CN207720138U - A kind of OTDR devices based on multi-channel optical fibre optical monitoring signal - Google Patents

Abstract

The utility model discloses an OTDR device based on multi-channel optical fiber optical signal monitoring, which comprises a main control unit, an optical sending unit, an optical branching unit, an oscilloscope unit, N coupling units and N optical branching detection units. The main control unit is respectively connected to the optical sending unit and the oscilloscope unit, the optical sending unit is connected to the optical branching unit, and the optical branching unit is correspondingly connected to the N coupling units, and each of the The input ends of the coupling units are respectively connected to the optical branching unit and an optical branching detection unit, and the output ports of each coupling unit are correspondingly connected to an optical fiber to be tested, and each of the optical branching detection units is corresponding to the optical branching detection unit. The main control unit is connected. The utility model has the advantages that the monitoring, searching and locating of multi-channel optical fiber fault points to be tested can be carried out simultaneously, and the testing speed is fast and the measuring accuracy is high.

Description

An OTDR device based on multi-channel optical fiber optical signal monitoring

technical field

The utility model relates to the field of optical time domain reflection, in particular to an OTDR device based on multi-channel optical fiber optical signal monitoring.

Background technique

Optical Time-Domain Reflectometry (OTDR) is a precision optoelectronic integrated instrument made by using Rayleigh scattering and backscattering produced by Fresnel reflection when light is transmitted in an optical fiber. Widely used in the maintenance and construction of optical cable lines, it can measure the length of optical fiber, transmission attenuation of optical fiber, joint attenuation and fault location.

At present, there are two main types of OTDR used for optical fiber fault location monitoring: single-photon detection OTDR for single-photon level weak light detection and ordinary OTDR for non-single-photon level light detection; avalanche photodiode (APD) ) as a common photosensitive detection element in the field of laser communication, because of its high detection sensitivity, it is an indispensable component in OTDR.

Among them, the avalanche photodiode of the single photon detection OTDR works in the gated Geiger mode, while the avalanche photodiode of the ordinary OTDR works in the linear mode; the avalanche photodiode working in the linear mode can work in the continuous signal without considering the post-pulse effect The acquisition state has the advantage of fast measurement time, but due to the low gain of the avalanche photodiode working in the linear mode, it cannot detect weak and small optical signals. Therefore, the measurement accuracy and measurement distance of ordinary OTDR are limited.

Although single-photon detection OTDR can detect extremely weak optical signals smaller than thermal noise, it can obtain higher measurement accuracy, longer measurement distance and larger dynamic range than ordinary OTDR, which can make up for the shortcomings of ordinary OTDR. However, because the avalanche photodiode of the single-photon detection OTDR works in the gated Geiger mode, it has a certain dead time due to the influence of the after-pulse, resulting in a low repetition rate of the gate pulse of the single-photon detector, and can only work in point-by-point scanning. mode, and it often takes a long time to complete a detection task; when the measurement accuracy is higher and the number of scanning points is more, the detection time required for single-photon detection OTDR is longer; when the post-pulse probability is greater, the single-photon detection OTDR The longer the dead time that needs to be set.

In addition, because the avalanche photodiode is a capacitive device, when the gate pulse signal is loaded on the avalanche photodiode to charge and discharge it, the corresponding noise will be introduced, which will submerge the effective signal of the photo-generated avalanche and affect the detection result; at the same time, the change of temperature It will also have a certain impact on the detection performance of the avalanche photodiode, which will cause the instability of the working performance of the avalanche photodiode and make the location and search of the fault point of the optical fiber inaccurate.

Contents of the invention

The purpose of the utility model is to provide an OTDR device based on multi-channel optical fiber optical signal monitoring to solve the defects in the background technology.

In order to achieve the above object, the technical solution adopted by the utility model is: an OTDR device based on multi-channel optical fiber optical signal monitoring, including a main control unit, an optical transmission unit, an optical branching unit, an oscilloscope unit, N coupling units and N optical branching detection units, the main control unit is respectively connected to the optical sending unit and the oscilloscope unit, the optical sending unit is connected to the optical branching unit, and the optical branching unit corresponds to the N coupling units are connected, the input end of each coupling unit is connected to an optical branching unit and an optical branching detection unit, and the output end of each coupling unit is connected to an optical fiber to be tested, and each of the coupling units is connected to an optical branching unit and an optical branching detection unit. The optical branch detection units are correspondingly connected with the main control unit.

Further, the main control unit includes a single-chip microcomputer, a pulse signal generator, a signal attenuation driver and a data processor, and the pulse signal generator, a signal attenuation driver and a data processor are connected to the single-chip microcomputer respectively;

The optical sending unit includes a pulse light source and an adjustable attenuator, the pulse light source is connected to the pulse signal generator and the adjustable attenuator respectively, and the adjustable attenuator is connected to the signal attenuation driver and the optical attenuator respectively. branching unit connection;

Each of the optical branch detection units includes a 1x2 optical splitter, a common detection unit and a single photon detection unit, each of the 1x2 optical splitter input ports is connected to a coupling unit, and each of the 1x2 optical splitters The output ends of the detectors are respectively connected to a common detection unit and a single photon detection unit.

Further, the optical branching unit is a 1xN optical splitter; the oscilloscope unit is a waveform display, and the waveform display includes N displays corresponding to the detection light waveform curves output by the optical branching detection unit area; each of the coupling units is a directional coupler or a circulator; wherein, N is an integer ≥ 2.

Further, each of the common detection units includes a first photodetection module, a filter, a first signal amplifier, and a first analog-to-digital converter connected in sequence, and each first photodetection module also corresponds to a 1x2 An output port of the optical splitter is connected, and each of the first A/D converters is also correspondingly connected to the data processor of the main control unit, and each of the first photodetection modules includes a first avalanche photodiode, The first temperature control module and the first packaging box; each of the first temperature control modules includes a first refrigerator, a first heater and a first temperature sensor, and each of the first refrigerator and a first heating The sensors are respectively connected with the single-chip microcomputer of the main control unit, each of the first temperature sensors is respectively connected with the single-chip microcomputer of the main control unit and the pin of a first avalanche photodiode, and each of the first photodetection modules The corresponding first avalanche photodiode, the first refrigerator, the first heater and the first temperature sensor are all correspondingly packaged in one of the first packaging boxes.

Further, each of the single-photon detection units includes a second photodetection module, a bias voltage module, a clock module, a gate pulse module, a noise suppression module, a pulse shaping module, and a photon counter, and each of the bias voltage modules corresponds to It is connected with the single-chip microcomputer of the main control unit and a second photoelectric detection module, and each said clock module is connected with the pulse signal generator of the main control unit and a gate pulse module respectively, and each said gate pulse module is corresponding with the main control unit The single-chip microcomputer of the unit is connected with a second photoelectric detection module, and each noise suppression module is respectively connected with a second photoelectric detection module and a pulse shaping module, and each photon counter is respectively corresponding with the data processor of the main control unit and a pulse each of the second photodetection modules is connected to an output port of a 1x2 optical splitter, and each of the second photodetection modules includes a second avalanche photodiode, a second temperature control module and The second packaging box; each of the second temperature control modules includes a second refrigerator, a second heater and a second temperature sensor, and each of the second refrigerator and the second heater is respectively corresponding to the main The microcontroller of the control unit is connected, and each of the second temperature sensors is connected to the microcontroller of the main control unit and the pins of a second avalanche photodiode, and the second avalanche photodiode corresponding to each of the second photodetection modules The photodiode, the second refrigerator, the second heater and the second temperature sensor are all correspondingly packaged in one of the second packaging boxes.

Further, each of the bias voltage modules is a voltage source module, and they are respectively connected to the single-chip microcomputer of the main control unit and correspondingly connected to the cathode of a second avalanche photodiode; each of the bias voltage modules is used for The second avalanche photodiode connected to it correspondingly provides the reverse bias voltage required for operation.

Further, each of the gate pulse modules is a gate pulse generator, and is respectively connected to a clock module and correspondingly connected to the cathode of a second avalanche photodiode, and each of the gate pulse modules includes a phase-locked loop Circuit, frequency divider and second signal amplifier, the output end of each said phase-locked loop circuit is correspondingly connected with a second signal amplifier, the input end of each said phase-locked loop circuit is correspondingly connected with a clock module, each Each of the phase-locked loop circuits includes a phase detector, a loop filter, and a voltage-controlled oscillator connected in sequence; each of the gate pulse modules is used to output a gate control signal, which is the second avalanche photoelectric connected to it correspondingly. The diode is charged and discharged to control the avalanche and quenching process of the second avalanche photodiode. Each of the clock modules is used to control the synchronous triggering of the gate pulse module and pulse signal generator connected to it, so that the gate The gating signal output by the pulse module and the bias voltage signal output by the bias module are loaded to the second avalanche photodiode in a sequential manner, so that the second avalanche photodiode works in the Geiger gating mode, thereby achieving single-photon level Light intensity signal detection.

Further, each of the noise suppression modules includes a band-pass filter, a low-pass filter and a third signal amplifier; each input of the band-pass filter is correspondingly connected to an output of a gate pulse module, and each of the band-pass filters The output end of the pass filter is correspondingly connected to the cathode of a second avalanche photodiode; each of the input ends of the low-pass filter is correspondingly connected to the anode of a second avalanche photodiode, and each of the output ends of the low-pass filter corresponds to It is connected with a third signal amplifier input; each of the third signal amplifier output is correspondingly connected with a pulse shaping module; each of the bandpass filters is used to filter out the gating output by the corresponding gate pulse module The sideband noise and harmonic noise signal brought in the signal; each of the low-pass filters is used to filter out the gating signal output by the corresponding gate pulse module and pass through the corresponding second avalanche photodiode photoelectric The converted noise signal is used to obtain an effective photo-generated carrier avalanche signal.

Further, each of the pulse shaping modules includes a pulse discriminator, a pulse shaping circuit, and a second analog-to-digital converter; each of the input terminals of the pulse discriminator is correspondingly connected to a third signal amplifier output, and each The output end of the pulse discriminator is correspondingly connected to the input end of a pulse shaping circuit, each of the output ends of the pulse shaping circuit is correspondingly connected to the input end of a second A/D converter, each of the second A/D The output end of the converter is correspondingly connected with the input end of a photon counter, and each output end of the photon counter is correspondingly connected with the data processor of the main control unit.

Compared with the prior art, the utility model has the beneficial effects that: the utility model can accurately locate and search the fault points of multiple optical fibers to be tested, which is beneficial to improve the operation and maintenance work efficiency of the operation monitoring personnel on the optical fiber lines and reduce the The investment in the monitoring cost of the optical fiber link has the advantages of high work efficiency, accurate measurement results, and fast monitoring speed.

Description of drawings

Fig. 1 is the structural block diagram of the OTDR device based on multi-channel optical fiber optical signal monitoring of the present invention;

Fig. 2 is the structural block diagram of the specific embodiment of the OTDR device based on multi-channel optical fiber optical signal monitoring of the present invention;

Fig. 3 is a structural block diagram based on each common detection unit in Fig. 2;

Fig. 4 is a block diagram based on each single photon detection unit in Fig. 3;

Fig. 5 is the circuit connection block diagram based on the gate pulse module of Fig. 4;

In the figure: 1. Main control unit; 11. Single-chip microcomputer; 12. Pulse signal generator; 13. Signal attenuation driver; 14. Data processor; 2. Optical sending unit; 21. Pulse light source; 22. Adjustable attenuator; 3. Optical splitting unit; 4. Oscilloscope unit; 5. Coupling unit; 6. Optical splitting detection unit; 61. 1x2 optical splitter; 62. Common detection unit; 621. First photoelectric detection module; 621a. First Avalanche photodiode; 621b, first temperature control module; 621b-1, first refrigerator; 621b-2, first heater; 621b-3, first temperature sensor; 621c, first packaging box; 622, filter 623, the first signal amplifier; 624, the first analog/digital converter; 63, the single photon detection unit; 631, the second photoelectric detection module; 631a, the second avalanche photodiode; 631b, the second temperature control module; 631b-1, the second refrigerator; 631b-2, the second heater; 631b-3, the second temperature sensor; 631c, the second packaging box; 632, the bias module; 633, the clock module; 634, the gate pulse Module; 634a, phase-locked loop circuit; 634b, frequency divider; 634c, second signal amplifier; 635, noise suppression module; 635a, band-pass filter; 635b, low-pass filter; 635c, third signal amplifier; 636 , a pulse shaping module; 636a, a pulse amplitude discriminator; 636b, a pulse shaping circuit; 636c, a second analog/digital converter; 637, a photon counter; 7, an optical fiber to be tested.

Detailed ways

In order to make the technical means, creative features, goals and effects achieved by the utility model easy to understand, how the utility model is implemented will be further described below in conjunction with the accompanying drawings and specific embodiments.

As shown in Figure 1, an OTDR device based on multi-channel optical fiber optical signal monitoring provided by the utility model includes a main control unit 1, an optical transmission unit 2, an optical branching unit 3, an oscilloscope unit 4, and N coupling units 5 and N optical branching detection units 6; the main control unit 1 is respectively connected to an optical sending unit 2 and an oscilloscope unit 4; the optical sending unit 2 is connected to an optical branching unit 3, and the optical branching unit 3 corresponds to N The coupling unit 5 is connected, the input end of each coupling unit 5 is connected to an output end of the optical branching unit 3 and an optical branching detection unit 6, and the output end of each coupling unit 5 is correspondingly connected to an optical fiber 7 to be tested; Each optical branch detection unit 6 is correspondingly connected to the main control unit 1 .

As shown in Figure 2, in the present embodiment, the main control unit 1 includes a single-chip microcomputer 11, a pulse signal generator 12, a signal attenuation driver 13 and a data processor 14, and a pulse signal generator 12, a signal attenuation driver 13 and a data processor 14 All are respectively connected with the single-chip microcomputer 11;

The optical sending unit 2 includes a pulse light source 21 and an adjustable attenuator 22, the pulse light source 21 is connected with the pulse signal generator 12 and the adjustable attenuator 22 respectively, and the adjustable attenuator 22 is connected with the signal attenuation driver 13 and the optical branching unit 3 respectively connection; the pulse light source 21 emits high-speed near-infrared light in the 1550nm band, and the optical splitting unit 3 is a 1xN splitter;

The oscilloscope unit 4 is a waveform display, and the waveform display is provided with N display areas corresponding to the detection light waveform curve output by the optical branch detection unit 6;

Each coupling unit 5 is a directional coupler or a circulator;

Each optical branch detection unit 6 includes a 1×2 beam splitter 61 , a common detection unit 62 and a single photon detection unit 63 .

Wherein, N is an integer ≥ 2, according to the usual habit of viewing pictures in windows, it is best to set N equal to 4.

As shown in Figure 3, wherein, each common detection unit 62 all comprises the first photodetection module 621, the filter 622, the first signal amplifier 623 and the first A/D converter 624 connected in sequence, each first photoelectric The input end of the detection module 621 is correspondingly connected to an output port of a 1×2 optical splitter 61, and each first analog/digital converter 624 is also correspondingly connected to the data processor 14 of the main control unit 1;

Each first photodetection module 621 includes a first avalanche photodiode 621a, a first temperature control module 621b and a first packaging box 621c, and each first temperature control module 621b includes a first refrigerator 621b-1, The first heater 621b-2 and the first temperature sensor 621b-3, each of the first refrigerator 621b-1 and the first heater 621b-2 are respectively connected to the single-chip microcomputer 11 of the main control unit 1, each first temperature The sensors 621b-3 are respectively connected to the single-chip microcomputer 11 of the main control unit 1 and the pins of a first avalanche photodiode 621a, and the first avalanche photodiode 621a and the first refrigerator 621b corresponding to each first photodetection module -1. The first heater 621b-2 and the first temperature sensor 621b-3 are correspondingly packaged in a first packaging box 621c, and each first temperature control module 621b passes through the first refrigerator 621b-1 and the first The heaters 621b-2 all adjust the temperature in the corresponding first packaging box 621c, and the first avalanche photoelectric sensor 621b-3 packaged in the corresponding first packaging box 621c will be sensed in real time. The operating temperature of the diode 621a is fed back to the single-chip microcomputer 11 of the main control unit 1, and the first refrigerator 621b-1 and the first heater 621b-2 are controlled by the single-chip microcomputer 11 to control the cooling or heating, so as to realize the temperature control in the first packaging box 621c, The first avalanche photodiode 621a is kept at a suitable working temperature at all times, thereby effectively avoiding the unstable performance of the first avalanche photodiode 621a due to temperature rise, which affects the accuracy of light intensity signal detection results of ordinary detection units.

As shown in Figure 4, wherein, each single photon detection unit 63 all comprises the second photodetection module 631, bias voltage module 632, clock module 633, gate pulse module 634, noise suppression module 635, pulse shaping module 636 and photon counter 637;

The input end of each bias voltage module 632 is correspondingly connected with the single-chip microcomputer 11 of the main control unit 1, and the output end of each bias voltage module 632 is correspondingly connected with the input end of a second photodetection module 631, and each second photodetection module The input end of 631 is also respectively connected with an output port of a 1x2 optical splitter 61 and an output end of a gate pulse module 634, and the other output port of each 1x2 optical splitter 61 is correspondingly connected with a first photodetection module 621 The input end of each second photodetection module 631 corresponds to a noise suppression module 635, a pulse shaping module 636 and a photon counter 637 connected in sequence, and the input end of each gate pulse module 634 corresponds to The single-chip microcomputer 11 of the main control unit 1 is connected with a clock module 633; each clock module 633 is also connected with the pulse signal generator 12 and the single-chip microcomputer 11 of the main control unit 1 respectively, and each photon counter 637 is also corresponding to the main control unit respectively. 1 data processor 14 is connected;

Each second photodetection module 631 includes a second avalanche photodiode 631a, a second temperature control module 631b, and a second packaging box 631c; each second temperature control module 631b includes a second refrigerator 631b-1, The second heater 631b-2 and the second temperature sensor 631b-3, each of the second refrigerator 631b-1 and the second heater 631b-2 are respectively connected with the single chip microcomputer 11 of the main control unit 1, each second temperature The sensors 631b-3 are respectively connected to the single-chip microcomputer 11 of the main control unit 1 and the pins of a second avalanche photodiode 631a, and the corresponding second avalanche photodiode 631a and the second refrigerator 631b of each second photodetection module -1. The second heater 631b-2 and the second temperature sensor 631b-3 are correspondingly packaged in a second packaging box 631c, and each second temperature control module 631b passes through the second refrigerator 631b-1 and the second The heaters 631b-2 all adjust the temperature in the corresponding second packaging box 631c, and the second avalanche photoelectric sensor 631b-3 packaged in the corresponding second packaging box 631c will sense the temperature in real time. The operating temperature of the diode 631a is fed back to the single-chip microcomputer 11 of the main control unit 1, and the second refrigerator 631b-1 and the second heater 631b-2 are controlled by the single-chip microcomputer 11 to control the cooling or heating, so as to realize the temperature control in the first packaging box 621c, Make the second avalanche photodiode 631a be at a suitable working temperature at all times, thereby effectively avoiding the unstable performance of the second avalanche photodiode 631a caused by the temperature rise, which affects the accuracy of the light intensity signal detection result of the single photon detection unit .

Each bias module 632 is a voltage source module, and is respectively connected to the single-chip microcomputer 11 of the main control unit 1 and correspondingly connected to the cathode of a second avalanche photodiode 631a; The correspondingly connected second avalanche photodiode 631a provides the required reverse bias voltage for operation.

Each gate pulse module 634 is a gate pulse generator, and is respectively connected to a clock module 633 and a bias voltage module 632. As shown in FIG. 5, each gate pulse module 634 includes a phase-locked loop circuit 634a , a frequency divider 634b and a second signal amplifier 634c, the output end of each phase-locked loop circuit 634a is correspondingly connected with a second signal amplifier 634c, and the input end of each phase-locked loop circuit 634a is correspondingly connected with a clock module 633, Each phase-locked loop circuit 634a includes a phase detector 634a-1, a filter 634a-2 and a voltage-controlled oscillator 634a-3 connected in sequence; each gate pulse module 634 is used to output a gate control signal for corresponding connection The bias voltage module 632 performs charge and discharge control, generates a reverse bias voltage loaded on the second avalanche photodiode 631a, and realizes the avalanche and quenching process control of the second avalanche photodiode 631a;

When the reverse bias voltage generated by the bias module 632 is loaded on the second avalanche photodiode 631a and is greater than or equal to the avalanche voltage of the second avalanche photodiode 631a, then from the optical fiber 7 to be tested through Rayleigh scattering and Fresnel reflection The returned photons will be incident on the second avalanche photodiode 631a to generate a large number of photo-generated carriers, that is, form an avalanche signal;

When the reverse bias voltage generated by the bias module 632 is applied to the second avalanche photodiode 631a and is less than the avalanche voltage of the second avalanche photodiode 631a, the light from the optical fiber 7 to be tested through Rayleigh scattering and Fresnel reflection The returned photons are not enough to generate photogenerated carriers, that is, the second avalanche photodiode 63a is quenched;

Each clock module 633 is used to control the gate pulse module 634 and the pulse signal generator 12 correspondingly connected to it to trigger synchronously, so that the gate control signal output by the gate pulse module 634 and the pulse light signal sent by the pulse signal generator 12 follow the The clock is loaded to the second avalanche photodiode 631a, so that the second avalanche photodiode 631a works in a Geiger-gated mode, thereby realizing single-photon level light intensity signal detection.

Each noise suppression module 635 comprises a band-pass filter 635a, a low-pass filter 635b, and a third signal amplifier 635c; each band-pass filter 635a input is correspondingly connected with a gate pulse module 634 output, and each band-pass filter The output terminal of the device 635a is correspondingly connected with the cathode of a second avalanche photodiode 631a; the input terminal of each low-pass filter 635b is correspondingly connected with the anode of a second avalanche photodiode 631a, and the output terminal of each low-pass filter 635b is correspondingly connected with the anode of a second avalanche photodiode 631a The input terminal of a third signal amplifier 635c is connected; the output terminal of each third signal amplifier 635c is correspondingly connected with a pulse shaping module 636;

Each band-pass filter 635a is used to filter out sideband noise and harmonic noise signals brought by the gating signal output by the corresponding gating module 634;

Each low-pass filter 635b is used to filter out the noise signal introduced by the gate control signal output by the corresponding gate pulse module 634 and produced after the photoelectric conversion of the corresponding second avalanche photodiode 631a, thereby obtaining effective photogenerated Carrier avalanche signal.

Each pulse shaping module 636 includes a pulse discriminator 636a, a pulse shaping circuit 636b, and a second analog-to-digital converter 636c; the input end of each pulse discriminator 636a is correspondingly connected to the output end of a third signal amplifier 636c, each The output end of the pulse discriminator 636a is correspondingly connected to the input end of a pulse shaping circuit 636b, and the output end of each pulse shaping circuit 636b is correspondingly connected to the input end of a second analog/digital converter 636c, and each second analog/digital converter The output terminal of 636c is correspondingly connected to the input terminal of a photon counter 637 , and the output terminal of each photon counter 637 is correspondingly connected to the data processor 14 of the main control unit 1 .

Each pulse shaping module 636 is used to shape and convert the obtained effective avalanche analog signal into a standard digital signal and output it to the digital processor 14 of the main control unit. After being analyzed and processed by the digital processor 14, the corresponding display area on the waveform display The corresponding OTDR detection optical waveform signal is shown at .

In this embodiment, the first avalanche photodiode 621 a and the second avalanche photodiode 631 a are InGaAs or InP avalanche photodiodes.

Finally, the above descriptions are only embodiments of the present utility model, and are not intended to limit the patent scope of the present utility model. Any equivalent structure or equivalent process conversion made by using the specification of the utility model and the contents of the accompanying drawings, or directly or indirectly Applications in other relevant technical fields are all included in the scope of patent protection of the utility model in the same way.

Claims (9)

1. a kind of OTDR devices based on multi-channel optical fibre optical monitoring signal, it is characterised in that：Including main control unit (1), light are sent Unit (2), optical branching unit (3), oscillography unit (4), N number of coupling unit (5) and N number of optical branching probe unit (6), the master Control unit (1) is connect with the smooth transmission unit (2) and oscillography unit (4) respectively, the smooth transmission unit (2) and the light point Road unit (3) connects, and optical branching unit (3) correspondence is connect with N number of coupling unit (5), each coupling unit (5) input terminal correspondence is connect with the optical branching unit (3) and an optical branching probe unit (6), and each coupling is single First (5) output end correspondence is connect with a testing fiber (7), and each optical branching probe unit (6) corresponds to and the master control Unit (1) connects.

2. the OTDR devices according to claim 1 based on multi-channel optical fibre optical monitoring signal, it is characterised in that：The master control Unit (1) includes microcontroller (11), pulse signal generator (12), signal decaying driver (13) and data processor (14), the pulse signal generator (12), signal decaying driver (13) and data processor (14) respectively with the monolithic Machine (11) connects；

The smooth transmission unit (2) include light-pulse generator (21) and adjustable attenuator (22), the light-pulse generator (21) respectively with The pulse signal generator (12) and the adjustable attenuator (22) connection, the adjustable attenuator (22) respectively with the letter Number decaying driver (13) and optical branching unit (3) connection；

Each optical branching probe unit (6) includes optical splitter (61), a common detection unit (62) and a list of a 1x2 Photon detection unit (63), each 1x2 optical splitters (61) input terminal correspondence is connect with a coupling unit (5), each described Correspondence is connect 1x2 optical splitters (61) output end with a common detection unit (62) and a single photon detection unit (63) respectively.

3. the OTDR devices according to claim 1 based on multi-channel optical fibre optical monitoring signal, it is characterised in that：The light point Road unit (3) is 1xN optical splitters, and the oscillography unit (4) is waveform oscilloscope, and the waveform oscilloscope includes N number of waveform Curve viewing area；Each coupling unit (5) is directional coupler or circulator；Wherein, the integer that N is >=2.

4. the OTDR devices according to claim 2 based on multi-channel optical fibre optical monitoring signal, it is characterised in that：It is each described Common detection unit (62) is put comprising sequentially connected first photoelectric detection module (621), filter (622), the first signal Big device (623) and the first A/D converter (624), each first photoelectric detection module (621) also corresponding point with a 1x2 One output port of light device (61) connects, and each first A/D converter (624) is also corresponding and main control unit (1) Data processor (14) connects, and each first photoelectric detection module (621) includes the first avalanche photodide (621a), the first temperature control module (621b) and the first Package boxes (621c)；Each first temperature control module (621b) includes There are the first refrigerator (621b-1), primary heater (621b-2) and the first temperature sensor (621b-3), each described first Refrigerator (621b-1) and primary heater (621b-2) are respectively connect with the microcontroller of main control unit (1) (11), Mei Gesuo State the first temperature sensor (621b-3) respectively with the microcontroller of the main control unit (1) (11) and one first avalanche optoelectronic two The pin of pole pipe (621a) connects, each corresponding first avalanche photodide of first photoelectric detection module (621) The corresponding envelope of (621a), the first refrigerator (621b-1), primary heater (621b-2) and the first temperature sensor (621b-3) In first Package boxes (621c).

5. the OTDR devices according to claim 2 based on multi-channel optical fibre optical monitoring signal, it is characterised in that：It is each described Single photon detection unit (63) includes the second photoelectric detection module (631), biasing module (632), clock module (633), door Pulse module (634), noise suppression module (635), shaping pulse module (636) and photon counter (637), it is each described inclined Correspondence is connect die block (632) with the microcontroller (11) of main control unit (1) and one second photoelectric detection module (631) respectively, Each clock module (633) corresponds to the pulse signal generator (12) and a portal vein die block with main control unit (1) respectively (634) it connects, each portal vein die block (634) corresponds to the microcontroller (11) and one second light with main control unit (1) respectively The connection of electric detecting module (631), each noise suppression module (635) respectively it is corresponding with one second photoelectric detection module (631) and One shaping pulse module (636) connects, and each photon counter (637) corresponds to the data processor with main control unit (1) respectively (14) and a shaping pulse module (636) connection, each second photoelectric detection module (631) correspond to and 1x2 light splitting One output port of device (61) connects, and each second photoelectric detection module (631) includes two pole of the second avalanche optoelectronic Manage (631a), the second temperature control module (631b) and the second Package boxes (631c)；Each second temperature control module (631b) packet Containing the second refrigerator (631b-1), secondary heater (631b-2) and second temperature sensor (631b-3), each described the Two refrigerators (631b-1) and secondary heater (631b-2) are respectively connect with the microcontroller of main control unit (1) (11), each The second temperature sensor (631b-3) respectively with two pole of the microcontroller of main control unit (1) (11) and one second avalanche optoelectronic Manage the pin connection of (631a), each corresponding second avalanche photodide of second photoelectric detection module (631) The corresponding envelope of (631a), the second refrigerator (631b-1), secondary heater (631b-2) and second temperature sensor (631b-3) In second Package boxes (631c).

6. the OTDR devices according to claim 5 based on multi-channel optical fibre optical monitoring signal, it is characterised in that：It is each described Biasing module (632) is voltage source module, and respectively it is corresponding with the connection of the microcontroller (11) of main control unit (1) and it is corresponding and The cathode of one second avalanche photodide (631a) connects.

7. the OTDR devices according to claim 5 based on multi-channel optical fibre optical monitoring signal, it is characterised in that：It is each described Portal vein die block (634) is gate generator, and respectively corresponding with a clock module (633) connection and corresponding and one the The cathode of two avalanche photodides (631a) connects, and each portal vein die block (634) includes phase-locked loop circuit (634a), frequency divider (634b) and second signal amplifier (634c), the output end pair of each phase-locked loop circuit (634a) Ying Yuyi second signals amplifier (634c) connects, and the input terminal of each phase-locked loop circuit (634a) corresponds to and a clock mould Block (633) connects, and each phase-locked loop circuit (634a) includes sequentially connected phase discriminator (634a-1), loop filter (634a-2) and voltage controlled oscillator (634a-3).

8. the OTDR devices according to claim 5 based on multi-channel optical fibre optical monitoring signal, it is characterised in that：It is each described Noise suppression module (635) includes bandpass filter (635a), low-pass filter (635b) and third signal amplifier (635c)； Each bandpass filter (635a) input terminal correspondence is connect with portal vein die block (634) output end, each band logical Filter (635a) output end correspondence is connect with the cathode of one second avalanche photodide (631a)；Each low-pass filtering Device (635b) input terminal correspondence is connect with the anode of one second avalanche photodide (631a), each low-pass filter (635b) output end correspondence is connect with third signal amplifier (635c) input terminal；Each third signal amplifier (635c) output end correspondence is connect with a shaping pulse module (636).

9. the OTDR devices according to claim 8 based on multi-channel optical fibre optical monitoring signal, it is characterised in that：It is each described Shaping pulse module (636) includes pulse amplitude discriminator (636a), pulse shaper (636b) and the second A/D converter (636c)；Each pulse amplitude discriminator (636a) input terminal correspondence is connect with third signal amplifier (635c) output end, Each pulse amplitude discriminator (636a) output end correspondence is connect with a pulse shaper (636b) input terminal, each arteries and veins Shaping circuit (636b) output end correspondence is rushed to connect with one second A/D converter (636c) input terminal, each second mould/ Number converter (636c) output end correspondence is connect with a photon counter (637) input terminal, each photon counter (637) Output end correspondence is connect with the data processor (14) of main control unit (1).