Optical time domain reflection detection device

Abstract

The utility model relates to an optical time domain reflection detection device, which comprises a shell, a circulator, a light source module for outputting laser, a receiving module and an optical fiber connection structure for connecting a detected optical fiber, an installation cavity and three installation channels communicated with the installation cavity are formed in the shell, and the light source module, the receiving module and the optical fiber connecting structure are arranged in the three installation channels respectively; the circulator is provided with a first port corresponding to the light source module, a second port corresponding to the optical fiber connecting structure and a third port corresponding to the receiving module; a collimation assembly used for collimating light output from the light source module is arranged between the light source module and the first port, a first convergence assembly used for converging light output from the second port is arranged between the optical fiber connection structure and the second port, and a light filtering assembly is arranged between the receiving module and the third port. The optical time domain reflection detection device provided by the utility model can solve the problems of large optical crosstalk and low coupling efficiency.

Description

Technical Field

[0001] The utility model relates to the technical field of optical communication, in particular to an optical time domain reflectometry detection device. Background Art

[0002] An optical time domain reflectometer (OTDR for short) is an important test instrument in a fiber optic communication system. The optical emission module of the OTDR emits a set optical pulse signal. According to the principle of backward Fresnel reflection and Rayleigh scattering, the reflected optical signal is converted by an optical receiving module (including an avalanche photodiode (APD for short)), and then data processing and analysis are carried out by a signal processing unit to obtain parameters such as the average loss of the measured optical fiber. It can measure the actual length and average loss of the optical fiber in the fiber optic communication system, and at the same time can detect, locate and measure many types of events on the optical fiber link, such as points with large losses formed by optical fiber splicing, connectors, bends, etc. in the link.

[0003] In the existing optical time domain reflectometer, the form of 45° film coupling is generally adopted, which has the problems of large optical crosstalk and low coupling efficiency. Summary of the Utility Model

[0004] The main purpose of the utility model is to propose an optical time domain reflectometry detection device, aiming to provide an optical time domain reflectometry detection device with small optical crosstalk and high coupling efficiency.

[0005] To achieve the above purpose, an optical time domain reflectometry detection device proposed by the utility model includes a housing, a circulator, a light source module for outputting laser, a receiving module, and an optical fiber connection structure for connecting the optical fiber to be measured;

[0006] The housing forms an installation cavity and three installation channels respectively communicating with the installation cavity, and the light source module, the receiving module, and the optical fiber connection structure are respectively arranged in the three installation channels;

[0007] The circulator has a first port corresponding to the light source module, a second port corresponding to the optical fiber connection structure, and a third port corresponding to the receiving module; the light output from the light source module enters the circulator from the first port and then is output to the optical fiber to be measured through the second port and the optical fiber connection structure; the light reflected from the optical fiber to be measured enters the circulator from the second port and then is output to the receiving module from the third port;

[0008] Among them, a collimating component for collimating the light output from the light source module is provided between the light source module and the first port, a first converging component for converging the light output from the second port is provided between the optical fiber connection structure and the second port, and a filtering component is provided between the receiving module and the third port.

[0009] According to some embodiments of the present invention, the collimating assembly includes a first C-lens lens, the converging assembly includes a second C-lens lens, and the spherical ends of the first C-lens lens and the second C-lens lens are both facing the circulator.

[0010] According to some embodiments of the present invention, one end of the first C-lens lens and / or the second C-lens lens away from its own spherical end has an inclined surface inclined relative to the perpendicular plane of the optical axis.

[0011] According to some embodiments of the present invention, a second focusing component for focusing the light output from the filtering component is provided between the receiving module and the filtering component.

[0012] According to some embodiments of the present invention, the second converging component includes a third C-lens lens disposed in the mounting cavity, and the spherical end of the third C-lens lens faces the filter component.

[0013] According to some embodiments of the present invention, the filter assembly includes a filter and a filter holder disposed in the mounting cavity, and the filter and the third C-lens lens are detachably mounted on opposite ends of the filter holder.

[0014] According to some embodiments of the present invention, the optical fiber connection structure includes an optical fiber pin, and one end of the optical fiber pin is coated with an anti-reflection film.

[0015] According to some embodiments of the present invention, the optical fiber connection structure and the first convergence component are spaced apart.

[0016] According to some embodiments of the present invention, the distance between the light source module and the collimating component is adjustable; and / or the distance between the optical fiber connection structure and the first converging component is adjustable.

[0017] According to some embodiments of the present invention, the light source module includes a buried heterostructure laser.

[0018] The utility model has at least the following beneficial effects:

[0019] In the present utility model, by replacing the form of 45° film coupling with the circulator, the fiber insertion loss can be reduced, enabling the fiber connection structure to receive more light emitted from the light source module, improving the coupling efficiency and the spot quality. In addition, the collimation component can convert the light output from the light source module into parallel light and input it into the first port of the circulator, and output it from the second port. The first focusing component can convert the parallel light output from the second port into converging light and couple it through the receiving port of the fiber connection structure. Through this form of parallel light transmission, the coupling efficiency between the light source module and the receiving module can be further improved while elongating the optical path. Brief Description of the Drawings

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0021] Figure 1 Structural schematic diagram of an optical time domain reflectometry detection device provided by an embodiment of the present utility model;

[0022] Figure 2 For Figure 1 Cross-sectional schematic diagram of the optical time domain reflectometry detection device in

[0023] Figure 3 For Figure 1 Structural schematic diagram of the filter holder in

[0024] Figure 4 For Figure 1 Internal optical path schematic diagram from the light source module to the fiber connection structure in the optical time domain reflectometry detection device in

[0025] Figure 5 For Figure 1 Internal optical path schematic diagram from the fiber connection structure to the receiving module in the optical time domain reflectometry detection device in

[0026] Explanation of the reference numerals:

[0027] 100 - Optical time domain reflectometry detection device; 1 - Housing; 11 - Installation cavity; 2 - Light source module; 3 - Receiving module; 4 - Optical fiber connection structure; 41 - Optical fiber pin; 5 - Circulator; 6 - Collimation assembly; 61 - First C-lens; 7 - First focusing assembly; 71 - Second C-lens; 8 - Second focusing assembly; 81 - Third C-lens; 9 - Filter assembly; 91 - Filter; 92 - Filter holder; 10 - Cover plate; 12 - First adjusting ring; 13 - Second adjusting ring. Detailed implementation manners

[0028] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0029] It should be noted that if there are directional indications (such as up, down, left, right, front, back,...) involved in the embodiments of the present invention, the directional indications are only used to explain the relative position relationship and movement conditions between components in a specific posture (as shown in the drawings). If the specific posture changes, the directional indications will also change accordingly.

[0030] In addition, if there are descriptions such as "first" and "second" involved in the embodiments of the present invention, the descriptions of "first" and "second" are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In addition, the meaning of "and / or" appearing throughout the text includes three parallel solutions. Taking "A and / or B" as an example, it includes solution A, solution B, or a solution where A and B are satisfied simultaneously. In addition, the technical solutions between the embodiments can be combined with each other, but it must be based on the fact that those of ordinary skill in the art can implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the protection scope required by the present invention.

[0031] The present invention provides an optical time domain reflectometry detection device. Figures 1-5 This is a specific embodiment of the optical time domain reflectometry detection device provided by the present invention.

[0032] As Figure 1 and Figure 2, an embodiment of the present utility model provides an optical time domain reflectometry detection device 100, which includes a housing 1, a circulator 5, a light source module 2 for outputting laser light, a receiving module 3, and an optical fiber connection structure 4 for connecting the optical fiber under test; the housing 1 forms an installation cavity 11 and three installation channels respectively communicating with the installation cavity 11, and the light source module 2, the receiving module 3, and the optical fiber connection structure 4 are respectively arranged in the three installation channels; the circulator 5 has a first port corresponding to the light source module 2, a second port corresponding to the optical fiber connection structure 4, and a third port corresponding to the receiving module 3; the light output from the light source module 2 enters the circulator 5 from the first port and then is output to the optical fiber under test through the optical fiber connection structure 4 from the second port; the light reflected from the optical fiber under test enters the circulator 5 from the second port and then is output to the receiving module 3 from the third port; wherein, a collimating component 6 for collimating the light output from the light source module 2 is arranged between the light source module 2 and the first port, a first focusing component 7 for focusing the light output from the second port is arranged between the optical fiber connection structure 4 and the second port, and a filter component 9 is arranged between the receiving module 3 and the third port.

[0033] It should be noted that the circulator 5 is a multi-port device, and the transmission of electromagnetic waves can only circulate in one direction. For example, in this embodiment, the optical path can only be transmitted from the first port of the circulator 5 to the second port of the circulator 5, and from the second port of the circulator 5 to the third port of the circulator 5.

[0034] The light source module only needs to be able to emit laser light. For example, it can be a laser emitter or a laser with components such as an optical fiber amplifier, etc. The receiving module is mainly used to receive optical signals and can be a receiving detector, etc.

[0035] Please refer to Figure 4 and Figure 5Schematic diagram of the internal optical path. The working principle of the optical time domain reflectometry detection device 100 provided by the present utility model: After connecting the optical fiber under test to the optical fiber connection structure 4, the test laser is emitted through the light source module 2. After the light passes through the collimation assembly 6, it is converted into parallel light and enters the first port of the circulator 5, and then is output from the second port of the circulator 5. After passing through the first focusing assembly 7, the parallel light is converted into convergent light and then coupled and converged to the receiving port of the optical fiber connection structure 4, and then transmitted to the optical fiber under test. According to the principle of backward Fresnel reflection and Rayleigh scattering, part of the light will be reflected back in the optical fiber under test. Due to the unidirectional function of the circulator 5, the reflected light will enter the second port of the circulator 5 and be output from the third port of the circulator 5. After being filtered by the filter assembly 9, it is received by the receiving module 3, and the receiving module 3 further processes the received optical signal to obtain the detection data result.

[0036] In the present utility model, by replacing the 45° film coupling form with the circulator 5, the fiber insertion loss can be reduced, so that the optical fiber connection structure 4 can receive more light emitted by the light source module 2, improving the coupling efficiency and the spot quality. In addition, the collimation assembly 6 can convert the light output from the light source module 2 into parallel light and input it into the first port of the circulator 5, and output it from the second port. The first focusing assembly 7 can convert the parallel light output from the second port into convergent light and couple and converge it to the receiving port of the optical fiber connection structure 4. Through this form of parallel light transmission, the coupling efficiency between the light source module 2 and the receiving module 3 can be further improved while stretching the optical path.

[0037] Specifically, the collimation assembly 6 includes a first C-lens, and the focusing assembly includes a second C-lens. The spherical ends of the first C-lens and the second C-lens both face the circulator 5. It should be noted that the C-lens is a spherical lens with a cylindrical axial light passing, one end of which is spherical and the other end is flat. Since the spherical ends of the first C-lens and the second C-lens both face the circulator 5, the first C-lens has a collimation function, and the second C-lens has a focusing function.

[0038] Furthermore, in some embodiments, one end of the first C-lens and / or the second C-lens facing away from its own spherical end has an inclined surface inclined with respect to the plane perpendicular to the optical axis. In this way, the optical path reflection in the optical path transmission can be reduced through this inclined surface, so as to reduce the optical crosstalk degree from the transmitting end to the receiving end. The angle between one end of the first C-lens and the second C-lens facing away from the spherical end and the plane perpendicular to the optical axis is 3° - 5°, preferably 4°.

[0039] Specifically, it can be understood that the light reflected from the fiber under test will be converted into parallel light after passing through the second C-lens. This parallel light will be input into the second port of the circulator 5 and output from the third port. In order to enable the receiving module 3 to receive convergent light and improve the coupling efficiency and spot quality, in some embodiments, a second converging component 8 for converging the light output from the filter component 9 is provided between the receiving module 3 and the filter component 9. In this way, after the reflected light passes through the second converging component 8, the transmitted light will be converted into convergent light and input to the light inlet of the receiving module 3.

[0040] Further, the second converging component 8 includes a third C-lens lens disposed in the installation cavity 11, and the spherical end of the third C-lens lens faces the filter component 9. In this way, the light output from the filter component 9 can be converged by the third C-lens lens and then output to the receiving module 3.

[0041] Specifically, in some embodiments, the filter component 9 includes a filter film and a filter film bracket 92 disposed in the installation cavity 11, and the filter film 91 and the third C-lens lens are detachably mounted at opposite ends of the filter film bracket 92. It can be understood that the filter film bracket 92 is generally only used to mount and fix the filter film 91. However, with the above solution, by also detachably mounting the third C-lens lens in the filter film bracket 92, the installation and coupling space of the installation cavity 11 is saved, which is beneficial to the miniaturized design of the product. In addition, the types of the third C-lens lens and the filter film 91 can be replaced according to requirements to suit different test scenarios. Preferably, the filter film 91 includes a 0° filter film.

[0042] Specifically, in some embodiments, the optical fiber connection structure 4 includes an optical fiber ferrule 41, and an antireflection film is plated on one end of the optical fiber ferrule 41. Among them, the antireflection film is an optical thin film, and its main function is to reduce the reflection on the surface of optical components, thereby increasing the intensity of transmitted light and further reducing the optical crosstalk degree from the transmitting end to the receiving end.

[0043] Further, in some embodiments, the optical fiber connection structure 4 and the first converging component 7 are spaced apart to avoid direct contact, which may result in low point accuracy and affect the coupling efficiency. Moreover, the optical fiber ferrule 41 and the first converging component 7 can also adopt a passive alignment method, enabling adjustment in the X-axis, Y-axis, and Z-axis directions for both during the installation process to improve the coupling efficiency.

[0044] Specifically, in some embodiments, the distance between the light source module 2 and the collimating assembly 6 is adjustable; thus, the coupling efficiency between the two can be improved by adjusting the distance therebetween. In addition, the distance between the optical fiber connection structure 4 and the first converging assembly 7 is adjustable. Similarly, the coupling efficiency between the two can also be improved by adjusting the distance therebetween. It should be noted that either of the above two solutions can be selected to improve the coupling efficiency, or both can be adopted simultaneously to further improve the coupling efficiency.

[0045] Further, in some embodiments, the light source module 2 is installed in the corresponding installation channel through the first adjustment ring 12, and the optical fiber connection structure 4 is installed in the corresponding installation channel through the second adjustment ring 13. Thus, the light source module 2 can adjust its distance from the collimating assembly 6 through the first adjustment ring 12, and the optical fiber connection structure 4 can adjust its distance from the first converging assembly 7 through the second adjustment ring 13.

[0046] Specifically, it should be noted that there are mainly two structures for the waveguide structure of semiconductor lasers at present: 1. Ridge waveguide RWG structure; 2. Buried heterostructure BH structure. In some embodiments of the present invention, the light source module 2 includes a buried heterostructure laser, and the chip of this laser has a small divergence angle, which can improve the coupling efficiency.

[0047] Specifically, in some embodiments, the laser is welded and fixed on the housing 1; the optical fiber connection structure 4 is welded and fixed on the housing 1. Thus, through laser welding connection, the shear resistance at the connection can be improved to enhance the reliability of the product.

[0048] It can be understood that, in order to facilitate placing each component in the installation cavity 11 for installation, in some embodiments, the housing 1 is provided with an installation opening communicating with the installation cavity 11, and a cover plate 10 is detachably connected to the installation opening. Thus, the product can also be adjusted or repaired by removing the cover plate 10.

[0049] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. An optical time domain reflectometry detection device, characterized in that It includes a housing, a circulator, a light source module for outputting laser light, a receiving module, and an optical fiber connection structure for connecting the optical fiber to be tested; The housing forms an installation cavity and three installation channels respectively connected to the installation cavity, and the light source module, the receiving module and the optical fiber connection structure are respectively arranged in the three installation channels; The circulator has a first port corresponding to the light source module, a second port corresponding to the optical fiber connection structure, and a third port corresponding to the receiving module; the light output from the light source module is input into the circulator from the first port and then output from the second port to the optical fiber under test through the optical fiber connection structure; the light reflected from the optical fiber under test is input into the circulator from the second port and then output from the third port to the receiving module; Among them, a collimating component for collimating the light output from the light source module is provided between the light source module and the first port, a first converging component for converging the light output from the second port is provided between the optical fiber connection structure and the second port, and a filtering component is provided between the receiving module and the third port.

2. The optical time domain reflectometry detection device according to claim 1, characterized in that, The collimating assembly includes a first C-lens lens, and the converging assembly includes a second C-lens lens. The spherical ends of the first C-lens lens and the second C-lens lens are both facing the circulator.

3. The optical time domain reflectometry detection device according to claim 2, characterized in that An end of the first C-lens lens and / or the second C-lens lens away from its own spherical end has an inclined surface inclined relative to the perpendicular plane of the optical axis.

4. The optical time domain reflectometry detection device according to claim 1, wherein A second converging component for converging the light output from the filter component is disposed between the receiving module and the filter component.

5. The optical time domain reflectometry detection device according to claim 4, characterized in that, The second converging component comprises a third C-lens lens arranged in the mounting cavity, and the spherical end of the third C-lens lens faces the filter component.

6. The optical time domain reflectometry detection device according to claim 5, wherein, The filter assembly comprises a filter and a filter holder arranged in the mounting cavity, and the filter and the third C-lens are detachably mounted on opposite ends of the filter holder.

7. The optical time domain reflectometry detection device according to claim 1, characterized in that The optical fiber connection structure comprises an optical fiber pin, one end of which is plated with an anti-reflection film.

8. The optical time domain reflectometry detection device according to claim 1, characterized in that The optical fiber connection structure is spaced apart from the first convergence component.

9. The optical time domain reflectometry detection device according to claim 1, characterized in that The distance between the light source module and the collimating component is adjustable; and / or the distance between the optical fiber connection structure and the first converging component is adjustable.

10. The optical time domain reflectometry detection device according to claim 1, characterized in that, The light source module includes a buried heterostructure laser.

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