WO2022048467A1 - 一种光信号检测装置、方法及相关设备 - Google Patents

一种光信号检测装置、方法及相关设备 Download PDF

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WO2022048467A1
WO2022048467A1 PCT/CN2021/114053 CN2021114053W WO2022048467A1 WO 2022048467 A1 WO2022048467 A1 WO 2022048467A1 CN 2021114053 W CN2021114053 W CN 2021114053W WO 2022048467 A1 WO2022048467 A1 WO 2022048467A1
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signal
optical signal
module
conversion module
voltage
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PCT/CN2021/114053
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English (en)
French (fr)
Inventor
陈飞
李明
吴春阳
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华为技术有限公司
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Priority to EP21863534.0A priority Critical patent/EP4199376A4/en
Publication of WO2022048467A1 publication Critical patent/WO2022048467A1/zh
Priority to US18/176,638 priority patent/US20230213408A1/en

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    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04BTRANSMISSION
    • H04B10/00Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
    • H04B10/07Arrangements for monitoring or testing transmission systems; Arrangements for fault measurement of transmission systems
    • H04B10/071Arrangements for monitoring or testing transmission systems; Arrangements for fault measurement of transmission systems using a reflected signal, e.g. using optical time domain reflectometers [OTDR]
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01MTESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
    • G01M11/00Testing of optical apparatus; Testing structures by optical methods not otherwise provided for
    • G01M11/30Testing of optical devices, constituted by fibre optics or optical waveguides
    • G01M11/31Testing of optical devices, constituted by fibre optics or optical waveguides with a light emitter and a light receiver being disposed at the same side of a fibre or waveguide end-face, e.g. reflectometers
    • G01M11/3109Reflectometers detecting the back-scattered light in the time-domain, e.g. OTDR
    • G01M11/3145Details of the optoelectronics or data analysis
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04BTRANSMISSION
    • H04B10/00Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
    • H04B10/07Arrangements for monitoring or testing transmission systems; Arrangements for fault measurement of transmission systems
    • H04B10/075Arrangements for monitoring or testing transmission systems; Arrangements for fault measurement of transmission systems using an in-service signal
    • H04B10/079Arrangements for monitoring or testing transmission systems; Arrangements for fault measurement of transmission systems using an in-service signal using measurements of the data signal
    • H04B10/0795Performance monitoring; Measurement of transmission parameters

Definitions

  • the present application relates to the field of optical communication, and in particular, to an optical signal detection apparatus, method and related equipment.
  • OTDR Optical Time Domain Reflectometer, Optical Time Domain Reflectometer
  • the optical signal may have Fresnel reflection, Rayleigh scattering and other phenomena in the measured fiber, so as to reflect a part of the optical signal back to the OTDR, and the OTDR will process the returned optical signal. , to obtain data that can reflect the measured index situation inside the measured fiber.
  • the dynamic range of the OTDR can reflect the longest distance measured by the OTDR.
  • the larger the dynamic range the better the curve shape in the measurement result and the longer the measurable distance.
  • the larger the dynamic range of the OTDR the more the OTDR can process the optical signal returned from the position with the larger distance difference.
  • An optical signal detection device is usually included in the OTDR to detect and process the returned optical signal.
  • the current optical signal detection device in the OTDR has limited signal sampling capability, resulting in low measurement accuracy and actual dynamic range of the OTDR.
  • the present application provides an optical signal detection device, method and related equipment, through which the integrity of signal sampling in the process of processing a received optical signal can be improved, thereby improving the measurement accuracy of optical fiber measurement equipment and the accuracy of optical fiber measurement equipment. actual dynamic range.
  • a first aspect of the embodiments of the present application provides an optical signal detection device, which can be used to process an optical signal detected in a detection period of the optical signal, and the device includes a photoelectric conversion module, a control module, a gain adjustment module, and a Analog-to-digital conversion module.
  • the above functional modules or units can be deployed independently of each other, or some functional modules or units can be integrated together. In an optional manner, each module or function may be partially or fully integrated in the chip.
  • the photoelectric conversion module is used to receive the optical signal and convert the received optical signal into an electrical signal;
  • the control module is used to obtain the first gain value corresponding to the first detection period, and the first detection period is a detection period in the detection cycle, Different detection periods in the detection period correspond to different gain values, and the first gain value is used to control the gain adjustment module to adjust the amplitude of the electrical signal;
  • the analog-to-digital conversion module is used to sample the adjusted electrical signal.
  • the electrical signal is within the sampling range of the analog-to-digital conversion module.
  • the detection period of the optical signal includes at least two different detection periods, and different detection periods correspond to different gain values.
  • the optical signal returned from the near end of the measured fiber and the optical signal returned from the far end of the measured fiber can be in different detection periods.
  • the gain adjustment module can use different gain values to adjust the amplitude, so that The adjusted electrical signal is within the sampling range of the analog-to-digital conversion module, which ensures the integrity of the electrical signal sampling, thereby improving the measurement accuracy of the optical fiber measurement device and the actual dynamic range of the optical fiber measurement device.
  • the electrical signal converted by the photoelectric conversion module is a current signal
  • the gain adjustment module may include a first voltage conversion unit and a voltage attenuation unit; the first voltage conversion unit is used to convert the current signal converted into a voltage signal; the voltage attenuation unit is used for attenuating the converted voltage signal according to the first gain value.
  • the gain adjustment module further includes a first amplifying unit, and the first amplifying unit is configured to linearly amplify the attenuated voltage signal, and send the linearly amplified voltage signal to the analog-to-digital conversion module.
  • the electrical signal converted by the photoelectric conversion module is a current signal
  • the gain adjustment module includes a current attenuation unit and a second voltage conversion unit;
  • the current signal is attenuated;
  • the second voltage conversion unit is used for converting the attenuated current signal into a voltage signal.
  • the voltage signal converted by the second voltage conversion unit is within the sampling range of the analog-to-digital conversion module, and is used for transmission to the analog-to-digital conversion module for sampling
  • the gain adjustment module further includes a second amplifying unit for linearly amplifying the converted voltage signal, and sending the linearly amplified voltage signal to the analog-to-digital conversion module, and the amplified voltage signal is in the analog-to-digital conversion module. within the sampling range.
  • the electrical signal converted by the photoelectric conversion module is a current signal
  • the gain adjustment module includes a third voltage conversion unit
  • the third voltage conversion unit is used to convert the electrical signal according to the first gain value.
  • the current signal is converted into a voltage signal.
  • the voltage signal converted by the second voltage conversion unit is within the sampling range of the analog-to-digital conversion module, and is used for transmission to the analog-to-digital conversion module for sampling
  • the gain adjustment module further includes a second amplifying unit for linearly amplifying the converted voltage signal, and sending the linearly amplified voltage signal to the analog-to-digital conversion module, and the amplified voltage signal is in the analog-to-digital conversion module. within the sampling range.
  • the electrical signal converted by the photoelectric conversion module is a current signal
  • the gain adjustment module includes a fourth voltage conversion unit and a third amplification unit; the fourth voltage conversion unit is used to convert the current The signal is converted into a voltage signal; the third amplifying unit is used for linearly amplifying the converted voltage signal according to the first gain value, and sending the linearly amplified voltage signal to the analog-to-digital conversion module.
  • control module is further configured to perform digital compensation on the digital signal sampled by the analog-to-digital conversion module according to a first compensation value, where the first compensation value is based on the first gain value definite.
  • the control module Through the digital compensation of the control module, the electrical signals adjusted by different gain values in each detection period can be restored to the electrical signals adjusted by the unified gain value, which ensures the continuity of the change curve of the optical signal intensity with the distance, thereby improving the above-mentioned Accuracy and readability of curve information.
  • the gain value corresponding to the detection period is based on one or both of the maximum and minimum values of the optical signal intensity received within the detection period, and the analog-to-digital conversion module.
  • the sampling range is determined.
  • a second aspect of the embodiments of the present application provides an optical signal detection method for processing an optical signal detected in a detection period of the optical signal, the method is applied to an optical signal detection device, and the optical signal detection device includes a photoelectric conversion device module, analog-to-digital conversion module, gain adjustment module and control module; the photoelectric conversion module is used for receiving optical signals and converting the optical signals into electrical signals.
  • the control module obtains the first gain value corresponding to the first detection period, the first detection period is a detection period in the detection period, different detection periods in the detection period correspond to different gain values, and the first gain value is determined by
  • the amplitude of the electrical signal is adjusted by the control gain adjustment module, the adjusted electrical signal is used for sampling by the analog-to-digital conversion module, and the adjusted electrical signal is within the sampling range of the analog-to-digital conversion module.
  • the detection period of the optical signal includes at least two different detection periods, and different detection periods correspond to different gain values.
  • the optical signal returned from the near end of the measured fiber and the optical signal returned from the far end of the measured fiber can be in different detection periods.
  • the control module can control the gain adjustment module through different gain values. Adjustment, so that the adjusted electrical signal is within the sampling range of the analog-to-digital conversion module, which ensures the integrity of the electrical signal sampling, thereby improving the measurement accuracy of the optical fiber measurement equipment and the actual dynamic range of the optical fiber measurement equipment.
  • control module may further perform digital compensation on the digital signal sampled by the analog-to-digital conversion module according to the first compensation value, and the first compensation value is determined according to the first gain value .
  • the control module can restore the electrical signal adjusted by different gain values in each detection period to the electrical signal adjusted by the unified gain value, which ensures the continuity of the curve of the optical signal intensity with the distance, thereby improving the above curve. Accuracy and readability of information.
  • the gain value corresponding to the detection period is based on one or both of the maximum value and the minimum value of the optical signal intensity received during the detection period, and the analog-to-digital conversion module The sampling range is determined.
  • a third aspect of the embodiments of the present application provides another optical signal detection device for processing the optical signal detected in the detection period of the optical signal, the device includes a photoelectric conversion module, a control module and an electrical signal processing module.
  • the photoelectric conversion module is used to receive the optical signal; the control module is used to obtain the first gain value corresponding to the first detection period, the first detection period is a detection period in the detection period, and different detection periods in the detection period correspond to different Gain value, the first gain value is used to control the photoelectric conversion module to adjust the intensity of the received optical signal; the photoelectric conversion module is also used to convert the adjusted optical signal into an electrical signal; the electrical signal processing module is used to The electrical signal is sampled, wherein the electrical signal converted by the photoelectric conversion module is within the sampling range of the electrical signal processing module; or, the electrical signal processing module is used to amplify the converted electrical signal and perform Sampling, wherein the electrical signal amplified by the electrical signal processing module is within the sampling range of the electrical signal processing module.
  • the detection period of the optical signal includes at least two different detection periods, and different detection periods correspond to different gain values.
  • the optical signal returned from the near end of the measured fiber and the optical signal returned from the far end of the measured fiber can be in different detection periods.
  • the photoelectric conversion module can be used to adjust the intensity of the optical signal with different gain values for the optical signals received in different detection periods, so that when the electrical signal converted from the adjusted optical signal is transmitted to the analog-to-digital conversion module, It is within the sampling range of the analog-to-digital conversion module, which ensures the sampling integrity of the signal, thereby improving the measurement accuracy of the optical fiber measurement equipment and the actual dynamic range of the optical fiber measurement equipment.
  • a fourth aspect of the embodiments of the present application provides an optical signal detection apparatus
  • the optical signal detection apparatus may include a processor, a memory, and a receiver, wherein the processor, the memory, and the receiver are connected to each other, and the receiver is used for receiving a signal (such as receiving an optical signal), the memory is used to store the program, the processor is used to call the program stored in the memory, and when the program is executed by the computer, the optical signal detection method in the second aspect above is implemented.
  • a fifth aspect of the embodiments of the present application provides an optical fiber measurement device, the optical fiber measurement device includes an optical signal detection device, a transmission device, a transmission device, and a control device; wherein the control device is configured to trigger the transmission device to emit light according to input configuration information Signal; the transmission device is used to transmit the optical signal emitted by the transmitting device to the optical fiber to be measured, and also to transmit the optical signal received from the optical fiber to be measured to the optical signal detection device; the optical signal detection device is the first aspect or the third aspect The optical signal detection device described in any one of the above; the control device is further configured to perform digital signal processing on the signal output by the optical signal detection device, and output the result obtained by the digital signal processing.
  • a sixth aspect of the embodiments of the present application provides a computer-readable medium, where a program is stored in the computer-readable medium, and when the program is run on a computer, the computer executes the optical signal detection method in the second aspect.
  • a seventh aspect of the embodiments of the present application provides a chip, where the chip includes a processor and a communication interface, the processor is coupled to the communication interface, and is used to implement all of the optical signal detection apparatus in the first aspect or any optional implementation manner. or part of the functions, or realize all or part of the functions of the optical signal detection device in the third aspect.
  • FIG. 1 is a schematic structural diagram of an OTDR provided by an embodiment of the present application.
  • FIG. 2 is a schematic structural diagram of an optical signal detection device in an OTDR provided by an embodiment of the present application
  • FIG. 3 is a schematic diagram of an OTDR detection result provided by an embodiment of the present application.
  • FIG. 4 is a schematic structural diagram of an optical signal detection apparatus provided by an embodiment of the present application.
  • FIG. 5 is a schematic structural diagram of a voltage attenuation unit provided by an embodiment of the present application.
  • FIG. 6 is a schematic structural diagram of a gain adjustment module provided by an embodiment of the present application.
  • FIG. 7 is a schematic structural diagram of another gain adjustment module provided by an embodiment of the present application.
  • FIG. 8 is a schematic structural diagram of another gain adjustment module provided by an embodiment of the present application.
  • FIG. 9 is a schematic structural diagram of another gain adjustment module provided by an embodiment of the present application.
  • FIG. 10 is a schematic structural diagram of another gain adjustment module provided by an embodiment of the present application.
  • FIG. 11 is a schematic diagram of yet another OTDR test result provided by an embodiment of the present application.
  • FIG. 12 is a schematic diagram of digital compensation of an OTDR measurement result provided by an embodiment of the present application.
  • FIG. 13 is a schematic diagram of another OTDR detection result provided by an embodiment of the present application.
  • FIG. 14 is a schematic structural diagram of another optical signal detection apparatus provided by an embodiment of the present application.
  • FIG. 15 is a schematic structural diagram of another optical signal detection apparatus provided by an embodiment of the present application.
  • FIG. 1 is a schematic structural diagram of an OTDR provided by the embodiment of the present application, as shown in FIG. 1 .
  • the OTDR includes a control device 10 , a transmission device 20 , a transmission device 30 and an optical signal detection device 40 .
  • the control device 10 is used for driving the transmitting device 20 to emit an optical signal according to the received configuration parameters, and the transmitting device 30 is used for transmitting the optical signal emitted by the transmitting device 20 to the optical fiber to be measured; the optical signal generates Fresnel in the optical fiber to be measured. Reflection and Rayleigh scattering, etc., return part of the optical signal to the OTDR, the transmission device 30 is also used to receive the optical signal returned from the measured fiber, and transmit the optical signal received from the measured fiber to the optical signal detection device 40, and the optical signal is detected.
  • the device 40 is used to detect the optical signal and process the detected optical signal into a digital signal; the control device 10 can also be used to perform digital signal processing on the digital signal output by the optical signal detection device 40 and output the result obtained by the digital signal processing.
  • the OTDR may further include a display device 50 , and the display device 50 may be configured to receive the digital signal processing result output by the control device 10 and display the digital signal processing result.
  • the control device 10 may output the digital signal processing result to other devices or devices, and display or perform other processing on the digital signal processing results through other devices or devices.
  • control device 10 may include a processor, and the processor may be a central processing unit (CPU), a digital signal processor (digital signal processing, DSP) or an application specific integrated circuit (application specific integrated circuit). , ASIC) etc.
  • the received configuration parameters may be processed by the processor, so as to drive the transmitting device 20 to emit an optical signal, or the processor may perform digital signal processing on the signal output by the optical signal detection device 40 .
  • the configuration parameters received by the control device 10 may be configuration parameters input by the user, for example, the configuration parameters may include the wavelength of the optical signal transmitted by the transmitting device 20, the pulse width of the optical signal, the power intensity of the optical signal, and the measurement range of the OTDR (which may be Indicates the currently measured maximum length) and other parameters.
  • the digital signal processing performed by the control device 10 on the digital signal output by the optical signal detection device 40 may include normalization processing on the digital signal.
  • the digital signal can be normalized by the optical power of the optical signal received by the optical signal detection device 40 at the initial moment of the detection period.
  • control The device 10 can determine the corresponding electric power according to the voltage digital signal, and then determine the relative value of the above-mentioned electric power and the above-mentioned optical power (the relative value is in dB), and the relative value is used as the result of normalization processing;
  • the voltage signal converted from the optical signal received by the optical signal detection device 40 at the initial moment of the detection period is used to normalize the digital signal.
  • the control device 10 The relative value of the amplitude of the voltage digital signal output by the optical signal detection device 40 and the amplitude of the voltage signal converted from the optical signal received at the initial moment of the detection cycle can be calculated (the relative value is in dB), and the relative value is used as the normalization value. the result of the processing; etc.
  • Computational digital signal processing may also include digital domain noise reduction processing of digital signals, and the like.
  • the transmitting device 20 may include a laser 201 and a laser driver 202
  • the laser 201 may be a laser diode (Laser Diode, LD), which is used to transmit an optical signal with high coherence
  • the laser driver 202 may be used to provide a suitable LD for the LD.
  • the bias current and modulation current make the bias current slightly larger than the threshold current of the LD, so that the LD works in the linear region, so as to stabilize the emitted light signal.
  • the transmission device 30 may include an optical circulator, which is a multi-port optical device with non-reciprocal characteristics.
  • an optical circulator which is a multi-port optical device with non-reciprocal characteristics.
  • the port output from the input port, and the loss of the input port leading to other ports is very large, forming an unconnected port, so that the optical signal emitted from the transmitting device 20 can be transmitted to the measured fiber, and the light returned from the measured fiber can be realized.
  • the signal is transmitted to the optical signal detection device 40 .
  • the optical signal detection device 40 can be used to receive the optical signal, convert the optical signal into an electrical signal, and can also be used to amplify and sample the electrical signal.
  • the digital signal after sampling can indicate that the OTDR receives the signal at different times. changes in the intensity of the optical signal.
  • the optical signal detection device 40 usually includes a photoelectric conversion module, an electrical signal amplification module, and an analog-to-digital conversion module. In the process of processing the received optical signal, the optical signal detection device 40 first converts the received optical signal through the photoelectric conversion module. Converted to an electrical signal, the electrical signal obtained by direct conversion of the optical signal is relatively weak, and needs to be amplified by the electrical signal amplifying module before it can be recognized and sampled by the analog-to-digital conversion module.
  • FIG. 2 is a schematic structural diagram of an optical signal detection device in an OTDR provided by an embodiment of the present application.
  • the optical signal detection device 40 includes an optical detection module 401 and a transimpedance amplification module. 402 , a linear amplification module 403 and an analog-to-digital conversion module 404 .
  • the optical detection module 401 is used to receive the optical signal and convert the received optical signal into a current signal; the transimpedance amplification module 402 is used to convert the current signal obtained by the optical detection module 401 into a voltage signal; the linear amplification module 403 is used to The voltage signal obtained by the transimpedance amplification module 402 is linearly amplified; the analog-to-digital conversion module 404 is used for sampling the voltage signal amplified by the linear amplification module 403 .
  • the electrical signal amplification module of the optical signal detection device 40 in FIG. 2 includes a transimpedance amplification module 402 and a linear amplification module 403 .
  • the transimpedance amplifying module 402 realizes the amplification of the electrical signal through a resistor with a fixed resistance value. Since the resistance value of the resistor is fixed, the signal amplification gain of the transimpedance amplifying module 402 is fixed.
  • the linear amplifier module 403 also usually uses a voltage amplifier with a fixed gain, so the overall amplification gain of the optical signal detection device 40 with this structure is fixed.
  • the overall amplification gain of the optical signal detection device 40 is fixed, that is to say, when the optical signal detection device 40 processes the optical signal received at any time, it is linearly amplified according to the fixed gain.
  • the intensity of the optical signal returned from the near-end and the optical signal returned from the far end of the fiber under test is quite different, resulting in an electrical signal converted from the optical signal returned from the near end of the measured fiber (referred to as the near-end electrical signal for the convenience of description)
  • the intensity of the electrical signal converted from the optical signal returned from the far end of the measured fiber (denoted as the far-end electrical signal for the convenience of description) is quite different.
  • the linear amplification of the electrical signal may cause the near-end electrical signal to be amplified to exceed the maximum electrical signal that can be recognized by the analog-to-digital conversion module, and/or it may cause the far-end electrical signal to be amplified and still be lower than the analog-to-digital conversion module.
  • the minimum electrical signal identified, the above two possible situations will cause the OTDR to lose the measurement information of the measured fiber, reduce the test accuracy of the OTDR, and the actual dynamic range of the OTDR.
  • an APD Anagonal Photodiode Detector, avalanche photodetector
  • the amplitude range of the current signal obtained by the APD converting the received optical signal is about 1pA-1uA, that is, the ratio of the maximum current to the minimum current is about It is 10 6 times; after the transimpedance amplifier module and linear amplifier module with fixed amplification gain, the ratio of the maximum voltage to the minimum voltage of the input analog-to-digital conversion module is still about 10 6 times, and the sampling range of the analog-to-digital conversion module (also It is the sampling range, or the identifiable range, which can indicate the minimum voltage signal and/or the maximum voltage signal sampled) is usually 0.5mV-500mV, the ratio of the minimum identifiable voltage to the maximum identifiable voltage is 10 3 times, the modulus The sampling range of the digital conversion module is smaller than the range of the input voltage.
  • the voltage signal converted by the 1pA current signal is amplified to the sampling range of the analog-to-digital conversion module, the voltage signal converted by the 1uA current signal must be amplified, which is greater than the maximum sampling voltage of the analog-to-digital conversion module. If the voltage signal converted by the current signal is amplified to the sampling range of the analog-to-digital conversion module, the voltage signal converted by the 1pA current signal must be amplified and smaller than the minimum sampling voltage of the analog-to-digital conversion module. Therefore, the above two situations must make The voltage signal input to the analog-to-digital conversion module cannot be fully recognized, and part of the voltage signal is lost.
  • the OTDR can obtain the change of the electrical signal converted from the optical signal over time, and the intensity of the optical signal in the optical signal detection device 40 can be obtained.
  • the change of the electrical signal with time can also reflect the change of the optical signal with time.
  • the transmission rate of the optical signal in the optical fiber is fixed, so the time of receiving the optical signal and the transmission distance of the optical signal correspond to each other. According to the change of the optical signal with time, the change of the intensity of the optical signal with the distance can be obtained.
  • the closer the optical signal is to the OTDR the greater the intensity of the optical signal during the transmission of the measured optical fiber.
  • the variation of the intensity with distance can be represented as a straight line that gradually decreases with increasing distance.
  • the measured fiber is affected by some factors, and the loss of the optical signal may not be uniform. For example, there is a connection between the OTDR and the measured fiber, which may cause strong reflection of the optical signal. , there may be fusion splices or connections in the measured fiber, which will cause strong scattering or reflection of the optical signal.
  • the measured fiber may be damaged and bent during use, which will cause strong optical signal Therefore, in the actual measurement process, the change curve of the intensity of the optical signal with the distance is usually not a regular straight line, but it should be shown that the optical signal is stronger at the closer distance. , while the optical signal is weaker at a farther distance.
  • FIG. 3 is a schematic diagram of an OTDR detection result provided by an embodiment of the present application. In the coordinate system shown in FIG.
  • the gray solid line represents the measured signal change curve, from the near end to the far end.
  • the electrical signal at a closer distance appears as a horizontal line segment (curve segment 1 in Figure 3); until the electrical signal increases with the distance.
  • the analog-to-digital conversion module can perform normal electrical signal sampling, so that the curve appears to gradually decrease as the distance increases (curve segment 2 in Figure 3); as the distance increases , the electrical signal drops below the minimum electrical signal that can be recognized by the analog-to-digital conversion module, and the analog-to-digital conversion module cannot recognize the electrical signal and sample it normally, so that the curve prematurely appears as an invalid and frequently abrupt sawtooth shape (as shown in Figure 3). Curve segment 3). Therefore, this optical signal detection device with a fixed amplification gain will cause the loss of part of the electrical signal, which affects the measurement accuracy of the OTDR and the actual dynamic range of the OTDR.
  • the optical signal detection device provided in the embodiment of the present application can be applied to an optical fiber measurement device (such as an OTDR or other optical fiber sensor) that measures an optical signal in an optical fiber.
  • an optical fiber measurement device such as an OTDR or other optical fiber sensor
  • the optical fiber measurement device of an OTDR is example is introduced.
  • the optical signal detection device is used to process the optical signal detected in the detection period of the optical signal, and the sampling integrity of the electrical signal can be ensured during the processing, thereby improving the measurement accuracy of the optical fiber measurement equipment and the actual dynamic performance of the optical fiber measurement equipment. Scope.
  • the detection period of the optical signal is introduced first.
  • the detection period of the optical signal is the time when the optical signal detection device performs one measurement on the fiber to be measured.
  • An optical signal that gradually returns from the near end to the far end. That is to say, at the initial moment of the detection period, the OTDR starts to receive and process the optical signal at the nearest end position. At the last moment of the detection period, the OTDR receives and processes the optical signal at the set farthest position.
  • the detection period of the optical signal may be the time interval between two pulses emitted by the transmitting device in the OTDR.
  • the transmitting device starts to transmit the first pulse at time t1, and starts to transmit the first pulse at time t2.
  • the time difference between time t2 and time t1 is the detection period of the optical signal.
  • the detection period of the optical signal may be the sampling period set for the analog-to-digital conversion module in the OTDR, and the analog-to-digital conversion module performs sampling at a certain sampling frequency within the sampling period, such as converting the analog to digital conversion
  • the module is set to sample at a sampling frequency of 10M times/second within 1.7ms, and 1.7ms is the detection period of the optical signal.
  • the detection period of the optical signal may be the detection time of the optical signal for one pulse transmitted by the transmitting device in the OTDR. For a certain pulse, if the corresponding detection period of the optical signal ends, the optical signal detection device will detect the optical signal for the next pulse of the pulse, or the optical signal detection device stops the detection of the optical signal.
  • the detection period of the optical signal may be determined according to the measurement range of the OTDR, and the measurement range may indicate the currently measured maximum length, which may be determined according to the maximum length and the propagation speed of the optical signal in the optical fiber Determine the detection period of the optical signal.
  • the maximum length indicated by the measurement range is 170km
  • the propagation speed of the optical signal in the optical fiber is 2 ⁇ 10 8 m/s.
  • the test result includes the change curve of the intensity of the optical signal with the distance, and the maximum length of the current measurement indicated by the measurement range of the OTDR can be set to be greater than the actual The value of the length of the fiber to be measured, for example, the maximum length indicated by the measurement range of the OTDR can be set to be between 1.5 times and 2 times the length of the actual fiber to be measured, so that the actual optical signal loss in the measured fiber can be Clearly and completely reflected through the curve.
  • optical signal detection apparatus provided by the embodiments of the present application with reference to FIG. 4 to FIG. 15 .
  • FIG. 4 is a schematic structural diagram of an optical signal detection device provided by an embodiment of the application.
  • the optical signal detection device 4 may include a photoelectric conversion module 41 , a control module 42 , and a gain adjustment module 43 and analog-to-digital conversion module 44. in:
  • the photoelectric conversion module 41 is used for receiving the optical signal and converting the optical signal into an electrical signal
  • the control module 42 is used to obtain the first gain value corresponding to the first detection period, the first detection period is a detection period in the detection period, different detection periods in the detection period correspond to different gain values, and the first gain value is used to control
  • the gain adjustment module 43 adjusts the amplitude of the electrical signal
  • the analog-to-digital conversion module 44 is used for sampling the adjusted electrical signal, and the adjusted electrical signal is within the sampling range of the analog-to-digital conversion module 44 .
  • the detection period of the optical signal includes at least two different detection periods, and different detection periods correspond to different gain values.
  • the optical signal returned from the near end of the measured fiber and the optical signal returned from the far end of the measured fiber can be in different detection periods.
  • the gain adjustment module 43 can use different gain values for amplitude adjustment,
  • the adjusted electrical signal is within the sampling range of the analog-to-digital conversion module, which ensures the integrity of the electrical signal sampling, thereby improving the measurement accuracy of the OTDR and the actual dynamic range of the OTDR.
  • the detection period of the optical signal may include at least two detection periods, and the detection period may be any length less than the detection period. For example, if the detection period is in milliseconds (ms), the detection period may be in milliseconds, microseconds ( us) level, nanosecond (ns) level, picosecond (ps) level, femtosecond (fs) level, etc. There are many ways to divide the detection period. Any of the division methods can divide the initial moment of the detection period and the last moment of the detection period into different detection periods, and then the amplitude of the electrical signal can be adjusted according to different gain values.
  • the amplitude of the electrical signal converted from some or all of the optical signals received at the beginning of the detection period is adjusted to be within the sampling range of the analog-to-digital conversion module 44, and/or so that some or all of the converted optical signals received at the end of the detection period are The amplitude of the electrical signal is adjusted to be within the sampling range of the analog-to-digital conversion module 44 to improve the integrity of electrical signal acquisition.
  • the three alternative division manners of the detection period are described in detail below.
  • the measurement result of the optical fiber to be measured by the fixed-gain OTDR, and the detection capability of the analog-to-digital conversion module 44 for electrical signals (this capability can be reflected by the sampling range of the analog-to-digital conversion module 44) , to divide the detection period.
  • the effective curve segment is generally close to a straight line segment that gradually decreases with increasing distance.
  • the effective curve segment (curve segment 2 in Fig. 3) is located between the horizontal line segment (curve segment 1 in Fig. 3) and the zigzag curve segment with frequent mutation (curve segment 3 in Fig. 3). between.
  • the variation law of the amplitude of the electrical signal transmitted to the analog-to-digital conversion module 44 in the whole detection period can be determined, and then the detection period can be divided according to the detection period, so that each Both the maximum amplitude and the minimum amplitude of the electrical signal transmitted to the analog-to-digital conversion module 44 in the detection period can be adjusted within the sampling range of the analog-to-digital conversion module 44 according to the same linear adjustment coefficient.
  • the sampling range of the analog-to-digital conversion module 44 can be reflected by the curve of the OTDR detection result (the overall performance of the curve is an effective curve segment that gradually decreases as time increases, corresponding to the analog-to-digital conversion
  • the signal in the sampling range of the module 44 that is, the maximum amplitude and the minimum amplitude of the electrical signal transmitted to the analog-to-digital conversion module 44 within the same detection period are respectively corresponding points in the coordinate system of the detection result, can be according to For the same moving direction and moving distance, translate up or down to the range of the ordinate value (that is, the value of the signal size) corresponding to the above-mentioned effective curve segment in the coordinate system of the measurement result curve.
  • the maximum amplitude and the minimum amplitude of the electrical signal transmitted to the analog-to-digital conversion module 44 may differ by 5dB to 30dB.
  • the detection period may be divided according to the optical loss parameter of the optical fiber to be measured and the sampling range of the analog-to-digital conversion module 44 .
  • the optical loss parameter of the measured fiber can indicate the loss of the optical signal in the measured optical fiber per unit length, and then according to the optical loss parameter, the transmission speed of the optical signal in the measured optical fiber and the sampling range of the analog-to-digital conversion module 44, determine each The duration of each detection period, and then the detection period is divided into detection periods according to the determined duration of the detection period.
  • the loss of the optical signal in a unit length of the fiber to be measured is multiplied by the transmission speed of the optical signal in the measured fiber (the unit can be km/s), and the unit time of the optical signal can be obtained.
  • the inherent loss in the measured fiber (unit can be dB/s), and then according to the sampling range of the analog-to-digital conversion module, determine the relative value of the maximum value and the minimum value in the sampling range (the unit can be dB), and then determine the relative value.
  • the ratio of the value to the loss of the optical signal in the measured fiber per unit time confirm an arbitrary value greater than zero and less than or equal to the ratio as the preset duration of the detection period.
  • each preset time period is divided into a detection period, and if there is a remaining period in the detection period that is less than the above-mentioned preset period, the period less than the preset period can be determined as a detection period. .
  • the measurement results of the optical fiber to be measured can be divided into detection periods according to the fixed gain OTDR, for example, the period corresponding to the horizontal line segment in the curve of the detection results is divided into a detection period, and the overall performance is divided into a detection period.
  • the time period corresponding to the effective curve segment that gradually decreases with the increase of the distance into a detection time period the time period corresponding to the jagged curve segment with frequent mutation is divided into a detection time period.
  • the detection period corresponding to the measurement result in Fig. 3 is 1.7ms
  • the signal size curve corresponding to the distance from 0 to 20km includes horizontal line segments.
  • the detection time corresponding to the detection period from 0 to 20km can be divided into the same
  • the signal size curve corresponding to the distance between 20km and 100km as a whole is an effective curve segment that decreases with the increase of the distance, which can effectively characterize the change law of the signal size.
  • the corresponding detection time in the detection cycle is divided into the same detection period (ie 0.2ms to 1ms); the signal size curve corresponding to the distance after 100km includes the change from the effective curve segment to the invalid frequent mutation zigzag curve segment, The detection time corresponding to the distance after 100 km in the detection period is divided into the same detection period (ie, 1 ms to 1.7 ms).
  • the detection period includes a plurality of detection periods
  • the first detection period can be any one of the detection periods, that is to say, at any time in the detection period, the control module 42 can determine the detection period at the moment, Further, the period is used as the first detection period to realize the function of obtaining the first gain value corresponding to the first detection period in the embodiment of the present application.
  • the gain value corresponding to each detection period may have various representation forms, and the specific form is not limited. If the gain value corresponding to the detection period is in dB, the gain value corresponding to the detection period can be any positive value, any negative value or zero. The gain value can be any positive number. It should be understood that if the gain value is in dB, the amplification or attenuation of the amplitude of the electrical signal can be represented by the positive and negative of the gain value; it can also be represented by a positive gain value according to the object of the gain value.
  • the object of action can be a Variable Electric Attenuator (VEA).
  • a positive gain value represents the adjustable electrical attenuator's ability to adjust the amplitude of the electrical signal. The larger the gain value, the more the amplitude of the electrical signal can be attenuated. to a smaller magnitude.
  • the gain value corresponding to each detection period may be determined according to one or both of the maximum value and the minimum value of the received optical signal intensity within the detection period, and the sampling range of the analog-to-digital conversion module 44 .
  • the maximum value of the received optical signal intensity in the detection period is P max
  • the minimum value of the received optical signal strength is P min
  • the sampling range of the analog-to-digital conversion module 44 is (A min , A max )
  • the first gain value is used to control the first component in the gain adjustment module to adjust the amplitude of the electrical signal, and other components in the optical signal detection device 4 except the first component
  • the total gain value of the signal or the amplitude adjustment of the electrical signal converted from the optical signal is G, then, the first gain value T satisfies the following conditions: P min +G+T ⁇ A min , and/or, P max +G+ T ⁇ A max .
  • the units of the optical signal strength (P max and P min ), the sampling range (A min and A max ), the first gain value (T), and the total gain value (G) in the above conditions are all dB. Since P min and/or P max may be different in different detection periods, the first gain values corresponding to different detection periods are different.
  • optical signal detection device 4 The following specifically introduces the functional realization of the optical signal detection device 4 and each module:
  • the optical signal detection device 4 may also include a filter module (not shown in FIG. 4 ).
  • the filter module may be connected between the gain adjustment module 43 and the analog-to-digital conversion module 44, using It is used to perform analog filtering on the electrical signal adjusted by the gain adjusting module 43 to eliminate electrical noise in the electrical signal.
  • the optical signal detection device 4 can also include a timing module (not shown in FIG. 4 ), which can be connected to the control module 42 for timing and transmit timing information to the control module 42, and the timing information is controlled by the control module. 42 is used to determine the detection period in the detection period.
  • the timing module can be implemented by a hardware timing module or a software timing module.
  • the photoelectric conversion module 41 includes a photodetector (also known as a photodetector, etc.), and the photodetector is used to convert the received optical signal into a current signal based on the photoelectric effect, and the converted current signal is used by the photoelectric conversion module 41.
  • a photodetector also known as a photodetector, etc.
  • the photodetector is used to convert the received optical signal into a current signal based on the photoelectric effect, and the converted current signal is used by the photoelectric conversion module 41.
  • the current signal converted by the photodetector is converted into a voltage signal by the photoelectric conversion module 41, and the converted voltage signal is used for output.
  • control module 42 may include a processor, the processor may be a combination of one or more of a CPU, a DSP, and an ASIC, and the processor may be used to obtain, within the first detection period, the corresponding The first gain value, and then the first gain value can be used to control the gain adjustment module 43 to adjust the amplitude of the electrical signal.
  • the function of the control module 42 and the function of the control device in the OTDR can be realized by the same processor or the same group of processors, or can be realized by using different processors, or, the processor that realizes part of the functions of the control module 42 can also be realized at the same time. Part of the function of the OTDR control device.
  • control module 42 may be specifically configured to obtain the first gain value corresponding to the first detection period according to the corresponding relationship between the detection period and the gain value. corresponding to the detection period.
  • the correspondence between the detection period and the gain value may be pre-stored in memory, which may include high-speed random access memory, and may also include non-volatile memory, such as one or more disk storage devices, flash memory devices, or Other non-volatile solid state storage devices, etc.
  • the above-mentioned memory can be a part of the control module 42, and in another implementation, the above-mentioned memory can be a memory other than the control module 42, for example, can be the memory in the control device in the OTDR; another example, It can also be the memory of other devices or the memory of the Internet cloud, and then the corresponding relationship between the detection period and the gain value can be obtained by the control module 42 from the memory of other devices or the cloud through the communication interface of the OTDR.
  • the analog-to-digital conversion module 44 includes an analog-to-digital converter (Analog-to-Digital Converter, ADC), and the analog-to-digital converter is used for sampling, holding, quantization and encoding.
  • ADC Analog-to-Digital Converter
  • the continuous analog signal with continuous amplitude is converted into digital signal with discrete time and amplitude, and the obtained digital signal is transmitted to the control device of the OTDR for digital signal processing.
  • the first gain value is used to control the gain adjustment module 43 to adjust the amplitude of the first electrical signal.
  • the first gain value can be used by the control module 42 to be transmitted to the gain adjustment module 43, and then be transmitted to the gain adjustment module 43 by the gain adjustment module.
  • 43 is used to adjust the amplitude of the electrical signal.
  • the control module 42 may also be used to send the indication information of the first gain value to the gain adjustment module 43, and then the gain adjustment module 43 is specifically used for the indication according to the first gain value
  • the information acquires the first gain value to adjust the amplitude of the electrical signal.
  • the detection period includes two detection periods 1 and 2.
  • the detection period 1 corresponds to the gain value A
  • the detection period 2 corresponds to the gain value B.
  • the indication information of the gain value A can be set to a low level
  • the gain value The indication information of B can be set to a high level. If the control module 42 obtains the corresponding gain value A within the detection period 1, it can transmit a low level to the gain adjustment module 43.
  • the gain value B can transmit a high level to the gain adjustment module 43, and then the gain adjustment module 43 can be used to obtain the gain value A for amplitude adjustment of the electrical signal when a low level is detected, and can be used to adjust the amplitude of the electrical signal when a high level is detected. Obtain the gain value B to adjust the amplitude of the electrical signal.
  • the gain adjustment module 43 may include a memory for storing the corresponding relationship between the indication information and the gain value, and the corresponding relationship is used by the gain adjustment module 43 to obtain the first gain value according to the indication information of the first gain value.
  • the gain adjustment module 43 may include different components, and implement the amplitude adjustment of the electrical signal according to the first gain value in different ways. Several alternative implementations of the gain adjustment module 43 are described with reference to FIGS. 5 to 10 below.
  • the electrical signal converted by the photoelectric conversion module 41 is a current signal
  • the gain adjustment module 43 includes a first voltage conversion unit and a voltage attenuation unit
  • the first voltage conversion unit can be used to convert the photoelectric conversion module 41 Convert the converted current signal into a voltage signal
  • the voltage attenuation unit may be configured to attenuate the voltage signal converted by the first voltage conversion unit according to the first gain value.
  • the first voltage conversion unit may include a trans-impedance amplifier (Trans-impedance Amplifier, TIA), and the trans-impedance amplifier includes a resistor, which can be used to convert the current signal into a trans-impedance amplifier (TIA). voltage signal.
  • TIA Trans-impedance Amplifier
  • the voltage attenuation unit may include a fast adjustable voltage attenuator, and the fast adjustable voltage attenuator may be used to quickly adjust its own attenuation coefficient according to the first gain value, and adjust the attenuation coefficient according to the adjusted voltage.
  • the voltage attenuation unit may be composed of at least two electrical attenuators having a fixed attenuation capability for voltage signals and different attenuation capabilities for voltage signals, and a control electrical attenuator On or off the electrical switch is realized.
  • FIG. 5 is a schematic structural diagram of a voltage attenuation unit provided by an embodiment of the present application. The voltage attenuation unit shown in FIG.
  • the 5 includes an electrical attenuator 1 , an electrical attenuator 2 and an electrical Attenuator 3, the three electrical attenuators are connected in parallel with each other, and the electrical switch 1 and the electrical switch 2 selectively turn on the above three electrical attenuators, so that the electrical attenuator corresponding to the first gain value is connected to the circuit for electrical power. attenuation of the signal.
  • the voltage signal attenuated by the voltage attenuation unit is in the sampling range of the analog-to-digital conversion module 44, and the attenuated voltage can be used for transmission to the analog-to-digital conversion. Module 44 performs sampling.
  • the voltage signal attenuated by the voltage attenuation unit can be used to amplify into the sampling range of the analog-to-digital conversion module 44, and then the amplified voltage signal is used for transmission to the analog-to-digital conversion module 44 for sampling
  • FIG. 6 is a schematic structural diagram of a gain adjustment module provided by an embodiment of the present application, which may be introduced by referring to FIG. 6 as an example.
  • the first voltage conversion unit 431 is configured to convert the current signal output by the analog-to-digital conversion module 44 into a voltage signal, and transmit the converted voltage signal to the voltage attenuation unit 432 .
  • the voltage attenuator 432 may be connected to the control module 42 for receiving the first gain value obtained by the control module 42 or receiving indication information of the first gain value obtained by the control module 42 .
  • the voltage attenuation unit 432 is configured to attenuate the voltage signal converted by the first voltage conversion unit 431 according to the first gain value.
  • the first amplifying unit 433 is connected to the voltage attenuating unit 432, and is used to linearly amplify the voltage signal attenuated by the voltage attenuating unit 432.
  • the amplified voltage signal is within the sampling range of the analog-to-digital conversion module 44 and can be used for transmission to the analog-to-digital conversion module 44.
  • the digital conversion module 44 performs sampling.
  • the first amplifying unit 433 may include a voltage linear amplifier, such as a low noise amplifier (Low Noise Amplifier, LNA).
  • LNA Low Noise Amplifier
  • the electrical signal converted by the photoelectric conversion module 41 is a current signal
  • the gain adjustment module 43 includes a current attenuator and a second voltage conversion unit
  • the current attenuator unit can be used to convert the photoelectricity according to the first gain value.
  • the current signal converted by the conversion module 41 is attenuated
  • the second voltage conversion unit may be used to convert the current signal attenuated by the current attenuation unit into a voltage signal.
  • the current attenuation unit may include a fast electrically adjustable current attenuator, and the fast adjustable current attenuator may be used to quickly adjust its own attenuation coefficient according to the first gain value, and adjust the attenuation coefficient according to the adjustment The latter attenuation coefficient attenuates the current signal.
  • the current attenuator may use at least two electrical attenuators that have a fixed attenuation capability to the current signal and different attenuation capabilities to the current signal, and control the electrical attenuator. On or off the electrical switch is realized.
  • the specific example is similar to the example shown in FIG. 5 and will not be described in detail.
  • the second voltage conversion unit may include a transimpedance amplifier, and the transimpedance amplifier includes a resistor, which may be used to convert a current signal into a voltage signal.
  • the voltage signal converted by the second voltage conversion unit is in the sampling range of the analog-to-digital conversion module 44, and the converted voltage signal can be For transmission to the analog-to-digital conversion module 44 for sampling.
  • the voltage signal converted by the second voltage conversion unit can be used to amplify into the sampling range of the analog-to-digital conversion module 44, and then the amplified voltage signal is used to transmit the amplified voltage signal to the analog-to-digital conversion module 44 for processing.
  • FIG. 7 is a schematic structural diagram of another gain adjustment module provided by an embodiment of the present application, which can be introduced with reference to FIG. 7 .
  • the current attenuation unit 434 may be connected to the control module 42 for receiving the first gain value obtained by the control module 42 or receiving indication information of the first gain value obtained by the control module 42 .
  • the current attenuation unit 434 is configured to attenuate the current signal digitally output by the analog-to-digital conversion module 44 according to the first gain value, and transmit the attenuated current signal to the second voltage conversion unit 435 .
  • the second voltage converting unit 435 may be configured to convert the current signal attenuated by the current attenuating unit 434 into a voltage signal.
  • the second amplifying unit 436 is connected to the second voltage converting unit 435, and is used for linearly amplifying the voltage signal converted by the second voltage converting unit 435.
  • the amplified voltage signal is within the sampling range of the analog-to-digital conversion module 44, and can be used with It is then transmitted to the analog-to-digital conversion module 44 for sampling.
  • the second amplifying unit 436 may include a voltage linear amplifier.
  • the electrical signal converted by the photoelectric conversion module 41 is a current signal
  • the gain adjustment module 43 may include a third voltage conversion unit, and the third voltage conversion unit may be used to convert the photoelectricity according to the first gain value.
  • the current signal obtained by the conversion module 41 is converted into a voltage signal.
  • the third voltage conversion unit includes a transimpedance amplifier with adjustable resistance, and the transimpedance amplifier with adjustable resistance can be used to adjust its own operation according to the first gain value resistance, and convert the input current signal into a voltage signal according to the adjusted working resistance.
  • the third voltage conversion unit may be implemented by at least two resistors with fixed resistance values and different resistance values, and a fast switching switch, such as a fast controllable resistance value.
  • the silicon switch is further turned on or off by rapidly switching the switch to achieve selective conduction of resistors with different resistance values, so as to realize the voltage conversion of the current signal by connecting the resistor corresponding to the first gain value to the circuit.
  • the voltage signal converted by the third voltage conversion unit in an optional way, is within the sampling range of the analog-to-digital conversion module, and the converted voltage signal can be used as It is then transmitted to the analog-to-digital conversion module 44 for sampling.
  • the voltage signal converted by the third voltage conversion unit can be used to amplify the sampling range of the analog-to-digital conversion module 44 , and then the amplified voltage signal is used for transmission to the analog-to-digital conversion module 44
  • FIG. 8 is a schematic structural diagram of another gain adjustment module provided by an embodiment of the present application, which can be introduced with reference to FIG. 8 .
  • the third voltage conversion unit 437 may be connected to the control module 42 for receiving the first gain value obtained by the control module 42 or receiving indication information of the first gain value obtained by the control module 42 .
  • the third voltage conversion unit 437 may be configured to convert the current signal output by the analog-to-digital conversion module 44 into a voltage signal according to the first gain value.
  • the second amplifying unit 438 is connected to the third voltage converting unit 437, and is used for linearly amplifying the voltage signal converted by the third voltage converting unit 437.
  • the amplified voltage signal is within the sampling range of the analog-to-digital conversion module 44, and can be used with It is then transmitted to the analog-to-digital conversion module 44 for sampling.
  • the second amplifying unit 438 may include a voltage linear amplifier.
  • the electrical signal converted by the photoelectric conversion module 41 is a current signal
  • the gain adjustment module 43 includes a fourth voltage conversion unit and a third amplification unit
  • the fourth voltage conversion unit is used to convert the photoelectric conversion unit.
  • the obtained current signal is converted into a voltage signal
  • the third amplifying unit is used to linearly amplify the voltage signal converted by the fourth voltage conversion unit according to the first gain value, and send the linearly amplified voltage signal to the analog-to-digital conversion module. 44 for sampling.
  • the fourth voltage conversion unit includes a transimpedance amplifier, and the transimpedance amplifier includes a resistor, which can be used to convert a current signal into a voltage signal.
  • the third amplifying unit may include a linear amplifier with an adjustable amplification factor, and the linear amplifier with an adjustable amplification factor may be used to adjust its own amplification factor according to the first gain value, and
  • the voltage signal converted by the fourth voltage conversion unit is linearly amplified according to the adjusted amplification factor, and the amplified voltage signal is within the sampling range of the analog-to-digital conversion module 44 and can be transmitted to the analog-to-digital conversion module 44 for sampling.
  • the electrical signals transmitted to the analog-to-digital conversion module 44 are all voltage signals, and the analog-to-digital conversion module 44 can be used to sample the received voltage signal, and then In some optional ways, the analog-to-digital conversion module 44 can also be used to sample the received current signal, and can input the current signal to the analog-to-digital conversion module 44 to sample the current signal.
  • the fifth and sixth types are combined below. Alternative implementations are introduced.
  • the electrical signal converted by the photoelectric conversion module 41 is a current signal
  • the gain adjustment module 43 includes a fourth amplifying unit, and the fourth amplifying unit is used to convert the electrical signal converted by the photoelectric conversion module 41 according to the first gain value.
  • the current signal is linearly amplified, and the amplified current signal is sent to the analog-to-digital conversion module 44 .
  • the fourth amplifying unit includes a linear amplifier with an adjustable amplification factor, and the linear amplifier with an adjustable amplification factor is used to adjust its own amplification factor according to the first gain value, and according to the adjustment
  • the latter amplification factor linearly amplifies the current signal converted by the photoelectric conversion module 41 .
  • FIG. 9 is a schematic structural diagram of another gain adjustment module provided by an embodiment of the present application.
  • the fourth amplifying unit 439 may be connected to the control module 42 for receiving the information obtained by the control module 42 the first gain value, or receive the indication information of the first gain value obtained by the control module 42 .
  • the fourth amplifying unit 439 can be connected between the photoelectric conversion module 41 and the analog-to-digital conversion module 44 for receiving the current signal output by the photoelectric conversion module 41 and outputting the linearly amplified current signal to the analog-to-digital conversion module 44 .
  • the electrical signal converted by the photoelectric conversion module 41 is a current signal
  • the gain adjustment module includes a current attenuation unit and a fifth amplifying unit
  • the current attenuation unit is used for the photoelectric conversion module 41 according to the first gain value.
  • the converted current signal is attenuated, and the attenuated current signal is sent to the fifth amplifying unit.
  • the fifth amplifying unit is used to linearly amplify the current signal attenuated by the current attenuating unit, and transmit the amplified current signal to the analog-to-digital conversion module 44 .
  • the current attenuation unit may include a fast electrically adjustable current attenuator, and the fast adjustable current attenuator may be used to quickly adjust its own attenuation coefficient according to the first gain value, and adjust the attenuation coefficient according to the adjustment The latter attenuation coefficient attenuates the current signal.
  • the fifth amplifying unit may include a current linear amplifier.
  • FIG. 10 is a schematic structural diagram of another gain adjustment module provided by an embodiment of the present application.
  • the first gain value or receiving the indication information of the first gain value obtained by the control module 42 .
  • the current attenuation unit 440 may be configured to attenuate the current signal converted by the photoelectric conversion module 41 according to the first gain value.
  • the fifth amplifying unit 441 is connected to the current attenuating unit 440, and is used to linearly amplify the current signal attenuated by the current attenuating unit 440.
  • the amplified voltage signal is within the sampling range of the analog-to-digital conversion module 44 and can be used for transmission to the analog-to-digital conversion module 44.
  • the digital conversion module 44 performs sampling.
  • the gain adjustment module 43 may adjust the amplitude of the electrical signal under the control of the first gain value.
  • the gain adjustment module 43 may adjust the amplitude between the first gain value and the second gain value.
  • the amplitude of the electrical signal is adjusted under the common control of the gain value, and the second gain value and the first gain value can be respectively used to control different components in the gain adjustment module 43 to adjust the amplitude of the electrical signal, so that it is finally transmitted to the analog-digital
  • the electrical signal of the conversion module 44 is within the sampling range of the analog-to-digital conversion module 44 .
  • the voltage attenuation unit 432 is used to attenuate the voltage signal converted by the first voltage conversion unit 431 under the control of the first gain value, and the first voltage conversion unit 431 can be used for Adjust its own working resistance under the control of the second gain value, and convert the current signal converted by the photoelectric conversion module 41 into a voltage signal through the adjusted working resistance, and transmit the converted voltage signal to the voltage attenuation unit 432, the voltage attenuation unit
  • the attenuated voltage signal 432 is transmitted to the first amplifying unit 433 , and the voltage signal amplified by the first amplifying unit 433 is within the sampling range of the analog-to-digital conversion module 44 .
  • the first voltage conversion unit 431 can be connected to the control module 42 (the connection relationship is not shown in the figure), and is used to receive the second gain value sent by the control module 42 or receive an indication of the second gain value sent by the control module 42 information.
  • the first gain value may be the gain value corresponding to the first detection period obtained by the control module 42 according to the corresponding relationship between the detection period and the gain value set for the voltage attenuation unit 432, and the second gain value may be the gain value obtained by the control module 42 from the control module 42 for the first detection period.
  • the acquired gain value corresponding to the first detection period In the corresponding relationship between the detection period and the gain value set by the voltage conversion unit 431, the acquired gain value corresponding to the first detection period.
  • the third voltage conversion unit 437 is used to convert the current signal converted by the photoelectric conversion module 41 into a voltage signal under the control of the first gain value
  • the second amplification unit 438 may It is used to adjust the self-amplification coefficient under the control of the second gain value, and linearly amplify the voltage signal converted by the third voltage conversion unit 437 according to the adjusted amplification coefficient, and the amplified voltage signal is in the sampling of the analog-to-digital conversion module 44. within the range.
  • the second amplifying unit 438 can be connected with the control module 42 (the connection relationship is not shown in the figure), and is used for receiving the second gain value sent by the control module 42 or receiving the indication information of the second gain value sent by the control module 42 .
  • the first gain value may be the gain value corresponding to the first detection period obtained by the control module 42 according to the corresponding relationship between the detection period and the gain value set for the third voltage conversion unit 437
  • the second gain value may be the gain value obtained by the control module 42 from the first detection period.
  • the acquired gain value corresponding to the first detection period In the corresponding relationship between the detection period and the gain value set for the second amplifying unit 438 , the acquired gain value corresponding to the first detection period.
  • the above two methods can flexibly control the adjustment of the amplitude of the electrical signal through the first gain value and the second gain value respectively.
  • two gain adjustment modules can also be used. The above modules jointly control the adjustment of the amplitude of the electrical signal through different gain values, which will not be described in detail here.
  • the gain adjustment module 43 can be switched in time. It can adjust the amplitude to match the current optical signal, so as to achieve a better measurement effect.
  • the gain switching time of the gain adjustment module 43 can be controlled to be between 0.1 ns and 100 ns.
  • the relevant introduction of the above six alternative implementations is only an exemplary introduction to the gain adjustment module 43, and the gain adjustment module 43 may also have other implementations of adjusting the electrical signal according to the first gain value, which are not limited here, such as
  • the electrical signal converted by the photoelectric conversion module 41 is a voltage signal
  • the gain adjustment module 43 includes a linear amplification module.
  • the linear amplification module can be used to linearly amplify the voltage signal converted by the photoelectric conversion module 41 according to the first gain value.
  • the amplified voltage signal Within the sampling range of the analog-to-digital conversion module 44, it can be used for transmission to the analog-to-digital conversion module 44 for sampling, etc., which are not exhaustive here.
  • the amplitude adjustment of the electrical signal is performed by the gain adjustment module 43 under the control of different gain values in different detection periods, so that the electrical signals in each detection period can be adjusted to be within the sampling range of the analog-to-digital conversion module 44, ensuring that the electrical signal Integrity of sampling.
  • the detection results of the optical signal detection device 4 using this solution and the optical signal detection device using a fixed gain are introduced by comparison with FIG. 3 and FIG. 11 .
  • FIG. 11 is a schematic diagram of another OTDR test result provided by an embodiment of the application.
  • the three detection periods are the period 1 of receiving the optical signal returned from the distance of 0 to 20km, the period 2 of receiving the optical signal returned from the distance of 20km to 100km, and the period of receiving the optical signal returned from the distance after 100km. 3.
  • a gain value of 1 can be used to amplify the signal, so that the signal that originally appeared as a horizontal line at the near end in FIG. 3 drops to the analog-to-digital conversion module 44 Within the sampling range of , and then sampled by the analog-to-digital conversion module 44 to obtain a curve segment that overall decreases as the distance increases (as shown by the dotted line segment between 0 and 20km in Fig. 11 ); returns for the distance from 20km to 100km
  • the electrical signal converted from the optical signal can be amplified with a gain value of 2.
  • the electrical signal converted from the optical signal returned from a distance of 20km to 100km can be amplified with a gain value of 2.
  • the amplified electrical signal is in the analog-to-digital conversion module.
  • a curve segment (the curve segment between 20km and 100km in Figure 11) is sampled by the analog-to-digital conversion module 44 to obtain a curve segment that decreases as the distance increases; for the optical signal returned after a distance of 100km
  • the converted electrical signal can be amplified with a gain value of 3, so that the sawtooth-like signal at the far end, which was prematurely ineffective and frequently mutated in Fig. 3, rises to the sampling range of the analog-to-digital conversion module, and then passes through the analog-to-digital conversion module.
  • 44 samples are obtained as a whole, which is a curve segment that decreases as the distance increases (the dashed line segment after 100km in Figure 11). Among them, the gain value 1, the gain value 2, and the gain value 3 are different from each other.
  • the measurement range received by the OTDR may be larger than the actual length of the fiber being measured (for example, the measurement range of the OTDR is between 1.5 times and 2 times the actual length of the fiber being measured), so the curve after 100km in Figure 11 There may still be jagged curve segments with frequent abrupt changes in the segment, which are used to represent invalid signals detected by the optical signal detection device 4 in the time after the optical signal returns from the actual farthest end of the optical fiber to be measured.
  • the control module 42 may also be configured to perform digital compensation on the digital signal sampled by the analog-to-digital conversion module 44 according to the first compensation value.
  • the first compensation value may be a compensation value corresponding to the first detection period, and the actual signal variation law within the first detection period is restored through digital compensation.
  • the method for determining the first compensation value will be specifically described below.
  • the first compensation value may be determined according to the first gain value. If in the first detection period, the signal in the optical signal detection device 4 is only adjusted in amplitude under the control of the first gain value, then the units of the first compensation value and the first gain value are the same, or the first compensation value and the first In the case where the representation of the gain value is the same (for example, the unit of the first compensation value and the first gain value may both be dB, or both the first compensation value and the first gain value are expressed in multiples, etc.), the first compensation value may be equal to the absolute value of the first gain value.
  • the first compensation value is the opposite of the first gain value
  • the control module When 42 is used for digital compensation, the amplitude of the digital signal obtained by analog-to-digital conversion can be added to the first compensation value, so as to realize the compensation and amplification of the original amplitude compensation of the first gain value control attenuation;
  • the unit is dB, and the first gain value is a positive number, which means that the electrical signal is amplified under the control of the first gain value, then the first compensation value is the inverse of the first gain value, and the control module 42 is used for digital compensation
  • the amplitude of the digital signal obtained by the analog-to-digital conversion is added to the first compensation value, so as to realize the compensation and attenuation of the original amplitude of the first gain value control and amplification.
  • the first compensation value may be the difference obtained by subtracting the first gain value from the preset value. If the first gain value is in the form of a multiple, the first compensation value may be the preset value divided by the first gain value. to the merchant.
  • the preset value may be the maximum gain value among the gain values corresponding to each detection period in the detection period.
  • the overall gain of the optical signal detection device 4 in the first detection period is obtained, and the overall gain of the optical signal detection device 4 in other detection periods of the detection period is obtained, according to each The largest overall gain among the overall gains corresponding to the detection period and the overall gain of the first detection period determine the first compensation value. For example, if the unit of the first compensation value and the maximum overall gain is dB, the first compensation value is the difference between the above-mentioned maximum overall gain and the overall gain in the first detection period; if the first compensation value and the maximum overall gain are in dB The gain is in the form of multiples, and the first compensation value is the ratio of the above-mentioned maximum overall gain to the overall gain in the first detection period.
  • the overall gain of the optical signal detection device in the detection period can be determined according to the adjustment gain of each component (module or unit) in the optical signal detection device 4 to the optical signal or the electrical signal converted from the optical signal;
  • the configuration parameters of the signal detection device 4 are obtained, and the configuration parameters may include the overall gain of the optical signal detection device 4 in each detection period.
  • the gain value of the photoelectric conversion module 41 is denoted as G APD
  • the gain value of the first voltage conversion unit 431 is denoted as G TIA
  • the voltage attenuation unit 432 The gain value is denoted as G VEA (that is, equal to the first gain value, the first gain value is a negative number, and the smaller the first gain value is, the more the attenuation of the voltage signal is)
  • the gain value of the first amplifying unit 433 is denoted as G LNA
  • the above gain values are in dB
  • the gain value of the voltage attenuation unit 432 in FIG. 5 varies with the detection period.
  • the gain value can also be set to different gain values with different detection periods.
  • This method of determining the first compensation value can use the maximum overall gain of the optical signal detection device 4 as a reference to restore the digital signal in each detection period, and the restored digital signal can reflect the actual signal change law in the detection period.
  • control device of the OTDR is used to perform digital signal processing on the digital signal output by the optical signal detection device 4, and the control module 42 can be used to perform digital compensation before the digital signal processing, or can perform compensation after the digital signal processing.
  • the control module 42 can be used to calculate the relative value of the digital signal output by the optical signal detection device 4 and the signal intensity corresponding to the initial moment of the detection period.
  • the control module 42 can be used to calculate the relative value before calculating the relative value.
  • digitally compensate the digital signal according to the first compensation value in another alternative, the control module 42 may be configured to perform digital compensation on the digital signal according to the first compensation value after calculating the relative value.
  • FIG. 12 is a schematic diagram of digital compensation of an OTDR measurement result provided by an embodiment of the present application, and FIG. 12 shows an example corresponding to FIG. 10.
  • the gain value 1 corresponding to time period 1 is negative
  • the gain value corresponding to time period 2 is 0,
  • the gain value corresponding to time period 3 is positive value.
  • the gain value and compensation value in this example are both dB is the unit, the compensation value 1 is determined according to the gain value 1, the compensation value 2 is determined according to the gain value 2, the compensation value 3 is determined according to the gain value 3, and the compensation value 1 and the gain value 1 are opposite numbers to each other, the compensation value The value 2 and the gain value 2 are both 0, and the compensation value 3 and the gain value 3 are opposite to each other.
  • the solid line in the coordinate system of FIG. 12 represents the curve in FIG.
  • the solid line segment before 20 km is obtained after the electrical signal is attenuated under the control of the gain value of 1, and then sampled and processed by the analog-to-digital conversion module 44; is 0, and the solid line segment between 20km and 100km is the electrical signal that is not amplified or attenuated under the control of the gain value 2, and is sampled and processed by the analog-to-digital conversion module 44; since the gain value 3 is a positive number, the solid line segment after 100km It is obtained after the electrical signal is amplified under the control of the gain value of 3, and then sampled and processed by the analog-to-digital conversion module 44.
  • the control module 42 can perform digital compensation on the digital signal in the period 1 through the compensation value 1.
  • the compensation value 1 is a positive value and is equal to the absolute value of the gain value 1. Therefore, through the compensation of the compensation value 1, the actual value before 20km can be converted into The line segment is translated up to the dashed line segment shown 20km ago.
  • the gain value 2 and the compensation value 2 corresponding to time period 2 are both 0, so the position of the solid line segment between 20km and 100km remains unchanged.
  • the control module 42 can also perform digital compensation on the digital signal in the period 3 through the compensation value 3.
  • the compensation value is a negative value and is equal to the absolute value of the gain value 3.
  • the actual value after 100km can be converted into The line segment is translated down to the dashed line segment shown after 100km.
  • the compensation value 1 cancels the attenuation effect of the gain value 1 on the electrical signal
  • the compensation value 3 cancels the amplifying effect of the gain value 3 on the electrical signal
  • the gain value 2 and the compensation value 2 are both 0, so after panning, you can see Figure 11
  • the three curve segments after translation become continuous curves (the gray curve in the coordinate system of Fig.
  • FIG. 11 indicates that the solid line segment and the dashed line segment between 20km and 100km overlap), which are used to represent the optical signal
  • the detection device 4 uses the same gain to process a curve obtained by processing the electrical signal converted from the optical signal received in each detection period.
  • FIG. 13 is a schematic diagram of another OTDR detection result provided by an embodiment of the present application.
  • FIG. 13 shows a digital signal obtained by performing digital compensation on the digital signal shown in FIG. 11 . the displayed curve.
  • connection relationship involved in the above description may be a direct connection relationship or an indirect connection relationship through one or more components.
  • each of the above-mentioned functional modules or units may be deployed independently of each other, or some functional modules or units may be integrated together.
  • each of the above modules or functions may be partially or fully integrated in a chip.
  • FIG. 14 is a schematic structural diagram of another optical signal detection device provided by an embodiment of the present application.
  • the optical signal detection device 14 may include a photoelectric conversion module 141, a control module 142, and an electrical signal processing module.
  • Module 143 in:
  • the photoelectric conversion module 141 is used for receiving optical signals.
  • the control module 142 is used to obtain the first gain value corresponding to the first detection period, the first detection period is a detection period in the detection period, different detection periods in the detection period correspond to different gain values, and the first gain value is used to control
  • the photoelectric conversion module 141 adjusts the intensity of the received optical signal.
  • the photoelectric conversion module 141 is also used to convert the adjusted optical signal into an electrical signal.
  • the electrical signal processing module 143 is used to sample the converted electrical signal, wherein the electrical signal converted by the photoelectric conversion module 141 is within the sampling range of the electrical signal processing module; or, the electrical signal processing module 143 is used to sample the converted electrical signal.
  • the electrical signal is amplified, and the amplified electrical signal is sampled, wherein the electrical signal amplified by the electrical signal processing module 143 is within the sampling range of the electrical signal processing module 143 .
  • the optical signal detection device 14 may further include a filtering module and/or a timing module (neither are shown in FIG. 14 ).
  • control module 142 may be configured to perform digital compensation on the digital signal sampled by the analog-to-digital conversion module 144 according to the first compensation value, where the first compensation value is determined according to the first gain value.
  • the photoelectric conversion module 141 may include an optical amplification unit with adjustable gain, and the optical amplification unit may be used to adjust the intensity of the received optical signal according to the first gain value.
  • the optical amplifying unit may include an adjustable optical amplifier, and the adjustable optical amplifier can adjust its own amplification factor according to the first gain value, and amplify the received optical signal according to the adjusted amplification factor.
  • the optical amplifying unit may be implemented by at least two optical amplifiers that have fixed amplifying capabilities for optical signals and different amplifying capabilities to optical signals, and an optical switch that controls whether the optical amplifiers work.
  • the optical amplifier corresponding to the gain value is turned on and amplifies the optical signal.
  • the photoelectric conversion module 141 may include an optical attenuation unit with adjustable gain, and the optical attenuation unit may be used to adjust the intensity of the received optical signal according to the first gain value.
  • the optical attenuation unit may include an adjustable optical attenuator, and the adjustable optical attenuator can adjust its own attenuation coefficient according to the first gain value, and attenuate the received optical signal according to the adjusted attenuation coefficient.
  • the optical attenuation unit can be realized by at least two optical attenuators with fixed attenuation capability to the optical signal and different attenuation capabilities of the optical signal, and an optical switch for controlling whether the optical attenuator works, controlled by the optical switch.
  • the optical attenuator corresponding to the first gain value is turned on and attenuates the optical signal.
  • the electrical signal processing module 143 may include an analog-to-digital conversion unit, and the electrical signal converted by the photoelectric conversion module 141 is within the sampling range of the analog-to-digital conversion unit.
  • the electrical signal processing module 143 includes an analog-to-digital conversion unit and an electrical signal amplifying unit, and the electrical signal amplifying unit can be used to amplify the electrical signal converted by the photoelectric conversion module.
  • the electrical signal is within the sampling range of the analog-to-digital conversion module.
  • the electrical signal amplifying unit may include one or more of electrical signal amplifying components such as a transimpedance amplifier and a linear amplifier, which are not specifically limited.
  • the detection period of the optical signal includes at least two different detection periods, and different detection periods correspond to different gain values.
  • the optical signal returned from the near end of the fiber under test and the optical signal returned from the far end of the fiber under test may Received in different detection periods, the photoelectric conversion module can be used for optical signals received in different detection periods, using different gain values to adjust the intensity of the optical signal, so that the electrical signal converted from the adjusted optical signal is transmitted to the analog signal.
  • the digital conversion module is used, it is within the sampling range of the analog-to-digital conversion module, which ensures the sampling integrity of the signal, thereby improving the measurement accuracy of the OTDR and the actual dynamic range of the OTDR.
  • FIG. 15 is a schematic structural diagram of another optical signal detection apparatus provided by an embodiment of the present application.
  • the optical signal detection apparatus 15 shown in FIG. 15 includes a processor 151 , a memory 152 and a receiver 153 . These components may be connected through a bus 154 or other means, and FIG. 15 takes the connection through a bus as an example. in:
  • the processor 151 may be a general-purpose processor, such as a central processing unit, and may also be a digital signal processor, an application-specific integrated circuit, or one or more integrated circuits configured to implement embodiments of the present application.
  • the processor 151 may be used to read and execute computer readable instructions.
  • the processor 151 may be configured to call a program stored in the memory 152, such as an implementation program in the optical signal detection method provided by the embodiments of the present application, and execute the instructions contained in the program to implement the corresponding method. for example.
  • the processor 151 is configured to acquire the first gain value corresponding to the first time period, or perform digital signal processing on the digital signal obtained by analog-to-digital conversion, and so on.
  • the memory 152 can be coupled with the processor 151 through the bus 154 , and the memory 152 can also be integrated with the processor 151 .
  • Memory 152 is used to store various software programs and/or sets of instructions.
  • memory 152 may include high-speed random access memory, and may also include non-volatile memory, such as one or more magnetic disk storage devices, flash memory devices, or other non-volatile solid-state storage devices.
  • the memory 152 is used for storing data, such as storing gain values corresponding to each detection period, and the like.
  • the receiver 153 is used for receiving signals, such as receiving optical signals returned from the measured optical signals.
  • the components included in the optical signal detection device in FIG. 15 can realize the functions of the optical signal detection device in any of the embodiments shown in FIGS. 4 to 10 , or the modules or units in the optical signal detection device in FIG. 14 .
  • FIGS. 4 to 10 or the modules or units in the optical signal detection device in FIG. 14 .
  • FIG. 15 For the specific implementation manner and the corresponding beneficial effects, reference may be made to the specific introduction of the embodiment corresponding to the foregoing FIG. 4 to FIG. 10 or FIG. 14 , which will not be repeated here.
  • the embodiment of the present application also provides an optical signal detection method, the method is used for processing the optical signal detected in the detection period of the optical signal, the method can be applied to an optical signal detection device, and the optical signal detection device can include a photoelectric A conversion module, an analog-to-digital conversion module, a gain adjustment module and a control module.
  • the photoelectric conversion module is used for receiving an optical signal and converting the received optical signal into an electrical signal.
  • the method may include:
  • the control module obtains the first gain value corresponding to the first detection period, the first detection period is a detection period in the detection period, different detection periods in the detection period correspond to different gain values, and the first gain value is used to control the gain adjustment module
  • the amplitude of the electrical signal is adjusted, the adjusted electrical signal is used for sampling by the analog-to-digital conversion module, and the adjusted electrical signal is within the sampling range of the analog-to-digital conversion module.
  • the method may further include that the control module performs digital compensation on the digital signal sampled by the analog-to-digital conversion module according to the first compensation value, and the first compensation value is determined according to the first gain value.
  • the gain value corresponding to the detection period is determined according to one or both of the maximum value and the minimum value of the optical signal intensity received during the detection period, and the sampling range of the analog-to-digital conversion module.
  • the optical signal detection method can be applied to the optical signal detection device shown in any of FIG. 4 to FIG. 10 .
  • the optical signal detection method please refer to the aforementioned FIG. 4 to FIG. 13 .
  • the specific introduction of the corresponding embodiment will not be repeated here.
  • the embodiment of the present application provides another optical signal detection method.
  • the method is used to process the optical signal detected in the detection period of the optical signal.
  • the method can be applied to an optical signal detection device, and the optical signal detection device can include a photoelectric A conversion module, a control module, and an electrical signal processing module, the photoelectric conversion module is used for receiving optical signals, and the method may include:
  • the control module obtains the first gain value corresponding to the first detection period, the first detection period is a detection period in the detection period, different detection periods in the detection period correspond to different gain values, and the first gain value is used to control the photoelectric conversion module
  • the intensity of the received optical signal is adjusted; the adjusted optical signal is used by the photoelectric conversion module to convert into an electrical signal, and the converted electrical signal is within the sampling range of the electrical signal processing module, and is used for sampling by the electrical signal processing module.
  • the adjusted electrical signal is used for amplification by the electrical signal processing module, and the amplified electrical signal is within the sampling range of the electrical signal processing module and is used for sampling by the electrical signal processing module.
  • the optical signal detection method can be applied to the optical signal detection device described in any of the embodiments corresponding to FIG. 14 .
  • the optical signal detection method in the optical signal detection device please refer to the above-mentioned corresponding FIG. 14 The specific introduction of the embodiment will not be repeated here.
  • Embodiments of the present application further provide an optical fiber measurement device, including an optical signal detection device, a transmission device, a transmission device, and a control device.
  • the optical signal detection device may further include a display device.
  • the optical signal detection device may be the optical signal detection device in any of the embodiments shown in FIG. 4 to FIG. 10 , or the optical signal detection device in FIG. 14 , and the functions of the emission device, the transmission device, the control device and the display device are
  • the optical fiber measurement equipment of this paper is introduced, and the detection process of the optical detection equipment is introduced as an example.
  • the detection parameters of the optical signal detection device are introduced. It is assumed that in the optical signal detection device shown in FIG. 5, only the voltage attenuation unit 432 is a component with adjustable gain, and other components (including modules and units) are for fixed gain components. And assuming that the test range is 170km, and the transmission speed of the optical signal in the measured fiber is 2 ⁇ 10 8 m/s, the detection period of the optical signal is 1.7ms. And assuming that in the measurement result curve of the fixed gain OTDR, the horizontal line segment is included between 0 and 20km, and the distance after 100km includes the jagged curve segment with frequent mutation, then the detection period can be divided into three t1, t2 and t3.
  • the detection period wherein the period t1 is 0 to 0.2ms, the period t2 is 0.2ms to 1ms, and the period t3 is 1ms to 1.7ms.
  • the voltage attenuation unit 432 is determined according to the gain of the photoelectric conversion of the photoelectric conversion module 41, the gain of the voltage conversion of the first voltage conversion unit 431, the gain of the linear amplification of the first amplifying unit 433, and the sampling range of the analog-to-digital conversion module 44.
  • the gain value corresponding to the t1 period is -28dB
  • the gain value corresponding to the t2 period is -12dB
  • the gain value corresponding to the t3 period is 0,
  • the corresponding compensation value of the t1 period is 28dB
  • the corresponding compensation value of the t2 period is 12dB
  • the compensation value corresponding to the t3 period is 0.
  • the control device 10 controls the transmitting device to emit pulses, and the photoelectric conversion module 41 continues to receive the optical signal returned from the measured optical fiber during the optical signal detection period, converts it into a current signal, and passes the first signal.
  • the voltage conversion single power supply 431 is converted into a voltage signal and then transmitted to the voltage attenuation unit 432 .
  • the control module 42 obtains the gain value of -28dB corresponding to t1, and controls the voltage attenuation unit 432 to attenuate the amplitude of the voltage signal by 28dB; during the period of t2, the control module 42 obtains the gain value of -12dB corresponding to t2, and controls The voltage attenuating unit 432 attenuates the amplitude of the voltage signal by 12 dB; in the period of t3, the control module 42 obtains a gain value of 0 corresponding to t3, and controls the voltage attenuating unit 432 not to adjust the amplitude of the voltage signal.
  • the voltage signal output by the voltage attenuation unit 432 is amplified by the first amplifying unit 433 and then transmitted to the analog-to-digital conversion module 44 for sampling.
  • the control device 10 performs digital signal processing on the digital signal sampled by the analog-to-digital conversion module 44, performs 28dB digital compensation on the digital signal processing result in the t1 period, and performs 12dB on the digital signal processing result in the t2 period. Digital compensation is not performed on the digital signal processing results in the t3 period. After the digital signal processing results in the t1, t2 and t3 periods are compensated, a continuous and complete detection result curve in the detection period is obtained.
  • the third voltage conversion unit 437 is a component with adjustable gain, and other components (including modules and units) are components with fixed gain.
  • the detection parameters of the optical signal detection device, the duration of the detection period, and the division of the detection period are respectively the same as the above information corresponding to the optical signal detection device in FIG. 5 .
  • the gain value corresponding to the third voltage conversion unit 437 in the period t1 is determined.
  • the gain value corresponding to 6dB and t2 period is 14dB
  • the gain value corresponding to t3 period is 20dB
  • the corresponding compensation value corresponding to t1 period is 14dB
  • the corresponding compensation value of t2 period is 6dB
  • the corresponding compensation value of t3 period is 0.
  • the control device 10 controls the transmitting device to emit pulses, and the photoelectric conversion module 41 continues to receive the optical signal returned from the measured optical fiber during the optical signal detection period, converts it into a current signal, and transmits it to the first optical signal.
  • Three voltage conversion modules 437 are used to convert the optical signal returned from the measured optical fiber during the optical signal detection period, converts it into a current signal, and transmits it to the first optical signal.
  • the control module 42 obtains the gain value of 6dB corresponding to t1, and controls the third voltage conversion module 437 to perform voltage conversion on the received current signal according to the gain of 6dB; during the period of t2, the control module 42 obtains the gain corresponding to t2. value of 14dB, and controls the third voltage conversion module 437 to perform voltage conversion on the received current signal according to the gain of 14dB; in the period of t3, the control module 42 obtains the gain value corresponding to t3 20dB, and controls the third voltage conversion module 437 according to A gain of 20dB performs voltage conversion on the received current signal.
  • the voltage signal output by the third voltage conversion module 437 is amplified by the second amplifying unit 438 and then transmitted to the analog-to-digital conversion module 44 for sampling.
  • the control device 10 performs digital signal processing on the digital signal sampled by the analog-to-digital conversion module 44, performs 14dB digital compensation on the digital signal processing result in the t1 period, and performs 6dB digital compensation on the digital signal processing result in the t2 period, Digital compensation is not performed on the digital signal processing results in the t3 period. After the digital signal processing results in the t1, t2 and t3 periods are compensated, a continuous and complete detection result curve in the detection period is obtained.
  • Embodiments of the present application provide a computer-readable medium, where a program is stored in the computer-readable medium, and when the program runs on a computer, the computer enables the computer to execute any of the optical signal detection methods provided by the embodiments of the present application.
  • An embodiment of the present application provides a chip, where the chip includes a processor and a communication interface, the processor is coupled to the communication interface, and is used to implement all or part of the functions of the optical signal detection apparatus shown in any one of FIG. 4 to FIG. 10 , or All or part of the functions of the optical signal detection device in FIG. 14 are realized.

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Abstract

本申请提供了一种光信号检测装置、方法及相关设备,该装置可以用于对在光信号的检测周期内检测的光信号进行处理,该装置包括光电转换模块、控制模块、增益调节模块和模数转换模块。其中,光电转换模块用于接收光信号,将接收的光信号转换为电信号;控制模块用于获取第一检测时段对应的第一增益值,第一检测时段为检测周期中的一个检测时段,检测周期内不同的检测时段对应不同的增益值,第一增益值用于控制增益调节模块对所述电信号的幅度进行调节;模数转换模块用于对调节后的电信号进行采样,调节后的电信号处于模数转换模块的采样量程内。该装置可以提高光纤测量设备的测量准确性和光纤测量设备的实际动态范围。

Description

一种光信号检测装置、方法及相关设备
本申请要求于2020年9月3日提交中国国家知识产权局、申请号为202010917024.9、申请名称为“一种光信号检测装置、方法及相关设备”的中国专利申请的优先权,其全部内容通过引用结合在本申请中。
技术领域
本申请涉及光通信领域,尤其涉及一种光信号检测装置、方法及相关设备。
背景技术
OTDR(Optical Time Domain Reflectometer,光时域反射仪)是光纤测量技术领域中的重要仪表,广泛应用于光缆线路的检测、维护和施工中,实现对光纤的长度测量、光纤接头损耗的测量、光纤故障点的定位等功能。OTDR在工作时可以向被测量光纤发送光信号,光信号在被测量光纤中可能发生菲涅尔反射、瑞利散射等现象,从而向OTDR反射回一部分光信号,OTDR对返回的光信号进行处理,得到可以反映被测量光纤内部的被测量指标情况的数据。
OTDR的动态范围可以反映OTDR测量的最长距离,动态范围越大,测量结果中的曲线线型越好,可测距离也越长。OTDR的动态范围越大,也就表示OTDR可以对从距离相差越大的位置返回的光信号进行处理。在OTDR内通常包含光信号检测装置,用于对返回的光信号进行检测和处理,目前的OTDR内光信号检测装置对信号的采样能力有限,导致OTDR的测量准确性和实际动态范围较低。
发明内容
本申请提供一种光信号检测装置、方法及相关设备,通过本申请可以提高对接收到的光信号处理的过程中信号采样的完整性,进而提高光纤测量设备的测量准确性和光纤测量设备的实际动态范围。
本申请实施例第一方面提供了一种光信号检测装置,该装置可以用于对在光信号的检测周期内检测的光信号进行处理,该装置包括光电转换模块、控制模块、增益调节模块和模数转换模块。上述各个功能模块或单元可以彼此独立部署,也可以将部分功能模块或单元集成在一起。可选的方式中,各个模块或功能可以部分或全部地集成在芯片中。
其中,光电转换模块用于接收光信号,将接收的光信号转换为电信号;控制模块用于获取第一检测时段对应的第一增益值,第一检测时段为检测周期中的一个检测时段,检测周期内不同的检测时段对应不同的增益值,第一增益值用于控制增益调节模块对所述电信号的幅度进行调节;模数转换模块用于对调节后的电信号进行采样,调节后的电信号处于模数转换模块的采样量程内。
光信号的检测周期包括至少两个不同的检测时段,不同检测时段对应不同的增益值,从被测量光纤近端返回的光信号以及从被测量光纤远端返回的光信号可以在不同检测时段内接收,进而针对从被测量光纤近端返回的光信号转换得到的电信号,以及从被测量光纤远端返回的光信号转换得到电信号,增益调节模块可以采用不同的增益值进行幅度调节,使调节后 的电信号处于模数转换模块的采样量程内,保证了电信号采样的完整性,进而提高光纤测量设备的测量准确性和光纤测量设备的实际动态范围。
结合第一方面,在一种可选的方式中,光电转换模块转换的电信号为电流信号,增益调节模块可以包括第一电压转换单元和电压衰减单元;第一电压转换单元用于将电流信号转换为电压信号;电压衰减单元用于根据第一增益值,对转换得到的电压信号进行衰减。
进一步可选的,增益调节模块还包括第一放大单元,第一放大单元用于对衰减后的电压信号进行线性放大,并将线性放大后的电压信号发送给模数转换模块。
结合第一方面,在另一种可选的方式中,光电转换模块转换的电信号为电流信号,增益调节模块包括电流衰减单元和第二电压转换单元;电流衰减单元用于根据第一增益值对电流信号进行衰减;第二电压转换单元用于将衰减后的电流信号转换为电压信号。
该可选方式中,一种可替换的实现中,第二电压转换单元转换的电压信号处于模数转换模块的采样量程内,用于传输给模数转换模块进行采样,另一种可替代的实现中,增益调节模块还包括第二放大单元,用于对转换得到的电压信号进行线性放大,并将线性放大后的电压信号发送给模数转换模块,放大后的电压信号处于模数转换模块的采样量程内。
结合第一方面,在另一种可选的方式中,光电转换模块转换的电信号为电流信号,增益调节模块包括第三电压转换单元,第三电压转换单元用于根据第一增益值,将电流信号转换为电压信号。
该可选方式中,一种可替换的实现中,第二电压转换单元转换的电压信号处于模数转换模块的采样量程内,用于传输给模数转换模块进行采样,另一种可替代的实现中,增益调节模块还包括第二放大单元,用于对转换得到的电压信号进行线性放大,并将线性放大后的电压信号发送给模数转换模块,放大后的电压信号处于模数转换模块的采样量程内。
结合第一方面,在另一种可选的方式中,光电转换模块转换的电信号为电流信号,增益调节模块包括第四电压转换单元和第三放大单元;第四电压转换单元用于将电流信号转换为电压信号;第三放大单元用于根据第一增益值,对转换得到的电压信号进行线性放大,并将线性放大后的电压信号发送给模数转换模块。
结合第一方面,在另一种可选的方式中,控制模块还用于根据第一补偿值,对模数转换模块采样得到的数字信号进行数字补偿,第一补偿值是根据第一增益值确定的。通过控制模块的数字补偿,可以将各个检测时段内采用不同增益值调节的电信号还原为统一增益值调节下的电信号,保证了光信号强度随距离的变化曲线的连续性,进而提高了上述曲线信息的准确性和可读性。
结合第一方面,在又一种可选的方式中,检测时段对应的增益值是根据在检测时段内接收的光信号强度的最大值和最小值中的一个或两个、以及模数转换模块的采样量程确定的。
本申请实施例第二方面提供了一种光信号检测方法,用于对在光信号的检测周期内检测的光信号进行处理,该方法应用于光信号检测装置,该光信号检测装置包括光电转换模块、模数转换模块、增益调节模块和控制模块;光电转换模块用于接收光信号,并将光信号转换为电信号。
在该方法中,控制模块获取第一检测时段对应的第一增益值,第一检测时段为检测周期中的一个检测时段,检测周期内不同的检测时段对应不同的增益值,第一增益值用于控制增益调节模块对电信号的幅度进行调节,调节后的电信号被模数转换模块用于采样,且调节后的电信号处于模数转换模块的采样量程内。
光信号的检测周期包括至少两个不同的检测时段,不同检测时段对应不同的增益值,从 被测量光纤近端返回的光信号以及从被测量光纤远端返回的光信号可以在不同检测时段内接收,进而针对从被测量光纤近端返回的光信号转换得到的电信号,以及从被测量光纤远端返回的光信号转换得到电信号,控制模块可以通过不同的增益值控制增益调节模块进行幅度调节,使调节后的电信号处于模数转换模块的采样量程内,保证了电信号采样的完整性,进而提高光纤测量设备的测量准确性和光纤测量设备的实际动态范围。
结合第二方面,在一种可选的方式中,控制模块还可以根据第一补偿值,对模数转换模块采样得到的数字信号进行数字补偿,第一补偿值是根据第一增益值确定的。控制模块通过数字补偿,可以将各个检测时段内采用不同增益值调节的电信号还原为统一增益值调节下的电信号,保证了光信号强度随距离的变化曲线的连续性,进而提高了上述曲线信息的准确性和可读性。
结合第二方面,在另一种可选的方式中,检测时段对应的增益值是根据在检测时段内接收的光信号强度的最大值和最小值中的一个或两个、以及模数转换模块的采样量程确定的。
本申请实施例第三方面提供了另一种光信号检测装置,用于对在光信号的检测周期内检测的光信号进行处理,该装置包括光电转换模块、控制模块和电信号处理模块。
其中,光电转换模块用于接收光信号;控制模块用于获取第一检测时段对应的第一增益值,第一检测时段为检测周期中的一个检测时段,检测周期内不同的检测时段对应不同的增益值,第一增益值用于控制光电转换模块对接收的光信号的强度进行调节;光电转换模块还用于将调节后的光信号转换为电信号;电信号处理模块用于对转换后的电信号进行采样,其中,光电转换模块转换后的电信号处于电信号处理模块的采样量程内;或者,电信号处理模块用于对转换后的电信号进行放大,并对放大后的电信号进行采样,其中,电信号处理模块放大后的电信号处于电信号处理模块的采样量程内。
光信号的检测周期包括至少两个不同的检测时段,不同检测时段对应不同的增益值,从被测量光纤近端返回的光信号以及从被测量光纤远端返回的光信号可以在不同检测时段内接收,针对光电转换模块可以用于针对不同检测时段接收到的光信号,采用不同的增益值进行光信号强度的调节,使得调节后的光信号转换得到的电信号传输至模数转换模块时,处于模数转换模块的采样量程内,保证了信号的采样完整性,进而提高光纤测量设备的测量准确性和光纤测量设备的实际动态范围。
本申请实施例第四方面提供了一种光信号检测装置,该光信号检测装置可以包括处理器、存储器和接收器,其中,处理器、存储器和接收相互连接,其中,接收器用于接收信号(如接收光信号),存储器用于存储程序,处理器用于调用存储器中存储的程序,程序当被计算机执行时,实现上述第二方面中的光信号检测方法。
本申请实施例第五方面提供了一种光纤测量设备,该光纤测量设备包括光信号检测装置、发射装置、传送装置及控制装置;其中,控制装置用于根据输入的配置信息触发发射装置发射光信号;传送装置用于将发射装置发射的光信号传输给被测量光纤,还用于将从被测量光纤接收的光信号传输给光信号检测装置;光信号检测装置为第一方面或第三方面中任一所述光信号检测装置;控制装置还用于对光信号检测装置输出的信号进行数字信号处理,并输出数字信号处理得到的结果。
本申请实施例第六方面提供了一种计算机可读介质,计算机可读介质存储有程序,当该程序在计算机上运行时,使得计算机执行上述第二方面中的光信号检测方法。
本申请实施例第七方面提供一种芯片,芯片包括处理器和通信接口,处理器与通信接口耦合,用于实现上述第一方面或任一种可选的实现方式中光信号检测装置的全部或部分功能, 或者实现上述第三方面中光信号检测装置的全部或部分功能。
附图说明
为了更清楚地说明本申请实施例中的技术方案,下面将对实施例中所需要使用的附图作简单地介绍,显而易见地,下面描述中的附图仅仅是本申请的一些实施例,对于本领域普通技术人员来讲,在不付出创造性劳动的前提下,还可以根据这些附图获得其他的附图。
图1为本申请实施例提供的一种OTDR的结构示意图;
图2为本申请实施例提供的一种OTDR中光信号检测装置的结构示意图;
图3为本申请实施例提供的一种OTDR检测结果的示意图;
图4为本申请实施例提供的一种光信号检测装置的结构示意图;
图5为本申请实施例提供的一种电压衰减单元的结构示意图;
图6为本申请实施例提供的一种增益调节模块的结构示意图;
图7为本申请实施例提供的另一种增益调节模块的结构示意图;
图8为本申请实施例提供的另一种增益调节模块的结构示意图;
图9为本申请实施例提供的另一种增益调节模块的结构示意图;
图10为本申请实施例提供的另一种增益调节模块的结构示意图;
图11为本申请实施例提供的又一种OTDR测试结果的示意图;
图12为本申请实施例提供的一种OTDR测量结果的数字补偿示意图;
图13为本申请实施例提供的又一种OTDR检测结果的示意图;
图14为本申请实施例提供的另一种光信号检测装置的结构示意图;
图15为本申请实施例提供的另一种光信号检测装置的结构示意图。
具体实施方式
下面将结合本申请实施例中的附图,对本申请实施例中的技术方案进行清楚、完整地描述,显然,所描述的实施例仅是本申请一部分实施例,而不是全部的实施例。基于本申请中的实施例,本领域普通技术人员在没有做出创造性劳动前提下所获得的所有其他实施例,都属于本申请保护的范围。
在介绍本申请实施例的光信号检测装置之前,首先结合图1和图2介绍OTDR内部实现,首先参阅图1,图1为本申请实施例提供的一种OTDR的结构示意图,如图1所示,OTDR包括控制装置10、发射装置20、传送装置30和光信号检测装置40。
控制装置10用于根据接收到的配置参数,驱动发射装置20发射光信号,传送装置30用于将发射装置20发射的光信号传输给被测量光纤;光信号在被测量光纤中发生菲涅尔反射和瑞利散射等,向OTDR返回部分光信号,传送装置30还用于接收从被测量光纤返回的光信号,将从被测量光纤接收的光信号传输给光信号检测装置40,光信号检测装置40用于检测光信号,将检测到的光信号处理为数字信号;控制装置10还可以用于对光信号检测装置40输出的数字信号进行数字信号处理,并输出数字信号处理得到的结果。
可选的,如图1所示,OTDR还可以包括显示装置50,显示装置50可以用于接收控制装置10输出的数字信号处理的结果,并显示数字信号处理的结果。另一种实现方式中,控制装置10可以将数字信号处理的结果输出给其他设备或装置,通过其他设备或装置对数字信号处理的结果进行显示或进行其他处理。
可选的,控制装置10可以包括处理器,处理器可以是中央处理器(central processing unit, CPU),还可以是数字信号处理器(digital signal processing,DSP)或专用集成电路(application specific integrated circuit,ASIC)等。进而可以通过处理器处理接收到的配置参数,从而驱动发射装置20发射光信号,或通过处理器对光信号检测装置40输出的信号进行数字信号处理。
控制装置10接收到的配置参数可以为用户输入的配置参数,例如,配置参数可以包括发射装置20发射的光信号的波长、光信号的脉冲宽度、光信号的功率强度、OTDR的测量范围(可以指示当前测量的最大长度)等参数。
控制装置10对光信号检测装置40输出的数字信号进行的数字信号处理,可以包括对数字信号的归一化处理。比如,可以通过光信号检测装置40在检测周期的初始时刻接收的光信号的光功率,进行数字信号的归一化处理,具体的,若光信号检测装置40输出的信号为电压数字信号,控制装置10可以通过根据电压数字信号确定出对应的电功率,进而确定上述电功率与上述光功率的相对值(该相对值采用dB为单位),该相对值作为归一化处理的结果;又如,可以通过光信号检测装置40在检测周期的初始时刻接收的光信号转换的电压信号,进行数字信号的归一化处理,具体的,若光信号检测装置40输出的信号为电压数字信号,控制装置10可以计算光信号检测装置40输出的电压数字信号的幅度,与检测周期初始时刻接收的光信号转换的电压信号的幅度的相对值(该相对值采用dB为单位),该相对值作为归一化处理的结果;等等。计算数字信号处理还可以包括对数字信号的数字域降噪处理等。
可选的,发射装置20可以包括激光器201以及激光器驱动202,激光器201可以为激光二极管(Laser Diode,LD),用于发射相干性高的光信号,激光器驱动202可以用于为LD提供合适的偏置电流和调制电流,使偏置电流略大于LD的阈值电流,使LD工作在线性区,从而稳定发射光信号。
可选的,传送装置30可以包括光环形器,光环形器是一种多端口、非互易特性的光器件,光从光环形器的某一端口输入时,仅能以较低损耗从指定的端口输出,而该输入的端口通向其他端口的损耗都非常大,形成不相通端口,从而可以实现将从发射装置20发射的光信号传送给被测量光纤,而从被测量光纤返回的光信号被传输给光信号检测装置40。
可选的,光信号检测装置40可以用于接收光信号,并将光信号转换为电信号,还可以用于对电信号进行放大以及采样,采样之后的数字信号可以表示OTDR在不同时刻接收到的光信号的强度变化情况。
光信号检测装置40中通常包含光电转换模块、电信号放大模块和模数转换模块,光信号检测装置40在对接收到的光信号处理的过程中,首先通过光电转换模块将接收到的光信号转换为电信号,光信号直接转换得到的电信号的较为微弱,需要经过电信号放大模块的放大,才能够被模数转换模块识别并采样。
在光信号检测装置40中,电信号放大模块的放大增益通常是固定的,即任意时刻接收到的光信号转换得到的电信号,均采用同一放大增益值进行放大。举例来说,参阅图2,图2为本申请实施例提供的一种OTDR中光信号检测装置的结构示意图,如图2所示,光信号检测装置40包括光探测模块401、跨阻放大模块402、线性放大模块403和模数转换模块404。
光探测模块401用于接收光信号,并将接收到的光信号转换为电流信号;跨阻放大模块402用于将光探测模块401得到的电流信号转换为电压信号;线性放大模块403用于对跨阻放大模块402得到的电压信号进行线性放大;模数转换模块404用于对线性放大模块403放大后的电压信号进行采样。
应理解,图2中的光信号检测装置40的电信号放大模块包括跨阻放大模块402和线性放大模块403。电信号在图2的光信号检测装置40中传输的过程中,可以在跨阻放大模块402 和线性放大403中得到放大。其中,跨阻放大模块402在将电流信号转换为电压信号的过程中,通过固定阻值的电阻实现了电信号的放大,由于电阻阻值固定,跨阻放大模块402的信号放大增益是固定的;此外,线性放大模块403也通常使用增益固定的电压放大器,因此,这种结构的光信号检测装置40的总体放大增益为固定的。
光信号检测装置40的总体放大增益为固定的,也就是说,光信号检测装置40对在任一时刻接收的光信号进行处理时,均是按照固定增益进行线性放大的,而由于从被测量光纤近端返回的光信号和从被测量光纤远端返回的光信号的强度差别较大,导致从被测量光纤近端返回的光信号转换得到的电信号(为便于描述记为近端电信号)和从被测量光纤远端返回的光信号转换得到的电信号(为便于描述记为远端电信号)强度差别较大,进而如果电信号放大模块按照同一放大增益对近端电信号和远端电信号进行线性放大,可能会使得近端电信号被放大后超出模数转换模块可识别的最大电信号,和/或,可能会使得远端电信号被放大后依然低于模数转换模块可识别的最小电信号,上述两种可能的情况都会造成OTDR对被测量光纤的测量信息的丢失,降低OTDR的测试准确性,以及OTDR的实际动态范围。
比如,针对动态范围为40dB的OTDR,通常使用APD(Avalanche Photodiode Detector,雪崩光电探测器)作为光探测器,用于接收光信号,并将光信号转换为电流信号,若激光二极管的脉冲峰值功率为20dBm,APD在一定偏压下的响应度为10mA/mW,APD将接收到的光信号转换得到的电流信号的幅值范围约为1pA-1uA之间,即最大电流和最小电流的比值约为10 6倍;经过固定放大增益的跨阻放大模块和线性放大模块后,输入模数转换模块的最大电压和最小电压的比值依然约为10 6倍,而模数转换模块的采样量程(也就是采样范围,或者是可识别范围,可以指示采样的最小电压信号和/或最大电压信号)通常为0.5mV-500mV,最小的可识别电压和最大的可识别电压的比值为10 3倍,模数转换模块的采样范围小于输入电压的范围。若将1pA的电流信号转换的电压信号被放大至模数转换模块的采样范围,就必然使1uA的电流信号转换的电压信号被放大后,大于模数转换模块最大的采样电压,若将1uA的电流信号转换的电压信号被放大至模数转换模块的采样范围,就必然使1pA的电流信号转换的电压信号被放大后,小于模数转换模块最小的采样电压,因此,上述两种情况必然使得输入模数转换模块的电压信号不能完全被识别,部分电压信号丢失。
一种应用场景中,随着光信号检测装置40持续对光信号的接收以及处理,OTDR可以得到由光信号转换得到的电信号随时间的变化情况,在光信号检测装置40中光信号的强度和电信号的幅值为线性关系,因此,电信号随时间的变化情况也可以体现光信号随时间的变化情况。而光信号在光纤中的传输速率是一定的,因此接收光信号的时间和光信号的传输距离是互相对应的,根据光信号随时间的变化情况就可以得到光信号的强度随距离的变化情况。
依据光信号在被测量光纤中传输过程中不断衰减的特性,不难得到,光信号在被测量光纤传输的过程中,越靠近OTDR的位置光信号的强度越大,反之强度越小,光信号的强度随距离的变化可以表现为随距离的增加而逐渐下降的一条直线。但实际测量过程中,被测量光纤受一些因素的影响,对光信号的损耗可能不是均匀的,比如OTDR和被测量光纤之间存在连接处,可能会对光信号造成较强的反射,又如,被测量光纤中可能存在熔接处或连接处,会对光信号造成较强的散射或反射,又如,被测量光纤在使用过程中可能受损出现弯折处,会对光信号造成较强的散射、反射,甚至透射,等等,因此,在实际测量过程中,光信号的强度随距离的变化曲线通常不是一条规则的直线,但整体上应表现为距离较近的位置光信号较强,而距离较远的位置光信号较弱。
然而,若光信号检测装置40采用固定放大增益进行信号放大,可能出现模数转换模块 对电信号的采样范围,小于经过电信号放大模块放大后的电信号的幅值范围,那么模数转换模块针对近端电信号的采样可能会出现饱和,在曲线中体现为水平线段,针对远端电信号的采样可能会无法识别,在曲线中过早地体现为频繁突变的锯齿曲线段。举例来说,参见图3,图3为本申请实施例提供的一种OTDR检测结果的示意图,图3所示坐标系中,灰色实线表示测量得到的信号变化曲线,由近端向远端进行分析该曲线,如图3中所示,由于近端电信号较强,使得较近距离的电信号表现为水平线段(如图3中的曲线段1);直到电信号随距离的增加而下降到模数转换模块的采样范围内时,模数转换模块可进行正常的电信号采样,使得曲线表现为随距离增加而逐渐下降(如图3中的曲线段2);随着距离的增加,电信号下降至模数转换模块可识别的最小电信号以下,模数转换模块无法正常识别电信号并进行采样,使得曲线过早地表现为无效的频繁突变的锯齿状(如图3中的曲线段3)。因此,这种放大增益固定的光信号检测装置会造成部分电信号的丢失,影响OTDR的测量准确性,以及OTDR的实际动态范围。
本申请实施例提供的光信号检测装置,可以应用在对光纤中的光信号进行测量的光纤测量设备(如OTDR或其他光纤传感器等)中,本申请实施例中以OTDR这一光纤测量设备为例进行介绍。该光信号检测装置用于对光信号的检测周期内检测的光信号进行处理,在处理过程中可以保证电信号的采样完整性,进而提高光纤测量设备的测量准确性和光纤测量设备的实际动态范围。在介绍本申请实施例提供的光信号检测装置之前,先介绍光信号的检测周期。
光信号的检测周期是光信号检测装置对被测量光纤进行一次测量的时间,在光信号的检测周期内,随着时间的推移,光信号检测装置接收到的光信号,可以作为从被测量光纤近端到远端逐渐返回的光信号。也就是说,在检测周期初始时刻,OTDR开始针对最近端位置接收光信号并进行处理,在检测周期最后一刻,OTDR针对设定的最远端位置接收光信号并进行处理,光信号的检测周期有多种确定方式,举例介绍几种确定方式。
在第一种可选的方式中,光信号的检测周期可以是OTDR中发射装置发射两次脉冲之间的时间间隔,比如发射装置在t1时刻开始发射第一个脉冲,在t2时刻开始发射第二个脉冲,t2时刻和t1时刻之间的时间差为光信号的检测周期。
在第二种可选的方式中,光信号的检测周期可以是针对OTDR中模数转换模块设定的采样周期,模数转换模块在采样周期内一定的采样频率进行采样,比如将模数转换模块设置为在1.7ms内以10M次/秒的采样频率进行采样,1.7ms为光信号的检测周期。
在第三种可选的方式中,光信号的检测周期可以为针对OTDR中发射装置中发射的一个脉冲的光信号检测时间。针对某一脉冲,若其对应的光信号的检测周期结束,那么光信号检测装置将针对该脉冲的下一个脉冲进行光信号的检测,或者光信号检测装置停止光信号的检测。
在第四种可选的实现方式中,光信号的检测周期可以是根据OTDR的测量范围确定的,测量范围可以指示当前测量的最大长度,根据该最大长度以及光信号在光纤中的传播速度可以确定光信号的检测周期,比如测量范围指示的最大长度为170km,光信号在光纤中的传播速度为2×10 8m/s,光信号传输至该最大长度并返回所占用的时长可以作为光信号的检测周期,即检测周期T=170×10×2/(2×10 8)=1.7ms。
应理解,在OTDR对光纤的光损耗情况的测试场景中,测试结果包括光信号的强度随与距离的变化曲线,可以将上述OTDR的测量范围所指示的当前测量的最大长度,设置为大于 实际的被测量光纤长度的数值,比如,可以将OTDR的测量范围指示的最大长度设置为实际的被测量光纤长度的1.5倍-2倍之间,从而使得实际的被测量光纤中光信号损耗情况可以清楚完整地通过曲线体现出来。
下面结合图4-图15介绍本申请实施例提供的光信号检测装置。
参阅图4,图4为本申请实施例提供的一种光信号检测装置的结构示意图,如图4所示,所述光信号检测装置4可以包括光电转换模块41、控制模块42、增益调节模块43和模数转换模块44。其中:
光电转换模块41用于接收光信号,并将光信号转换为电信号;
控制模块42用于获取第一检测时段对应的第一增益值,第一检测时段是检测周期中的一个检测时段,检测周期内不同的检测时段对应不同的增益值,第一增益值用于控制增益调节模块43对电信号的幅度进行调节;
模数转换模块44用于对调节后的电信号进行采样,调节后电信号处于模数转换模块44的采样量程内。
光信号的检测周期包括至少两个不同的检测时段,不同检测时段对应不同的增益值,从被测量光纤近端返回的光信号以及从被测量光纤远端返回的光信号可以在不同检测时段内接收,进而针对从被测量光纤近端返回的光信号转换得到的电信号,以及从被测量光纤远端返回的光信号转换得到电信号,增益调节模块43可以采用不同的增益值进行幅度调节,使调节后的电信号处于模数转换模块的采样量程内,保证了电信号采样的完整性,进而提高OTDR的测量准确性和OTDR的实际动态范围。
首先具体介绍光信号检测周期中的检测时段,以及检测时段对应的增益值:
光信号的检测周期可以包括至少两个检测时段,检测时段可以为小于检测周期时长的任意时长,比如,若检测周期为毫秒(ms)级,那么检测时段的时长可以是毫秒级、微秒(us)级、纳秒(ns)级、皮秒(ps)级、飞秒(fs)级等。检测时段的划分方式可以有多种,任意一种划分方式都可以将检测周期的初始时刻和检测周期的最后时刻划分进不同的检测时段,进而可以按照不同增益值进行电信号的幅度调节,使得在检测周期初始阶段接收的部分或全部光信号转换的电信号的幅度调节至模数转换模块44的采样量程内,和/或,使得在检测周期末尾阶段接收到的部分或全部光信号转换的电信号的幅度调节至模数转换模块44的采样量程内,提高电信号采集的完整性。下面具体介绍三种可替换的检测时段的划分方式。
一种可替代的实现方式中,可以根据固定增益的OTDR对被测量光纤的测量结果,以及模数转换模块44对电信号的检测能力(该能力可以通过模数转换模块44的采样量程体现),进行检测时段的划分。
具体来说,固定增益的OTDR对被测量光纤的测量结果中,存在一段可以有效反映光信号变化规律的曲线段,该有效的曲线段整体接近一条随距离增加而逐渐下降的直线段,例如,在图3的测量结果中有效的曲线段(如图3中曲线段2)位于水平线段(如图3中曲线段1)和频繁突变的锯齿状曲线段(如图3中曲线段3)之间。进而,根据有效的曲线段接近的直线段的斜率,可以确定出在整个检测周期中,传输至模数转换模块44的电信号的幅值变化规律,进而可以针对检测周期划分检测时段,使得各个检测时段中传输至模数转换模块44的电信号的最大幅值和最小幅值均可以按照同一线性调节系数调节至模数转换模块44的采样量程内。
从OTDR的检测结果曲线的角度来说,由于模数转换模块44的采样量程可以通过OTDR 检测结果的曲线体现(曲线中整体表现为随时间增大而逐渐下降的有效曲线段,对应模数转换模块44的采样量程内的信号),也就是,在同一检测时段内传输至模数转换模块44的电信号的最大幅值和最小幅值各自在检测结果的坐标系中对应的点,可以按照同一移动方向和移动距离,向上平移或向下平移至上述有效曲线段在测量结果曲线的坐标系中对应的纵坐标取值(也就是信号大小的取值)范围内。可选的,同一检测时段内,传输至模数转换模块44的电信号的最大幅值和最小幅值可以相差5dB至30dB。
另一种可替代的实现方式中,可以根据被测量光纤的光损耗参数、以及模数转换模块44的采样量程进行检测时段的划分。被测量光纤的光损耗参数可以指示光信号在单位长度的被测量光纤中的损耗,进而根据光损耗参数、光信号在被测量光纤内的传输速度和模数转换模块44的采样量程,确定每个检测时段的时长,进而根据确定的检测时段的时长,对检测周期进行检测时段的划分。
比如,光信号在单位长度的被测量光纤中的损耗(单位可以为dB/km)与光信号在被测量光纤中的传输速度(单位可以为km/s)相乘,可以得到光信号单位时间内在被测量光纤中的损耗(单位可以为dB/s),进而根据模数转换模块的采样量程,确定采样量程中的最大值与最小值的相对值(单位可以为dB),进而确定该相对值与光信号单位时间内在被测量光纤中的损耗的比值,确认一个大于零、且小于或等于该比值的任意数值,作为检测时段的预设时长。进而从检测周期的起始时刻开始,每预设时长的时段划分为一个检测时段,若检测周期内剩余一段小于上述预设时长的时段,可以将该小于预设时长的时段确定为一个检测时段。
又一种可替代的实现方式中,可以根据固定增益的OTDR对被测量光纤的测量结果进行检测时段的划分,比如将检测结果的曲线中水平线段对应的时段划分为一个检测时段,将整体表现为随距离增加而逐渐下降的有效曲线段对应的时段划分为一个检测时段,将表现为频繁突变的锯齿状的曲线段对应的时段划分为一个检测时段。
比如图3中,图3中的测量结果对应的检测周期为1.7ms,0至20km的距离对应的信号大小曲线中包含水平线段,可以将0至20km在检测周期中对应的检测时间划分为同一检测时段(即0至0.2ms);20km至100km之间的距离对应的信号大小曲线整体表现为随距离增加而下降的有效曲线段,可以有效表征信号大小的变化规律,可将20km至100km之间的距离在检测周期中对应的检测时间划分为同一检测时段(即0.2ms至1ms);100km之后的距离对应的信号大小曲线包含从有效曲线段变化成的无效的频繁突变锯齿状曲线段,将100km之后的距离在检测周期中对应的检测时间划分为同一检测时段(即1ms至1.7ms)。
应理解,检测周期中包含多个检测时段,第一检测时段可以是其中的任意一个检测时段,也就是说在检测周期内的任意时刻,控制模块42都可以确定该时刻所处的检测时段,进而将该时段作为第一检测时段,实现本申请实施例中获取第一检测时段对应的第一增益值的功能。
各个检测时段对应的增益值可以有多种表示形式,具体形式不做限制。若检测时段对应的增益值采用dB为单位,则检测时段对应的增益值可以为任一正值、任一负值或零,若检测时段对应的增益值为倍数的形式,则检测时段对应的增益值可以为任一正数。应理解,若增益值采用dB为单位,可以通过增益值的正和负分别表示对电信号的幅度的放大或衰减;也可以根据增益值的作用对象采用正的增益值表示,比如,增益值的作用对象可以是可调电衰减器(Variable Electric Attenuator,VEA),使用正的增益值表示可调电衰减器的对电信号的幅度调节能力,增益值越大表示可以将电信号的幅值衰减为更小的幅值。
各个检测时段对应的增益值可以是根据检测时段内接收到的光信号强度的最大值和最小值中的一个或两个、以及模数转换模块44的采样量程确定的。比如,针对检测周期内任意 一个检测时段,假设该检测时段内接收到的光信号强度的最大值为P max,接收到的光信号强度的最小值为P min,模数转换模块44的采样量程为(A min,A max),并假设第一增益值用于控制增益调节模块中的第一组件对电信号的幅度进行调节,光信号检测装置4中除第一组件以外的其他组件对光信号、或者对光信号转换的电信号的幅度调节的总增益值为G,那么,第一增益值T满足以下条件:P min+G+T≥A min,和/或,P max+G+T≤A max。其中,上述条件中光信号强度(P max和P min)、采样量程(A min和A max)、第一增益值(T)、总增益值(G)的单位均为dB。由于不同的检测时段的P min和/或P max可能不同,因此,不同的检测时段对应的第一增益值不同。
下面具体介绍光信号检测装置4及各个模块的功能实现:
可选的,光信号检测装置4还可以包括滤波模块(图4中未示出),一种可选的方式中,滤波模块可以连接于增益调节模块43和模数转换模块44之间,用于对增益调节模块43调节之后的电信号进行模拟滤波,消除电信号中的电噪声等。
可选的,光信号检测装置4还可以包括计时模块(图4中未出示),该计时模块可以与控制模块42相连,用于计时,并向控制模块42传输计时信息,计时信息被控制模块42用于确定在检测周期内所处于的检测时段。该计时模块可通过硬件计时模块实现,也可以通过软件计时模块实现。
可选的,光电转换模块41包括光探测器(又称光检测器等),光探测器用于基于光电效应将接收到的光信号转换为电流信号,转换得到的电流信号被光电转换模块41用于输出,或者,光探测器转换得到的电流信号被光电转换模块41用于转换为电压信号,转换得到的电压信号用于输出。
可选的,控制模块42可以包括处理器,处理器可以是CPU、DSP、ASIC中的一种或多种的组合,处理器可以用于在第一检测时段内,获取第一检测时段对应的第一增益值,进而第一增益值可以用于控制增益调节模块43对电信号的幅度进行调节。控制模块42的功能、以及OTDR中控制装置的功能可以通过同一处理器或同一组处理器实现,也可以使用不同的处理器实现,或者,实现控制模块42部分功能的处理器,同时也可以实现OTDR控制装置的部分功能。
进一步的,控制模块42可以具体用于根据检测时段和增益值的对应关系,获取第一检测时段对应的第一增益值,在检测时段和增益值的对应关系中,第一增益值与第一检测时段对应。
更进一步的,检测时段和增益值的对应关系可以预存在存储器中,存储器可以包括高速随机存取的存储器,并且也可包括非易失性存储器,例如一个或多个磁盘存储设备、闪存设备或其他非易失性固态存储设备,等等。一种实现方式中,上述存储器可以为控制模块42中的一部分,另一种实现中,上述存储器可以是控制模块42以外的存储器,比如,可以是OTDR中的控制装置中的存储器;又如,也可以是其他设备的存储器或互联网云端的存储器中,进而检测时段和增益值的对应关系可以被控制模块42通过OTDR的通信接口从其他设备或云端的存储器中获取。
可选的,模数转换模块44包括模数转换器(Analog-to-Digital Converter,ADC),模数转换器用于通过取样、保持、量化及编码的过程,将输入模数转换模块44的时间连续、幅值也连续的模拟信号转换为时间离散、幅值也离散的数字信号,并将得到的数字信号传输给OTDR的控制装置进行数字信号处理。
第一增益值用于控制增益调节模块43对第一电信号的幅度进行调节,一种实现方式中, 第一增益值可以被控制模块42用于传输给增益调节模块43,进而被增益调节模块43用于对电信号进行幅度的调节。
另一种实现方式中,第一增益值确定后,控制模块42还可以用于向增益调节模块43发送第一增益值的指示信息,进而增益调节模块43具体用于根据第一增益值的指示信息获取第一增益值进行电信号的幅度调节。比如,检测周期包含两个检测时段1和检测时段2两个检测时段,检测时段1对应增益值A,检测时段2对应增益值B,增益值A的指示信息可以设为低电平,增益值B的指示信息可以设为高电平,若控制模块42在检测时段1内获取到对应的增益值A,可以向增益调节模块43传输低电平,若控制模块42在检测时段内获取到对应的增益值B,可以向增益调节模块43传输高电平,进而增益调节模块43在检测到低电平时可以用于获取增益值A进行电信号的幅度调节,在检测到高电平时可以用于获取增益值B进行电信号的幅度调节。进一步的,增益调节模块43中可以包括存储器,用于存储指示信息与增益值的对应关系,该对应关系被增益调节模块43用于根据第一增益值的指示信息获取第一增益值。
增益调节模块43可以包括不同的组件,通过不同方式实现根据第一增益值对电信号的幅度调节,结合下面图5-图10举例介绍增益调节模块43的几种可替换的实现方式。
第一种可替换的实现方式中,光电转换模块41转换的电信号为电流信号,增益调节模块43包括可以第一电压转换单元和电压衰减单元,第一电压转换单元可以用于将光电转换模块41转换得到的电流信号转换为电压信号,电压衰减单元可以用于根据第一增益值,对第一电压转换单元转换得到的电压信号进行衰减。
其中,第一电压转换单元的一种可选实现方式中,第一电压转换单元可以包括跨阻放大器(Trans-impedance Amplifier,TIA),跨阻放大器中包括电阻,可以用于将电流信号转换为电压信号。
其中,电压衰减单元的一种可选实现方式中,电压衰减单元可以包括快速可调电压衰减器,快速可调电压衰减器可以用于根据第一增益值快速调节自身衰减系数,并按照调节后的衰减系数对电压信号进行衰减。
其中,电压衰减单元的另一种可选实现方式中,电压衰减单元可以由至少两个对电压信号有固定衰减能力、且对电压信号衰减能力互不相同的电衰减器,以及控制电衰减器接通与否的电开关实现。可以参阅图5中的示例,图5为本申请实施例提供的一种电压衰减单元的结构示意图,图5所示的电压衰减单元中包括互相并联的电衰减器1、电衰减器2和电衰减器3,三个电衰减器互相并联,且通过电开关1和电开关2对上述三个电衰减器的选择性接通,实现将第一增益值对应的电衰减器接入电路进行电信号的衰减。
进一步的,关于电压衰减单元衰减后的信号,一种可选方式中,电压衰减单元衰减后的电压信号处于模数转换模块44的采样量程中,衰减后的电压可以用于传输给模数转换模块44进行采样。另一种可选方式中,电压衰减单元衰减后的电压信号可以被用于放大至模数转换模块44的采样量程内,进而放大后的电压信号用于传输给被模数转换模块44进行采样,例如,图6为本申请实施例提供的一种增益调节模块的结构示意图,可以参阅图6举例介绍。
如图6所示,第一电压转换单元431用于将模数转换模块44输出的电流信号转换为电压信号,并将转换的电压信号传输给电压衰减单元432。电压衰减器432可以与控制模块42连接,用于接收控制模块42获取的第一增益值,或接收控制模块42获取的第一增益值的指示信息。电压衰减单元432用于根据第一增益值对第一电压转换单元431转换得到的电压信号进行衰减。第一放大单元433与电压衰减单元432连接,用于对电压衰减单元432衰减后 的电压信号进行线性放大,放大后的电压信号处于模数转换模块44的采样量程内,可以用于传输给模数转换模块44进行采样。可选的,第一放大单元433可以包括电压线性放大器,如低噪声放大器(Low Noise Amplifier,LNA)。
第二种可替换的实现方式中,光电转换模块41转换的电信号为电流信号,增益调节模块43包括电流衰减器和第二电压转换单元,电流衰减单元可以用于根据第一增益值对光电转换模块41转换得到的电流信号进行衰减,第二电压转换单元可以用于将电流衰减单元衰减后的电流信号转换为电压信号。
其中,电流衰减单元的一种可选实现方式中,电流衰减单元可以包括快速电可调电流衰减器,快速可调电流衰减器可以用于根据第一增益值快速调节自身衰减系数,并按照调节后的衰减系数对电流信号进行衰减。
其中,电流衰减单元的另一种可选实现方式中,电流衰减器可以通过至少两个对电流信号有固定衰减能力、且对电流信号衰减能力互不相同的电衰减器,以及控制电衰减器接通与否的电开关实现。具体示例与图5所示的示例类似,不再详述。
其中,第二电压转换单元的一种可选实现方式中,第二电压转换单元可以包括跨阻放大器,跨阻放大器中包括电阻,可以用于将电流信号转换为电压信号。
进一步的,关于第二电压转换单元转换得到的电压信号,一种可选的方式中,第二电压转换单元转换后的电压信号处于模数转换模块44的采样量程中,转换后的电压信号可以用于传输给模数转换模块44进行采样。另一种可选方式中,第二电压转换单元转换后的电压信号可以被用于放大至模数转换模块44的采样量程内,进而放大后的电压信号用于传输给模数转换模块44进行采样,例如,图7为本申请实施例提供的另一种增益调节模块的结构示意图,可以参阅图7进行介绍。
如图7所示,电流衰减单元434可以与控制模块42连接,用于接收控制模块42获取的第一增益值,或接收控制模块42获取的第一增益值的指示信息。电流衰减单元434用于根据第一增益值对模数转换模块44数输出的电流信号进行衰减,并将衰减后的电流信号传输给第二电压转换单元435。第二电压转换单元435可以用于将电流衰减单元434衰减后的电流信号转换为电压信号。第二放大单元436与第二电压转换单元435连接,用于对第二电压转换单元435转换得到的电压信号进行线性放大,放大后的电压信号处于模数转换模块44的采样量程内,可以用于传输给模数转换模块44进行采样。可选的,第二放大单元436可以包括电压线性放大器。
第三种可替代的实现方式中,光电转换模块41转换的电信号为电流信号,增益调节模块43可以包括第三电压转换单元,第三电压转换单元可以用于根据第一增益值,将光电转换模块41得到的电流信号转换为电压信号。
其中,第三电压转换单元的一种可选实现方式中,第三电压转换单元包括阻值可调的跨阻放大器,阻值可调的跨阻放大器可以用于根据第一增益值调节自身工作电阻,并根据调节后的工作电阻将输入的电流信号转换为电压信号。
其中,第三电压转换单元的另一种可选实现方式中,第三电压转换单元可以通过至少两个阻值固定、且阻值互不相同的电阻,以及快速切换开关实现,如快速可控硅开关,进而通过快速切换开关的导通或关闭对不同阻值的电阻实现选择性导通,实现将第一增益值对应的电阻接入电路对电流信号进行电压转换。
进一步的,关于第三电压转换单元转换后的电压信号,一种可选的方式中,第三电压转换单元转换后的电压信号处于模数转换模块的采样量程内,转换后的电压信号可以用于传输 给模数转换模块44进行采样。另一种可选的方式中,第三电压转换单元转换后的电压信号可以被用于放大至模数转换模块44的采样量程内,进而放大后的电压信号用于传输给模数转换模块44进行采样,例如,图8为本申请实施例提供的另一种增益调节模块的结构示意图,可以参阅图8进行介绍。
如图8所示,第三电压转换单元437可以与控制模块42连接,用于接收控制模块42获取的第一增益值,或接收控制模块42获取的第一增益值的指示信息。第三电压转换单元437可以用于根据第一增益值将模数转换模块44输出的电流信号转换为电压信号。第二放大单元438与第三电压转换单元437连接,用于对第三电压转换单元437转换得到的电压信号进行线性放大,放大后的电压信号处于模数转换模块44的采样量程内,可以用于传输给模数转换模块44进行采样。第二放大单元438可以包括电压线性放大器。
第四种可替代的实现方式中,光电转换模块41转换的电信号为电流信号,增益调节模块43包括第四电压转换单元和第三放大单元,第四电压转换单元用于将光电转换单元转换得到的电流信号转换为电压信号,第三放大单元用于根据第一增益值,对第四电压转换单元转换得到的电压信号进行线性放大,并将线性放大后的电压信号发送给模数转换模块44进行采样。
其中,第四电压转换单元的一种可选实现方式中,第四电压转换单元包括跨阻放大器,跨阻放大器中包括电阻,可以用于将电流信号转换为电压信号。
其中,第三放大单元的一种可选实现方式中,第三放大单元可以包括放大系数可调的线性放大器,放大系数可调的线性放大器可以用于根据第一增益值调节自身放大系数,并根据调节后的放大系数对第四电压转换单元转换得到的电压信号进行线性放大,放大后的电压信号处于模数转换模块44的采样量程内,可以用于传输给模数转换模块44进行采样。
应理解,上述第一种至第四种可替代的实现方式中,传输给模数转换模块44的电信号均为电压信号,模数转换模块44可用于对接收到的电压信号进行采样,又一些可选的方式中,模数转换模块44也可以用于对接收到的电流信号进行采样,可以向模数转换模块44输入电流信号进行电流信号的采样,下面结合第五种和第六种可替代的实现方式介绍。
第五种可替代的实现方式中,光电转换模块41转换的电信号为电流信号,增益调节模块43包括第四放大单元,第四放大单元用于根据第一增益值对光电转换模块41转换的电流信号进行线性放大,并将放大后的电流信号发送给模数转换模块44。
其中,第四放大单元的一种可选实现方式中,第四放大单元包括放大系数可调的线性放大器,放大系数可调的线性放大器用于根据第一增益值调节自身放大系数,并根据调节后的放大系数对光电转换模块41转换得到的电流信号进行线性放大。
例如,参阅图9,图9为本申请实施例提供的另一种增益调节模块的结构示意图,如图9所示,第四放大单元439可以与控制模块42连接,用于接收控制模块42获取的第一增益值,或接收控制模块42获取的第一增益值的指示信息。第四放大单元439可以连接于光电转换模块41和模数转换模块44之间,用于接收光电转换模块41输出的电流信号,并向模数转换模块44输出线性放大后的电流信号。
第六种可替代的实现方式中,光电转换模块41转换的电信号为电流信号,增益调节模块包括电流衰减单元和第五放大单元,电流衰减单元用于根据第一增益值对光电转换模块41转换的电流信号进行衰减,并将衰减后的电流信号发送给第五放大单元。第五放大单元用于对电流衰减单元衰减后的电流信号进行线性放大,并将放大后的电流信号传输给模数转换模块44。
其中,电流衰减单元的一种可选实现方式中,电流衰减单元可以包括快速电可调电流衰减器,快速可调电流衰减器可以用于根据第一增益值快速调节自身衰减系数,并按照调节后的衰减系数对电流信号进行衰减。
其中,第五放大单元的一种可选实现方式中,第五放大单元可以包括电流线性放大器。
例如,参阅图10,图10为本申请实施例提供的另一种增益调节模块的结构示意图,如图9所示,电流衰减单元440可以与控制模块42连接,用于接收控制模块42获取的第一增益值,或接收控制模块42获取的第一增益值的指示信息。电流衰减单元440可以用于根据第一增益值对光电转换模块41转换的电流信号进行衰减。第五放大单元441与电流衰减单元440连接,用于对电流衰减单元440衰减后的电流信号进行线性放大,放大后的电压信号处于模数转换模块44的采样量程内,可以用于传输给模数转换模块44进行采样。
应理解,上述六种可替代的实现方式中,增益调节模块43可以在第一增益值控制下对电信号的幅度进行调节,可选的,增益调节模块43可以在第一增益值和第二增益值的共同控制下对电信号的幅度进行调节,第二增益值与第一增益值可以分别用于控制增益调节模块43中不同的组件对电信号的幅度进行调节,使得最终传输至模数转换模块44的电信号处于模数转换模块44的采样量程内。
例如,在图6所示的增益调节模块中,电压衰减单元432用于在第一增益值的控制下对第一电压转换单元431转换的电压信号进行衰减,第一电压转换单元431可以用于在第二增益值的控制下调节自身工作电阻,并通过调节后的工作电阻将光电转换模块41转换的电流信号转换为电压信号,并将转换的电压信号传输至电压衰减单元432,电压衰减单元432衰减后的电压信号传输至第一放大单元433,第一放大单元433放大后的电压信号处于模数转换模块44的采样量程内。其中,第一电压转换单元431可以与控制模块42连接(图中未示出连接关系),用于接收控制模块42发送的第二增益值,或者接收控制模块42发送的第二增益值的指示信息。第一增益值可以是控制模块42根据针对电压衰减单元432设置的检测时段和增益值的对应关系,获取到的第一检测时段对应的增益值,第二增益值可以是控制模块42从针对第一电压转换单元431设置的检测时段和增益值的对应关系中,获取到的第一检测时段对应的增益值。
又如,在图8所示的增益调节模块中,第三电压转换单元437用于在第一增益值的控制下将光电转换模块41转换的电流信号转换成电压信号,第二放大单元438可以用于在第二增益值的控制下调节自身放大系数,并按照调节后的放大系数对第三电压转换单元437转换的电压信号进行线性放大,放大后的电压信号处于模数转换模块44的采样量程内。其中,第二放大单元438可以与控制模块42连接(图中未示出连接关系),用于接收控制模块42发送的第二增益值,或者接收控制模块42发送的第二增益值的指示信息。第一增益值可以是控制模块42根据针对第三电压转换单元437设置的检测时段和增益值的对应关系,获取到的第一检测时段对应的增益值,第二增益值可以是控制模块42从针对第二放大单元438设置的检测时段和增益值的对应关系中,获取到的第一检测时段对应的增益值。
应理解,上述两种方式针对增益调节模块中两个模块,分别通过第一增益值和第二增益值灵活地控制电信号的幅度的调节,另一些实现方式中,还可以增益调节模块两个以上的模块,分别通过不同的增益值共同控制电信号的幅度的调节,此处不再详述。
通过对上述六种可替代的实现方式的介绍,不难理解,增益调节模块在不同检测时段之间进行增益切换的时间越短,即增益切换得越快,可以及时地将增益调节模块43切换为与当前光信号匹配的幅值调节能力,从而达到更好的测量效果。可选的,可以将增益调节模块43 的增益切换时间控制在0.1ns至100ns之间。
上述六种可替代的实现方式的相关介绍仅为针对增益调节模块43示例性的介绍,增益调节模块43还可以有其他根据第一增益值调节电信号的实现方式,此处不做限制,比如光电转换模块41转换的电信号为电压信号,增益调节模块43包括线性放大模块,线性放大模块可以用于根据第一增益值对光电转换模块41转换的电压信号进行线性放大,放大后的电压信号处于模数转换模块44的采样量程内,可被用于传输给模数转换模块44进行采样,等等,此处不再穷举。
通过增益调节模块43在不同检测时段内在不同增益值的控制下进行电信号的幅度调节,使得各个检测时段的电信号均可以被调节至模数转换模块44的采样量程内,保证了对电信号进行采样的完整性。结合图3和图11比对介绍采用本方案的光信号检测装置4与采用增益固定的光信号检测装置的检测结果。
如图3所示,若采用固定增益的光信号检测装置,最后得到的曲线中,近端电信号表现为一条水平直线,远端电信号过早表现为无效的频繁突变的锯齿状,若采用本申请中不同检测时段中增益可调的光信号检测装置4,将检测周期划分为三个检测时段,具体可以参阅图11,图11为本申请实施例提供的又一种OTDR测试结果的示意图,三个检测时段分别为接收从0至20km的距离返回的光信号的时段1、接收从20km至100km的距离返回的光信号的时段2、以及接收从100km之后的距离返回的光信号的时段3。
如图11中所示,针对从0至20km的距离返回的光信号转换的电信号,可以采用增益值1进行放大,使得图3中近端原本表现为水平线的信号下降至模数转换模块44的采样量程内,进而通过模数转换模块44采样得到整体表现为随距离增加而下降的曲线段(如图11中0至20km之间的虚线段所示);针对从20km至100km的距离返回的光信号转换的电信号,可以采用增益值2进行放大,针对从20km至100km的距离返回的光信号转换的电信号,可以采用增益值2进行放大,放大后的电信号处于模数转换模块44的采样量程内,通过模数转换模块44采样得到整体表现为随距离增加而下降的曲线段(如图11中20km至100km之间的曲线段);针对从100km的距离之后返回的光信号转换的电信号,可以采用增益值3进行放大,使得图3中远端原本过早表现为无效的频繁突变的锯齿状的信号上升至模数转换模块的采样量程内,进而通过模数转换模块44采样得到整体表现为随距离增加而下降的曲线段(如图11中100km之后的虚线段)。其中,增益值1、增益值2和增益值3互不相同。
需要说明的是,由于OTDR接收的测量范围可能大于被测量光纤的实际长度(比如OTDR的测量范围为实际的被测量光纤长度的1.5倍-2倍之间),因此图11中100km之后的曲线段中依然可能存在频繁突变的锯齿状的曲线段,用于表示在光信号从被测量光纤的实际的最远端返回之后的时间里,光信号检测装置4检测到的无效信号。
不难理解,对光信号检测装置4在检测周期内的不同检测时段,使用不同增益值进行电信号的放大,可能会使得使光信号的强度随距离的变化曲线中,不同检测时段对应的曲线不连续,也就是会在检测时段的初始时刻或最后时刻出现断点,比如图11中所示的曲线中,检测周期划分为三个检测时段,图11中的曲线包含20km距离处和100km距离处的两个断点。因此,可选的,控制模块42还可以用于根据第一补偿值对模数转换模块44采样得到的数字信号进行数字补偿。可选的,检测周期内不同的检测时段对应不同的补偿值,第一补偿值可以是第一检测时段对应的补偿值,通过数字补偿还原出第一检测时段内实际的信号变化规律。下面具体进行介绍第一补偿值的确定方法。
一种可替代的确定第一补偿值的方法中,第一补偿值可以是根据第一增益值确定的。若 第一检测时段内,光信号检测装置4中的信号仅在第一增益值的控制下进行幅度调节,那么在第一补偿值和第一增益值的单位相同,或者第一补偿值和第一增益值表示形式相同的情况下(比如第一补偿值和第一增益值单位可以均是dB,或者第一补偿值和第一增益值均采用倍数的表示形式,等),第一补偿值可以与第一增益值的绝对值相等。比如,若第一增益值的单位为dB,且第一增益值为负数,电信号在第一增益值的控制下进行了衰减,那么第一补偿值为第一增益值的相反数,控制模块42用于数字补偿时,可以将模数转换得到的数字信号的幅值与第一补偿值相加,从而实现将原本第一增益值控制衰减的幅值补偿放大回来;若第一增益值的单位为dB,且第一增益值为正数,即表示电信号在第一增益值的控制下进行了放大,那么第一补偿值为第一增益值的相反数,控制模块42用于数字补偿时将模数转换得到的数字信号的幅值与第一补偿值相加,从而实现将原本第一增益值控制放大的幅值补偿衰减回来。
另一种可替代的确定第一补偿值的方法中,若第一检测时段内,光信号检测装置4中的信号仅在第一增益值的控制下进行幅度调节,那么在第一增益值的单位为dB时,第一补偿值可以是预设数值减去第一增益值得到的差值,若第一增益值为倍数的形式,第一补偿值可以是预设数值除以第一增益值得到的商。可选的,预设数值可以是检测周期中各个检测时段应的增益值中最大的增益值。
又一种可替代的确定第一补偿值的方法中,获取光信号检测装置4在第一检测时段的总体增益,并获取光信号检测装置4在检测周期的其他检测时段的总体增益,根据各个检测时段对应的总体增益中最大的总体增益,与第一检测时段的总体增益确定第一补偿值。例如,若第一补偿值以及最大的总体增益的单位均为dB,第一补偿值为上述最大的总体增益与第一检测时段内的总体增益的差值;若第一补偿值以及最大的总体增益为倍数形式,第一补偿值为上述最大的总体增益与第一检测时段内的总体增益的比值。其中,光信号检测装置在检测时段内的总体增益可以是根据光信号检测装置4内各个组件(模块或单元)对光信号或对光信号转换的电信号的调节增益确定的;也可以根据光信号检测装置4的配置参数获取的,配置参数中可以包含光信号检测装置4在各个检测时段内的总体增益。
例如,如图5中的光信号检测装置4,在第一检测时段内,光电转换模块41的增益值记为G APD,第一电压转换单元431的增益值记为G TIA,电压衰减单元432的增益值记为G VEA(也就等于第一增益值,第一增益值为负数,且第一增益值越小表示对电压信号的衰减越多),第一放大单元433的增益值记为G LNA,上述各个增益值采用dB为单位,那么,在第一检测时段内,光信号检测装置4的总体增益G 1为:G 1=G APD+G TIA+G VEA+G LNA,同样方式,可以计算出光电转换模块41在其他各个检测时段的总体增益G n,确定出G 1和G n中的最大值G max,进而将G max减去G 1得到的差值,确定为第一补偿值。应理解,图5中电压衰减单元432的增益值随检测时段的不同而不同,可选的,光电转换模块41、第一电压转换单元431、第一放大单元433中的一个或多个,其增益值也可以随检测时段的不同而设置不同的增益值。这种确定第一补偿值的方法可以以光信号检测装置4的最大总体增益为基准,对各个检测时段内的数字信号进行还原,还原后的数字信号可以反映检测周期内实际的信号变化规律。
应理解,OTDR的控制装置用于对光信号检测装置4输出的数字信号进行数字信号处理,控制模块42可以用于在数字信号处理之前进行数字补偿,也可以在数字信号处理之后进行补偿。例如,控制模块42可以用于计算光信号检测装置4输出的数字信号与检测周期初始时刻对应的信号强度的相对值,一种可替代方式中,控制模块42可以用于在计算该相对值之前,根据第一补偿值对数字信号进行数字补偿;另一种可替代方式中,控制模块42可以用于在计算该相对值之后,根据第一补偿值对数字信号进行数字补偿。
下面以图12和图13为例介绍数字补偿的补偿结果,参阅图12,图12为本申请实施例提供的一种OTDR测量结果的数字补偿示意图,图12示出了针对图10对应的示例进行数字补偿的过程,假设时段1对应的增益值1为负值,时段2对应的增益值为0,时段3对应的增益值为正值,假设本示例中的增益值和补偿值均采用dB为单位,补偿值1是根据增益值1确定的,补偿值2是根据增益值2确定的,补偿值3是根据增益值3确定的,且补偿值1和增益值1互为相反数,补偿值2和增益值2均为0,补偿值3和增益值3互为相反数。图12的坐标系中的实线表示图11中的曲线,20km之前的实线段是电信号在增益值1的控制下衰减后,被模数转换模块44采样后处理得到的;由于增益值2为0,20km至100km之间的实线段是电信号未在增益值2控制下放大或衰减,被模数转换模块44采样后处理得到的;由于增益值3为正数,100km之后的实线段是电信号在增益值3的控制下放大后,被模数转换模块44采样后处理得到的。
控制模块42可以通过补偿值1对时段1中的数字信号进行数字补偿,补偿值1为正值,且与增益值1的绝对值相等,因此通过补偿值1的补偿,可以将20km之前的实线段向上平移至20km之前所示的虚线段处。时段2对应的增益值2和补偿值2均为0,因此20km至100km之间的实线段的位置不变。控制模块42还可以通过补偿值3对时段3中的数字信号进行数字补偿,补偿值为负值,且与增益值3的绝对值相等,因此通过补偿值3的补偿,可以将100km之后的实线段向下平移至100km之后所示的虚线段。补偿值1将增益值1对电信号的衰减作用抵消,补偿值3将增益值3对电信号的放大作用抵消,而增益值2和补偿值2均为0,因此平移之后,可以如图11中的实线所示,平移后的三条曲线段变为连续曲线(图11的坐标系中的灰色的曲线表示,其中20km至100km之间的实线段和虚线段重叠),用于表示光信号检测装置4在光信号的检测周期内,对各个检测时段内接收的光信号转换的电信号采用相同的增益进行处理得到的曲线。更清晰的视图也可以参见图13,图13为本申请实施例提供的又一种OTDR检测结果的示意图,图13中示出了针对图11所示的数字信号进行数字补偿后得到的数字信号所表现的曲线。
在模数转换模块44采样之前,不同检测时段采用不同增益值调节电信号的幅度,可以保证模数转换模块44采样的电信号均处于采样量程内,在模数转换模块44采样之后,为保证数字信号的准确性,通过控制模块42的数字补偿,可以将各个检测时段内采用不同增益值调节的电信号还原为统一增益值调节下的电信号,保证了光信号强度随距离的变化曲线的连续性,进而提高了上述曲线信息的准确性和可读性。
应理解,以上描述中涉及的连接关系可以是直接相连关系,也可以通过一个或多个器件的间接相连关系。此外,以上所述的各个功能模块或单元可以彼此独立部署,也可以将部分功能模块或单元集成在一起。可选的,上述各个模块或功能可以部分或全部地集成在芯片中。
参阅图14,图14为本申请实施例提供的另一种光信号检测装置的结构示意图,如图14所示,该光信号检测装置14可以包括光电转换模块141、控制模块142和电信号处理模块143。其中:
光电转换模块141用于接收光信号。控制模块142用于获取第一检测时段对应的第一增益值,第一检测时段为检测周期中的一个检测时段,检测周期内不同的检测时段对应不同的增益值,第一增益值用于控制光电转换模块141对接收的光信号的强度进行调节。光电转换模块141还用于将调节后的光信号转换为电信号。电信号处理模块143用于对转换后的电信号进行采样,其中,光电转换模块141转换后的电信号处于电信号处理模块的采样量程内; 或者,电信号处理模块143用于对转换后的电信号进行放大,并对放大后的电信号进行采样,其中,电信号处理模块143放大后的电信号处于电信号处理模块143的采样量程内。
可选的,光信号检测装置14还可以包括滤波模块和/或计时模块(在图14中均未示出)。
可选的,控制模块142可以用于根据第一补偿值对模数转换模块144采样得到的数字信号进行数字补偿,第一补偿值是根据第一增益值确定的。
其中,关于光信号的检测周期中检测时段的划分方式,各检测时段对应的增益值形式及确定方式,控制模块142、滤波模块和计时模块的具体功能实现,第一增益值的指示方式,以及数字信号的数字补偿方式,均可参阅图4-图13对应实施例中相应的介绍,此处不再赘述。
在光电转换模块141的一种实现方式中,光电转换模块141可以包括增益可调的光放大单元,该光放大单元可以用于根据第一增益值对接收到的光信号的强度进行调节。
进一步的,该光放大单元可以包括可调光放大器,可调光放大器可以根据第一增益值调节自身放大系数,并按照调节后的放大系数对接收到的光信号进行放大。
进一步的,光放大单元可以由至少两个对光信号有固定放大能力、且对光信号的放大能力互不相同的光放大器,以及控制光放大器是否工作的光开关实现,通过光开关控制第一增益值对应的光放大器导通并对光信号进行放大。
在光电转换模块141的又一种实现方式中,光电转换模块141可以包括增益可调的光衰减单元,该光衰减单元可以用于根据第一增益值对接收到的光信号的强度进行调节。
进一步的,该光衰减单元可以包括可调光衰减器,可调光衰减器可以根据第一增益值调节自身的衰减系数,并按照调节后的衰减系数对接收到的光信号进行衰减。
进一步的,光衰减单元可以由至少两个对光信号有固定衰减能力、且对光信号的衰减能力互不相同的光衰减器,以及控制光衰减器是否工作的光开关实现,通过光开关控制第一增益值对应的光衰减器导通并对光信号进行衰减。
在电信号处理模块143的一种实现方式中,电信号处理模块143可以包括模数转换单元,光电转换模块141转换后的电信号处于模数转换单元的采样量程内。
在电信号处理模块143的又一种实现方式中,电信号处理模块143包括模数转换单元和电信号放大单元,电信号放大单元可以用于对光电转换模块转换的电信号进行放大,放大后的电信号处于模数转换模块的采样量程内。其中,电信号放大单元可以包括跨阻放大器、线性放大器等电信号放大组件中的一种或多种,具体不做限定。
本申请实施例中光信号的检测周期包括至少两个不同的检测时段,不同检测时段对应不同的增益值,从被测量光纤近端返回的光信号以及从被测量光纤远端返回的光信号可以在不同检测时段内接收,针对光电转换模块可以用于针对不同检测时段接收到的光信号,采用不同的增益值进行光信号强度的调节,使得调节后的光信号转换得到的电信号传输至模数转换模块时,处于模数转换模块的采样量程内,保证了信号的采样完整性,进而提高OTDR的测量准确性和OTDR的实际动态范围。
上述图4至图10中任一所示实施例中的光信号检测装置,或图14中的光信号检测装置可以以图15所示的光信号检测装置15实现。如图15所示,图15为本申请实施例提供的另一种光信号检测装置的结构示意图,图15所示的光信号检测装置15包括:处理器151、存储器152和接收器153。这些部件可通过总线154或者其他方式连接,图15以通过总线连接为例。其中:
处理器151可以是通用处理器,例如中央处理器,还可以是数字信号处理器、专用集成 电路,或者是被配置成实施本申请实施例的一个或多个集成电路。处理器151可用于读取和执行计算机可读指令。具体的,处理器151可用于调用存储于存储器152中的程序,如本申请的实施例提供的光信号检测方法中的实现程序,并执行该程序包含的指令以实现对应的方法。比如。处理器151用于获取第一时段对应的第一增益值,或者对模数转换得到的数字信号进行数字信号处理,等等。
存储器152可以和处理器151通过总线154耦合,存储器152也可以与处理器151集成在一起。存储器152用于存储各种软件程序和/或多组指令。具体的,存储器152可包括高速随机存取的存储器,并且也可包括非易失性存储器,例如一个或多个磁盘存储设备、闪存设备或其他非易失性固态存储设备。存储器152用于存储数据,比如存储各个检测时段对应的增益值等。
接收器153用于接收信号,比如接收从被测量光信号返回来的光信号等。
关于图15的光信号的检测装置包括的组件可实现图4至图10中任一所示实施例中的光信号检测装置、或图14中的光信号检测装置中模块或单元的功能,其具体实现方式及相应的有益效果,可参考前述图4至图10、或图14对应的实施例的具体介绍,此处不再赘述。
本申请实施例还提供了一种光信号检测方法,该方法用于对光信号的检测周期内检测的光信号进行处理,该方法可以应用于光信号检测装置,该光信号检测装置可以包括光电转换模块、模数转换模块、增益调节模块和控制模块,光电转换模块用于接收光信号,并将接收的光信号转换为电信号,该方法可以包括:
控制模块获取第一检测时段对应的第一增益值,第一检测时段为检测周期中的一个检测时段,检测周期内不同的检测时段对应不同的增益值,第一增益值用于控制增益调节模块对电信号的幅度进行调节,调节后的电信号被模数转换模块用于采样,且调节后的电信号处于模数转换模块的采样量程内。
可选的,该方法还可以包括控制模块根据第一补偿值,对模数转换模块采样得到的数字信号进行数字补偿,第一补偿值是根据第一增益值确定的。
可选的,检测时段对应的增益值是根据在检测时段内接收的光信号强度的最大值和最小值中的一个或两个、以及模数转换模块的采样量程确定的。
该光信号检测方法可以应用于图4至图10中任一所示的光信号检测装置,该光信号检测方法在光信号检测装置中的实现方式及有益效果,可参考前述图4至图13对应的实施例的具体介绍,此处不再赘述。
本申请实施例提供了另一种光信号检测方法,该方法用于对光信号的检测周期内检测的光信号进行处理,该方法可以应用于光信号检测装置,该光信号检测装置可以包括光电转换模块、控制模块、和电信号处理模块,光电转换模块用于接收光信号,该方法可以包括:
控制模块获取第一检测时段对应的第一增益值,第一检测时段为检测周期中的一个检测时段,检测周期内不同的检测时段对应不同的增益值,第一增益值用于控制光电转换模块对接收的光信号的强度进行调节;调节后的光信号被光电转换模块用于转换为电信号,转换后的电信号处于电信号处理模块的采样量程内,被电信号处理模块用于采样,或者调节后的电信号被电信号处理模块用于进行放大,放大后的电信号处于电信号处理模块的采样量程内,被电信号处理模块用于采样。
该光信号检测方法可以应用于图14对应的实施例中任一所述的光信号检测装置,该光 信号检测方法在光信号检测装置中的实现方式及有益效果,可参考前述图14对应的实施例的具体介绍,此处不再赘述。
本申请实施例还提供了一种光纤测量设备,包括光信号检测装置、发射装置、传送装置及控制装置。可选的,光信号检测装置还可以包括显示装置。
其中,光信号检测装置可以为图4至图10中任一所示实施例中的光信号检测装置、或图14中的光信号检测装置,发射装置、传送装置、控制装置及显示装置的功能实现可分别参阅图1对应的实施例中控制装置10、发射装置20、传送装置30和显示装置50的相应介绍,此处不再赘述,仅结合包含图5或图7中的光信号检测装置的光纤测量设备,举例介绍该光检测设备的检测过程。
结合图5进行介绍:首先介绍光信号检测装置的检测参数,假设图5所示的光信号检测装置中,仅有电压衰减单元432为增益可调的组件,其他组件(包括模块和单元)均为增益固定的组件。且假设测试量程为170km,光信号在被测量光纤中的传输速度为2×10 8m/s,则光信号的检测周期为1.7ms。且假设在固定增益的OTDR的测量结果曲线中,0至20km之间包含水平线段,在100km之后的距离包含频繁突变的锯齿状曲线段,则可以将检测周期划分为t1、t2和t3三个检测时段,其中,t1时段为0至0.2ms,t2时段为0.2ms至1ms,t3时段为1ms至1.7ms。且假设根据光电转换模块41的光电转换的增益、第一电压转换单元431电压转换的增益、第一放大单元433线性放大的增益、以及模数转换模块44的采样量程,确定出电压衰减单元432在t1时段对应的增益值为-28dB、t2时段对应的增益值为-12dB,t3时段对应的增益值为0,相应的t1时段对应的补偿值为28dB、t2时段对应的补偿值为12dB、t3时段对应的补偿值为0。
光纤测量设备接收测量指令后,控制装置10控制发射装置发射脉冲,光电转换模块41在光信号检测周期内持续接收从被测量光纤返回的光信号,并将其转换为电流信号,并经第一电压转换单电源431转换为电压信号后传输给电压衰减单元432。
在t1时段内,控制模块42获取t1对应的增益值-28dB,并控制电压衰减单元432对电压信号的幅度衰减28dB;在t2时段内,控制模块42获取t2对应的增益值-12dB,并控制电压衰减单元432对电压信号的幅度衰减12dB;在t3时段内,控制模块42获取t3对应的增益值0,并控制电压衰减单元432不对电压信号的幅度进行调节。
电压衰减单元432输出的电压信号经第一放大单元433放大后传输给模数转换模块44采样。同时控制装置10对模数转换模块44采样的数字信号进行数字信号处理,并对t1时段内的数字信号处理结果进行28dB的数字补偿,对t2时段内的数字信号处理结果进行12dB的数字补偿,对t3时段内的数字信号处理结果不进行数字补偿,对t1、t2和t3时段的数字信号处理结果补偿完后,得到检测周期内连续且信息完整的检测结果曲线。
结合图7进行介绍:假设图7所示的光信号检测装置中,仅有第三电压转换单元437为增益可调的组件,其他组件(包括模块和单元)均为增益固定的组件。光信号检测装置的检测参数以及检测周期的时长、检测时段的划分,分别与上述对图5的光信号检测装置的信息对应相同。假设根据图7中光电转换模块41的光电转换的增益、第二放大单元438线性放大的增益、以及模数转换模块44的采样量程,确定出第三电压转换单元437在t1时段对应的增益值为6dB、t2时段对应的增益值为14dB,t3时段对应的增益值为20dB,相应的t1时段对应的补偿值为14dB、t2时段对应的补偿值为6dB、t3时段对应的补偿值为0。
光纤测量设备接收测量指令后,控制装置10控制发射装置发射脉冲,光电转换模块41 在光信号检测周期内持续接收从被测量光纤返回的光信号,并将其转换为电流信号,并传输给第三电压转换模块437。
在t1时段内,控制模块42获取t1对应的增益值6dB,并控制第三电压转换模块437按照6dB的增益对接收的电流信号进行电压转换;在t2时段内,控制模块42获取t2对应的增益值14dB,并控制第三电压转换模块437按照14dB的增益对接收到的电流信号进行电压转换;在t3时段内,控制模块42获取t3对应的增益值20dB,并控制第三电压转换模块437按照20dB的增益对接收到的电流信号进行电压转换。
第三电压转换模块437输出的电压信号经第二放大单元438放大后传输给模数转换模块44采样。同时控制装置10对模数转换模块44采样的数字信号进行数字信号处理,并对t1时段内的数字信号处理结果进行14dB的数字补偿,对t2时段内的数字信号处理结果进行6dB的数字补偿,对t3时段内的数字信号处理结果不进行数字补偿,对t1、t2和t3时段的数字信号处理结果补偿完后,得到检测周期内连续且信息完整的检测结果曲线。
本申请实施例提供了一种计算机可读介质,计算机可读介质存储有程序,当该程序在计算机上运行时,使得计算机执行上本申请实施例提供的任一光信号检测方法。
本申请实施例提供一种芯片,该芯片包括处理器和通信接口,处理器与通信接口耦合,用于实现图4-图10中任一所示的光信号检测装置的全部或部分功能,或者实现图14中的光信号检测装置的全部或部分功能。
在本申请实施例的描述中,除非另有说明,“/”表示或的意思,例如,A/B可以表示A或B;本文中的“和/或”仅仅是一种描述关联对象的关联关系,表示可以存在三种关系,例如,A和/或B,可以表示:单独存在A,同时存在A和B,单独存在B这三种情况。另外,在本申请实施例的描述中,“多个”是指两个或多于两个。
本申请的说明书和权利要求书及所述附图中的术语“第一”、“第二”、“第三”和“第四”等是用于区别不同对象,而不是用于描述特定顺序。此外,术语“包括”和“具有”以及它们任何变形,意图在于覆盖不排他的包含。例如包含了一系列步骤或单元的过程、方法、系统、产品或设备没有限定于已列出的步骤或单元,而是可选地还包括没有列出的步骤或单元,或可选地还包括对于这些过程、方法、产品或设备固有的其它步骤或单元。
本领域普通技术人员可以理解,在本申请的各种实施例中,上述各过程的序号的大小并不意味着执行顺序的先后,各过程的执行顺序应以其功能和内在逻辑确定,而不应对本申请实施例的实施过程构成任何限定。

Claims (13)

  1. 一种光信号检测装置,用于对在光信号的检测周期内检测的光信号进行处理,其特征在于,所述装置包括光电转换模块、控制模块、增益调节模块和模数转换模块;
    所述光电转换模块用于接收光信号,将所述光信号转换为电信号;
    所述控制模块用于获取第一检测时段对应的第一增益值,所述第一检测时段为所述检测周期中的一个检测时段,所述检测周期内不同的检测时段对应不同的增益值,所述第一增益值用于控制所述增益调节模块对所述电信号的幅度进行调节;
    所述模数转换模块用于对所述调节后的电信号进行采样,所述调节后的电信号处于所述模数转换模块的采样量程内。
  2. 根据权利要求1所述的装置,其特征在于,所述光电转换模块转换的电信号为电流信号,所述增益调节模块包括第一电压转换单元和电压衰减单元;
    所述第一电压转换单元用于将所述电流信号转换为电压信号;
    所述电压衰减单元用于根据所述第一增益值,对转换得到的所述电压信号进行衰减。
  3. 根据权利要求2所述的装置,其特征在于,所述增益调节模块还包括第一放大单元,所述第一放大单元用于对衰减后的所述电压信号进行线性放大,并将线性放大后的所述电压信号发送给所述模数转换模块。
  4. 根据权利要求1所述的装置,其特征在于,所述光电转换模块转换的电信号为电流信号,所述增益调节模块包括电流衰减单元和第二电压转换单元;
    所述电流衰减单元用于根据所述第一增益值对所述电流信号进行衰减;
    所述第二电压转换单元用于将衰减后的所述电流信号转换为电压信号。
  5. 根据权利要求1所述的装置,其特征在于,所述光电转换模块转换的电信号为电流信号,所述增益调节模块包括第三电压转换单元,所述第三电压转换单元用于根据所述第一增益值,将所述电流信号转换为电压信号。
  6. 根据权利要求4或5所述的装置,其特征在于,所述增益调节模块还包括第二放大单元,用于对转换得到的所述电压信号进行线性放大,并将线性放大后的所述电压信号发送给所述模数转换模块。
  7. 根据权利要求1所述的装置,所述光电转换模块转换的电信号为电流信号,所述增益调节模块包括第四电压转换单元和第三放大单元;
    所述第四电压转换单元用于将所述电流信号转换为电压信号;
    所述第三放大单元用于根据所述第一增益值,对转换得到的所述电压信号进行线性放大,并将线性放大后的所述电压信号发送给所述模数转换模块。
  8. 根据权利要求1-7中任一项所述的装置,其特征在于,所述控制模块还用于根据第一 补偿值,对所述模数转换模块采样得到的数字信号进行数字补偿,所述第一补偿值是根据所述第一增益值确定的。
  9. 根据权利要求1-8中任一所述的装置,其特征在于,所述检测时段对应的增益值是根据在所述检测时段内接收的光信号强度的最大值和最小值中的一个或两个、以及所述模数转换模块的采样量程确定的。
  10. 一种光信号检测方法,用于对在光信号的检测周期内检测的光信号进行处理,所述方法应用于光信号检测装置,其特征在于,所述光信号检测装置包括光电转换模块、模数转换模块、增益调节模块和控制模块;所述光电转换模块用于接收光信号,并将所述光信号转换为电信号;
    所述方法包括:
    所述控制模块获取第一检测时段对应的第一增益值,所述第一检测时段为所述检测周期中的一个检测时段,所述检测周期内不同的检测时段对应不同的增益值,所述第一增益值用于控制所述增益调节模块对所述电信号的幅度进行调节,所述调节后的电信号被所述模数转换模块用于采样,且所述调节后的电信号处于所述模数转换模块的采样量程内。
  11. 根据权利要求10所述的方法,其特征在于,所述方法还包括:
    所述控制模块根据第一补偿值,对所述模数转换模块采样得到的数字信号进行数字补偿,所述第一补偿值是根据所述第一增益值确定的。
  12. 根据权利要求10或11所述的方法,其特征在于,所述检测时段对应的增益值是根据在所述检测时段内接收的光信号强度的最大值和最小值中的一个或两个、以及所述模数转换模块的采样量程确定的。
  13. 一种光纤测量设备,其特征在于,包括光信号检测装置、发射装置、传送装置及控制装置;
    所述控制装置用于根据输入的配置信息触发所述发射装置发射光信号;
    所述传送装置用于将所述发射装置发射的光信号传输给被测量光纤,还用于将从所述被测量光纤接收的光信号传输给所述光信号检测装置;
    所述光信号检测装置为权利要求1-权利要求9中任一所述光信号检测装置;
    所述控制装置还用于对所述光信号检测装置输出的信号进行数字信号处理,并输出数字信号处理得到的结果。
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