to the optical amplification device; The visible light source is connected to one end of the optical fiber to be tested and is used to emit visible light to the optical fiber to be tested; The optical amplification device is used to move along the axis direction of the optical fiber to be tested after the visible light source emits the visible light and perform amplification processing on the passing detection light; during the movement of the optical amplification device, the detection light passes through the refractive index matching oil in the optical amplification device and is emitted from the light exit side of the optical amplification device to the optical imaging device; The optical imaging device is configured to generate a corresponding optical imaging result based on the detection light emitted from the light-emitting side of the optical magnification device and the visible light passing through the optical fiber to be measured, so as to obtain defect detection information of the optical fiber to be measured according to the optical imaging result.

[0007] According to a fiber optic defect detection system provided by the present invention, the optical magnification device includes a first objective lens and a second objective lens, wherein: The refractive index matching oil is adsorbed in the objective lens gap between the light-emitting side of the first objective lens and the light-incident side of the second objective lens; A collimating lens is provided between the light-incident side of the first objective lens and the broadband light source, and a focusing lens is provided between the light-emitting side of the second objective lens and the optical imaging device; The detection light emitted by the broadband light source forms a parallel light beam after passing through the collimating lens and is emitted to the light-incident side of the first objective lens. The parallel light beam forms a converging light beam after passing through the first objective lens, the refractive index matching oil, the second objective lens and the focusing lens in sequence, and is emitted to the optical imaging device.

[0008] According to a fiber optic defect detection system provided by the present invention, the first objective lens is provided with a first linear displacement platform, and the second objective lens is provided with a second linear displacement platform, wherein: The first linear displacement platform and the second linear displacement platform are configured to drive the first objective lens and the second objective lens to move synchronously to adjust the test part of the optical fiber to be measured in the refractive index matching oil.

[0009] According to a fiber optic defect detection system provided by the present invention, the system further includes a fiber rotation control device, and the fiber rotation control device is configured to rotate the optical fiber to be measured to adjust the spatial observation angle of the optical fiber to be measured.

[0010] According to a fiber optic defect detection system provided by the present invention, the magnification of the first objective lens and the second objective lens is at least 50 times, and the numerical aperture is greater than 0.6.

[0011] According to a fiber optic defect detection system provided by the present invention, the wavelength range of the detection light emitted by the broadband light source is 400 nm to 2400 nm.

[0012] According to a fiber optic defect detection system provided by the present invention, the fiber fixing groove is provided with a pressing block for fixing the coating parts at both ends of the optical fiber to be measured after the two ends of the optical fiber to be measured are placed in the groove.

[0013] According to an optical fiber defect detection system provided by the present invention, the system further includes a driving integrated control device, which is configured to generate corresponding control instructions according to the real-time optical imaging result to drive the broadband light source, the visible light source, the optical amplification device, and the optical imaging device to perform corresponding operations.

[0014] The present invention also provides an optical fiber defect detection method based on the above optical fiber defect detection system, including: After determining that the test part of the optical fiber to be tested is in the refractive index matching oil in the optical amplification device, a detection light is emitted to the test part of the optical fiber to be tested through the broadband light source, and visible light is emitted from one end of the optical fiber to be tested through the visible light source; When the optical amplification device moves along the axis direction of the optical fiber to be tested, corresponding optical imaging results are generated according to the detection light emitted from the light output side of the optical amplification device and the visible light passing through the optical fiber to be tested; According to the optical imaging result, defect detection information of the optical fiber to be tested is obtained.

[0015] According to an optical fiber defect detection method provided by the present invention, the obtaining the defect detection information of the optical fiber to be tested according to the optical imaging result includes: The optical fiber to be tested is rotated, and during the rotation of the optical fiber to be tested, defect position detection information in the optical fiber to be tested is determined according to the position change information of the defect bright spots in the optical imaging result, wherein the defect bright spots are bright spots formed in the optical imaging result based on the visible light passing through the defect position of the optical fiber to be tested.

[0016] The optical fiber defect detection system and method provided by the present invention fix both ends of the optical fiber to be tested passing through the refractive index matching oil in the optical amplification device through an optical fiber fixing groove, and use the cladding part of the optical fiber to be tested as the test part. Then, a detection light is emitted to the test part through the broadband light source, and the visible light source emits visible light from one end of the optical fiber. Thus, during the process of the optical amplification device moving along the optical fiber axis, the detection light is amplified and emitted to the optical imaging device to generate an optical imaging result, and defect detection information of the optical fiber is obtained, improving the accuracy and efficiency of optical fiber defect detection. Description of the Drawings

[0017] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the following drawings are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0018] Figure 1Schematic diagram of the radial end face of an existing special optical fiber with a complex structure; Figure 2 Schematic diagram of the structure of the optical fiber defect detection system provided by the present invention; Figure 3 Schematic diagram of the flow of the optical fiber defect detection method provided by the present invention; Reference numerals: 201: Optical fiber fixing groove; 202: Broadband light source; 203: Visible light source; 204: Optical amplification device; 205: Optical imaging device; 206: Optical fiber to be measured; 207: Refractive index matching oil; 208: Collimating mirror; 209: Focusing mirror; 210: Optical fiber rotation control device; 2011: Pressing block; 2041: First objective lens; 2042: Second objective lens; 2043: First linear displacement platform; 2044: Second linear displacement platform. Detailed implementation manners

[0019] To make the objectives, technical solutions and advantages of the present invention clearer, the technical solutions in the present invention will be clearly and completely described below with reference to the accompanying drawings in the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present invention without creative efforts shall fall within the protection scope of the present invention.

[0020] The features of the terms "first" and "second" in this application may explicitly or implicitly include one or more of such features. In the description of this application, unless otherwise specified, the meaning of "a plurality" is two or more.

[0021] In the description of this application, it should be understood that the orientation or positional relationship indicated by the terms "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing this application and simplifying the description, rather than indicating or implying 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 a limitation to this application.

[0022] In the description of the present application, it should be noted that unless otherwise clearly specified and defined, the terms "installation", "connection", and "coupling" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0023] Figure 2 The structural schematic diagram of the optical fiber defect detection system provided by the present invention is as Figure 2 shown. The present invention provides an optical fiber defect detection system, including an optical fiber fixing groove 201, a broadband light source 202, a visible light source 203, an optical amplification device 204, and an optical imaging device 205, wherein: The optical fiber fixing groove 201 is used to fix both ends of the optical fiber under test 206 after the optical fiber under test 206 passes through the refractive index matching oil 207 in the optical amplification device 204. Among them, the broadband light source 202 and the optical amplification device 204 are on the same optical axis, the axis direction of the optical fiber under test 206 is perpendicular to the optical axis, and the test part of the optical fiber under test 206 in the refractive index matching oil 207 is the cladding part; The broadband light source 202 is arranged on the light incident side of the optical amplification device 204 and is used to emit detection light to the optical amplification device 204; The visible light source 203 is connected to one end of the optical fiber under test 206 and is used to emit visible light to the optical fiber under test 206; The optical amplification device 204 is used to move along the axis direction of the optical fiber under test 206 after the visible light source 203 emits the visible light, and perform amplification processing on the passing detection light; during the movement of the optical amplification device 204, the detection light passes through the refractive index matching oil 207 in the optical amplification device 204 and is emitted from the light emitting side of the optical amplification device 204 to the optical imaging device 205; The optical imaging device 205 is used to generate a corresponding optical imaging result according to the detection light emitted from the light emitting side of the optical amplification device 204 and the visible light passing through the optical fiber under test 206, so as to obtain the defect detection information of the optical fiber under test 206 according to the optical imaging result.

[0024] In the present invention, the main function of the optical fiber fixing groove 201 is to fix both ends of the optical fiber under test 206. After the optical fiber under test 206 passes through the refractive index matching oil 207 in the optical amplification device 204, the optical fiber fixing groove 201 can ensure the stability and accuracy of the optical fiber during the test. During the test, the axial direction of the optical fiber under test 206 is perpendicular to the optical axis where the broadband light source 202 and the optical amplification device 204 are located, so that the detection light will perpendicularly irradiate the cladding part of the optical fiber.

[0025] In the present invention, the broadband light source 202 is arranged on the light incident side of the optical amplification device 204 and is used to emit detection light to the optical amplification device 204. Since the detection light is light in a wide spectral range, it can cover various defect characteristics that may exist in the optical fiber. The broadband light source 202 and the optical amplification device 204 are on the same optical axis to ensure that the detection light can accurately and efficiently irradiate the test part of the optical fiber under test 206.

[0026] Based on the above embodiments, the wavelength range of the detection light emitted by the broadband light source 202 is from 400 nm to 2400 nm.

[0027] In the present invention, after the detection light with a wavelength range of 400 nm to 2400 nm emitted by the broadband light source 202 passes through the collimating mirror 208, it further forms a parallel light beam with a diameter of about 3 ± 0.3 cm.

[0028] The visible light source 203 is connected to one end of the optical fiber under test 206 and is used to emit visible light to the optical fiber under test 206. The visible light is used for auxiliary detection or as a reference light to help analyze the defect situation in the optical fiber. In the present invention, the emission of the visible light source 203 cooperates with the detection light of the broadband light source 202 to jointly provide the necessary optical conditions for optical fiber defect detection.

[0029] After the visible light source 203 emits visible light, the optical amplification device 204 moves along the axial direction of the optical fiber under test 206. During the movement, the optical amplification device 204 amplifies the passing detection light to improve the intensity and clarity of the detection light. During the movement of the optical amplification device 204, the detection light passes through the refractive index matching oil 207 in the optical amplification device 204. The refractive index matching oil 207 can reduce the refractive loss of light between the optical fiber and the optical amplification device and improve the imaging quality.

[0030] In the present invention, the amplified detection light is emitted from the light-emitting side of the optical amplification device 204 to the optical imaging device 205. The optical imaging device 205 generates corresponding optical imaging results based on the detection light emitted from the light-emitting side of the optical amplification device 204 and the visible light passing through the optical fiber under test 206. These optical imaging results can clearly show the defect conditions in the optical fiber, such as cracks, bubbles, impurities, etc. According to the optical imaging results, the defect detection information of the optical fiber under test 206 can be obtained, providing an important basis for the quality evaluation and use of the optical fiber, and realizing efficient and accurate defect detection of the optical fiber under test 206. In the present invention, the optical imaging device 205 can be composed of a Charge-Coupled Device (CCD for short). By converting the optical imaging results of the optical fiber under test 206 into electrical signals and displaying the imaging information, it is convenient for observing and analyzing the optical fiber defects.

[0031] The optical fiber defect detection system provided by the present invention fixes both ends of the optical fiber under test passing through the refractive index matching oil in the optical amplification device through the optical fiber fixing groove, and uses the cladding part of the optical fiber under test as the test part. Then, a broadband light source is used to emit detection light to the test part, and a visible light source emits visible light from one end of the optical fiber. Thus, during the process of the optical amplification device moving along the optical fiber axis, the detection light is amplified and emitted to the optical imaging device to generate optical imaging results, and the optical fiber defect detection information is obtained, improving the accuracy and efficiency of optical fiber defect detection.

[0032] Based on the above embodiments, the optical amplification device 204 includes a first objective lens 2041 and a second objective lens 2042, where: The refractive index matching oil 207 is adsorbed in the objective lens gap between the light-emitting side of the first objective lens 2041 and the light-incident side of the second objective lens 2042; A collimating lens 208 is arranged between the light-incident side of the first objective lens 2041 and the broadband light source 202, and a focusing lens 209 is arranged between the light-emitting side of the second objective lens 2042 and the optical imaging device 205; The detection light emitted by the broadband light source 202 forms a parallel light beam after passing through the collimating lens 208 and is emitted to the light-incident side of the first objective lens 2041. The parallel light beam forms a converging light beam after passing through the first objective lens 2041, the refractive index matching oil 207, the second objective lens 2042, and the focusing lens 209 in sequence, and is emitted to the optical imaging device 205.

[0033] In the present invention, the optical amplification device 204 mainly consists of a first objective lens 2041 and a second objective lens 2042. An objective lens gap is formed between the light-emitting side of the first objective lens 2041 and the light-incident side of the second objective lens 2042. A refractive index matching oil 207 is adsorbed in this gap. The function of the refractive index matching oil 207 is to reduce the refraction loss of light when passing through the objective lens gap and improve the imaging quality.

[0034] Furthermore, a collimating lens 208 is provided between the light-incident side of the first objective lens 2041 and the broadband light source 202. After the detection light emitted by the broadband light source 202 passes through the collimating lens 208, a parallel light beam will be formed, which is beneficial for subsequent optical amplification and imaging.

[0035] In the present invention, the formed parallel light beam is emitted to the light-incident side of the first objective lens 2041. After being refracted and amplified by the first objective lens 2041, the parallel light beam enters the refractive index matching oil 207. In the refractive index matching oil 207, the refraction loss of the parallel light beam is reduced, thereby maintaining the intensity and clarity of the parallel light beam. Then, the parallel light beam enters the second objective lens 2042 and is further refracted and amplified.

[0036] In the present invention, a focusing lens 209 is provided between the light-emitting side of the second objective lens 2042 and the optical imaging device 205. The parallel light beam amplified by the second objective lens 2042 enters the focusing lens 209. The focusing lens 209 converges the parallel light beam into a point or a small light spot, and the formed converging light is emitted to the optical imaging device 205 for generating an optical imaging result.

[0037] Based on the above embodiments, the magnification of the first objective lens 2041 and the second objective lens 2042 is at least 50 times, and the numerical aperture is greater than 0.6.

[0038] In the present invention, objective lenses with high magnification (more than 50 times) and high numerical aperture (greater than 0.60) are used for optical amplification imaging, and the distance between the objective lens gaps between the two objective lenses is adjusted to be less than 600 um so that the objective lens gap is filled with the fiber refractive index matching oil 207 to reduce the refraction of light in the cladding and the oil.

[0039] Through the synergistic effect of the collimating lens, objective lenses, refractive index matching oil and focusing lens, the optical amplification device 204 in the present invention realizes the efficient amplification and focusing of the detection light.

[0040] Based on the above embodiments, the first objective lens 2041 is provided with a first linear displacement platform 2043, and the second objective lens 2042 is provided with a second linear displacement platform 2044, where: The first linear displacement platform 2043 and the second linear displacement platform 2044 are used to drive the first objective lens 2041 and the second objective lens 2042 to move synchronously, so as to adjust the test part of the optical fiber 206 to be measured in the refractive index matching oil 207.

[0041] In the present invention, the first objective lens 2041 is used to receive and preliminarily amplify the detection light emitted by the broadband light source 202. The first linear displacement platform 2043 is connected to the first objective lens 2041 and is used to drive the first objective lens 2041 to perform linear movement along a specific direction (i.e., the axial direction of the optical fiber 206 to be measured).

[0042] The second objective lens 2042 is used to receive the detection light amplified by the first objective lens 2041 and further perform amplification processing. The second linear displacement platform 2044 is connected to the second objective lens 2042 and is used to drive the second objective lens 2042 to perform linear movement.

[0043] In the present invention, the first linear displacement platform 2043 and the second linear displacement platform 2044 can drive the first objective lens 2041 and the second objective lens 2042 to move simultaneously or in a predetermined coordinated manner, so as to adjust the axial spatial position of the optical fiber 206 to be measured and obtain fiber imaging information at different axial positions. This synchronous movement mechanism ensures that the relative positions between the first objective lens 2041 and the second objective lens 2042 remain unchanged, thereby maintaining the magnification and imaging quality of the optical amplification device 204.

[0044] In the present invention, through the synchronous movement of the first linear displacement platform 2043 and the second linear displacement platform 2044, the positions of the first objective lens 2041 and the second objective lens 2042 can be precisely adjusted. This position adjustment directly affects the test part of the optical fiber 206 to be measured in the refractive index matching oil 207. By moving the objective lens, different positions on the optical fiber can be selected for testing, so as to achieve precise detection of the optical fiber.

[0045] Based on the above embodiments, the system further includes an optical fiber rotation control device 210, and the optical fiber rotation control device 210 is used to rotate the optical fiber 206 to be measured to adjust the spatial observation angle of the optical fiber 206 to be measured.

[0046] In the present invention, the optical fiber rotation control device 210 cooperates with other components of the optical amplification device 204 (such as the first objective lens 2041, the second objective lens 2042, etc.) to jointly realize the detection and observation of the optical fiber 206 to be measured.

[0047] The main function of the optical fiber rotation control device 210 is to rotate the optical fiber to be measured 206, which is used to adjust the spatial angle of the optical fiber to be measured 206, achieve rotation of 0 - 360°, so as to observe the internal defects of the optical fiber from different angles. In the present invention, this rotation can be carried out around the axis of the optical fiber, or in other forms of rotation, specifically depending on the design of the device and the detection requirements. By rotating the optical fiber to be measured 206, the observation angle of the optical fiber relative to the optical amplification device 204 can be changed.

[0048] During the optical fiber detection process, different observation angles may reveal different characteristics on the surface or inside of the optical fiber. For example, some defects may only be clearly observable at specific angles. Therefore, by adjusting the spatial observation angle of the optical fiber to be measured 206 through the optical fiber rotation control device 210 in the present invention, the accuracy and comprehensiveness of the detection can be improved, which helps to discover more potential defects or abnormalities, thereby ensuring the quality and performance of the optical fiber.

[0049] Based on the above - mentioned embodiment, the optical fiber fixing groove 201 is provided with a pressing block 2011, which is used to fix the coating parts at both ends of the optical fiber to be measured 206 after both ends of the optical fiber to be measured 206 are placed in the groove.

[0050] In the present invention, the main function of the optical fiber fixing groove 201 is to fix the optical fiber to be measured 206, ensuring that it maintains a stable and accurate position during the detection process. Among them, the selection of the groove depth is determined according to the outer diameters of the optical fiber cladding and coating, so as to ensure that the optical fiber can be placed tightly and stably in the groove.

[0051] The pressing block 2011 is a component provided on the optical fiber fixing groove 201. When both ends of the optical fiber to be measured 206 are placed in the groove, the pressing block 2011 acts on the coating parts at both ends of the optical fiber. The main function of the pressing block 2011 is to fix the optical fiber, preventing it from shifting during the detection process, thereby ensuring the accuracy and stability of the detection.

[0052] Based on the above - mentioned embodiment, the system further includes a driving integrated control device, which is used to generate corresponding control instructions according to the real - time optical imaging result, so as to drive the broadband light source 202, the visible light source 203, the optical amplification device 204 and the optical imaging device 205 to perform corresponding operations.

[0053] In the present invention, the driving integrated control device is used to receive and process the real - time optical imaging result from the optical imaging device 205. Based on these imaging results, the driving integrated control device will generate corresponding control instructions to coordinate and control the operations of other components in the system.

[0054] Specifically, the actual optical imaging device 205 captures images of the optical fiber in real time and transmits the image data to the drive integrated control device. The drive integrated control device processes and analyzes the image data to identify defects, anomalies, or other features in the optical fiber. Furthermore, based on the real-time optical imaging results, the drive integrated control device generates corresponding control instructions, which may include adjusting the emission intensity of the broadband light source 202, changing the emission state of the visible light source 203, driving the optical amplification device 204 to move or rotate, and adjusting the imaging parameters of the optical imaging device 205. For example, if the optical imaging results show that a certain part of the optical fiber requires more detailed observation, the drive integrated control device may send instructions to the optical amplification device 204 to move or rotate to adjust the observation angle. At the same time, the emission states of the broadband light source 202 and the visible light source 203 can also be adjusted to optimize the imaging quality, thereby improving the accuracy and efficiency of detection.

[0055] Figure 3 is a schematic flow diagram of the optical fiber defect detection method provided by the present invention, as Figure 3 shown, the present invention provides an optical fiber defect detection method based on the optical fiber defect detection system described in the above embodiments, including: Step 301, after determining that the test part of the optical fiber to be tested is in the refractive index matching oil inside the optical amplification device, emit detection light to the test part of the optical fiber to be tested through the broadband light source, and emit visible light from one end of the optical fiber to be tested through the visible light source.

[0056] In the present invention, after determining that the test part of the optical fiber to be tested is already in the refractive index matching oil inside the optical amplification device, the broadband light source and the visible light source are started. The broadband light source emits detection light to the test part of the optical fiber to be tested. This detection light has a wide spectral range and can cover various defect characteristics that may exist in the optical fiber. At the same time, the visible light source emits visible light from one end of the optical fiber to be tested. This beam of visible light can be used for auxiliary detection or as a reference light to help analyze the defect situation in the optical fiber.

[0057] Step 302, when the optical amplification device moves along the axis direction of the optical fiber to be tested, generate corresponding optical imaging results according to the detection light emitted from the light output side of the optical amplification device and the visible light passing through the optical fiber to be tested.

[0058] In the present invention, the optical amplification device moves along the axis direction of the optical fiber to be tested. At this time, the detection light passes through the test part of the optical fiber and is affected by the internal structure and defects of the optical fiber. The detection light enters the optical amplification device and then is emitted from the light output side of the optical amplification device.

[0059] Meanwhile, the visible light passing through the optical fiber to be measured will also be captured by the optical imaging device together with the detection light. The optical imaging device converts the information of the detection light and the visible light into an intuitive optical image according to the received detection light and visible light, and generates a corresponding optical imaging result.

[0060] Step 303, according to the optical imaging result, obtain the defect detection information of the optical fiber to be measured.

[0061] In the present invention, the defect detection information of the optical fiber to be measured is obtained through abnormal features (such as dark spots, bright spots, cracks, etc.) in the optical imaging result. These defect detection information may include the position, size, shape, and type of the defect, etc., providing a basis for the quality evaluation and use of the optical fiber.

[0062] The optical fiber defect detection method provided by the present invention fixes both ends of the optical fiber to be measured passing through the refractive index matching oil in the optical amplification device through the optical fiber fixing groove, and uses the cladding part of the optical fiber to be measured as the test part. Then, a broadband light source is used to emit detection light to the test part, and a visible light source emits visible light from one end of the optical fiber. Thus, during the process of the optical amplification device moving along the optical fiber axis, the detection light is amplified and emitted to the optical imaging device to generate an optical imaging result, and the optical fiber defect detection information is obtained, improving the accuracy and efficiency of optical fiber defect detection.

[0063] Based on the above embodiments, the obtaining the defect detection information of the optical fiber to be measured according to the optical imaging result includes: Rotate the optical fiber to be measured, and during the rotation of the optical fiber to be measured, determine the defect position detection information in the optical fiber to be measured according to the position change information of the defect bright spot in the optical imaging result, where the defect bright spot is a bright spot formed in the optical imaging result based on the visible light passing through the defect position of the optical fiber to be measured.

[0064] In the present invention, taking the specific positioning process of the optical fiber defect position as an example for illustration, the specific steps are as follows: Step 1, sequentially turn on the broadband light source, the first linear displacement platform, the second linear displacement platform, and the optical fiber rotation control device, and perform a zeroing operation through the zeroing function of the motor controllers in the first linear displacement platform, the second linear displacement platform, and the optical fiber rotation control device to ensure that each component is in the initial state.

[0065] Step 2, take the optical fiber to be measured, remove the coating layer with a length of about 10 cm, and wipe the surface of the cladding with alcohol to ensure that the surface is clean and free of residues. Place the optical fiber with the coated part in the optical fiber rotation control device, and place both ends of the cladding part of the optical fiber in the first linear displacement platform and the second linear displacement platform respectively to fix the optical fiber and facilitate subsequent operations.

[0066] Step 3: Take a small amount of optical fiber refractive index matching oil and drop it into the gap between the first objective lens and the second objective lens. Due to the action of surface tension, the matching oil will be adsorbed in the objective lens gap, immersing the fiber cladding part between the first objective lens and the second objective lens into the refractive index matching oil, thereby reducing the refraction of light in the cladding and the oil and improving the imaging quality.

[0067] Step 4: The detection light emitted by the broadband light source is converted into parallel light by the collimating lens and enters the optical amplification device composed of the first objective lens and the second objective lens. Among them, the optical fiber located in the refractive index matching oil, after the detection light passes through the optical amplification device, is injected into the optical imaging device through the focusing lens to form a clear image of the optical fiber.

[0068] Step 5: Adjust the first linear displacement platform and the second linear displacement platform to make the fiber under test focus clearly and have distinct boundaries in the optical imaging device to ensure the accuracy of subsequent defect detection.

[0069] Step 6: Turn on the visible light source and inject visible light into one end of the fiber under test near the coating. When the visible light propagates in the fiber under test, if it encounters abnormal conditions such as impurities and defects in the cladding or core, the propagation path of the light will change, and it will no longer continue to transmit forward but scatter in all directions. This scattered light is captured in the optical imaging device and displayed as "bright spots". By analyzing the position and characteristics of the "bright spots", the specific position and nature of the internal defects of the optical fiber can be determined. Specifically, the "bright spots" that appear in the optical imaging device may be located inside the core or in other layers outside the core. The fiber under test can be rotated 0 - 360° through the optical fiber rotation control device to observe whether the "bright spots" rotate out of the core range, thereby determining their specific positions. If the "bright spots" always remain within the core range during the rotation process, it indicates that the defect is located inside the core; if the "bright spots" rotate out of the core at a certain angle, it indicates that the defect is located in other layers outside the core. For the determination of the specific position of other layers outside the core, the position can be further determined according to the foregoing method.

[0070] Step 7: Adjust the first linear displacement platform and the second linear displacement platform, and gradually axially move the fiber under test step by step according to the actual situation. At the same time, during the movement, it is necessary to ensure that the fiber boundary focuses clearly in the optical imaging device.

[0071] The optical fiber defect detection method provided by the present invention can obtain the optical fiber defect information at different axial and radial positions in a short time, greatly improving the detection efficiency. Through the objective lens with high magnification and high numerical aperture and the refractive index matching oil, high-resolution imaging of the internal structure of the optical fiber is achieved, improving the accuracy of defect detection, and it is applicable to various types and structures of special optical fibers, having good versatility and scalability.

[0072] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than limiting it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An optical fiber defect detection system, characterized in that: It includes an optical fiber fixing groove, a broadband light source, a visible light source, an optical magnifying device and an optical imaging device, wherein: The optical fiber fixing groove is used to fix the two ends of the optical fiber to be tested after the optical fiber to be tested passes through the refractive index matching oil in the optical amplifying device, wherein the broadband light source and the optical amplifying device are on the same optical axis, the axial direction of the optical fiber to be tested is perpendicular to the optical axis, and the test portion of the optical fiber to be tested in the refractive index matching oil is the cladding portion; The broadband light source is arranged at the light-incoming side of the optical amplifying device, and is used to emit detection light to the optical amplifying device; The visible light source is connected to one end of the optical fiber to be tested, and is used to emit visible light to the optical fiber to be tested; The optical amplifying device is used to move along the axial direction of the optical fiber to be tested after the visible light source emits the visible light, and amplify the passing detection light; during the movement of the optical amplifying device, the detection light passes through the refractive index matching oil in the optical amplifying device and is emitted from the light output side of the optical amplifying device to the optical imaging device; The optical imaging device is used to generate corresponding optical imaging results based on the detection light emitted by the light output side of the optical amplifying device and the visible light passing through the optical fiber to be tested, so as to obtain defect detection information of the optical fiber to be tested based on the optical imaging results.

2. The optical fiber defect detection system according to claim 1, characterized in that: The optical magnifying device comprises a first objective lens and a second objective lens, wherein: The refractive index matching oil is adsorbed in the objective lens gap between the light exiting side of the first objective lens and the light entering side of the second objective lens; A collimator is provided between the light-incoming side of the first objective lens and the broadband light source, and a focusing lens is provided between the light-outgoing side of the second objective lens and the optical imaging device; The detection light emitted by the broadband light source forms a parallel light beam after passing through the collimating lens and is emitted to the light input side of the first objective lens. The parallel light beam forms a convergent light after passing through the first objective lens, the refractive index matching oil, the second objective lens and the focusing lens in sequence and is emitted to the optical imaging device.

3. The optical fiber defect detection system according to claim 2, characterized in that: The first objective lens is provided with a first linear displacement platform, and the second objective lens is provided with a second linear displacement platform, wherein: The first linear displacement platform and the second linear displacement platform are used to drive the first objective lens and the second objective lens to move synchronously to adjust the test position of the optical fiber to be tested in the refractive index matching oil.

4. The optical fiber defect detection system according to claim 2, characterized in that: The system further comprises an optical fiber rotation control device, and the optical fiber rotation control device is used to rotate the optical fiber to be tested so as to adjust the spatial observation angle of the optical fiber to be tested.

5. The optical fiber defect detection system according to claim 2, characterized in that: The magnification of the first objective lens and the second objective lens is at least 50 times, and the numerical aperture is greater than 0.

6.

6. The optical fiber defect detection system according to claim 1, characterized in that: The wavelength range of the detection light emitted by the broadband light source is 400nm to 2400nm.

7. The optical fiber defect detection system according to claim 1, characterized in that: The optical fiber fixing groove is provided with a pressing block, which is used to fix the coating parts at both ends of the optical fiber to be tested after each end of the optical fiber to be tested is placed in the groove.

8. The optical fiber defect detection system according to claim 1, characterized in that: The system also includes a drive integrated control device, which is used to generate corresponding control instructions based on the real-time optical imaging results to drive the broadband light source, the visible light source, the optical amplification device and the optical imaging device to perform corresponding operations.

9. An optical fiber defect detection method based on the optical fiber defect detection system according to any one of claims 1 to 8, characterized in that: include: After determining that the test portion of the optical fiber to be tested is located in the refractive index matching oil in the optical amplification device, emitting detection light to the test portion of the optical fiber to be tested by a broadband light source, and emitting visible light from one end of the optical fiber to be tested by a visible light light source; When the optical amplifying device moves along the axial direction of the optical fiber to be tested, a corresponding optical imaging result is generated according to the detection light emitted by the light-emitting side of the optical amplifying device and the visible light passing through the optical fiber to be tested; According to the optical imaging result, defect detection information of the optical fiber to be tested is obtained.

10. The optical fiber defect detection method according to claim 9, characterized in that: The step of obtaining defect detection information of the optical fiber to be tested according to the optical imaging result includes: The optical fiber to be tested is rotated, and during the rotation of the optical fiber to be tested, defect position detection information in the optical fiber to be tested is determined according to position change information of the defect bright spot in the optical imaging result, wherein the defect bright spot is a bright spot formed in the optical imaging result based on the visible light passing through the defect position of the optical fiber to be tested.

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