WO2013097256A1 - 光时域反射仪及其获取测试信号的方法 - Google Patents

光时域反射仪及其获取测试信号的方法 Download PDF

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Publication number
WO2013097256A1
WO2013097256A1 PCT/CN2011/085214 CN2011085214W WO2013097256A1 WO 2013097256 A1 WO2013097256 A1 WO 2013097256A1 CN 2011085214 W CN2011085214 W CN 2011085214W WO 2013097256 A1 WO2013097256 A1 WO 2013097256A1
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Prior art keywords
signal
test
pulse
optical amplifier
semiconductor optical
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PCT/CN2011/085214
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English (en)
French (fr)
Inventor
田玉周
杨中文
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华为技术有限公司
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Application filed by 华为技术有限公司 filed Critical 华为技术有限公司
Priority to PCT/CN2011/085214 priority Critical patent/WO2013097256A1/zh
Priority to CN201180003114.6A priority patent/CN102577179B/zh
Priority to EP11864610.8A priority patent/EP2741432A4/en
Publication of WO2013097256A1 publication Critical patent/WO2013097256A1/zh

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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
    • G01M11/00—Testing of optical apparatus; Testing structures by optical methods not otherwise provided for
    • G01M11/30—Testing of optical devices, constituted by fibre optics or optical waveguides
    • G01M11/31—Testing 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
    • G01M11/3109—Reflectometers detecting the back-scattered light in the time-domain, e.g. OTDR
    • G01M11/3145—Details of the optoelectronics or data analysis
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
    • H04B10/07—Arrangements for monitoring or testing transmission systems; Arrangements for fault measurement of transmission systems
    • H04B10/071—Arrangements 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]

Definitions

  • the present invention relates to optical network testing technology, and more particularly to an optical time domain reflectometer and a method thereof for obtaining a test signal.
  • Optical Time-Domain Reflectometer is a kind of backscattering generated by Rayleigh scattering of light in an optical fiber, and Fresnel reflection generated by discontinuous points in the optical fiber. Integrated instrumentation. With the large number of applications of PON (Passive Optical Network) networks, OTDRs are increasingly being used for PON installation and acceptance, as well as for later monitoring.
  • PON Passive Optical Network
  • the OTDR is placed in the central office (CO) equipment room, and is connected to the optical fiber network by WDM (Wavelength Division Multiplexing) installed at the optical output end of the OLT (optical line terminal) to realize the monitoring band.
  • WDM Widelength Division Multiplexing
  • the download of the light signal is realized, that is, the test optical signal sent by the OTDR enters the optical signal (ie, uploaded) through the WDM, and then the backscattered light signal and the Fresnel reflected light generated from the test optical signal in the optical fiber.
  • the signal is returned to the OTDR via WDM (ie download).
  • an OTDR includes a digital signal processor (DSP), a pulse generator, a laser driver, a laser, a circulator, a photodetector (APD), and a transimpedance amplifier (TIA), amplifier (Amplifier) and analog-to-digital converter (ADC).
  • DSP digital signal processor
  • APD photodetector
  • TIA transimpedance amplifier
  • ADC analog-to-digital converter
  • the digital processor generates a periodic trigger pulse that is adjusted to a fixed pulse width and duty cycle signal by the pulse generator, followed by a high power drive by the laser driver.
  • the laser produces a pulsed laser that monitors the band.
  • the laser sends repeated high-power light pulses through the circulator into the backbone of the fiber under test.
  • Each branch after the light and the splitter.
  • the backward Rayleigh scattering and Fresnel reflected light signals of each branch are returned through the fiber backbone and finally enter the APD through the optical circulator.
  • the intensity of the backward Rayleigh scattering and Fresnel reflected light signals is related to the pulse width and intensity of the test light signal emitted by the OTDR. Generally, the larger the optical power, the larger the returned optical signal.
  • the APD converts the received optical signal into a current signal proportional to the light intensity of the optical signal.
  • the current signal is converted into a voltage signal by the TIA, amplified by the amplifier, enters the ADC, converted into a digital signal, and then sent to the digital processor to obtain Test curve.
  • the signal accumulation obtained by each repeated pulse test is completed inside the digital processor to improve the signal-to-noise ratio and more clearly obtain the reflected signal in the test curve. Since the connection between the trunk of the optical fiber and the optical splitter has discontinuous points, when the test optical signal arrives, a large reflected signal is generated, and the scattered signal generated by the test optical signal after the optical splitter is very weak. This results in drastic changes in the amplitude of the scattered and reflected signals produced by the test optical signal.
  • the response bandwidth of the APD and the circuit is narrow, which causes the reflected light signal at the splitter in the test curve obtained by the OTDR to have a long tail, which masks the relatively close attenuation and reflection of the optical signal after the splitter. That is to cover the joints, discontinuous points and other events.
  • the OTDR is basically unable to detect branching events, such as: fiber bending or fusion joints or PC (Physical Contact), and APC (Angled Physical Contact)
  • PC Physical Contact
  • APC Angled Physical Contact
  • the test curve obtained by the OTDR is obtained. It is difficult to distinguish these reflections, especially for adjacent reflected signals with large amplitude differences, which are basically indistinguishable through the test curve.
  • the embodiment of the invention provides an optical time domain reflectometer and a method for acquiring the test signal, so as to eliminate the blind zone of the OTDR test signal as much as possible, so that the reflected signal in the test signal can be easily distinguished.
  • Embodiments of the present invention provide an optical time domain reflectometer, including: a laser for transmitting test light to the network under test; a driver coupled to the pulse generator for converting a pulse signal generated by the pulse generator into a control signal for driving the semiconductor optical amplifier; Connected to the driver for selectively absorbing or amplifying a test signal from the network under test, under control of a control signal of the driver, wherein the test signal is a reflected signal formed by reflection of the measured optical fiber network;
  • An embodiment of the present invention further provides a method for acquiring a test signal by using the above optical time domain reflectometer, comprising: a digital signal processor controlling a pulse generator to generate a pulse signal to operate the semiconductor optical amplifier in a switching state; The pulse signal is in a switching state under control; when the semiconductor optical amplifier is in an open state, the photodetector receives a test signal from the passive optical network under test.
  • the optical time domain reflectometer and the method for acquiring the test signal enable the semiconductor optical amplifier (SOA) to be in a switching state, so that when the test signal returned by the passive optical network under test is a large signal, Turning off the SOA without being received by the APD, basically eliminating the interference shielding of the large signal to the subsequent small signal, and then receiving the small signal after receiving the large signal by opening the SOA, thereby substantially eliminating the dead zone of the test signal; and by different in the densely reflected area The location turns on the SOA and receives the test signal, thereby realizing the differentiation of all reflected signals in the area.
  • SOA semiconductor optical amplifier
  • FIG. 1 is a flowchart of a method for acquiring a test signal by an optical time domain reflectometer according to an embodiment of the present invention
  • 2A is a flowchart of another method for acquiring a test signal by an optical time domain reflectometer according to an embodiment of the present invention
  • FIG. 2B is a schematic diagram of a connection between an OTDR and a passive optical network under test according to an embodiment of the present invention
  • FIG. 3 is a flowchart of another method for acquiring a test signal by an optical time domain reflectometer according to an embodiment of the present invention
  • FIG. 4 is a flowchart of still another method for acquiring a test signal by an optical time domain reflectometer according to an embodiment of the present invention
  • FIG. 5 is a schematic structural diagram of an OTDR according to an embodiment of the present disclosure.
  • FIG. 6 is a timing chart of control of an SOA in an OTDR according to an embodiment of the present invention
  • FIG. 7 is an experimental simulation diagram of an embodiment of the present invention
  • FIG. 8 is a test curve obtained in a conventional manner
  • FIG. 9 is a diagram showing an internal timing relationship during operation of an OTDR according to an embodiment of the present invention.
  • the OTDR provided by the embodiments of the present invention includes: a laser, a pulse generator, a driver, a semiconductor optical amplifier (SOA), and a photodetector (APD).
  • SOA semiconductor optical amplifier
  • APD photodetector
  • the OTDR includes basic functions such as a digital processor (DSP), an optical circulator, a laser driver, a pulse generator of a laser, an amplifier, and an analog-to-digital converter (ADC). Since it is not the focus of the present invention, it will not be described again here.
  • DSP digital processor
  • ADC analog-to-digital converter
  • the laser is used to emit test light to the network under test, and the laser in the traditional OTDR can be used, and the pulse generator of the laser triggered by the DSP generates a pulse signal and is driven by the laser.
  • the actuator converts into a control signal of the laser, so that the laser emits light, that is, generates test light into the passive optical network under test, and obtains the scattered signal and the reflected signal by detecting the scattered signal and the reflected signal generated by the light in the passive optical network under test. And other events.
  • the digital processor is configured to generate an instruction for causing the pulse generator to generate a pulse signal, the instruction including information such as pulse width, period, and the like.
  • the digital processor can also generate instructions for generating a repetitive pulse signal by a pulse generator of the laser and a pulse generator of the SOA for acquiring a panoramic view of the passive optical network.
  • the panorama is a test signal for a complete passive optical network.
  • the optical circulator is configured to receive test signals from the passive optical network under test; those skilled in the art will appreciate that the optical circulator can also transmit optical signals generated by the laser to the passive optical network under test.
  • the pulse generator is coupled to the DSP for generating a corresponding pulse signal upon receiving an instruction from the DSP, such as generating a pulse signal during a test cycle, or generating a fixed pulse width and duty cycle as in a test cycle. Multiple repetitive pulse signals.
  • the driver is connected to the pulse generator for converting the pulse signal generated by the pulse generator into a current signal, and performing power amplification to obtain a control signal of the SOA.
  • the driving end of the SOA is connected to the driver, and the input end is connected to the optical circulator, and is configured to selectively absorb or amplify the test signal received by the optical circulator under the control of the control signal of the driver, wherein the test signal It is an optical signal formed by the test light being reflected or scattered by the network of the tested optical fiber.
  • the APD is connected to the output of the SOA, and is used to convert the amplified test signal of the SOA into a current signal.
  • the OTDR adds an optical device SOA to the conventional OTDR, which not only can generate a high signal-to-noise ratio gain through the optical signal inside thereof, but also can achieve a nanosecond driving speed due to the SOA.
  • SOA switch By controlling the SOA switch, it can solve the blind zone problem caused by the received large signal, and the problem that dense reflection is difficult to distinguish, and obtain high event resolution.
  • FIG. 1 is a flow chart of a method for acquiring a test signal by an optical time domain reflectometer according to an embodiment of the present invention, including:
  • Step 11 The digital signal processor controls the pulse generator to generate a pulse signal to operate the semiconductor optical amplifier in a switch state.
  • the photodetector receives the test from the passive optical network under test received by the optical circulator signal.
  • the OTDR is in a switching state by the semiconductor optical amplifier (SOA), so that when the test signal returned by the passive optical network under test is a large signal, the SOA can be closed without being received by the APD, thereby substantially eliminating the large signal pair.
  • SOA semiconductor optical amplifier
  • the interference shielding of the subsequent small signal, and then the small signal after receiving the large signal by opening the SOA, thereby substantially eliminating the dead zone of the test signal; and realizing the area by opening the SOA at different positions in the densely reflected area and receiving the test signal The distinction between all reflected signals.
  • FIG. 2A is a flowchart of a method for acquiring a test signal by an optical time domain reflectometer according to an embodiment of the present invention.
  • the SOA operates in a switch state
  • the method for the OTDR to acquire the test signal includes: Step 21:
  • the DSP generates an instruction according to the panoramic image of the passive optical network, so that the pulse generator generates a pulse for absorbing the large signal in the panoramic image. signal.
  • the large signal that is, the optical signal emitted by the OTDR, is a reflected light signal generated at the optical splitter in the passive optical network under test.
  • the panorama is a complete test signal graph of the passive optical network under test.
  • the OTDR accesses the tested passive optical network through WDM, and tests the optical network to obtain the test curve of the passive optical network.
  • the test curve can be obtained by a conventional OTDR test, or can be obtained by using the OTDR test provided by the embodiment of the present invention.
  • the SOA works in a normal state, and the driving pulse is an intermediate pulse signal as shown in FIG. 9, so that the SOA is turned on in each test cycle, and all returned test signals are received. , and zoom in to further improve the signal-to-noise ratio of the panorama.
  • the DSP issues repeated instructions during a test cycle, and the pulse generator of the laser generates a pulse signal of fixed pulse width and duty cycle, and triggers the pulse generator of the SOA to generate a continuous high level, so that the SOA is in the test cycle.
  • the internal state is kept open, that is, the test signal received by the optical circulator is amplified as a whole.
  • Step 22 The pulse generator generates a pulse signal according to the instruction in step 21 above.
  • Step 23 the pulse signal is converted into a high-power current signal by the driver;
  • Step 24 When the optical circulator receives a large signal, the SOA is turned off, that is, the SOA is in an absorbing state, and the large signal cannot be transmitted to the APD, thereby avoiding an influence on a subsequent small signal and forming a dead zone.
  • Step 25 When the optical circulator receives the small signal after the large signal, the semiconductor optical amplifier is turned on under the control of the current signal. At this time, since the influence of the large signal on the subsequent small signal has been eliminated in step 24, the reflected light signal after the splitter can be obtained, that is, the dead zone after the large signal is substantially eliminated.
  • Step 31 The DSP generates an instruction according to the panoramic image of the passive optical network, so that the pulse generator generates a single pulse signal, which is used in the above panorama
  • the densely reflective areas are sampled at a single point. That is, during a test cycle, the DSP issues an instruction that causes the pulse generator to generate only one pulse signal.
  • the generated pulse signal is located in a densely reflected area in the panoramic view, so that the SOA opens a period of time when the optical circulator receives the dense reflected light signal, and collects one of the reflected light signals.
  • the DSP issues an instruction that causes the pulse generator to generate only one pulse signal that is placed after the pulse signal of the previous test cycle, thereby causing the SOA to turn on when the optical circulator receives the dense reflected light signal.
  • the time period which is after the open period of the previous test period, causes the SOA to collect the reflected signal during the period. That is, the DSP performs single-point sampling on multiple densely reflected regions in the panorama, and obtains one of the reflected optical signals in each test cycle, thereby solving the problem that the densely reflected optical signals cannot be distinguished in the prior art. .
  • the SOA is turned on in a corresponding period of time, and one of the reflected light signals is received.
  • Step 32 The pulse generator generates a single pulse signal according to the above instruction.
  • Step 33 The single pulse signal is converted into a high-power current signal by a driver.
  • Step 34 The SOA opens when receiving the current signal, and amplifies the signal received by the optical circulator.
  • FIG. 4 is a flowchart of still another method for acquiring a test signal by an optical time domain reflectometer according to an embodiment of the present invention.
  • the SOA operates in a switch state
  • the method for the OTDR to acquire the test signal includes: Step 41: The DSP generates an instruction in each test cycle, so that the pulse generator generates a single pulse signal, and the single pulse signal of each test cycle The generation time is postponed in turn.
  • Step 44 When the SOA receives the current signal, it is turned on, and is received by the optical circulator. The signal is amplified.
  • the OTDR directly samples the passive optical network under test in multiple test cycles, and obtains an optical signal of one time period at a time, thereby eliminating the blind zone and solving the dense and indistinguishable reflected optical signal.
  • a WDM filter is further connected between the APD and the SOA, and the ASE noise of the SOA is filtered to avoid affecting the sensitivity of the APD, and further improving the test signal. Accuracy.
  • the structure of the OTDR will be described in detail below with reference to FIG. 5 as an example.
  • the OTDR includes a DSP 51, a first pulse generator 521, a first driver 522, a laser 520, an optical circulator 53, a second pulse generator 541, a second driver 542, an SOA 540, a WDM filter 55, an APD 56, and a TIA 57. , amplifier 58 and ADC 59.
  • the APD 56 is connected to a high level (HV)
  • the SOA 540 and WDM filters 55 are dual-port devices.
  • the DSP 51 generates a cycle trigger pulse command, and is adjusted by the first pulse generator 521 to a fixed pulse width and duty cycle digital signal, and then the first driver 522 performs high power driving, so that the laser 520 generates a monitoring band pulse laser. .
  • the pulsed laser enters the passive optical network under test through the optical circulator 53 and includes the optical fiber backbone and the optical splitter and the respective branches.
  • the backward Rayleigh scattered light signal and the Fresnel reflected light signal of each branch are returned to the optical circulator 53 through the fiber backbone.
  • the DSP 51 also generates an instruction that triggers the second pulse generator 541 to generate a pulse that, after passing through the second driver 542, causes the SOA 540 to obtain a suitable operating current.
  • the SOA 540 amplifies the returned optical signal.
  • the SOA 540 drive pulse can be sampled at different positions of the laser 520 repeat cycle to obtain a complete one cycle signal.
  • the SOA 540 drive pulse can also be a sustained high level when the SOA 540 is fully in one test cycle. Open state.
  • the timing relationship between laser 520 and SOA 540 is shown in Figure 6.
  • the driving pulse of the laser 520 is a single pulse.
  • FIG. 6 shows the driving pulses of the laser 520 for four test periods. It can be seen that the driving pulses of the laser 520 are the same for each test period.
  • the driving pulse of the SOA 540 is also a single pulse, and the position of the pulse signal is different for each test period, which can be regarded as sampling different positions of the repetition period of the laser 520, so that the SOA 540 can take the position of the pulse signal. Test the signal to achieve the purpose of distinguishing the reflected signal.
  • the SOA 540 When a drive pulse current is applied to the SOA 540, the SOA 540 operates in a low noise amplification state, and the optical signal is amplified.
  • the optical signal then enters the APD 56, which converts the optical signal into a current signal that is proportional to the intensity of the light.
  • the current signal outputted by the APD 56 is converted into a voltage signal by the TIA 57, amplified by the amplifier 58 and then input to the ADC 59, converted into a digital signal, and finally sent to the DSP 51 for processing, analysis, and synthesis.
  • the DSP 51 performs the accumulation of each of the repeated pulses internally, and also accumulates the plurality of panoramas to increase the signal-to-noise ratio of the panorama.
  • the OTDR provided in this embodiment can operate the SOA 540 in a pulsed state, similar to single-point sampling, that is, the SOA 540 is turned on at a certain time or for a short period of time.
  • the SOA 540 When the current is flowing, the SOA 540 operates in an absorbing state. At this time, the optical signal entering the SOA 540 from the optical fiber through the optical circulator 53 is highly isolated, and the reflected optical signal of the optical splitter does not enter the APD 56, thereby eliminating the reception of the APD 56. A blind zone created by the splitter's reflected light signal.
  • FIG. 7 is a graph showing experimental simulations of an embodiment of the present invention, relative to the conventional mode shown in Figure 8. It can be seen that the blind zone after the light splitter reflects the light signal in Fig. 7 is greatly shortened, and the blind zone is basically eliminated. Since it is a single point sampling, the reflection time depends on the switching speed and a higher resolution is achieved.
  • the testing process includes: activating laser 520, transmitting a repeating test light pulse.
  • the SOA 540 driver is set to drive normally, providing a suitable operating current. At this time, the SOA 540 operates in the through-amplification state, so that the continuous optical signal enters the rear APD 56, and even the optical signal received by the optical circulator 53 can enter the APD. 56.
  • the APD 56 converts the received optical signal into a current signal proportional to the intensity of the light, which is converted into a voltage signal by the TIA 57, amplified, converted into a digital signal by the ADC, and finally sent to the DSP 51 to obtain a panoramic image.
  • the accumulation of each repetitive pulse is done inside the DSP 51 to improve the signal to noise ratio of the panorama.
  • the DSP 51 calculates the waveform data obtained by the analysis, that is, the panorama, and gives the specific test interval for the sample test.
  • the laser 520 is restarted and a repeated test light pulse is sent.
  • the DSP 51 gives a drive pulse within a particular sampling interval and feeds it to the SOA 540.
  • the SOA 540 operates in a sampling state, providing a path for optical signals; When the SOA 540 has no operating current, it is in the absorption state, and the returned optical signal does not enter the APD 56.
  • the DSP 51 recombines the data from the two tests into a complete waveform.
  • the specific timing relationship is shown in FIG. 9.
  • the driving pulse signals of the lasers in each test cycle are the same, that is, the driving pulse of the laser is a repeated pulse signal; the normal driving pulse signal in the middle is SOA,
  • the SOA driver is a continuous high level signal, that is, the operating current is maintained in the SOA; the bottom is the SOA switching state driving pulse signal, it can be seen that the DSP triggers the second pulse at different positions of the test cycle.
  • the generator generates a pulse signal and drives the SOA to open, thereby realizing single point adoption, obtaining a single-point reflection signal, solving the problem that the traditional OTDR is difficult to distinguish in the blind area of the PON network application and densely reflected signals, and the implementation cost is low.
  • the OTDR controls the state of the SOA through the SOA and the state of the SOA, which solves the problem that the large reflection and the large attenuation of the optical splitter in the prior art exist simultaneously, and the blind zone of the traditional OTDR technology covers the event of most branches. And the low bandwidth of the traditional OTDR technology, which is indistinguishable from the dense reflected light signals after the splitter.

Abstract

本发明涉及一种光时域反射仪及其获取测试信号的方法，通过使半导体光放大器（SOA）处于开关状态，使得当被测无源光网络返回的测试信号为大信号时，能够通过关闭SOA而不被APD接收，基本消除大信号对后续小信号的干扰屏蔽，之后通过打开SOA接收大信号后的小信号，从而基本消除了测试信号的盲区；并且通过在密集反射的区域的不同位置打开SOA，接收测试信号，从而实现了该区域的所有反射信号的区分。

Description

光时域反射仪及其获取测试信号的方法
技术领域
本发明涉及光网络测试技术， 尤其涉及一种光时域反射仪及其仪获取测 试信号的方法。
背景技术
光时域反射仪 ( Optical Time-Domain Reflectometer, OTDR )是利用光在 光纤中的瑞利散射所产生的背向散射， 以及光在光纤中不连续点产生的菲涅 尔反射， 制成的光电一体化仪表。 随着 PON( Passive Optical Network,无源光网络）网络的大量应用， OTDR 越来越多的被应用于 PON的铺设验收， 以及后期的监控。
OTDR放在局端（ Central Office, CO )机房，通过 OLT( optical line terminal, 光缆终端设备）的光纤输出端加装的 WDM( Wavelength Division Multiplexing, 波分复用）接入光纤网络， 实现监控波段的光信号的上下载。 其中， 实现监 控波段的光信号的上下载， 即 OTDR发出的测试光信号通过 WDM进入光信 号（即上载）， 之后从测试光信号在光纤中产生的后向散射光信号及菲涅尔反 射光信号， 通过 WDM返回到 OTDR (即下载）。 测试光信号的波长与 ODN ( Optical Distribution Network, 光配线网络） 中的业务光信号的波长不同， 一般为 1650nm, 因而， OTDR的监控不会影响光网络的正常运营。 通常， OTDR包括数字处理器（Digital Signal processor, DSP ), 脉冲发 生器（pulse )、 激光驱动器（driver ), 激光器（Laser )、 环形器（circulator ), 光电探测器（APD )、 跨阻抗放大器（TIA )、 放大器（Amplifier )及模数转换 器（ ADC )。 工作时， 数字处理器产生周期触发脉冲， 通过脉冲发生器后调整为固定 脉宽和占空比的信号， 之后由激光驱动器完成大功率驱动。 激光器产生监控 波段的脉冲激光。 激光器发送重复的高功率光脉冲， 通过环形器进入被测光纤的主干、 分 光器及分光器后的各个支路。 每个支路的后向瑞利散射和菲涅尔反射光信号都会通过光纤主干返回， 最后通过光环行器进入 APD。 后向瑞利散射和菲涅尔反射光信号的强度与 OTDR发出的测试光信号的脉冲宽度和光强相关。 一般光功率越大， 返回的 光信号也越大。
APD将接收到的光信号转变为和光信号的光强成比例的电流信号， 该电 流信号经过 TIA变为电压信号， 经过放大器放大后进入 ADC, 转换为数字信 号， 之后送到数字处理器， 得到测试曲线。 在数字处理器内部完成每个重复 脉冲测试得到的信号累加， 以提高信噪比， 更清楚地得到测试曲线中的反射 信号。 由于光纤的主干和分光器的连接处有不连续点产生， 因此， 当测试光信 号到达后会产生一个很大的反射信号， 并且， 测试光信号在分光器后产生的 散射信号会非常微弱 , 导致了测试光信号产生的散射信号和反射信号幅度的 剧烈变化。 而 OTDR中 APD及电路的响应带宽较窄， 使得 OTDR获得的测 试曲线中分光器处的反射光信号产生了很长的拖尾， 掩盖掉了分光器后比较 近的衰减和反射等光信号， 也即掩盖了接头、 不连续点等事件。 当分光器后 的光纤长度很短时， OTDR基本上无法探测到分支的事件， 如： 光纤弯曲或 者熔接接头或者 PC(Physical Contact, 端面为球面）连接器及 APC(Angled Physical Contact, 端面为倾斜的球面)连接器等， 造成了很大的测试盲区。 加 上在分光器处会有信号的双向衰减， 更加剧了盲区的长度。 并且， 当分光器 后的各分支光纤的长度非常接近时， 反射信号之间的距离较短， 会产生密集 反射信号， 但是由于 OTDR中 APD及电路的响应带宽较窄， 使得 OTDR得 到的测试曲线很难区分这些反射， 特别对于幅度相差很大的相邻反射信号， 通过测试曲线基本无法区分出来。
发明内容
本发明实施例提出一种光时域反射仪及其获取测试信号的方法， 以尽可 能消除 OTDR测试信号的盲区， 使测试信号中的反射信号易于区分。 本发明实施例提供了一种光时域反射仪， 包括： 激光器， 用于向被测光纤网络发射测试光； 驱动器， 与所述脉冲发生器相连， 用于将所述脉冲发生器生成的脉冲信 号转换为 用来驱动半导体光放大器的控制信号； 半导体光放大器， 与所述驱动器相连， 用于在所述驱动器的控制信号控 制下， 选择性地对来自所述被测光纤网络的测试信号进行吸收或放大， 其中 所述测试信号是所述测试光在所述被测光纤网络发生反射而形成的反射信 号；
光电探测器， 与所述半导体光放大器相连， 用于将所述半导体光放大器 放大后的测试信号转变为电流信号。 本发明实施例还提供了一种采用上述光时域反射仪获取测试信号的方 法， 包括： 数字信号处理器控制脉冲发生器生成脉冲信号， 以使半导体光放大器工 作在开关状态； 半导体光放大器在所述脉冲信号的控制下处于开关状态； 所述半导体光放大器处于打开状态下时， 光电探测器接收来自被测无源 光网络的测试信号。 本发明实施例提供的光时域反射仪及其获取测试信号的方法， 通过使半 导体光放大器（SOA )处于开关状态， 使得当被测无源光网络返回的测试信 号为大信号时， 能够通过关闭 SOA而不被 APD接收， 基本消除大信号对后 续小信号的干扰屏蔽， 之后通过打开 SOA接收大信号后的小信号， 从而基本 消除了测试信号的盲区； 并且通过在密集反射的区域的不同位置打开 SOA, 接收测试信号， 从而实现了该区域的所有反射信号的区分。
附图说明 为了更清楚地说明本发明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发明 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性的前 提下， 还可以根据这些附图获得其他的附图。 图 1为本发明实施例提供的一种光时域反射仪获取测试信号的方法的流 程图；
图 2A为本发明实施例提供的另一种光时域反射仪获取测试信号的方法 的流程图；
图 2B为本发明实施例提供的 OTDR与被测无源光网络的连接示意图； 图 3为本发明实施例提供的另一种光时域反射仪获取测试信号的方法的 流程图；
图 4为本发明实施例提供的又一种光时域反射仪获取测试信号的方法的 流程图；
图 5为本发明实施例提供的 OTDR的结构示意图；
图 6为本发明实施例提供的 OTDR中 SOA的控制时序图； 图 7为本发明实施例的实验仿真图形；
图 8为传统方式得到的测试曲线图； 图 9为本发明实施例提供的 OTDR工作时的内部时序关系图。
具体实施方式 下面将结合本发明实施例中的附图， 对本发明实施例中的技术方案进行 清楚、 完整地描述， 显然， 所描述的实施例仅仅是本发明一部分实施例， 而 不是全部的实施例。 基于本发明中的实施例， 本领域普通技术人员在没有作 出创造性劳动前提下所获得的所有其他实施例， 都属于本发明保护的范围。
本发明实施例提供的 OTDR包括： 激光器、 脉冲发生器、 驱动器、 半导 体光放大器（SOA )及光电探测器（APD )。 本领域技术人员可以理解， 除此 之外， OTDR还包括数字处理器（DSP )、 光环行器、 激光器的驱动器、 激光 器的脉冲发生器、 放大器及模数转换器（ADC )等基本功能器件， 由于不是 本发明的重点， 这里不再赘述。
其中， 激光器用于向被测光纤网络发射测试光， 可采用传统 OTDR中的 激光器， 由 DSP触发激光器的脉冲发生器生成脉冲信号， 并通过激光器的驱 动器转换为激光器的控制信号， 使激光器发光， 即生成测试光进入被测无源 光网络， 通过测试光在被测无源光网络中产生的散射信号和反射信号来获知 分光器、 连接点等事件。
数字处理器用于产生使脉冲发生器生成脉冲信号的指令， 该指令可包含 脉宽、 周期等信息。 本领域技术人员应理解为， 该数字处理器还可产生使激 光器的脉冲发生器及 SOA的脉冲发生器生成重复脉冲信号的指令，用于获取 无源光网络的全景图。 该全景图即一个完整的无源光网络的测试信号。
光环行器用于接收来自被测无源光网络的测试信号； 本领域技术人员应 理解为， 光环行器还可将激光器产生的光信号发送到被测无源光网络中。
脉冲发生器与 DSP相连，用于在接收到 DSP的指令时，生成相应的脉冲 信号， 如在一个测试周期内生成一个脉冲信号， 或者如在一个测试周期内生 成固定脉宽和占空比的多个重复脉冲信号。
驱动器与脉冲发生器相连， 用于将上述脉冲发生器生成的脉冲信号转变 为电流信号， 并进行功率放大， 得到 SOA的控制信号。
SOA的驱动端与驱动器相连， 输入端与上述光环行器相连， 用于在上述 驱动器的控制信号控制下， 选择性地对上述光环行器接收的测试信号进行吸 收或放大， 其中所述测试信号是所述测试光在所述被测光纤网络发生反射或 散射而形成的光信号。
APD与上述 SOA的输出端相连， 用于将上述 SOA放大后的测试信号转 变为电流信号。
本实施例中， OTDR在传统 OTDR的基础上增加了一个光器件 SOA, 不 仅可以对通过其内部的光信号产生高信噪比的增益，并且由于 SOA可以达到 纳秒级的驱动速度， 因此还可以通过控制 SOA的开关来解决接收到的大信号 造成的盲区问题， 以及密集反射难以区分的问题， 获得很高的事件分辨率。
图 1为本发明实施例提供的一种光时域反射仪获取测试信号的方法的流 程图， 包括：
步骤 11、 数字信号处理器控制脉冲发生器生成脉冲信号， 以使半导体光 放大器工作在开关状态； 步骤 12、 半导体光放大器在所述脉冲信号的控制下处于开关状态； 步骤 13、 所述半导体光放大器处于打开状态下时， 光电探测器接收光环 行器接收的来自被测无源光网络的测试信号。 本实施例中， OTDR通过使半导体光放大器（SOA )处于开关状态， 使 得当被测无源光网络返回的测试信号为大信号时，能够通过关闭 SOA而不被 APD接收， 基本消除大信号对后续小信号的干扰屏蔽， 之后通过打开 SOA 接收大信号后的小信号， 从而基本消除了测试信号的盲区； 并且通过在密集 反射的区域的不同位置打开 SOA, 接收测试信号， 从而实现了该区域的所有 反射信号的区分。
具体地， 图 2A 为本发明实施例提供的一种光时域反射仪获取测试信号 的方法的流程图。 本实施例中， SOA工作在开关状态， OTDR获取测试信号 的方法包括： 步骤 21、 DSP根据无源光网络的全景图产生指令， 使脉冲发生器生成用 于吸收上述全景图中大信号的脉冲信号。 其中， 大信号即 OTDR发出的光信号在被测无源光网络中分光器处产生 的反射光信号。 全景图即被测无源光网络的一个完整的测试信号曲线图， 如 图 2B所示， OTDR通过 WDM接入被测无源光网络， 对光网络进行测试 , 得 到无源光网络的测试曲线图。 该测试曲线图可通过传统的 OTDR测试获得， 也可采用本发明实施例提供的 OTDR测试得到。 当采用本发明实施例提供的 OTDR测试获得时， SOA工作在常态， 其驱 动脉冲如图 9所示的中间的脉冲信号，使 SOA在每个测试周期均处于打开状 态， 接收所有返回的测试信号， 并进行放大， 从而进一步提高全景图的信噪 比。 DSP在一个测试周期内发出重复的指令， 并且激光器的脉冲发生器产生 固定脉宽和占空比的脉冲信号，并触发 SOA的脉冲发生器产生一个持续的高 电平， 使 SOA在该测试周期内保持打开状态， 即对光环行器接收的测试信号 进行整体放大。 步骤 22、 脉冲发生器根据上述步骤 21中的指令生成脉冲信号。 步骤 23、 上述脉冲信号通过驱动器转变为大功率的电流信号； 步骤 24、 当光环行器接收大信号时， SOA关闭， 也即 SOA处于吸收态， 大信号不能被传递到 APD, 避免对后面的小信号产生影响， 而形成盲区。 步骤 25、 当光环行器接收大信号之后的小信号时， 半导体光放大器在上 述电流信号的控制下打开。此时由于步骤 24中已排除了大信号对后续小信号 的影响， 因而能够得到分光器后的反射光信号， 即基本消除了大信号后的盲 区。 图 3为本发明实施例提供的另一种光时域反射仪获取测试信号的方法的 流程图。 本实施例中， SOA工作在开关状态， OTDR获取测试信号的方法包 括： 步骤 31、 DSP根据无源光网络的全景图产生指令， 使脉冲发生器生成单 脉冲信号， 用于对上述全景图中的密集反射的区域进行单点采样。 即在一个测试周期内， DSP发出一个指令， 使脉冲发生器仅产生一个脉 冲信号。 而产生的脉冲信号位于全景图中的密集反射的区域内， 从而使 SOA 在光环行器接收密集反射光信号时打开一个时段， 采集到其中一个反射光信 号。
在下一个测试周期内， DSP发出一个指令， 使脉冲发生器也仅产生一个 脉冲信号， 该脉冲信号位于上一个测试周期的脉冲信号之后， 从而使 SOA在 光环行器接收密集反射光信号时打开一个时段， 该时段位于上一个测试周期 的打开时段之后， 使 SOA采集到该时段内的反射信号。 也即 DSP对全景图 中的密集反射的区域， 分多个测试周期进行单点采样， 每个测试周期获取其 中的一个反射光信号，以此解决现有技术中密集反射光信号无法区分的问题。 具体通过产生单脉冲信号， 使 SOA在相应的时段打开， 接收其中的一个反射 光信号来实现。
其中， 全景图详见上述图 2A所示实施例中的说明。 步骤 32、 脉冲发生器根据上述指令生成单脉冲信号。 步骤 33、 上述单脉冲信号通过驱动器转变为大功率的电流信号。 步骤 34、 SOA接收到上述电流信号时打开， 对光环行器接收到的信号进 行放大。 图 4为本发明实施例提供的又一种光时域反射仪获取测试信号的方法的 流程图。 本实施例中， SOA工作在开关状态， OTDR获取测试信号的方法包 括： 步骤 41、 DSP在每个测试周期产生一个指令， 使脉冲发生器生成一个单 脉冲信号， 每个测试周期的单脉冲信号生成时间依次往后顺延。 步骤 42、 脉冲发生器根据上述指令生成单脉冲信号； 步骤 43、 上述单脉冲信号通过驱动器转变为大功率的电流信号； 步骤 44、 SOA接收到上述电流信号时打开， 对光环行器接收到的信号进 行放大。 本实施例中， OTDR直接分多个测试周期对被测无源光网络进行单点采 样， 每次获得一个时段的光信号， 从而既消除了盲区， 又解决了反射光信号 密集而难以区分的问题 可选地， 本发明实施例提供的 OTDR中， 上述 APD与 SOA之间还连接 有 WDM滤波器， 用于滤除所述 SOA的 ASE噪声， 以避免影响 APD的灵敏 度， 进一步提高测试信号的精确度。 下面以图 5为例， 对 OTDR的结构进行详细说明。
OTDR包括 DSP 51、第一脉冲发生器 521、第一驱动器 522、激光器 520、 光环行器 53、 第二脉冲发生器 541、 第二驱动器 542、 SOA 540、 WDM滤波 器 55、 APD 56, TIA 57、 放大器 58及 ADC 59。 其中， APD 56连接有高电 平 （HV ), SOA 540、 WDM滤波器 55都是双端口器件。
DSP 51产生周期触发脉冲的指令， 通过第一脉冲发生器 521后调整为固 定脉宽和占空比的数字信号， 之后由第一驱动器 522完成大功率驱动， 使激 光器 520产生监控波段的脉冲激光。 脉冲激光通过光环行器 53进入被测无源光网络， 包括光纤主干及分光器 和各个支路。 每个支路的后向瑞利散射光信号和菲涅尔反射光信号都会通过光纤主干 返回到光环行器 53。 DSP 51还产生指令， 触发第二脉冲发生器 541生成脉冲， 经过第二驱动 器 542后， 使 SOA 540获得合适的工作电流。 SOA 540对返回的光信号进行 放大。
SOA 540的驱动脉冲可在激光器 520重复周期的不同位置采样， 从而获 得完整的一个周期的信号， SOA 540的驱动脉冲也可为一个持续的高电平， 时 SOA 540在一个测试周期内完全处于打开状态。
SOA 540无工作电流时， 处于吸收态， 返回的光信号不会进入 APD 56, 从而避免了前面大信号对小信号的影响， 消除了盲区效应。 激光器 520及 SOA 540的时序关系如图 6所示。 其中， 激光器 520的驱 动脉冲为单脉冲， 图 6示出了四个测试周期的激光器 520的驱动脉冲， 可以 看出， 每个测试周期激光器 520的驱动脉冲均相同。 SOA 540的驱动脉冲也 为单脉冲， 且每个测试周期， 脉冲信号的位置都不相同， 可看作是对激光器 520的重复周期的不同位置采样，这样， SOA 540可取脉冲信号所在位置处的 测试信号， 达到区分反射信号的目的。
当有驱动脉冲电流加在 SOA 540时， SOA 540工作在低噪声放大状态， 光信号会放大通过。
SOA 540输出的光信号，经过 WDM滤波器 55 ,滤除波长艮宽的 SOA 540 的 ASE噪声， 只允许激光器的波长通过。 之后光信号进入 APD 56, APD 56将光信号转变为和光强成比例的电流 信号。
APD 56输出的电流信号经过 TIA 57变为电压信号， 经过放大器 58放大 后进入 ADC 59, 转换为数字信号， 最后送到 DSP 51进行储存、 分析及合成 等处理。 当 SOA 540处于完全打开状态时， DSP 51将多个测试周期的全景图， 在 内部完成每个重复脉冲的累加， 也即将多个全景图进行累加， 以提高全景图 的信噪比。 本实施例提供的 OTDR可通过使 SOA 540工作于脉冲状态， 类似于单点 采样， 即在某一时刻或某一很短的时段内 SOA 540处于打开状态。 无脉冲驱 动电流时， SOA 540工作于吸收状态，此时从光纤通过光环行器 53进入 SOA 540的光信号被高度隔离， 不会有分光器的反射光信号进入 APD 56, 从而消 除了 APD 56由于接收分光器的反射光信号而产生的盲区。
由于 SOA 540的开关速度在 ns (纳秒）级以下， 通过提高驱动脉冲电流 的速度， 可以采集到密集反射的区域中的反射光信号， 经过 DSP 51处理后得 到传统 OTDR无法提供的高分辨率的测试信号曲线图。 图 7为本发明实施例的实验仿真图形， 相对于图 8所示的传统方式得到 的测试曲线。 可以看到， 图 7中分光器反射光信号后的盲区有很大缩短， 基 本消除盲区。 由于是单点采样， 反射时间取决于开关速度， 达到了较高的分 辨率。
对于典型的 PON网络在线测试， 时间比较关键。 在一个 CO局点， 可能 有多大几百个 PON口需要遍历测试， 因此， 为了提高测试效率， 可首先使用 传统模拟测试， 得到一个无源光网络的全景图， 包括主干光纤的长度。 各个 分光器的大概位置等信息。 然后再针对分光器及之后的光纤进行采样测试， 以达到把此段的盲区和分辨率提高的目的， 从而优化测试时间。 具体地， 测试过程包括： 启动激光器 520, 发送重复的测试光脉冲。
设置 SOA 540的驱动为常态驱动， 提供合适的工作电流， 此时 SOA 540 工作于直通放大状态， 使得连续的光信号进入后面的 APD 56, 也即使光环行 器 53接收的光信号都能够进入 APD 56。
APD 56将接收的光信号转变为和光强成比例的电流信号， 经过 TIA 57 变为电压信号， 经过放大后入 ADC转换为数字信号， 最后送到 DSP 51 , 得 到全景图。在 DSP 51内部完成每个重复脉冲的累加，以提高全景图的信噪比。
关闭激光器， DSP 51通过计算分析得到的波形数据即全景图， 给出具体 的需要采样测试的测试区间。
重新启动激光器 520, 发送重复的测试光脉冲。
DSP 51给出在特定采样区间内的驱动脉冲， 送入 SOA 540。
SOA 540工作于采样（sampling )状态， 提供光信号的通路； 驱动脉冲过 后 SOA 540无工作电流时， 处于吸收态， 返回的光信号不会进入 APD 56。
DSP 51将两次测试的数据重新组合为一个完整的波形图。 具体的时序关系如图 9所示， 四个测试周期中， 每个测试周期的激光器 的驱动脉冲信号均相同， 也即激光器的驱动脉冲为重复的脉冲信号； 中间为 SOA的常态驱动脉冲信号， 在所有测试周期中， SOA的驱动为持续高电平信 号， 即 SOA中保持有工作电流； 最下面为 SOA的开关状态驱动脉冲信号， 可以看出在测试周期的不同位置， DSP触发第二脉冲发生器生成脉冲信号， 驱动 SOA打开， 从而实现单点采用， 获取单点反射信号， 解决了传统 OTDR 在 PON网应用的盲区及密集反射信号难以区分等问题， 且实现的成本较低。 上述实施例中， OTDR通过 SOA及对 SOA的状态进行控制， 解决了现 有技术中分光器造成大反射和大的衰减同时存在， 而传统 OTDR技术的盲区 会覆盖掉大部分分支的事件的问题， 以及传统 OTDR技术带宽较低， 对分光 器之后的密集反射光信号难以区分的问题。 本领域普通技术人员可以理解： 实现上述方法实施例的全部或部分步骤 可以通过程序指令相关的硬件来完成， 前述的程序可以存储于一计算机可读 取存储介质中， 该程序在执行时， 执行包括上述方法实施例的步骤； 而前述 的存储介质包括： ROM、 RAM, 磁碟或者光盘等各种可以存储程序代码的介 质。
最后应说明的是： 以上实施例仅用以说明本发明的技术方案， 而非对其 限制； 尽管参照前述实施例对本发明进行了详细的说明， 本领域的普通技术 人员应当理解： 其依然可以对前述各实施例所记载的技术方案进行修改， 或 者对其中部分技术特征进行等同替换； 而这些修改或者替换， 并不使相应技 术方案的本质脱离本发明各实施例技术方案的精神和范围。

Claims

权 利 要求
1、 一种光时域反射仪， 其特征在于， 包括： 激光器， 用于向被测光纤网络发射测试光； 脉冲发生器， 用于生成脉冲信号； 驱动器， 与所述脉冲发生器相连， 用于将所述脉冲发生器生成的脉冲信 号转换为用来驱动半导体光放大器的控制信号； 半导体光放大器， 与所述驱动器相连， 用于在所述驱动器的控制信号控 制下， 选择性地对来自所述被测光纤网络的测试信号进行吸收或放大， 其中 所述测试信号是所述测试光在所述被测光纤网络发生反射而形成的反射信 号；
光电探测器， 与所述半导体光放大器相连， 用于将所述半导体光放大器 放大后的测试信号转变为电流信号。
2、 根据权利要求 1所述的光时域反射仪， 其特征在于， 所述半导体光放 大器与所述光电探测器之间还连接有 WDM滤波器， 用于滤除所述半导体光 放大器的 ASE噪声。
3、 根据权利要求 1或 2所述的光时域反射仪， 其特征在于， 还包括： 环行器， 用于将所述激光器发射的测试光输出到所述被测光纤网络， 并 将从所述被测光纤网络输入的测试信号输出给所述半导体光放大器。
4、 根据权利要求 1或 2所述的光时域反射仪， 其特征在于， 还包括： 数字处理器， 用于产生脉冲信号生成指令并将所述脉冲信号生成指令输 出给脉冲发生器；
其中所述脉冲发生器在从所述数字处理器提供接收到脉冲信号生成指令 时， 生成所述脉冲信号。
5、一种采用上述权利要求 1至 4中任一项的所述的光时域反射仪获取测 试信号的方法， 其特征在于， 包括： 数字信号处理器控制脉冲发生器生成脉冲信号， 以使半导体光放大器工 作在开关状态； 半导体光放大器在所述脉冲信号的控制下处于开关状态； 所述半导体光放大器处于打开状态下时， 光电探测器接收来自被测无源 光网络的测试信号。
6、根据权利要求 5所述的光时域反射仪获取测试信号的方法， 其特征在 于， 数字信号处理器控制脉冲发生器生成脉冲信号， 以使半导体光放大器工 作在开关状态， 包括： 数字处理器根据无源光网络的全景图产生指令， 使脉冲发生器生成用于 吸收所述全景图中大信号的脉冲信号； 脉冲发生器根据所述指令生成脉冲信号； 所述脉冲信号通过驱动器转变为大功率的电流信号。
7、根据权利要求 6所述的光时域反射仪获取测试信号的方法， 其特征在 于， 半导体光放大器在所述脉冲信号的控制下处于开关状态， 包括： 当光环行器接收大信号时， 半导体光放大器关闭； 当光环行器接收大信号之后的小信号时， 半导体光放大器在所述电流信 号的控制下打开。
8、根据权利要求 5所述的光时域反射仪获取测试信号的方法， 其特征在 于， 数字信号处理器控制脉冲发生器生成脉冲信号， 以使半导体光放大器工 作在开关状态， 包括： 数字处理器根据无源光网络的全景图产生指令， 使脉冲发生器生成单脉 冲信号， 用于对所述全景图中的密集反射的区域进行单点采样； 脉冲发生器根据所述指令生成单脉冲信号； 所述单脉冲信号通过驱动器转变为大功率的电流信号。
9、根据权利要求 8所述的光时域反射仪获取测试信号的方法， 其特征在 于， 半导体光放大器在所述脉冲信号的控制下处于开关状态， 包括： 半导体光放大器接收到所述电流信号时打开， 对光环行器接收到的信号 进行放大。
10、 根据权利要求 5所述的光时域反射仪获取测试信号的方法， 其特征 在于， 数字信号处理器控制脉冲发生器生成脉冲信号之前， 还包括： 数字信号处理器控制脉冲发生器生成另一脉冲信号， 以使所述半导体光 放大器处于常态； 所述半导体光放大器在所述另一脉冲信号的作用下保持打开状态。
11、 根据权利要求 5所述的光时域反射仪获取测试信号的方法， 其特征 在于， 数字信号处理器控制脉冲发生器生成脉冲信号， 以使半导体光放大器 工作在开关状态， 包括： 数字处理器在每个测试周期产生一个指令， 使脉冲发生器生成一个单脉 冲信号， 每个测试周期的单脉冲信号生成时间依次往后顺延； 脉冲发生器根据所述指令生成单脉冲信号；
所述单脉冲信号通过驱动器转变为大功率的电流信号。
12、 根据权利要求 11所述的光时域反射仪获取测试信号的方法， 其特征 在于， 半导体光放大器在所述脉冲信号的控制下处于开关状态， 包括： 半导体光放大器接收到所述电流信号时打开， 对光环行器接收到的信号 进行放大。
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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113517922A (zh) * 2020-04-09 2021-10-19 华为技术有限公司 一种信号检测方法和光时域反射仪
CN114124208A (zh) * 2021-12-09 2022-03-01 中山水木光华电子信息科技有限公司 一种消除物理点噪声干扰的光纤编码识别系统及方法

Families Citing this family (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103973362A (zh) * 2013-02-06 2014-08-06 中兴通讯股份有限公司 设置otdr测试参数集的方法及装置
CN106253989B (zh) * 2015-06-09 2019-04-16 广东海信宽带科技有限公司 光模块以及光信号输出控制方法
CN106595492A (zh) * 2016-12-16 2017-04-26 威海北洋电气集团股份有限公司 一种高分辨率光纤计长装置及方法
US10128943B2 (en) 2017-04-06 2018-11-13 At&T Intellectual Property I, L.P. Predictive maintenance of optical transport network system
EP3401662A1 (en) 2017-05-12 2018-11-14 ADVA Optical Networking SE A method and apparatus for measurement of a backscattered trace of a fiber
CN108063638B (zh) * 2017-12-13 2020-01-07 武汉电信器件有限公司 一种带光路保护功能的高灵敏度光接收器及其制作方法
CN108650022B (zh) * 2018-03-21 2020-08-07 北京奥普维尔科技有限公司 监控装置、获取修正因子的方法及应用监控装置的方法

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1704832A (zh) * 2004-06-02 2005-12-07 韩国电子通信研究院 使用增益钳制的光放大器的光传输线监视系统
CN1726664A (zh) * 2002-12-16 2006-01-25 阿斯顿光学技术有限公司 光学询问系统和传感器系统
CN101079668A (zh) * 2007-07-05 2007-11-28 华为技术有限公司 光纤故障定位设备、方法及装置

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS58113832A (ja) * 1981-12-28 1983-07-06 Fujitsu Ltd 光フアイバ破断点検出装置
US5046832A (en) * 1990-01-11 1991-09-10 Tektronix, Inc. Multimode acousto-optic switch and dead zone correction method
CN101442366B (zh) * 2007-11-23 2011-07-20 华为海洋网络有限公司 一种光调制系统和方法

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1726664A (zh) * 2002-12-16 2006-01-25 阿斯顿光学技术有限公司 光学询问系统和传感器系统
CN1704832A (zh) * 2004-06-02 2005-12-07 韩国电子通信研究院 使用增益钳制的光放大器的光传输线监视系统
CN101079668A (zh) * 2007-07-05 2007-11-28 华为技术有限公司 光纤故障定位设备、方法及装置

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113517922A (zh) * 2020-04-09 2021-10-19 华为技术有限公司 一种信号检测方法和光时域反射仪
CN114124208A (zh) * 2021-12-09 2022-03-01 中山水木光华电子信息科技有限公司 一种消除物理点噪声干扰的光纤编码识别系统及方法

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