Detection Method and Detection Device for Internal Defects of Optical Fiber

Abstract

The present application provides a method and a device for detecting internal defects of an optical fiber. The detection method includes: placing the optical fiber to be detected in a target environment so that the optical fiber to be detected maintains a target state; the optical fiber to be detected includes two opposite ends; injecting detection light from one end of the optical fiber to be detected to obtain the detection light exiting from the other end of the optical fiber to be detected; the injected detection light is single fundamental mode light, and the exiting detection light includes single fundamental mode light and non-fundamental mode light; respectively obtaining the powers of the single fundamental mode light and the non-fundamental mode light in the exiting detection light; determining the quantity level of the internal defects of the optical fiber to be detected according to the powers of the single fundamental mode light and the non-fundamental mode light in the exiting detection light. By correlating the generation of non-fundamental mode light with the microscopic defects inside the optical fiber, and determining the quantity level of the internal defects of the optical fiber to be detected according to the powers of the single fundamental mode light and the non-fundamental mode light in the obtained exiting detection light, the quantity of the defects in the optical fiber can be quantified to a certain extent and the severity of the defects can be reflected.

Description

Technical Field

[0001] This application relates to the field of detection technologies, and particularly to a method and a device for detecting internal defects of an optical fiber. Background Art

[0002] During the production process of an optical fiber, various defects will inevitably occur inside it. Therefore, it is necessary to detect the internal defects of the optical fiber to ensure the quality of the optical fiber leaving the factory.

[0003] In the related art, there are two ways to detect internal defects of an optical fiber. One way is to detect the optical fiber from one side by means of appearance detection after drawing and before coating. However, in order to protect the optical fiber, the interval time from drawing to coating is extremely short, and only serious macroscopic defects can be detected, while minor microscopic defects cannot be detected. Another way is to use an Optical Time-Domain Reflectometer (OTDR) to obtain attenuation information by using the backward scattered light generated when light propagates in the optical fiber. This way can only detect the strong backward scattered light caused by serious macroscopic defects. The above two ways both have certain technical bottlenecks in the detection of internal defects of the optical fiber and need to be improved and developed. Summary of the Invention

[0004] This application provides a method and a device for detecting internal defects of an optical fiber, which can detect the defects existing inside the optical fiber and quantitatively reflect the number level of microscopic defects inside the optical fiber.

[0005] To achieve the above object, this application provides a method for detecting internal defects of an optical fiber, including: placing the optical fiber to be detected in a target environment so that the optical fiber to be detected maintains a target state; the optical fiber to be detected includes two opposite ends; injecting detection light from one end of the optical fiber to be detected to obtain the detection light exiting from the other end of the optical fiber to be detected; the injected detection light is single fundamental mode light, and the exiting detection light includes single fundamental mode light and non-fundamental mode light; respectively obtaining the powers of the single fundamental mode light and the non-fundamental mode light in the exiting detection light; and determining the number level of internal defects of the optical fiber to be detected according to the powers of the single fundamental mode light and the non-fundamental mode light in the exiting detection light.

[0006] Wherein, the optical fiber to be detected includes a core and a cladding surrounding the core; the step of injecting detection light from one end of the optical fiber to be detected to obtain the detection light exiting from the other end of the optical fiber to be detected includes: injecting single fundamental mode light from the core at one end of the optical fiber to be detected to obtain the single fundamental mode light exiting from the core at the other end of the optical fiber to be detected and the non-fundamental mode light exiting from the cladding at the other end.

[0007] Among them, the step of respectively obtaining the power of the single fundamental mode light and the non-fundamental mode light in the emitted detection light includes: detecting and obtaining the power of the emitted detection light; stripping the non-fundamental mode light in the emitted detection light to detect and obtain the power of the emitted detection light after stripping the non-fundamental mode light; and respectively determining the power of the single fundamental mode light and the non-fundamental mode light in the emitted detection light according to the power of the emitted detection light and the power of the emitted detection light after stripping the non-fundamental mode light.

[0008] Among them, the non-fundamental mode light in the emitted detection light is stripped according to a preset stripping efficiency; the step of respectively determining the power of the single fundamental mode light and the non-fundamental mode light in the emitted detection light according to the power of the emitted detection light and the power of the emitted detection light after stripping the non-fundamental mode light includes: respectively determining the power of the single fundamental mode light and the non-fundamental mode light in the emitted detection light according to the power of the emitted detection light, the power of the emitted detection light after stripping the non-fundamental mode light, and the preset stripping efficiency.

[0009] Among them, the step of determining the number level of internal defects of the optical fiber to be measured according to the power of the single fundamental mode light and the non-fundamental mode light in the emitted detection light includes: determining the power ratio of the single fundamental mode light and the non-fundamental mode light in the emitted detection light according to the power of the single fundamental mode light and the non-fundamental mode light in the emitted detection light to obtain the light conversion ratio of the optical fiber to be measured; comparing the light conversion ratio of the optical fiber to be measured with a pre-established target light conversion ratio to determine the number level of internal defects of the optical fiber to be measured.

[0010] Among them, the target light conversion ratio includes a first light conversion ratio and a second light conversion ratio, and the method for establishing the target light conversion ratio includes the following steps: obtaining the light conversion ratios of a plurality of sample optical fibers belonging to the same specification; sorting the light conversion ratios of the plurality of sample optical fibers from large to small; taking the smallest light conversion ratio among the top twenty percent of the sorted light conversion ratios as the first light conversion ratio, and taking the smallest light conversion ratio among the top forty percent of the sorted light conversion ratios as the second light conversion ratio.

[0011] Among them, the step of comparing the light conversion ratio of the optical fiber to be measured with a pre-established target light conversion ratio to determine the number level of internal defects of the optical fiber to be measured includes: if the light conversion ratio of the optical fiber to be measured is greater than or equal to the first light conversion ratio, determining that the number level of internal defects of the optical fiber to be measured is the first level; if the light conversion ratio of the optical fiber to be measured is less than the first light conversion ratio and greater than or equal to the second light conversion ratio, determining that the number level of internal defects of the optical fiber to be measured is the second level; if the light conversion ratio of the optical fiber to be measured is less than the second light conversion ratio, determining that the number level of internal defects of the optical fiber to be measured is the third level; among them, the first level, the second level, and the third level respectively correspond to an increasing number of internal defects in the sample optical fiber.

[0012] Among them, the step of placing the optical fiber to be measured in a target environment to keep the optical fiber to be measured in a target state includes: placing the optical fiber to be measured in a fixed wire groove under target temperature conditions to keep the optical fiber to be measured in a target winding state or a linear state.

[0013] This application also provides a detection device for internal defects of an optical fiber, including: an optical fiber placement module for placing the optical fiber to be measured in a target environment to keep the optical fiber to be measured in a target state, where the optical fiber to be measured includes two opposite ends; a light source module for injecting a detection light from one end of the optical fiber to be measured, and the injected detection light is a single fundamental mode light; a light receiving module for obtaining the detection light exiting from the other end of the optical fiber to be measured, and the exiting detection light includes a single fundamental mode light and a non-fundamental mode light; a power acquisition module for respectively acquiring the powers of the single fundamental mode light and the non-fundamental mode light in the exiting detection light; and a defect level determination module for determining the quantity level of internal defects of the optical fiber to be measured according to the powers of the single fundamental mode light and the non-fundamental mode light in the exiting detection light.

[0014] Among them, the optical fiber to be measured is a single-mode optical fiber or a multi-mode optical fiber.

[0015] The beneficial effects of this application are as follows: In the detection method for internal defects of an optical fiber provided by this application, by placing the optical fiber to be measured in a target environment to keep the optical fiber to be measured in a target state, different optical fibers to be measured can be tested in the same environment and state, thereby avoiding interference from external factors on the testing process; by injecting a detection light from one end of the optical fiber to be measured to obtain the detection light exiting from the other end of the optical fiber to be measured, since the injected detection light is a single fundamental mode light and the exiting detection light includes a single fundamental mode light and a non-fundamental mode light, the generation of the non-fundamental mode light can be associated with the microscopic defects inside the optical fiber. Then, according to the powers of the single fundamental mode light and the non-fundamental mode light in the obtained exiting detection light, the quantity level of internal defects of the optical fiber to be measured can be determined, thereby quantifying and measuring the quantity of defects in the optical fiber to a certain extent and reflecting the severity of the defects. Description of the Drawings

[0016] In order to more clearly illustrate the technical solutions of this application, the drawings required for describing each embodiment formed according to this application will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative efforts.

[0017] Figure 1 It is a schematic flowchart of the detection method for internal defects of an optical fiber provided by an embodiment of this application;

[0018] Figure 2It is a schematic diagram of the optical path inside the optical fiber provided by an embodiment of the present application;

[0019] Figure 3 It is a further process schematic diagram of step S103 provided by an embodiment of the present application;

[0020] Figure 4 It is a further process schematic diagram of step S104 provided by an embodiment of the present application;

[0021] Figure 5 It is a structural schematic block diagram of a detection device for internal defects of an optical fiber provided by an embodiment of the present application. Specific Embodiments

[0022] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative efforts belong to the scope of protection of the present application.

[0023] In the description of the present application, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present 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 cannot be understood as a limitation to the present application. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present application, "a plurality" means two or more, unless otherwise specifically defined.

[0024] In the description of the present application, it should be noted that unless otherwise clearly specified and limited, the terms "installed", "connected", and ""connected"" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection, an electrical connection, or a communication connection; it may be directly connected, or indirectly connected through an intermediate medium, and it may be the internal communication of two elements or the interaction relationship between two elements. 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.

[0025] In this application, unless otherwise clearly defined and limited, the first feature being "on" or "under" the second feature may include direct contact between the first and second features, or may include indirect contact between the first and second features through additional features therebetween. Moreover, the first feature being "above", "over" and "on top of" the second feature includes the first feature being directly above and obliquely above the second feature, or merely indicating that the horizontal height of the first feature is higher than that of the second feature. The first feature being "under", "below" and "beneath" the second feature includes the first feature being directly below and obliquely below the second feature, or merely indicating that the horizontal height of the first feature is less than that of the second feature.

[0026] The following disclosure provides many different embodiments or examples for implementing different structures of this application. To simplify the disclosure of this application, components and settings of specific examples are described below. Of course, they are merely examples and are not intended to limit this application. In addition, this application may repeat reference numerals and / or reference letters in different examples. Such repetition is for the purpose of simplification and clarity, and does not itself indicate the relationship between the various embodiments and / or settings discussed. In addition, this application provides examples of various specific processes and materials, but those of ordinary skill in the art can be aware of the application of other processes and / or the use of other materials.

[0027] Please refer to Figure 1 , Figure 1 which is a schematic flowchart of a method for detecting internal defects of an optical fiber provided by this application. As Figure 1 shown, the detection method includes the following steps:

[0028] Step S101: Place the optical fiber to be measured in a target environment so that the optical fiber to be measured maintains a target state.

[0029] Among them, the optical fiber to be measured includes two relatively arranged ends. In one embodiment, in order to reduce the influence of external factors on the detection result, step S101 may specifically include the following steps: Place the optical fiber to be measured in a fixed wire groove under target temperature conditions so that the optical fiber to be measured maintains a target winding state or a linear state.

[0030] Specifically, by detecting the optical fiber to be measured under target temperature conditions, such as room temperature for example, it can be ensured that different optical fibers to be measured are detected at the same temperature, thereby avoiding differences in detection results of different individuals caused by temperature factors. By placing the optical fiber to be measured in a fixed wire groove so that the optical fiber to be measured maintains a target winding state or a linear state, differences in detection results of different individuals caused by the shape and internal stress factors of the optical fiber to be measured can be avoided.

[0031] Optionally, in the embodiments of the present application, according to one classification method, the optical fiber to be measured can be a single-mode optical fiber or a multi-mode optical fiber; according to another classification method, the optical fiber to be measured can be an active optical fiber or a passive optical fiber.

[0032] Step S102: Inject detection light from one end of the optical fiber to be measured to obtain the detection light exiting from the other end of the optical fiber to be measured.

[0033] Please refer to Figure 2 , Figure 2 which is a schematic diagram of the optical path inside the optical fiber provided by the embodiments of the present application. Among them, the incident detection light is single fundamental mode light, and the exiting detection light includes single fundamental mode light and non-fundamental mode light.

[0034] It should be noted that the inventors of the present application found in the research that during the production process of the optical fiber, various microscopic defects will inevitably occur inside it, such as: impurities, holes, nodules (aggregation of atoms in a non-target state), microcracks, fusion joints, etc. These microscopic defects will cause the single fundamental mode light to be converted into non-fundamental mode light such as single high-order mode and single low-order mode light.

[0035] Among them, the optical fiber to be measured includes a core and a cladding surrounding the core. In this embodiment, step S102 specifically includes: injecting single fundamental mode light from the core at one end of the optical fiber to be measured to obtain the single fundamental mode light exiting from the core at the other end of the optical fiber to be measured and the non-fundamental mode light exiting from the cladding at the other end.

[0036] Specifically, as Figure 2 shown, when there are defects inside the optical fiber to be measured, such as at the junction of the cladding and the core or inside the core, it will cause the light mode to change. For example, when the single fundamental mode light incident from the core passes through the defect inside the core, it changes the propagation direction of a part of the single fundamental mode light, resulting in a smaller incident angle of a part of the single fundamental mode light at the junction of the cladding and the core, thus refraction occurs, forming single high-order mode and single low-order mode light propagating in the cladding.

[0037] Step S103: Obtain the powers of the single fundamental mode light and the non-fundamental mode light in the exiting detection light respectively.

[0038] In some embodiments, the power P0 of the exiting detection light can be detected and obtained by using an optical power detector first, and then the exiting detection light is filtered, and then the power P1 of the filtered exiting detection light is detected and obtained. Among them, the single fundamental mode light or the non-fundamental mode light in the exiting detection light can be filtered out. If the single fundamental mode light in the exiting detection light is filtered out and it is completely filtered out, then the power P1 of the filtered exiting detection light is equal to the power P2 of the non-fundamental mode light in the exiting detection light, and the power P3 of the single fundamental mode light in the exiting detection light is equal to P0 minus P1.

[0039] Please refer toFigure 3 , Figure 3 is a further process schematic diagram of step S103. As shown in Figure 3 , in one embodiment, step S103 may include the following steps:

[0040] Step S1031: Detect and obtain the power of the emitted detection light;

[0041] Step S1032: Strip the non-fundamental mode light in the emitted detection light to detect and obtain the power of the emitted detection light after stripping the non-fundamental mode light;

[0042] Step S1033: Determine the power of the single fundamental mode light and the non-fundamental mode light in the emitted detection light according to the power of the emitted detection light and the power of the emitted detection light after stripping the non-fundamental mode light, respectively.

[0043] In one embodiment, when completely stripping the non-fundamental mode light in the emitted detection light, the power P2 of the non-fundamental mode light in the emitted detection light can be obtained by subtracting the power P1 of the emitted detection light after stripping the non-fundamental mode light obtained in step S1033 from the power P0 of the emitted detection light obtained in step S1031. Here, P0 is the power of the emitted detection light before stripping the non-fundamental mode light, and the power P3 of the single fundamental mode light in the emitted detection light is equal to P1.

[0044] In another embodiment, when the non-fundamental mode light in the emitted detection light cannot be completely stripped, that is, the non-fundamental mode light in the emitted detection light is stripped according to a preset stripping efficiency m (unit: dB). Specifically, a cladding mode stripper can be used to strip the non-fundamental mode light transmitted in the cladding, and the cladding mode stripper has a preset stripping efficiency m (unit: dB). Correspondingly, step S1033 may include: determining the power of the single fundamental mode light and the non-fundamental mode light in the emitted detection light according to the power of the emitted detection light, the power of the emitted detection light after stripping the non-fundamental mode light, and the preset stripping efficiency, respectively.

[0045] Specifically, the power P2 of the non-fundamental mode light in the emitted detection light before step S1032 and the power P4 of the non-fundamental mode light in the emitted detection light after step S1032 satisfy the relationship: Since stripping the non-fundamental mode light transmitted in the cladding does not affect the single fundamental mode light transmitted in the core, the power P0 of the emitted detection light obtained in step S1031 and the power P1 of the emitted detection light after stripping the non-fundamental mode light obtained in step S1033 satisfy the relationship: P0 - P1 = P2 - P4. Combining the above relationships, it can be determined that:

[0046] The power of the non-fundamental mode light in the emitted detection light

[0047] The power of single fundamental mode light in the emitted detection light

[0048] Step S104: Determine the quantity level of internal defects in the optical fiber under test according to the powers of single fundamental mode light and non-fundamental mode light in the emitted detection light.

[0049] Please refer to Figure 4 , Figure 4 which is a further process schematic diagram of step S104 provided in this embodiment. As Figure 4 shown, step S104 includes:

[0050] Step S1041: Determine the power ratio of single fundamental mode light and non-fundamental mode light in the emitted detection light according to the powers of single fundamental mode light and non-fundamental mode light in the emitted detection light, and obtain the light conversion ratio of the optical fiber under test;

[0051] Step S1042: Compare the light conversion ratio of the optical fiber under test with a pre-established target light conversion ratio to determine the quantity level of internal defects in the optical fiber under test.

[0052] Specifically, according to the power P3 of single fundamental mode light and the power P2 of non-fundamental mode light in the emitted detection light obtained in step S103, the power ratio of the two can be determined as P3 / P2, and the light conversion ratio of the optical fiber under test is obtained as wherein, since internal defects in the optical fiber are the reason for the optical mode conversion of single fundamental mode light, when the light conversion ratio of the optical fiber under test is smaller, it indicates that the power P2 of non-fundamental mode light in the emitted detection light is relatively larger, and the power P3 of single fundamental mode light in the emitted detection light is relatively smaller, thus reflecting that the number of internal defects in the optical fiber is more and the severity is also higher. Therefore, in the embodiment of the present application, by obtaining the light conversion ratio of the optical fiber under test, the quantity level of internal defects in the optical fiber can be quantified to a certain extent according to this light conversion ratio.

[0053] In one embodiment, the target light conversion ratio includes a first light conversion ratio and a second light conversion ratio, and the method for establishing the target light conversion ratio includes the following steps:

[0054] Obtain the light conversion ratios of multiple sample optical fibers belonging to the same specification;

[0055] Sort the light conversion ratios of the multiple sample optical fibers from largest to smallest;

[0056] Take the smallest light conversion ratio among the top twenty percent of the sorted light conversion ratios as the first light conversion ratio, and take the smallest light conversion ratio among the top forty percent of the sorted light conversion ratios as the second light conversion ratio.

[0057] Specifically, since there are no optical fibers without internal defects in reality, all optical fibers have a certain light conversion ratio. Therefore, it is necessary to obtain and compare the light conversion ratios of multiple sample optical fibers of the same specification. When a certain amount of data is accumulated, the qualified line and excellent line of the light conversion ratio of this specification of optical fiber can be defined, so as to realize the quantitative determination of the optical fiber quality. In the embodiments of the present application, the first light conversion ratio is used as the excellent line of the optical fiber light conversion ratio, and the second light conversion ratio is used as the qualified line. Optionally, the number of sample optical fibers can be set according to actual needs, such as 100, 200, 300, etc.

[0058] In one embodiment, step S1042 may specifically include:

[0059] If the light conversion ratio of the optical fiber to be tested is greater than or equal to the first light conversion ratio, determine that the quantity level of the internal defects of the optical fiber to be tested is the first level;

[0060] If the light conversion ratio of the optical fiber to be tested is less than the first light conversion ratio and greater than or equal to the second light conversion ratio, determine that the quantity level of the internal defects of the optical fiber to be tested is the second level; if the light conversion ratio of the optical fiber to be tested is less than the second light conversion ratio, determine that the quantity level of the internal defects of the optical fiber to be tested is the third level; wherein, the first level, the second level, and the third level respectively correspond to an increasing number of internal defects of the sample optical fiber.

[0061] Specifically, when it is determined that the quantity level of the internal defects of the optical fiber to be tested is the first level, it reflects that the number of internal defects of the optical fiber to be tested is small, and this optical fiber to be tested belongs to high-quality optical fiber; when it is determined that the quantity level of the internal defects of the optical fiber to be tested is the second level, it reflects that the number of internal defects of the optical fiber to be tested is average, and this optical fiber to be tested belongs to qualified optical fiber; when it is determined that the quantity level of the internal defects of the optical fiber to be tested is the third level, it reflects that the number of internal defects of the optical fiber to be tested is large, and this optical fiber to be tested belongs to unqualified optical fiber.

[0062] In the method for detecting internal defects of an optical fiber provided in the embodiments of the present application, by placing the optical fiber to be tested in a target environment to make the optical fiber to be tested maintain a target state, different optical fibers to be tested can be tested in the same environment and state, thereby avoiding the interference of external factors on the test process; by injecting detection light from one end of the optical fiber to be tested to obtain the detection light exiting from the other end of the optical fiber to be tested, since the incident detection light is single fundamental mode light, and the exiting detection light includes single fundamental mode light and non-fundamental mode light, the generation of non-fundamental mode light can be associated with the microscopic defects inside the optical fiber. Then, according to the powers of the single fundamental mode light and non-fundamental mode light in the obtained exiting detection light, the quantity level of the internal defects of the optical fiber to be tested can be determined, so as to quantitatively measure the number of defects in the optical fiber to a certain extent and reflect the severity of the defects.

[0063] Please refer to Figure 5, this application also provides a detection device for internal defects of an optical fiber. The detection device includes an optical fiber placement module 10, a light source module 20, a light receiving module 30, a power acquisition module 40, and a defect level determination module 50. Among them, the optical fiber placement module 10 is used to place the optical fiber to be tested in a target environment so that the optical fiber to be tested maintains a target state. The optical fiber to be tested includes two opposite ends. The light source module 20 is used to inject detection light from one end of the optical fiber to be tested, and the injected detection light is single fundamental mode light. The light receiving module 30 is used to obtain the detection light exiting from the other end of the optical fiber to be tested, and the exiting detection light includes single fundamental mode light and non-fundamental mode light. The power acquisition module 40 is used to respectively acquire the powers of the single fundamental mode light and the non-fundamental mode light in the exiting detection light. The defect level determination module 50 is used to determine the quantity level of internal defects of the optical fiber to be tested according to the powers of the single fundamental mode light and the non-fundamental mode light in the exiting detection light.

[0064] Among them, the optical fiber to be tested is a single-mode optical fiber or a multi-mode optical fiber.

[0065] The detection device provided by the embodiment of this application places the optical fiber to be tested in a target environment so that the optical fiber to be tested maintains a target state, enabling different optical fibers to be tested in the same environment and state, thereby avoiding interference from external factors during the testing process; by injecting detection light from one end of the optical fiber to be tested to obtain the detection light exiting from the other end of the optical fiber to be tested. Since the injected detection light is single fundamental mode light and the exiting detection light includes single fundamental mode light and non-fundamental mode light, the generation of non-fundamental mode light can be associated with microscopic defects inside the optical fiber. Then, according to the powers of the single fundamental mode light and the non-fundamental mode light in the obtained exiting detection light, the quantity level of internal defects of the optical fiber to be tested can be determined, thereby quantitatively measuring the number of defects in the optical fiber to a certain extent and reflecting the severity of the defects.

[0066] The above has introduced in detail a detection method and a detection device for internal defects of an optical fiber provided by the embodiment of this application. Specific examples are used in this article to elaborate on the principle and implementation manner of this application. The description of the above embodiments is only used to help understand the method and its core idea of this application; at the same time, for those skilled in the art, according to the idea of this application, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation of this application. Moreover, for those of ordinary skill in the art of this technology, without departing from the principle of this application, several improvements and refinements can be made, and these improvements and refinements are also regarded as the protection scope of this application.

Claims

1. A method for detecting internal defects of an optical fiber, characterized in that, Including: Placing the optical fiber to be measured in a target environment so that the optical fiber to be measured maintains a target state; The optical fiber to be measured includes two ends arranged oppositely; Injecting detection light from one end of the optical fiber to be measured to obtain detection light exiting from the other end of the optical fiber to be measured; the injected detection light is single fundamental mode light, and the exiting detection light includes single fundamental mode light and non-fundamental mode light; Respectively obtaining the powers of the single fundamental mode light and the non-fundamental mode light in the exiting detection light; According to the powers of the single fundamental mode light and the non-fundamental mode light in the exiting detection light, determining the power ratio of the single fundamental mode light and the non-fundamental mode light in the exiting detection light to obtain the light conversion ratio of the optical fiber to be measured; Comparing the light conversion ratio of the optical fiber to be measured with a pre-established target light conversion ratio to determine the quantity level of internal defects of the optical fiber to be measured.

2. The detection method for internal defects of an optical fiber according to claim 1, characterized in that, The optical fiber to be measured includes a core and a cladding surrounding the core; The step of injecting detection light from one end of the optical fiber to be measured to obtain detection light exiting from the other end of the optical fiber to be measured includes: Injecting single fundamental mode light from the core at one end of the optical fiber to be measured to obtain single fundamental mode light exiting from the core at the other end of the optical fiber to be measured and non-fundamental mode light exiting from the cladding at the other end.

3. The detection method for internal defects of an optical fiber according to claim 2, wherein The step of respectively obtaining the powers of the single fundamental mode light and the non-fundamental mode light in the exiting detection light includes: Detecting and obtaining the power of the exiting detection light; Removing the non-fundamental mode light in the exiting detection light to detect and obtain the power of the exiting detection light after removing the non-fundamental mode light; According to the power of the exiting detection light and the power of the exiting detection light after removing the non-fundamental mode light, respectively determining the powers of the single fundamental mode light and the non-fundamental mode light in the exiting detection light.

4. The detection method for internal defects of an optical fiber according to claim 3, characterized in that, Removing the non-fundamental mode light in the exiting detection light according to a preset stripping efficiency; the step of respectively determining the powers of the single fundamental mode light and the non-fundamental mode light in the exiting detection light according to the power of the exiting detection light and the power of the exiting detection light after removing the non-fundamental mode light includes: According to the power of the exiting detection light, the power of the exiting detection light after removing the non-fundamental mode light, and the preset stripping efficiency, respectively determining the powers of the single fundamental mode light and the non-fundamental mode light in the exiting detection light.

5. The method for detecting internal defects of an optical fiber according to claim 1, wherein The target light conversion ratio includes a first light conversion ratio and a second light conversion ratio, and the method for establishing the target light conversion ratio includes the following steps: Obtaining the light conversion ratios of multiple sample optical fibers of the same specification; Sorting the light conversion ratios of the multiple sample optical fibers from largest to smallest; Taking the smallest light conversion ratio among the top twenty percent of the sorted light conversion ratios as the first light conversion ratio, and taking the smallest light conversion ratio among the top forty percent of the sorted light conversion ratios as the second light conversion ratio.

6. The detection method of internal defects of an optical fiber according to claim 5, characterized in that, The step of comparing the light conversion ratio of the optical fiber to be measured with the pre-established target light conversion ratio to determine the quantity level of internal defects of the optical fiber to be measured includes: If the light conversion ratio of the optical fiber to be measured is greater than or equal to the first light conversion ratio, determining that the quantity level of internal defects of the optical fiber to be measured is the first level; If the light conversion ratio of the optical fiber to be measured is less than the first light conversion ratio and greater than or equal to the second light conversion ratio, determine that the quantity level of the internal defects of the optical fiber to be measured is the second level; If the light conversion ratio of the optical fiber to be measured is less than the second light conversion ratio, determine that the quantity level of the internal defects of the optical fiber to be measured is the third level; wherein, the first level, the second level and the third level respectively correspond to an increasing number of internal defects of the sample optical fiber in sequence.

7. The detection method for internal defects of an optical fiber according to claim 1, wherein The step of placing the optical fiber to be measured in a target environment to keep the optical fiber to be measured in a target state includes: Placing the optical fiber to be measured in a fixed wire groove under target temperature conditions to keep the optical fiber to be measured in a target winding state or a linear state.

8. A detection device for internal defects of an optical fiber, characterized in that, It includes: An optical fiber placement module, configured to place the optical fiber to be measured in a target environment to keep the optical fiber to be measured in a target state, and the optical fiber to be measured includes two opposite ends; A light source module, configured to inject detection light from one end of the optical fiber to be measured, and the injected detection light is single fundamental mode light; A light receiving module, configured to obtain the detection light exiting from the other end of the optical fiber to be measured, and the exiting detection light includes single fundamental mode light and non-fundamental mode light; A power acquisition module, configured to respectively acquire the powers of the single fundamental mode light and the non-fundamental mode light in the exiting detection light; A defect level determination module, configured to determine the power ratio of the single fundamental mode light and the non-fundamental mode light in the exiting detection light according to the powers of the single fundamental mode light and the non-fundamental mode light in the exiting detection light, and obtain the light conversion ratio of the optical fiber to be measured; Compare the light conversion ratio of the optical fiber to be measured with a pre-established target light conversion ratio to determine the quantity level of the internal defects of the optical fiber to be measured.

9. The detecting device for internal defects of an optical fiber according to claim 8, characterized in that, The optical fiber to be measured is a single-mode optical fiber or a multi-mode optical fiber.

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