A multi-channel synchronous acquisition optical fiber loss precision detection and analysis device

Abstract

The application discloses a kind of multi-channel synchronous acquisition's optical fiber loss precision detection analysis device, comprising: optical front-end execution module, the optical front-end execution module is used to generate probe light signal and selectively access to be measured optical fiber link;Synchronous control module, the synchronous control module is used to generate synchronous trigger signal and collect feedback light signal;Intelligent management decision module, the intelligent management decision module is used to control each module work and carry out data processing.The application is by being provided with reference optical path element with known reference optical characteristics in optical front-end execution module, and reference data is collected before each measurement again difference processing, effectively eliminates the influence of the insertion loss drift of optical path switching unit due to environmental temperature change, device aging and other factors on measurement result, significantly improves the precision of optical fiber link loss detection and the consistency of measurement result between different channels.

Description

Technical Field

[0001] This invention relates to the field of optical fiber sensing and optical communication testing technology, specifically to a multi-channel synchronous acquisition device for precise detection and analysis of optical fiber loss. Background Technology

[0002] An optical time domain reflectometer (OTDR) is an important testing instrument for characterizing the transmission characteristics of optical fibers, and it is widely used in optical fiber development, optical fiber communication engineering construction, and optical cable line maintenance. The OTDR utilizes the backscattering principle generated by Rayleigh scattering and Fresnel reflection of light propagating in optical fibers. It injects an optical pulse into the fiber under test and detects the scattered light signal returning along the backscattered light at the same end, thereby measuring the fiber length, transmission attenuation, splice attenuation, and locating faults. When the incident light pulse propagates in the line, it generates Rayleigh scattered light and Fresnel reflected light. The backscattered Rayleigh light returns along the fiber to the incident end. By observing and analyzing the pulse changes of this backscattered light, the OTDR can obtain the loss characteristics of the optical fiber.

[0003] As optical communication networks continue to expand, the demand for simultaneous monitoring of multiple optical fibers and multiple channels is increasing. Existing technologies have developed monitoring schemes that combine OTDRs with multi-channel optical switches. By switching channels through the optical switches, a single OTDR device can test multiple optical fiber links in turn. However, the insertion loss of multi-channel optical switches varies between different channels, and this loss drifts with changes in ambient temperature. However, existing technologies do not have an effective calibration mechanism to eliminate the impact of such channel-to-channel insertion loss differences and temperature drift on the loss measurement results, resulting in poor comparability of link loss data measured from different channels and making it difficult to achieve high-precision optical fiber loss detection. Summary of the Invention

[0004] The purpose of this invention is to provide a multi-channel synchronous acquisition optical fiber loss precision detection and analysis device to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A multi-channel synchronous acquisition optical fiber loss precision detection and analysis device includes:

[0007] An optical front-end execution module is used to generate a probe optical signal and selectively connect to the fiber optic link under test.

[0008] A synchronization control module, which is used to generate a synchronization trigger signal and acquire feedback optical signals;

[0009] An intelligent management decision-making module is used to control the operation of each module and perform data processing.

[0010] The optical front-end execution module includes:

[0011] An optical signal generating unit, wherein the optical signal generating unit is used to generate a detection optical signal;

[0012] An optical path switching unit is used to selectively connect the probe optical signal to the fiber optic link under test or the reference optical path element.

[0013] A reference optical path element, wherein the reference optical path element is a reference path having known reference optical characteristics.

[0014] The synchronization control module is communicatively connected to the optical front-end execution module. The synchronization control module is built based on a programmable logic device and is used to generate a high-precision synchronization trigger signal to control the emission time of the probe optical signal of the optical signal generation unit, and to synchronously collect the feedback optical signal generated when the probe optical signal is transmitted in the fiber optic link under test or the reference optical path element.

[0015] The intelligent management decision module is communicatively connected to the optical front-end execution module and the synchronous control module, and the intelligent management decision module includes a main control unit and a monitoring unit set independently of the main control unit.

[0016] This device also includes:

[0017] A power management unit is electrically connected to the optical front-end execution module, the synchronization control module, and the intelligent management decision module, respectively, and is used to provide working power to each module.

[0018] The power management unit includes at least a first power supply branch and a second power supply branch. The first power supply branch is used to provide continuous power to the temperature control component in the optical signal generating unit, the programmable logic device in the synchronization control module, and the monitoring unit. The second power supply branch is used to provide controllable power to the drive circuit in the optical signal generating unit.

[0019] The main control unit is configured as follows:

[0020] In the first working state, the output of the second power supply branch is turned off, so that the optical signal generating unit maintains a hot standby state. The so-called hot standby state refers to the standby mode in which the temperature control component in the optical signal generating unit keeps working to keep the laser at a constant temperature, but the laser driving circuit stops working and does not output probe light pulses.

[0021] The main control unit is also configured as follows:

[0022] Upon receiving the acquisition trigger command, the synchronous control module controls the optical path switching unit to first switch to the reference optical path element to acquire the first set of reference data, and then switch to the fiber optic link under test to acquire the second set of measurement data. Differential processing is then performed based on the first set of reference data and the second set of measurement data to eliminate the influence of environmental drift and transmission characteristic changes of the optical path switching unit on the detection results.

[0023] In this differential processing, the known reference optical characteristics of the reference optical path element are assumed to be... The optical parameter measurements of the first set of reference data are The optical parameter measurements of the second set of measurement data are as follows: The actual optical parameter values ​​of the fiber optic link under test Determined by the following formula:

[0024]

[0025] The above formula eliminates the influence of the insertion loss C of the optical path switching unit on the measurement results.

[0026] The monitoring unit is connected to the main control unit via a communication interface. The monitoring unit is used to monitor the status indication signal output by the main control unit in real time. When the status indication signal does not change as expected within a preset time threshold, the monitoring unit triggers a reset operation of the main control unit and the programmable logic device. The reset operation does not interrupt the power supply of the first power supply branch to the temperature control component.

[0027] This device also includes:

[0028] A data caching and transmission management module, which is communicatively connected to both the synchronization control module and the main control unit;

[0029] The data caching and transmission management module includes a buffer area and a storage area. The feedback optical signal collected by the synchronization control module is compressed and stored in the buffer area according to the acquisition time sequence. The main control unit sends the compressed data to the external receiving end in units of data packets through the network communication protocol, and removes the corresponding data packets from the buffer area after receiving the confirmation response from the external receiving end.

[0030] When network communication is interrupted, unacknowledged data packets are continuously stored in the storage area until network communication is restored and the transmission resumes from the point of interruption.

[0031] The optical path switching unit is an optical switch matrix. The common terminal of the optical path switching unit is connected to the optical signal generating unit through an optical transmission medium. The multiple output terminals of the optical path switching unit are respectively connected to the optical fiber link under test and the reference optical path element.

[0032] The known reference optical characteristics of the reference optical path element are pre-calibrated fixed optical parameters. When the main control unit performs the differential processing, it subtracts the optical parameter reference value of the first set of reference data from the optical parameter measurement value of the second set of measurement data, and combines the known reference optical characteristics to obtain the actual optical parameter value of the fiber optic link under test.

[0033] Compared with the prior art, the beneficial effects of the present invention are:

[0034] 1. This invention effectively eliminates the influence of insertion loss drift caused by factors such as ambient temperature changes and device aging on the measurement results by setting a reference optical path element with known reference optical characteristics in the optical front-end execution module and collecting reference data before differential processing before each measurement. This significantly improves the accuracy of fiber optic link loss detection and the consistency of measurement results between different channels.

[0035] 2. This invention provides continuous power to the temperature control component in the optical signal generation unit through a first power supply branch, keeping the laser in a constant-temperature standby state. When data acquisition is required, the second power supply branch quickly establishes the driving voltage, allowing the optical signal generation unit to enter normal operation within microseconds. This hierarchical power supply method avoids the damage to the laser's lifespan caused by frequent cold starts while ensuring rapid response capabilities. Attached Figure Description

[0036] Figure 1 This is a block diagram of the overall structure of the present invention;

[0037] Figure 2 This is a flowchart illustrating the synchronous triggering and signal acquisition process implemented by the synchronous control module of the present invention based on FPGA.

[0038] Figure 3 This is a schematic diagram of the hierarchical power supply architecture of the power management unit of the present invention;

[0039] Figure 4 This is a schematic diagram of the differential calibration process of the present invention;

[0040] Figure 5 This is a schematic diagram illustrating the workflow of the data caching and transmission management module of the present invention. Detailed Implementation

[0041] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0042] like Figure 1 As shown, the present invention provides a technical solution:

[0043] A multi-channel synchronous acquisition optical fiber loss precision detection and analysis device includes an optical front-end execution module, a synchronization control module, an intelligent management decision module, a power management unit, and a data buffer and transmission management module. The optical front-end execution module is connected to the optical fiber link under test through an optical transmission medium. The intelligent management decision module is communicatively or electrically connected to the optical front-end execution module, the synchronization control module, the power management unit, and the data buffer and transmission management module, respectively, to realize comprehensive management and control of the entire device.

[0044] Based on the above embodiments, the optical front-end execution module includes an optical signal generation unit, an optical path switching unit, and a reference optical path element. The optical signal generation unit is used to generate a probe optical signal. In this embodiment, the optical signal generation unit uses a semiconductor laser diode as a light source and integrates a temperature control component. The temperature control component uses a closed-loop temperature control circuit composed of a thermoelectric cooler and a thermistor to accurately control the operating temperature of the laser at a preset constant temperature operating point. The probe optical signal generated by the optical signal generation unit is transmitted to the optical path switching unit through an optical transmission medium.

[0045] Furthermore, the optical path switching unit is used to selectively connect the probe optical signal to the fiber optic link under test or the reference optical path element. In this embodiment, the optical path switching unit adopts an optical switch matrix based on microelectromechanical systems (MEMS) technology. Its common end is connected to the optical signal generating unit through an optical fiber, and multiple output ends are connected to the fiber optic link under test and the reference optical path element, respectively. When a measurement is required, the main control unit sends a channel switching command to the optical path switching unit through the communication interface to control the optical path switching unit to switch between the reference optical path element and each fiber optic link under test.

[0046] In this embodiment, the reference optical path element is a reference path with known reference optical characteristics. Specifically, the reference optical path element adopts a precisely calibrated reference fiber ring with a known accurate attenuation value. The two ends of the reference fiber ring are respectively connected to the two output ports of the optical path switching unit to form a closed reference loop.

[0047] Based on the above embodiments, the synchronization control module is communicatively connected to the optical front-end execution module. The synchronization control module is built based on a programmable logic device and is used to generate a high-precision synchronization trigger signal to control the emission time of the probe optical signal of the optical signal generation unit, and to synchronously collect the feedback optical signal generated when the probe optical signal is transmitted in the fiber optic link under test or the reference optical path element.

[0048] like Figure 2As shown, in this embodiment, the programmable logic device adopts a field-programmable gate array (FPGA). The synchronization control module generates a synchronization trigger signal with nanosecond precision through the programmable logic device. This synchronization trigger signal is used simultaneously by the synchronization trigger signal output terminal to trigger the optical signal generation unit to emit optical pulses and start the acquisition of feedback optical signals. Through the hardware-level timing control of the FPGA, the sampling start time deviation caused by the software instruction execution delay of the main control unit is eliminated.

[0049] Preferably, the adjustment accuracy between synchronization pulse signals implemented based on FPGA can reach 2 nanoseconds, and the minimum width of the synchronization pulse signal can reach 10 nanoseconds, thereby improving the accuracy of distance positioning.

[0050] The feedback optical signal acquired by the synchronous control module through the signal acquisition input terminal is the backscattered optical signal generated when the probe optical pulse is transmitted in the optical fiber.

[0051] Based on the above embodiments, the intelligent management decision module is communicatively connected to the optical front-end execution module and the synchronous control module, respectively. The intelligent management decision module includes a main control unit and a monitoring unit set independently of the main control unit.

[0052] In this embodiment, the main control unit is an embedded microcontroller or microprocessor, which is responsible for the operation management, data processing, network communication and command response of the entire device.

[0053] The monitoring unit is set up independently of the main control unit and is used to monitor the working status of the main control unit in real time. The monitoring unit adopts a dedicated watchdog monitoring chip or an independent low-power microcontroller and is connected to the main control unit through a communication interface. The monitoring unit monitors the status indication signal output by the main control unit in real time. When the status indication signal does not change as expected within a preset time threshold, the monitoring unit triggers the reset operation of the main control unit and the FPGA. Since the power supply of the monitoring unit is independently provided by the first power supply branch of the power management unit, and the reset operation does not interrupt the power supply of the first power supply branch to the temperature control component, the temperature control of the optical signal generation unit is not affected during the reset process, and the device can immediately resume operation after the reset.

[0054] Based on the above embodiments, the power management unit is electrically connected to the optical front-end execution module, the synchronization control module and the intelligent management decision module respectively, and is used to provide working power to each module. The power management unit includes at least a first power supply branch and a second power supply branch.

[0055] like Figure 3As shown, in this embodiment, the first power supply branch provides continuous power to the temperature control component in the optical signal generation unit through the power supply terminal of the temperature control component, provides continuous power to the FPGA in the synchronous control module through the power supply terminal of the programmable logic device, and provides continuous power to the monitoring unit through the power supply terminal of the monitoring unit. The first power supply branch always maintains output after the device is powered on, and does not interrupt the power supply even if the device is in standby or sleep mode.

[0056] The second power supply branch provides controllable power to the drive circuit (i.e., the pulse high-voltage drive circuit of the laser diode) in the optical signal generation unit through the power supply terminal of the drive circuit. The output of the second power supply branch is controlled by the main control unit and can be turned on or off according to the working status.

[0057] Based on the above embodiments, the main control unit is configured to have two main working states. In the first working state (i.e., standby or idle state), the main control unit turns off the output enable of the second power supply branch, causing the laser driving circuit in the optical signal generating unit to stop working. However, the temperature control component is continuously powered by the first power supply branch, so that the optical signal generating unit maintains a hot standby state. The so-called hot standby state refers to the standby mode in which the temperature control component in the optical signal generating unit keeps working and the laser keeps a constant temperature, but the laser driving circuit stops working and does not output probe light pulses. At this time, the power consumption of the whole machine is reduced to a low level, but the temperature of the laser is precisely controlled at the preset constant temperature working point.

[0058] Preferably, the temperature fluctuation range of the preset constant temperature working point is controlled within the set accuracy, for example, 25℃±0.5℃.

[0059] When the main control unit receives the acquisition trigger command, the device enters the second working state (i.e., the acquisition state). The main control unit first enables the second power supply branch to establish the working voltage for the laser driver circuit. Since the laser itself is already in a constant temperature state, the laser can immediately output stable light pulses after the driver circuit is powered on, without waiting for preheating. Subsequently, the main control unit controls the optical path switching unit through the synchronous control module to first switch to the reference optical path element to acquire the first set of reference data, and then switch to the fiber optic link under test to acquire the second set of measurement data.

[0060] like Figure 4As shown, further, the main control unit performs differential processing based on the first set of reference data and the second set of measurement data to eliminate the influence of environmental drift and transmission characteristic changes of the optical path switching unit on the detection results. The differential calibration process begins with receiving the acquisition trigger command, then controlling the optical path switching unit to switch to the reference optical path element, and the synchronous control module acquires the first set of reference data. Then, the optical path switching unit is controlled to switch to the fiber optic link under test, and the synchronous control module acquires the second set of measurement data. Then, the optical parameter measurement values ​​of the second set of measurement data are subtracted from the optical parameter reference values ​​of the first set of reference data, and combined with the known reference optical characteristics of the reference optical path element, the actual optical parameter values ​​of the fiber optic link under test are obtained and output.

[0061] In this embodiment, the known reference optical characteristics of the reference optical path element are pre-calibrated fixed optical parameters, such as known precise attenuation values. When the main control unit performs differential processing, it will process the optical parameter measurements of the second set of measurement data. (e.g., the logarithmic result of backscattered light power) minus the optical parameter reference value of the first set of reference data. (Also a logarithmic result), plus the known reference optical property values. The actual optical parameter values ​​of the fiber optic link under test are obtained. :

[0062] (1)

[0063] Specifically, let the insertion loss of the reference optical path element during each measurement be... (Given a fixed value), the insertion loss of the optical path switching unit under the current environmental conditions is: (Varies with temperature and channel) The true loss of the fiber optic link under test is While collecting the first set of reference data, the synchronous control module collects the measured values. Includes the loss of the reference optical path components And the loss of the optical path switching unit sum:

[0064] (2)

[0065] When collecting the second set of measurement data, the synchronous control module collects the measured values. Includes the actual loss of the fiber optic link under test. And the loss of the optical path switching unit sum:

[0066] (3)

[0067] Subtracting equation (3) from equation (2), the insertion loss of the optical path switching unit is... Offset:

[0068] (4)

[0069] Equation (1) can be obtained by rearranging equation (4):

[0070] (1)

[0071] This differential processing can deduct the insertion loss drift of the optical path switching unit in real time, so that the measurement results only reflect the loss characteristics of the optical fiber link under test itself.

[0072] like Figure 5 As shown, based on the above embodiment, the data caching and transmission management module is communicatively connected to the synchronization control module and the main control unit, respectively. The data caching and transmission management module includes a buffer area and a storage area. The feedback optical signal collected by the synchronization control module is compressed and stored in the buffer area according to the collection time sequence. The main control unit sends the compressed data to the external receiving end in units of data packets. After receiving the confirmation response from the external receiving end, the corresponding data packet is removed from the buffer area. If no confirmation response is received and the network communication is interrupted, the unconfirmed data packet is transferred to the storage area for storage. After the network is restored, the transmission will resume from the breakpoint.

[0073] In this embodiment, the cache area uses a high-speed cache storage medium, and the storage area uses a non-volatile storage medium. The compression process employs a lossless compression algorithm, and the main control unit sends the compressed data to the external receiving end in units of data packets via a network communication protocol.

[0074] Based on the above embodiments, the main control unit also includes at least two independent program storage areas and firmware cache areas. The main control unit receives firmware update data remotely sent through the communication interface, temporarily stores it in the firmware cache area and performs integrity verification. After the verification is passed, the firmware update data is written to the non-currently running program storage area and the startup configuration identifier is updated so that the system can start from the updated program storage area after the next reset.

[0075] Furthermore, the main control unit integrates a standard instrument control protocol stack and supports dual data center configuration based on multiple network transmission protocols. It can simultaneously send data to or receive instructions from two remote management platforms, and the acquisition trigger instructions are issued in the form of instruction frames through the dual data centers.

[0076] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A multi-channel synchronous acquisition optical fiber loss precision detection and analysis device, characterized in that, include: An optical front-end execution module is used to generate a probe optical signal and selectively connect to the fiber optic link under test. A synchronization control module, which is used to generate a synchronization trigger signal and acquire feedback optical signals; An intelligent management decision-making module is used to control the operation of each module and perform data processing.

2. The fiber optic loss precision detection and analysis device with multi-channel synchronous acquisition according to claim 1, characterized in that: The optical front-end execution module includes: An optical signal generating unit, wherein the optical signal generating unit is used to generate a detection optical signal; An optical path switching unit is used to selectively connect the probe optical signal to the fiber optic link under test or the reference optical path element. A reference optical path element, wherein the reference optical path element is a reference path having known reference optical characteristics.

3. The fiber optic loss precision detection and analysis device with multi-channel synchronous acquisition according to claim 1, characterized in that: The synchronization control module is communicatively connected to the optical front-end execution module. The synchronization control module is built based on a programmable logic device and is used to generate a high-precision synchronization trigger signal to control the emission time of the probe optical signal of the optical signal generation unit, and to synchronously collect the feedback optical signal generated when the probe optical signal is transmitted in the fiber optic link under test or the reference optical path element.

4. The fiber optic loss precision detection and analysis device with multi-channel synchronous acquisition according to claim 1, characterized in that: The intelligent management decision module is communicatively connected to the optical front-end execution module and the synchronous control module, and the intelligent management decision module includes a main control unit and a monitoring unit set independently of the main control unit.

5. The fiber optic loss precision detection and analysis device with multi-channel synchronous acquisition according to claim 1, characterized in that: The device further includes: A power management unit is electrically connected to the optical front-end execution module, the synchronization control module, and the intelligent management decision module, respectively, and is used to provide working power to each module. The power management unit includes at least a first power supply branch and a second power supply branch. The first power supply branch is used to provide continuous power to the temperature control component in the optical signal generating unit, the programmable logic device in the synchronization control module, and the monitoring unit. The second power supply branch is used to provide controllable power to the drive circuit in the optical signal generating unit.

6. The fiber optic loss precision detection and analysis device with multi-channel synchronous acquisition according to claim 1, characterized in that: The main control unit is configured as follows: In the first working state, the output of the second power supply branch is turned off, so that the optical signal generating unit maintains a hot standby state; Upon receiving a data acquisition trigger command, the synchronization control module controls the optical path switching unit to first switch to the reference optical path element to acquire the first set of reference data, and then switch to the fiber optic link under test to acquire the second set of measurement data. Differential processing is then performed based on the first set of reference data and the second set of measurement data to eliminate the influence of environmental drift and transmission characteristic changes of the optical path switching unit on the detection results.

7. The fiber optic loss precision detection and analysis device with multi-channel synchronous acquisition according to claim 4, characterized in that: The monitoring unit is connected to the main control unit via a communication interface. The monitoring unit is used to monitor the status indication signal output by the main control unit in real time. When the status indication signal does not change as expected within a preset time threshold, the monitoring unit triggers a reset operation of the main control unit and the programmable logic device. The reset operation does not interrupt the power supply of the first power supply branch to the temperature control component.

8. The fiber optic loss precision detection and analysis device with multi-channel synchronous acquisition according to claim 1, characterized in that: The device further includes: A data caching and transmission management module, which is communicatively connected to both the synchronization control module and the main control unit; The data caching and transmission management module includes a buffer area and a storage area. The feedback optical signal collected by the synchronization control module is compressed and stored in the buffer area according to the acquisition time sequence. The main control unit sends the compressed data to the external receiving end in units of data packets through the network communication protocol, and removes the corresponding data packets from the buffer area after receiving the confirmation response from the external receiving end. When network communication is interrupted, unacknowledged data packets are continuously stored in the storage area until network communication is restored and the transmission resumes from the point of interruption.

9. The fiber optic loss precision detection and analysis device with multi-channel synchronous acquisition according to claim 2, characterized in that: The optical path switching unit is an optical switch matrix. The common terminal of the optical path switching unit is connected to the optical signal generating unit through an optical transmission medium. The multiple output terminals of the optical path switching unit are respectively connected to the optical fiber link under test and the reference optical path element.

10. The fiber optic loss precision detection and analysis device with multi-channel synchronous acquisition according to claim 6, characterized in that: The known reference optical characteristics of the reference optical path element are pre-calibrated fixed optical parameters. When the main control unit performs the differential processing, it subtracts the optical parameter reference value of the first set of reference data from the optical parameter measurement value of the second set of measurement data, and combines the known reference optical characteristics to obtain the actual optical parameter value of the fiber optic link under test.

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