Optical path structure of optical cable inspection analyzer and optical cable inspection analysis method thereof

Abstract

The invention belongs to the technical field of optical cable inspection analysis, and discloses an optical cable inspection analyzer optical path structure and an optical cable inspection analysis method thereof, and the optical cable inspection analyzer optical path structure comprises a vibration cable searching function unit which is used for achieving the routing distribution and vibration detection of an optical cable; the link test function unit is used for testing the length, loss and joint quality of an optical cable link; the bending and cable fixing function unit is used for searching a single optical cable; the function switching unit is used for realizing switching of optical signal transmission paths in the optical cable; and the port switching unit is used for realizing multi-port expansion of the optical cable inspection analyzer. According to the optical path structure of the optical cable inspection analyzer, a vibration cable searching function, a bending cable fixing function, a link testing function and a port switching function can be integrated, and the optical path structure has the advantages of being multifunctional, high in integration, small in size and convenient to carry.

Description

Technical Field

[0001] The present invention relates to the technical field of optical cable line inspection and analysis, and in particular to an optical path structure of an optical cable line inspection analyzer and an optical cable line inspection and analysis method thereof. Background Art

[0002] In fields such as communications and energy infrastructure, distributed vibration sensing has become a core tool for solving the problem of optical cable positioning in complex environments. In response to operators' needs for route surveys of buried optical cables and oil pipeline optical cables, this equipment uses non-contact vibration sensing technology to achieve efficient and accurate route information collection, significantly improving resource management and maintenance efficiency. Vibration sensing and fault location utilize the sensitivity of optical fibers to external vibrations, and achieve non-contact detection by analyzing disturbance signals transmitted to optical cables by knocking on the ground, manhole covers or pipelines. Intelligent routing and resource management automatically obtains data such as optical cable length, coiling information, geographic coordinates, etc. by knocking on vibration points (such as manhole covers and overhead poles), and uploads them to the cloud through APP. By generating a digital optical cable network map, optical cable route surveys, return identification, and coil length measurements can be completed without drilling a well, significantly reducing manual maintenance efforts. Distributed vibration sensing effectively solves the operator's route survey challenges for buried optical cables and oil pipeline optical cables through non-contact vibration sensing and distributed sensing technology. Its high precision, long distance, and intelligent features not only improve resource management and maintenance efficiency, but also provide reliable guarantees for the safe operation of energy and communication infrastructure. However, the disadvantages of distributed vibration sensing are the small number of ports and the maximum effective test distance of approximately 50 km. It cannot measure the total length of the optical cable, and its dynamic range is greatly affected by the quality and loss of the connectors, making it impossible to judge the quality of the connectors.

[0003] Based on the above-mentioned distributed vibration sensing, the main existing solutions for optical cable routing distribution testing are usually as follows:

[0004] (1) Use separate DVS equipment and separate OTDR equipment. The DVS equipment is used for optical cable vibration testing, and the OTDR tests the length of the optical cable link. The two different devices are tested separately.

[0005] (2) The DVS device integrates modular OTDR test equipment. The DVS and OTDR modules each have separate optical path components, CPU, programmable logic devices, and power modules. The two communicate and transmit data through serial ports, SPI interfaces, or networks.

[0006] (3) Existing DVS devices generally have one or two device ports. If multiple optical cables are to be connected, external expansion of separate optical switch products is often used, and the two devices communicate through the serial port.

[0007] (4) Test solution for the optical switch module integrated inside the DVS device. The DVS and optical switch module have separate optical paths and hardware circuits, and the two communicate through the serial port.

[0008] However, existing optical cable routing distribution test solutions often have the following disadvantages:

[0009] (1) When multiple different test devices are tested separately, the number of test devices increases, it is inconvenient to carry, and the data is difficult to exchange.

[0010] (2) The effective distance and sensitivity of a single DVS measurement are greatly affected by connector loss and coupling quality, and it is unable to identify the connection quality between the device and the optical cable connector under test.

[0011] (3) DVS vibration detection is too sensitive. The vibration is effective for all optical cables in the pipeline well and cannot locate a single optical cable.

[0012] (4) The solution of integrating multiple modules is adopted, which results in independent optical paths, independent hardware, large equipment size, increased power consumption and reduced reliability.

[0013] Therefore, how to provide an optical path structure of an optical cable line inspection analyzer and an optical cable line inspection analysis method thereof that integrates multi-functions and high efficiency is a problem that needs to be solved urgently. Summary of the Invention

[0014] The embodiment of the present invention provides an optical path structure of an optical cable line patrol analyzer and an optical cable line patrol analysis method thereof, so as to solve the above-mentioned technical problems in the prior art.

[0015] To provide a basic understanding of some aspects of the disclosed embodiments, the following is a brief summary. This summary is not intended to be a comprehensive review, identify key or essential elements, or delineate the scope of these embodiments. Its sole purpose is to present some concepts in a simplified form as a prelude to the detailed description that follows.

[0016] According to a first aspect of an embodiment of the present invention, an optical path structure of an optical cable line inspection analyzer is provided.

[0017] In one embodiment, an optical path structure of an optical cable line inspection analyzer includes:

[0018] Vibration cable search unit, used to realize optical cable routing distribution and vibration detection;

[0019] Link test functional unit, used to test the length, loss and connector quality of the optical cable link;

[0020] Bending and fixing cable function unit, used to find a single optical cable;

[0021] A function switching unit, used to switch the optical signal transmission path in the optical cable;

[0022] Port switching unit, used to achieve multi-port expansion of the optical cable line patrol analyzer;

[0023] Wherein, one end of the vibration cable-finding function unit is connected to the second pin of the function switching unit, and the first pin of the function switching unit is connected to one end of the port switching unit;

[0024] One end of the link test functional unit is connected to one end of the bending and cabling functional unit, and the other end of the bending and cabling functional unit is connected to the third pin of the function switching unit.

[0025] In one embodiment, the vibration cable finding functional unit includes:

[0026] Narrow linewidth laser, used to achieve narrow linewidth light emission;

[0027] A modulator, used to realize modulation of pulsed light;

[0028] Erbium-doped fiber amplifier, used to amplify optical signals;

[0029] Filter, used to filter out noise from the erbium-doped fiber amplifier;

[0030] A first circulator, used for coupling optical signals and receiving and detecting optical signals;

[0031] The first detector is used to realize photoelectric signal conversion.

[0032] In one embodiment, after the first detector realizes the photoelectric signal conversion, the converted current signal is converted into a voltage signal through a transimpedance operational amplifier, and the voltage signal is amplified and filtered through an analog circuit, and then converted into a digital signal by an analog-to-digital converter, and then sent to a programmable logic device for processing.

[0033] In one embodiment, the link test functional unit includes:

[0034] two Fabry-Perot lasers for emitting pulsed light;

[0035] Wavelength division multiplexer, used to combine optical signals of different wavelengths;

[0036] The second circulator is used to realize the coupling of optical signals and the reception and detection of optical signals;

[0037] The second detector is used to realize photoelectric signal conversion.

[0038] In one embodiment, the two Fabry-Perot lasers include: a 1310 nm Fabry-Perot laser and a 1550 nm Fabry-Perot laser or a 1625 nm Fabry-Perot laser and a 1650 nm Fabry-Perot laser.

[0039] In one embodiment, the bending and cabling functional unit includes: a first optical switch, a second optical switch, and a polarizer;

[0040] The first optical switch and the second optical switch are used to realize the switching between the bending and cabling function unit and the link testing function unit;

[0041] Polarization analyzer is used to filter optical fiber signals and only allow optical fiber signals with the right polarization direction to pass through.

[0042] In one embodiment, the function switching unit includes:

[0043] The third optical switch is used to realize switching between the vibration cable finding function unit, the link testing function unit and the bending cable fixing function unit.

[0044] In one embodiment, the port switching unit includes:

[0045] The fourth optical switch is used to expand the port of the optical cable line patrol analyzer.

[0046] In one embodiment, the fourth optical switch is switched by outputting a set regulation voltage through a four-channel analog-to-digital converter, and amplifying the regulation voltage output by the four-channel analog-to-digital converter through a high-voltage operational amplifier to regulate and drive the fourth optical switch.

[0047] According to a second aspect of an embodiment of the present invention, a method for analyzing an optical cable inspection is provided.

[0048] In one embodiment, a fiber optic cable inspection and analysis method includes:

[0049] Select the port through the port switching unit to determine the output port corresponding to the optical cable under test;

[0050] Switch the optical cable line analyzer to the link test function unit to perform a link test to obtain the length, loss and connector quality parameters of the tested optical cable;

[0051] The quality of the connector is judged based on the connector quality parameters of the tested optical cable, and whether to perform port cleaning or port connection inspection is determined based on the judgment result;

[0052] Switch the optical cable line analyzer to the bending and fixing cable function unit or the vibration cable finding function unit, and search for a single optical cable when switching to the bending and fixing cable function unit;

[0053] When switching to the vibration cable search function unit, the route distribution of the tested optical cable is obtained, and the optical cable is inspected based on the search results of a single optical cable, the length of the tested optical cable, the loss of the tested optical cable and the route distribution of the tested optical cable.

[0054] The technical solution provided by the embodiment of the present invention may have the following beneficial effects:

[0055] The present invention can integrate the vibration cable finding function, bending cable fixing function, link testing function and port switching function into one through the optical path structure of the optical cable line patrol analyzer, and has the characteristics of multi-function, high integration, small size and easy portability; realizes multi-functional flexible switching and expansion of the number of output ports, increases the number of tested optical cables, and improves the testing efficiency of operators; and each functional unit can share the same hardware resources such as CPU and power supply, further reducing the power consumption, cost and number of connectors of the equipment, improving the data interaction process, improving testing efficiency and product reliability; effectively combining the results of multiple test functions to obtain more test results, which can improve the accuracy of measurement.

[0056] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0058] Figure 1 This is a schematic structural diagram of an optical path structure of an optical cable line inspection analyzer according to an exemplary embodiment;

[0059] Figure 2 This is a flow chart of a method for analyzing an optical cable inspection according to an exemplary embodiment;

[0060] Figure 3 is a schematic diagram of optical cable inspection in an optical cable inspection analysis method according to an exemplary embodiment;

[0061] Figure 4 The present invention is a flowchart illustrating an implementation of port selection in an optical cable line inspection and analysis method according to an exemplary embodiment.

[0062] In the figure: Ⅰ, vibration cable search function unit; Ⅱ, link test function unit; Ⅲ, bending cable fixing function unit; Ⅳ, function switching unit; Ⅴ, port switching unit. DETAILED DESCRIPTION

[0063] The following description and accompanying drawings sufficiently illustrate the specific embodiments herein to enable those skilled in the art to practice them. Portions and features of some embodiments may be included in or substituted for portions and features of other embodiments. The scope of the embodiments herein includes the entire scope of the claims, including all available equivalents thereof. Herein, the terms "first," "second," and the like are used solely to distinguish one element from another and do not require or imply any actual relationship or order between these elements. In practice, the first element can also be referred to as the second element, and vice versa. Furthermore, the terms "comprise," "comprising," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a structure, device, or apparatus comprising a list of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such structure, device, or apparatus. Without further limitation, an element defined by the phrase "comprising a..." does not preclude the presence of other identical elements in the structure, device, or apparatus comprising the element. The various embodiments herein are described in a progressive manner, with each embodiment focusing on its differences from the other embodiments. Similar or identical parts between the various embodiments can be referenced to each other.

[0064] The terms "longitudinal", "transverse", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like used herein to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are intended only to facilitate the description of this document and simplify the description, and are not intended to indicate or imply 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 on the present invention. In the description herein, unless otherwise specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, they can be mechanical or electrical connections, or they can be internal connections between two elements, they can be directly connected, or they can be indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms can be understood according to the specific circumstances.

[0065] As used herein, unless otherwise specified, the term "plurality" means two or more.

[0066] In this document, the character " / " indicates that the preceding and following objects are in an "or" relationship. For example, A / B means: A or B.

[0067] In this article, the term "and / or" describes the association relationship between objects, indicating that three relationships can exist. For example, A and / or B means: A or B, or A and B.

[0068] It should be understood that, although the various steps in the flowchart are shown in sequence as indicated by the arrows, these steps are not necessarily performed in the order indicated by the arrows. Unless otherwise specified herein, there is no strict order restriction on the execution of these steps, and these steps may be performed in other orders. Moreover, at least a portion of the steps in the figure may include multiple sub-steps or multiple stages, and these sub-steps or stages are not necessarily performed at the same time, but may be performed at different times. The execution order of these sub-steps or stages is not necessarily to be performed in sequence, but may be performed in turn or alternately with other steps or at least a portion of the sub-steps or stages of other steps.

[0069] In the absence of conflict, the embodiments of the present invention and the features thereof may be combined with each other.

[0070] Figure 1 An embodiment of the optical path structure of an optical cable line inspection analyzer of the present invention is shown.

[0071] In this optional embodiment, an optical path structure of an optical cable line patrol analyzer includes:

[0072] Vibration cable search function unit I, used to realize the routing distribution and vibration detection of optical cables;

[0073] Link test function unit II, used to test the length, loss and connector quality of the optical cable link;

[0074] Bending and fixing cable function unit III, used to find a single optical cable;

[0075] Function switching unit IV, used to switch the optical signal transmission path in the optical cable;

[0076] Port switching unit V, used to achieve multi-port expansion of the optical cable line patrol analyzer;

[0077] Among them, one end of the vibration cable search function unit I is connected to the second pin of the function switch unit IV, and the first pin of the function switch unit IV is connected to one end of the port switch unit V;

[0078] One end of the link test function unit II is connected to one end of the bending and cabling function unit III, and the other end of the bending and cabling function unit III is connected to the third pin of the function switching unit IV.

[0079] In this optional embodiment, the vibration cable finding functional unit I includes:

[0080] Narrow linewidth laser, used to achieve narrow linewidth light emission;

[0081] A modulator, used to realize modulation of pulsed light;

[0082] Erbium-doped fiber amplifier, used to amplify optical signals;

[0083] Filter, used to filter out noise from the erbium-doped fiber amplifier;

[0084] A first circulator, used for coupling optical signals and receiving and detecting optical signals;

[0085] The first detector (ie, PIN detector) is used to realize photoelectric signal conversion.

[0086] In this optional embodiment, after the first detector realizes the photoelectric signal conversion, the converted current signal is converted into a voltage signal through a transimpedance operational amplifier, and the voltage signal is amplified and filtered through an analog circuit and then converted into a digital signal by an analog-to-digital converter. After being converted into a digital signal, it is sent to a programmable logic device for processing.

[0087] In this optional embodiment, the link test functional unit II includes:

[0088] two Fabry-Perot lasers for emitting pulsed light;

[0089] Wavelength division multiplexer, used to combine optical signals of different wavelengths;

[0090] The second circulator is used to realize the coupling of optical signals and the reception and detection of optical signals;

[0091] The second detector (ie, APD detector) is used to realize photoelectric signal conversion.

[0092] In this optional embodiment, the two Fabry-Perot lasers include: a 1310 nm and a 1550 nm Fabry-Perot laser or a 1625 nm and a 1650 nm Fabry-Perot laser.

[0093] In this optional embodiment, the bending and cabling functional unit III includes: a first optical switch (i.e., optical switch S1), a second optical switch (i.e., optical switch S2), and a polarizer;

[0094] The first optical switch and the second optical switch are used to realize the switching between the bending and cabling function unit and the link testing function unit;

[0095] Polarization analyzer is used to filter optical fiber signals and only allow optical fiber signals with the right polarization direction to pass through.

[0096] In this optional embodiment, the function switching unit IV includes:

[0097] The third optical switch (ie optical switch S3) is used to implement switching between the vibration cable finding function unit, the link testing function unit and the bending cable fixing function unit.

[0098] In this optional embodiment, the port switching unit V includes:

[0099] The fourth optical switch (ie, the MEMS optical switch) is used to expand the port of the optical cable line patrol analyzer.

[0100] In this optional embodiment, the fourth optical switch is switched by outputting a set regulation voltage through a four-channel analog-to-digital converter, and amplifying the regulation voltage output by the four-channel analog-to-digital converter through a high-voltage operational amplifier to regulate and drive the fourth optical switch.

[0101] Distributed vibration sensing (DVS) is an intelligent monitoring device based on fiber optic vibration sensing technology. It realizes the dual functions of sensing and transmission through a single optical fiber. It can perform real-time analysis, positioning and early warning of disturbances along the optical cable. It is widely used in the operation and maintenance of optical cable lines and safety protection in the fields of communications, electricity, transportation, etc. Its main advantage is that it is sensitive to vibration measurement and can locate the position of vibration.

[0102] The Optical Time Domain Reflectometer (OTDR) is an extremely important and powerful test instrument in the field of fiber-optic communications. By injecting a pulsed light signal into an optical fiber, it measures the Rayleigh backscattered signal and Fresnel reflection signal, plotting the fiber's loss distribution against its length. This allows the measurement of parameters such as fiber length, loss, connectors, and reflectivity. OTDRs are primarily used to measure fiber characteristics, locate faults, and evaluate the quality of optical fiber links. The OTDR's measurement distance is much greater than that of a DVS. Its 1550nm wavelength and 40dB dynamic range enable testing of optical cables greater than 180km in length. It can also assess connector quality by measuring their reflectivity and loss.

[0103] The polarization detection-based optical cable finder (POTDR) uses the vibration of the optical cable to change the amplitude of the backward Rayleigh scattered signal and Fresnel reflected signal in the optical fiber. After passing through the polarizer, the amplitude change is more obvious. It is used to find and survey single optical cables. Its sensitivity is lower than that of DVS.

[0104] The above three technical products are all used for testing optical cables, but with different focuses. The optical path structure of the optical cable line patrol analyzer of the present invention can integrate the above three technologies together, using DVS technology as the main function to realize the routing distribution and vibration detection of optical cables, namely the vibration cable finding functional unit; measuring the total length and joint quality of the optical cable through optical time domain reflectometer technology, namely the link test functional unit, to inform the operator whether segmented testing or cleaning of the joints is required; using low-sensitivity optical cable survey, namely the bending and cable positioning functional unit, to further identify individual optical cables by using the bending of the optical cable, greatly improving the accuracy of the test. The main purpose is to realize multi-channel optical cable line patrol analysis, optical cable length testing, optical cable routing distribution direction survey, optical cable survey and positioning; mainly based on distributed vibration fiber optic sensing technology, the technology of optical time domain reflectometer, optical cable survey instrument and multi-port expansion and switching technology are integrated together through an integrated optical path, and then through the control of hardware and software, an effective combination of multiple functions of a single device is realized.

[0105] The optical path structure of the optical cable line inspection analyzer of the present invention mainly consists of five parts: a vibration cable detection function unit I (i.e., a DVS function unit), a link test function unit II (i.e., an OTDR function unit), a bending and fixing cable function unit III (i.e., a POTDR function unit), a function switching unit IV, and a port switching unit V.

[0106] Specifically, in the vibration cable-finding functional unit I, one end of the narrow-linewidth laser is connected to one end of the modulator, the other end of the modulator is connected to one end of the erbium-doped fiber amplifier, the other end of the erbium-doped fiber amplifier is connected to one end of the filter, the other end of the filter is connected to the first pin of the first circulator, and the second pin of the first circulator is connected to one end of the PIN detector.

[0107] Specifically, the current signal after photoelectric conversion is converted into a voltage signal through a transimpedance operational amplifier. The analog circuit amplifies and filters the voltage signal, and then performs analog-to-digital conversion by a high-speed ADC (analog-to-digital converter). The converted digital signal enters the programmable logic device for preprocessing, and is finally sent to the CPU for algorithm analysis to obtain test results, data display and transmission processing.

[0108] Specifically, in the link test functional unit II, one end of the 1310nm or 1625nm Fabry-Perot laser is connected to the first pin of the wavelength division multiplexer, one end of the 1550nm or 1650nm Fabry-Perot laser is connected to the second pin of the wavelength division multiplexer, the third pin of the wavelength division multiplexer is connected to the first pin of the second circulator, and one end of the APD detector is connected to the second pin of the second circulator.

[0109] Specifically, in the bending and cabling functional unit III, the P2 end of the optical switch S1 is connected to the P2 end of the optical switch S2, the P3 end of the optical switch S1 is connected to one end of the analyzer, and the other end of the analyzer is connected to the P3 end of the optical switch S2.

[0110] Specifically, in the function switching unit IV, the P1 end of the optical switch S3 is connected to the COM end of the MEMS optical switch; the P2 end of the optical switch S3 is connected to the third pin of the first circulator; and the P3 end of the optical switch S3 is connected to the P1 end of the optical switch S2.

[0111] Specifically, if Figure 4 As shown in Figure 5, in port switching unit V, the MEMS optical switch is switched by the CPU sending channel adjustment parameters to the DAC (digital-to-analog converter). The four-channel DAC outputs the set adjustment voltage. The DAC output is a low voltage with an amplitude not exceeding 2.5V. The driving voltage swing range of the MEMS optical switch's X+, X-, Y+, and Y- is 0-60V. The DAC output enters the high-voltage operational amplifiers (HV op amp 1, HV op amp 2, HV op amp 3, and HV op amp 4) for amplification, and then adjusts the voltage of the X+, X-, Y+, and Y- pins of the 1×N MEMS optical switch to achieve optical switch switching. The multifunctional optical cable line tracer analyzer defaults to the COM-P1 port being turned on. The COM-PN port is selected by adjusting the voltage values ​​corresponding to different channels.

[0112] Figure 2 An embodiment of an optical cable inspection and analysis method of the present invention is shown.

[0113] In this optional embodiment, a fiber optic cable inspection and analysis method includes:

[0114] Step S101, performing port selection through the port switching unit IV to determine the output port corresponding to the optical cable under test;

[0115] Step S102: Switch the optical cable line analyzer to the link test function unit II to perform a link test to obtain the length, loss, and connector quality parameters of the tested optical cable;

[0116] Step S103, judging the quality of the connector according to the connector quality parameters of the tested optical cable, and determining whether to perform port cleaning or port connection inspection according to the judgment result;

[0117] Step S104, switching the optical cable line inspection analyzer to the bending and cable fixing function unit III or the vibration cable finding function unit I, and searching for a single optical cable when switching to the bending and cable fixing function unit III;

[0118] Step S105, when switching to the vibration cable search function unit I, the routing distribution of the tested optical cable is obtained, and the optical cable is inspected based on the search result of a single optical cable, the length of the tested optical cable, the loss of the tested optical cable and the routing distribution of the tested optical cable.

[0119] The OTDR functional unit is used to test the length, loss, and connector quality of optical cable links. It primarily performs pulsed light transmission, optical signal coupling, and optical signal reception and detection. The transmitting end consists of 1310nm and 1550nm Fabry-Perot lasers (FD-LDs) (this section can be replaced with other lasers of equivalent specifications, such as 1625nm and 1650nm). These wavelengths are combined through a wavelength division multiplexer (WDM) and injected into a circulator. The 1310nm and 1550nm wavelengths can be used to test macrobends in optical cable links. The backscattered Rayleigh scattered signal and Fresnel emission signal from the tested optical cable are also injected through the circulator into the detector APD unit for photoelectric conversion. The converted current signal is converted to a voltage signal by a transimpedance operational amplifier. The analog circuit amplifies and filters the voltage signal before it is converted to digital by a high-speed ADC. The converted digital signal enters a programmable logic device for preprocessing and is finally fed into the CPU for algorithm analysis to generate test results, data display, and transmission processing.

[0120] The DVS functional unit is used to test the routing distribution of optical cable links. It primarily performs the emission of narrow-linewidth 1550nm light, pulsed light modulation, optical signal amplification, optical signal filtering, optical signal coupling, and optical signal reception and detection. A narrow-linewidth laser (LD) emits continuous, ultra-narrow linewidth laser light, which is modulated by an optical modulator into pulsed light corresponding to the spatial resolution. The modulated light has a narrow pulse width, a low duty cycle, and low power. Therefore, after being amplified by an erbium-doped fiber amplifier (EDFA), the noise of the amplifier is filtered out by a filter, and then coupled into the optical fiber under test via an optical circulator. The interfering backscattered Rayleigh signal is also injected into a photodetector through the circulator and converted into an electrical signal.

[0121] The POTDR unit, combined with the OTDR unit, switches S1 and S2 to locate a single optical cable. After the backscattered Rayleigh and Fresnel reflected signals from the tested optical cable pass through the analyzer, only the fiber signal with a single polarization direction passes through the circulator and enters the APD detector. Compared to light with all polarization directions, light with a fixed polarization direction has a higher detection sensitivity to changes in signal amplitude caused by fiber bending, thus enabling the detection of a single optical cable.

[0122] Optical switches S1, S2, and S3 are all 1×2 relay-type optical switches. By controlling the optical switches S3, S2, and S1 through software and hardware, the transmission path of the optical signal in the optical cable can be switched, thereby performing optical cable distribution route detection, identifying a single optical cable, and determining the total length, loss, and connector quality of the optical cable.

[0123] The port switching unit, comprised of a 1×N MEMS optical switch, enables multi-port expansion of the device. Operators can simultaneously access multiple ports and switch between them for testing via software and hardware. The MEMS optical switch is 1×N, with N selectable from 2 / 4 / 8 / 16 / 24 / 32 / 48 / 64, covering a range of 2-64 ports.

[0124] Table 1 shows the function switching implementation method of the DVS function unit, OTDR function unit, and POTDR function unit. Among them, in the 0 state (default state) of the 1×2 relay optical switch, the P1-P2 path is conductive, in the 1 state, the P1-P3 path is conductive, and the X state is any state.

[0125] Table 1 Correspondence between functions and optical switch states

[0126] Function Name Optical switch S3 Optical switch S2 Optical switch S1 DVS function 1 1 1 OTDR Function 1 0 0 POTDR Function 0 X X

[0127] The DVS functional unit operates in state 0 mode with optical switch S3. The optical path is DVS—P2 ​​(optical switch S3)—P1 (optical switch S3)—MEMS optical switch—device port (i.e., the output port of the MEMS optical switch). A 1550nm narrow-linewidth laser emits continuous light, which is amplified by a modulator, an EDFA, and a filter before being input into a circulator. The circulator output is injected into the optical cable under test through the P2-P1 channel of optical switch S3 and the COM- output port of the MEMS optical switch. The coherent backward Rayleigh scattered and Fresnel reflected signals in the optical cable are input through the MEMS optical switch port and fed into the first circulator in the opposite direction of the transmission direction. The output signal of the first circulator is then fed into a PIN detector for photoelectric conversion.

[0128] The OTDR functional unit operates with optical switch S3 in state 1, optical switch S2 in state 0, and optical switch S1 in state 0. The optical path is OTDR—P1 (optical switch S1)—P2 (optical switch S1)—P2 (optical switch S2)—P1 (optical switch S2)—P3 (optical switch S3)—P1 (optical switch S3)—MEMS optical switch—device port. Pulsed light from a 1310nm or 1550nm laser is input to a circulator via WDM. The circulator's output passes through the P1-P2 channel of optical switch S1, the P2-P1 channel of S2, and the P3-P1 channel of S3, and is injected into the optical cable under test through the COM- output port of the MEMS optical switch. Backscattered Rayleigh scattering and Fresnel reflection signals in the optical cable are input from the output port of the MEMS optical switch, in the opposite direction of transmission, to a second circulator. The output signal of the second circulator is input to an APD detector for photoelectric conversion.

[0129] The POTDR functional unit is configured with optical switch S3 operating in state 1, optical switch S2 operating in state 1, and optical switch S1 operating in state 1. The optical path is OTDR—P1 (optical switch S1)—P3 (optical switch S1)—polarization analyzer—P3 (optical switch S2)—P1 (optical switch S2)—P3 (optical switch S3)—P1 (optical switch S3)—MEMS optical switch—device port. Pulsed light from a 1310nm or 1550nm laser is input to a circulator via a WDM interface. The circulator's output passes through the P1-P2 channel of optical switch S1, the polarization analyzer, the P2-P1 channel of S2, the P3-P1 channel of S3, and the COM- output port of the MEMS optical switch before being injected into the optical cable under test. Polarization-sensitive backscattered Rayleigh and Fresnel reflection signals in the optical cable are fed into the circulator from the output port of the MEMS optical switch, in the opposite direction of transmission. The circulator's output signal is then fed into an APD detector for photoelectric conversion.

[0130] like Figure 3 As shown, the optical cable line patrol analyzer of the present invention first enters the port selection function to determine the device output port corresponding to the tested optical cable; then the optical cable line patrol analyzer switches to the OTDR function to perform a link test to test parameters such as the length, loss and connector quality of the tested optical cable. If the connector is judged to be poor, the operator needs to clean the port or check whether the port connection is in place; when the link test passes, it can switch to the POTDR function to bend the optical cable to determine the tested optical cable and the search for a single optical cable; after the link test passes or the cable is fixed, it can enter the DVS function to determine the routing distribution of the optical cable by knocking and vibrating the optical cable, and perform an optical cable inspection.

[0131] The optical path structure of the optical cable line patrol analyzer of the present invention realizes the switching of the optical path conduction paths of the DVS function, OTDR function and POTDR function through the combination of the states of optical switches S1, S2 and S3. The present invention also enables the CPU to control the 1×N MEMS optical switch through the DAC and high-voltage operational amplifier to achieve multi-port expansion and switching, with the number of ports covering a range of 2-64.

[0132] The optical path structure of the present invention integrates DVS function, POTDR function, OTDR function and port switching function in one, and has the characteristics of multi-function, high integration, small size and convenient portability.

[0133] The various functional units of the present invention share the same hardware resources such as CPU and power supply, which can reduce the power consumption, cost and number of connectors of the equipment, improve the process of data interaction, and enhance the test efficiency and product reliability.

[0134] The present invention is not limited to the structures described above and shown in the drawings, and various modifications and changes can be made without departing from the scope thereof. The scope of the present invention is limited only by the appended claims.

Claims

1. An optical path structure of an optical cable line patrol analyzer, characterized in that: include: Vibration cable search unit, used to realize optical cable routing distribution and vibration detection; Link test functional unit, used to test the length, loss and connector quality of the optical cable link; Bending and fixing cable function unit, used to find a single optical cable; A function switching unit, used to switch the optical signal transmission path in the optical cable; Port switching unit, used to achieve multi-port expansion of the optical cable line patrol analyzer; Wherein, one end of the vibration cable-finding function unit is connected to the second pin of the function switching unit, and the first pin of the function switching unit is connected to one end of the port switching unit; One end of the link testing functional unit is connected to one end of the bending and cabling functional unit, and the other end of the bending and cabling functional unit is connected to the third pin of the function switching unit.

2. The optical path structure of the optical cable line inspection analyzer according to claim 1, characterized in that: The vibration cable finding functional unit includes: Narrow linewidth laser, used to achieve narrow linewidth light emission; A modulator, used to realize modulation of pulsed light; Erbium-doped fiber amplifier, used to amplify optical signals; A filter, configured to filter out noise from the erbium-doped fiber amplifier; A first circulator, used for coupling optical signals and receiving and detecting optical signals; The first detector is used to realize photoelectric signal conversion.

3. The optical path structure of the optical cable line inspection analyzer according to claim 2, characterized in that: After the first detector realizes the photoelectric signal conversion, the converted current signal is converted into a voltage signal through a transimpedance operational amplifier, and the voltage signal is amplified and filtered through an analog circuit, and then converted into a digital signal by an analog-to-digital converter. After that, it is sent to a programmable logic device for processing.

4. The optical path structure of the optical cable line inspection analyzer according to claim 1, characterized in that: The link test functional unit includes: two Fabry-Perot lasers for emitting pulsed light; Wavelength division multiplexer, used to combine optical signals of different wavelengths; The second circulator is used to realize the coupling of optical signals and the reception and detection of optical signals; The second detector is used to realize photoelectric signal conversion.

5. The optical path structure of the optical cable line inspection analyzer according to claim 4, characterized in that: The two Fabry-Perot lasers include: 1310 nm and 1550 nm Fabry-Perot lasers or 1625 nm and 1650 nm Fabry-Perot lasers.

6. The optical path structure of the optical cable line inspection analyzer according to claim 1, characterized in that: The bending and cabling functional unit includes: a first optical switch, a second optical switch and a polarizer; The first optical switch and the second optical switch are used to realize the switching between the bending and cabling functional unit and the link testing functional unit; The polarization analyzer is used to screen the optical fiber signal and only allow the optical fiber signal of the polarization direction to pass.

7. The optical path structure of the optical cable line inspection analyzer according to claim 1, characterized in that: The function switching unit includes: The third optical switch is used to realize switching among the vibration cable finding function unit, the link testing function unit and the bending cable fixing function unit.

8. The optical path structure of the optical cable line inspection analyzer according to claim 1, characterized in that: The port switching unit includes: The fourth optical switch is used to expand the port of the optical cable line patrol analyzer.

9. The optical path structure of the optical cable line inspection analyzer according to claim 8, characterized in that: The switching mode of the fourth optical switch is as follows: a four-channel analog-to-digital converter outputs a set regulating voltage, and a high-voltage operational amplifier amplifies the regulating voltage output by the four-channel analog-to-digital converter to regulate and drive the fourth optical switch.

10. A method for analyzing optical cable inspection, characterized in that: include: Select the port through the port switching unit to determine the output port corresponding to the optical cable under test; Switch the optical cable line analyzer to the link test function unit to perform a link test to obtain the length, loss and connector quality parameters of the tested optical cable; The quality of the connector is judged based on the connector quality parameters of the tested optical cable, and whether to perform port cleaning or port connection inspection is determined based on the judgment result; Switch the optical cable line analyzer to the bending and fixing cable function unit or the vibration cable finding function unit, and search for a single optical cable when switched to the bending and fixing cable function unit; When switching to the vibration cable search function unit, the route distribution of the tested optical cable is obtained, and the optical cable is inspected based on the search results of a single optical cable, the length of the tested optical cable, the loss of the tested optical cable and the route distribution of the tested optical cable.

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