CN103036615B

CN103036615B - Optical time domain detector optical module and gigabit passive optical network breakpoint detection system

Info

Publication number: CN103036615B
Application number: CN201210555629.3A
Authority: CN
Inventors: 张洪铭; 张强; 金成浩; 赵其圣; 杨思更; 何鹏; 薛登山
Original assignee: Hisense Broadband Multimedia Technology Co Ltd
Current assignee: Hisense Broadband Multimedia Technology Co Ltd
Priority date: 2012-12-19
Filing date: 2012-12-19
Publication date: 2015-10-28
Anticipated expiration: 2032-12-19
Also published as: CN103036615A

Abstract

The invention discloses a kind of OTDR optical module and GPON breakpoint detection system.This system comprises: optical line terminal OLT, optical splitter, optical network unit ONU and optical time domain detector optical module, and OLT is connected with optical time domain detector optical module, and optical time domain detector optical module is connected with optical splitter; Optical time domain detector optical module, for receiving the light signal of the first wave length that OLT exports, is transmitted through optical splitter; Receive the light signal of the second wave length that ONU exports, be transmitted through OLT; Generate the light signal of three-wavelength, export, the light signal of the three-wavelength that reception Rayleigh scattering and Fresnel reflection return, carries out signal transacting, obtains breakpoint information according to signal processing results.Application the present invention, can simplify the normal transmission of breaking point detection flow process, safeguards system network signal.<pb pnum="1" />

Description

Optical module of optical time domain detector and breakpoint detection system of gigabit passive optical network

Technical Field

The present invention relates to an Optical fiber communication technology, and in particular, to an Optical Time Domain Reflectometer (OTDR) Optical module and a Gigabit Passive Optical Network (GPON) breakpoint detection system.

Background

In the current domestic market and international market, the optical fiber communication direction with high bandwidth, high speed and multiple service fusion is already applied; among The numerous solutions, The emergence of Fiber To The Home (FTTH) is considered to be The ultimate solution for broadband access, and The domestic market has been widely applied.

Among numerous FTTH schemes, GPON is concerned and becomes the mainstream optical access mode at present. In a GPON system, an Optical transmission medium, such as an Optical fiber/Optical cable, is often laid in a suburb or a submarine, and it is difficult to avoid a link fault or a transmission equipment fault due to a transmission link breakpoint, and in order to accurately locate a fault or a breakpoint, an Optical Time Domain Reflectometer (OTDR) Optical module is generally used for breakpoint detection. The OTDR is an optoelectronic integrated instrument manufactured by using rayleigh scattering when light is transmitted in an optical fiber and back scattering generated by fresnel reflection, and can be widely applied to maintenance and construction of an optical cable line, and can measure the length of the optical fiber, transmission attenuation of the optical fiber, joint attenuation, fault location, and the like.

Fig. 1 is a schematic structural diagram of a conventional gigabit passive optical network system. Referring to fig. 1, the system includes: an Optical Line Terminal (OLT), a Splitter (Splitter), and an Optical network Unit (ODU), wherein,

the OLT is generally disposed in a central office of an access network system of the optical fiber communication system, and is responsible for converting electrical signal data in an external switch into optical signal data and sending the optical signal data to the optical splitter, receiving an optical signal transmitted by the optical splitter, and converting the optical signal into an electrical signal and sending the electrical signal to the external switch;

the OLT is connected to the ONU through the Splitter, and the ONU is usually located at a central office, i.e., a user side or a building; splitter typically has 2N sharing interfaces, and if the input interface has a light intensity of 1, the output interface has a light intensity of 1/N.

For a gigabit passive optical network system (optical access system), an OLT is generally placed in a central office of telecommunications and then passes through an optical splitter, generally at least 1 minute 32, i.e. an OLT passes through an optical splitter, with 32 ONUs forming the gigabit passive optical network system.

In fig. 1, taking the number of ONUs as three as an example, it is assumed that there is a 10km long optical fiber between the OLT and the splitter, the distance between the splitter and ONU1 is 1km, the distance between the splitter and ONU2 is 2km, and the distance between the splitter and ONU3 is 10 km.

If the optical fiber between the subscriber and the ONU3 is broken at 7km, the optical fiber link between the OLT and the ONU3 will be failed, and the OTDR technique needs to be used for detecting the break point, so as to detect the location of the failure in time and perform maintenance.

Fig. 2 is a schematic structural diagram of a breakpoint detection system of a conventional gigabit passive optical network. Referring to fig. 2, the system includes: the OTDR includes an OTDR, an Optical Splitter (Splitter), and an Optical network unit (ODU, Optical network unit), where, compared to the gigabit passive Optical network system shown in fig. 1, when performing disconnection detection in an Optical time domain, it is necessary to disconnect the connection between the OLT and an Optical fiber, and connect the OTDR to a GPON system, that is, replace the OLT with the OTDR, and connect the OTDR to the Splitter through the Optical fiber. The OTDR emits optical pulses through the transmission interface, outputs the optical pulses into the optical fiber, and transmits the optical pulses to the ONU through the Splitter.

When an optical pulse is transmitted through an optical fiber, scattering and reflection occur due to the properties of the optical fiber itself and due to connectors, joints, bends or other similar events, wherein a portion of the scattered light and the reflected light are returned through the optical fiber to the OTDR, and the returned useful information is measured by a detector in the OTDR and used as time or curve segments at different positions in the optical fiber, and the specific position of the break point can be determined by analyzing the time or curve segments. That is, the OTDR characterizes the optical fiber using rayleigh scattering, which is caused by irregular scattering of the optical signal along the optical fiber, and fresnel reflection, which backscattering signals indicate the degree of attenuation (loss/distance) caused by the optical fiber, and thus, by measuring a portion of the scattered light returned to the OTDR receiving interface, the degree of attenuation (loss/distance) of the optical fiber can be obtained; fresnel reflections are discrete reflections caused by individual points in the entire fiber due to factors that cause changes in the inversion coefficient, at which points strongly backscattered light is reflected back. Thus, OTDR can locate a connection point, fiber termination or break point by using information from rayleigh scattering and fresnel reflection.

As can be seen from the above, in the existing GPON breakpoint detection system for performing optical fiber breakpoint detection based on an optical time domain detector, during the breakpoint detection, the existing GPON system needs to be disconnected first, then the OTDR is connected to the breakpoint detection system, an optical pulse is transmitted into an optical fiber through the OTDR, detection is performed by using rayleigh scattering of the optical pulse and fresnel reflected information, and a breakpoint detection flow is complex; further, during the detection, the OLT needs to be disconnected, thereby affecting the normal transmission of network signals at other non-disconnected points. For example, in the above example, when the optical fiber between the splitter and the ONU3 is broken, during the detection period, the OLT needs to be disconnected from the network, so that the signal transmission and reception of the ONU1 and the ONU2 are interrupted, and the normal operation of the GPON system is affected; moreover, when the GPON system frequently fails, frequent operations of disconnecting the OLT and plugging the OLT are required, and frequent plugging causes the operational reliability of the OLT to be reduced.

In summary, in the GPON breakpoint detection system in the prior art, during the breakpoint detection process, the detection flow is complex, and normal transmission of other network signals without a breakpoint is affected.

Disclosure of Invention

The embodiment of the invention provides an OTDR optical module, which simplifies the breakpoint detection process and ensures the normal transmission of system network signals.

The embodiment of the invention also provides a GPON breakpoint detection system, which simplifies the breakpoint detection process and ensures the normal transmission of system network signals.

According to an aspect of the present invention, there is provided an OTDR optical module, comprising: light path component, laser emitter, laser detector, breakpoint detection module and electric signal sampling circuit,

the optical path component is used for connecting an optical fiber connected with an external optical line terminal OLT through a built-in uplink optical fiber interface, connecting the optical fiber connected with an external optical splitter through a built-in downlink optical fiber interface, connecting the optical fiber with a laser transmitter through a built-in laser transmitting interface and connecting the optical fiber with a laser detector through a built-in laser receiving interface;

the laser transmitter is used for generating an optical signal with a third wavelength for detecting a breakpoint and outputting the optical signal to a laser transmitting interface of the optical path component when the breakpoint detection is carried out;

the laser detector is used for receiving the optical signal with the third wavelength output from the laser receiving interface of the optical path component, and converting the received optical signal with the third wavelength into a corresponding electric signal to be output;

the electric signal sampling circuit is connected with the laser detector, samples the electric signal output by the laser detector to obtain a digital signal and sends the digital signal to the breakpoint detection module;

and the breakpoint detection module is used for receiving the digital signal sent by the electric signal sampling circuit, analyzing the digital signal, comparing an analysis result with a result obtained by analyzing the sampling without the breakpoint in advance, and acquiring the position of the breakpoint or the fault point.

Preferably, the first and second liquid crystal films are made of a polymer,

the optical path component receives an optical signal with a first wavelength output by an external OLT through an optical fiber through an uplink optical fiber interface, transmits the optical signal to the optical fiber through a downlink optical fiber interface and transmits the optical signal to an external optical splitter; receiving an optical signal of a second wavelength output by an external optical network unit ONU through an optical fiber through a downlink optical fiber interface, transmitting the optical signal to the optical fiber through an uplink optical fiber interface, and transmitting the optical signal to the OLT;

receiving an optical signal with a third wavelength transmitted by a laser transmitter through a laser transmitting interface, outputting the optical signal to a downlink optical fiber interface, and outputting the optical signal by the downlink optical fiber interface; and receiving the reflected optical signal with the third wavelength through the downlink optical fiber interface, outputting the optical signal to the laser receiving interface, and outputting the optical signal to the laser detector through the laser receiving interface.

Preferably, the electrical signal sampling circuit is further configured to amplify and filter the received electrical signal after receiving the electrical signal output by the laser detector.

Preferably, the optical path component includes: a wavelength division multiplexer, and a circulator, wherein,

the WDM receives an optical signal with a first wavelength output by the OLT through the optical fiber through a built-in uplink optical fiber interface, transmits the optical signal to the optical fiber through a downlink optical fiber interface and transmits the optical signal to the optical splitter; receiving an optical signal of a second wavelength output by the ONU through the optical fiber through the downlink optical fiber interface, transmitting the optical signal to the optical fiber through the uplink optical fiber interface, and transmitting the optical signal to the OLT;

receiving the optical signal with the third wavelength output by the circulator through a built-in reflection interface, outputting the optical signal to a downlink optical fiber interface, and outputting the optical signal by the downlink optical fiber interface; receiving the reflected optical signal with the third wavelength through the downlink optical fiber interface, outputting the optical signal to the reflection interface, and outputting the optical signal to the circulator through the reflection interface;

the circulator is used for receiving the optical signal of the third wavelength transmitted by the laser transmitter through the built-in first interface and outputting the optical signal to the reflection interface of the WDM through the built-in second interface; and receiving the reflected third wavelength optical signal output by the reflection interface of the WDM through the second interface, and outputting the optical signal to the laser detector through the built-in laser receiving interface.

Preferably, the optical path component further includes an optical filter disposed between the laser receiving interface of the circulator and the laser detector, and the optical filter is configured to attenuate an optical signal of a third wavelength output from the laser receiving interface of the circulator.

Preferably, the laser transmitter includes: a laser emitting unit and a driving circuit unit, wherein,

and the driving circuit unit is used for driving the laser emitting unit to emit laser with a third wavelength when starting to perform breakpoint detection and outputting the laser to the first interface of the circulator.

Preferably, the laser transmitter further comprises:

and the control unit is used for generating a breakpoint detection electrical signal after receiving a breakpoint detection instruction of the external device and outputting the breakpoint detection electrical signal to the driving circuit unit so that the driving circuit unit drives the laser emission unit to emit laser with a third wavelength according to the received breakpoint detection electrical signal.

Preferably, the laser emission unit is a 1625nm distributed feedback laser emission light source.

Preferably, the laser detector comprises: a photodiode and a transimpedance amplifier TIA, wherein,

the photodiode is used for receiving the optical signal output from the laser receiving interface and outputting corresponding response current to the TIA;

and the TIA is used for receiving the response current and outputting a corresponding differential electric signal to the electric signal sampling circuit according to the received response current.

Preferably, the photodiode is an avalanche photodiode.

Preferably, the electrical signal sampling circuit includes:

and the analog-digital conversion ADC circuit is used for sampling the electric signal output by the laser detector and sending the digital signal obtained by sampling to the breakpoint detection module for storage.

Preferably, the electrical signal sampling circuit further includes an amplifying circuit, and the amplifying circuit is disposed between the laser detector and the ADC circuit, and amplifies the electrical signal output by the laser detector.

Preferably, the breakpoint detection module includes: a detection signal storage unit, a comparison unit, a normal operation signal storage unit and a breakpoint position determination unit, wherein,

the detection signal storage unit is used for storing the digital signal output by the ADC circuit in a detection state;

the normal operation signal storage unit is used for storing digital signals obtained by the gigabit passive optical network breakpoint detection system in a normal operation state;

the comparison unit is used for comparing the digital signal stored in the detection signal storage unit with the digital signal stored in the normal operation signal storage unit and outputting a comparison result;

and the breakpoint position determining unit is used for analyzing the comparison result output by the comparison unit and acquiring the position of the breakpoint or the fault point.

Preferably, the breakpoint detection module is a field programmable gate array, a programmable array logic, a single chip, a processor or a microcontroller.

A gigabit passive optical network breakpoint detection system, the system comprising: the optical line terminal OLT comprises an optical splitter and an optical network unit ONU, wherein the OLT transmits an optical signal with a first wavelength and receives an optical signal with a second wavelength transmitted by the ONU; the gigabit passive optical network breakpoint detection system further comprises: an optical time domain detector optical module is arranged,

the OLT is connected with an optical time domain detector optical module, and the optical time domain detector optical module is connected with the optical splitter;

the optical time domain detector optical module is used for receiving an optical signal with a first wavelength output by the OLT and transmitting the optical signal to the optical splitter; receiving an optical signal with a second wavelength output by the ONU, and transmitting the optical signal to the OLT; and generating an optical signal with a third wavelength, outputting, receiving the optical signal with the third wavelength returned by Rayleigh scattering and Fresnel reflection, processing the signal, and acquiring breakpoint information according to a signal processing result.

Preferably, the optical time domain detector optical module includes: light path component, laser emitter, laser detector, breakpoint detection module and electric signal sampling circuit,

the optical path component is connected with an optical fiber connected with the OLT through a built-in uplink optical fiber interface, connected with an optical fiber connected with the optical splitter through a built-in downlink optical fiber interface, connected with the laser transmitter through a built-in laser transmitting interface and connected with the laser detector through a built-in laser receiving interface;

Preferably, the first and second liquid crystal films are made of a polymer,

the optical path component receives an optical signal with a first wavelength output by the OLT through the optical fiber through the uplink optical fiber interface, transmits the optical signal to the optical fiber through the downlink optical fiber interface and transmits the optical signal to the optical splitter; receiving an optical signal of a second wavelength output by the ONU through the optical fiber through the downlink optical fiber interface, transmitting the optical signal to the optical fiber through the uplink optical fiber interface, and transmitting the optical signal to the OLT;

Preferably, the laser transmitter further comprises:

Preferably, the electrical signal sampling circuit includes:

the analog-digital conversion ADC circuit is used for sampling the electric signal output by the laser detector and sending the digital signal obtained by sampling to the breakpoint detection module for storage;

and the amplifying circuit is arranged between the laser detector and the ADC circuit and is used for amplifying the electric signal output by the laser detector.

As can be seen from the above description, the OTDR optical module and GPON breakpoint detection system of the embodiment of the present invention includes: the optical line terminal OLT is connected with the optical time domain detector optical module, and the optical time domain detector optical module is connected with the optical splitter; the optical time domain detector optical module is used for receiving an optical signal with a first wavelength output by the OLT and transmitting the optical signal to the optical splitter; receiving an optical signal with a second wavelength output by the ONU, and transmitting the optical signal to the OLT; and generating an optical signal with a third wavelength, outputting, receiving the optical signal with the third wavelength returned by Rayleigh scattering and Fresnel reflection, processing the signal, and acquiring breakpoint information according to a signal processing result. Therefore, when the breakpoint detection is carried out, the OLT does not need to be disconnected, so that the normal service communication in the GPON is not influenced, and the breakpoint detection flow is simplified on the basis of ensuring the normal transmission of the network signals of the system; furthermore, the frequent plugging of the OLT is reduced and the working reliability of the OLT is improved because frequent operations of disconnecting the OLT and plugging the OLT are not required.

Drawings

Fig. 1 is a schematic structural diagram of a conventional gigabit passive optical network system.

Fig. 2 is a schematic structural diagram of a breakpoint detection system of a conventional gigabit passive optical network.

Fig. 3 is a schematic structural diagram of a breakpoint detection system of a gigabit passive optical network according to an embodiment of the present invention.

Fig. 4 is a schematic structural diagram of an optical module of the optical time domain detector according to the embodiment of the present invention.

Fig. 5 is a schematic diagram of a breakpoint detection system of a gigabit passive optical network according to an embodiment of the present invention.

Fig. 6 is a schematic diagram of waveforms of digital signals stored in the breakpoint detection module.

Fig. 7 is a schematic diagram of the digital signal waveform and the distance calculated based on fig. 6.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be described in further detail below with reference to the accompanying drawings by way of examples of preferred embodiments. It should be noted, however, that the numerous details set forth in the description are merely for the purpose of providing the reader with a thorough understanding of one or more aspects of the present invention, which may be practiced without these specific details.

As used in this application, the terms "module," "system," and the like are intended to include a computer-related entity, such as but not limited to hardware, firmware, a combination of hardware and software, or software in execution. For example, a module may be, but is not limited to: a process running on a processor, an object, an executable, a thread of execution, a program, and/or a computer. For example, an application running on a computing device and the computing device may both be a module. One or more modules may reside within a process and/or thread of execution and a module may be localized on one computer and/or distributed between two or more computers.

In the existing GPON breakpoint detection system, during the breakpoint detection, the OLT needs to be disconnected first, then the OTDR is accessed to the breakpoint detection system to perform breakpoint detection, and after the detection is completed, the OTDR is disconnected, and the OLT is accessed to the breakpoint detection system to perform normal communication, so that the breakpoint detection flow is complex and normal transmission of network signals is affected.

In the embodiment of the invention, the on-line OTDR optical module is provided, breakpoint detection is carried out under the condition of not disconnecting an OLT, the OTDR optical module is connected in series to a gigabit passive optical network system, downlink optical signals output by the OLT and uplink optical signals transmitted to the OLT are transmitted in a transparent mode, OTDR detection light returned by scattering and reflecting of the optical signals transmitted by the OTDR optical module is received through transmitting the optical signals, breakpoint analysis is carried out, and a breakpoint analysis result is fed back to the system.

Fig. 3 is a schematic structural diagram of a breakpoint detection system of a gigabit passive optical network according to an embodiment of the present invention. Referring to fig. 3, the system includes: an Optical Line Terminal (OLT) 301, an optical splitter (splitter) 302, an optical time domain detector optical module 303, and an Optical Network Unit (ONU) 304, wherein the OLT301, the optical splitter 302, and the optical network unit ONU304 are respectively the same as the OLT, splitter, and ONU in the PON system in the prior art;

OLT301 is connected with optical time domain detector optical module 303, optical time domain detector optical module 303 is connected with optical splitter 302, optical splitter 302 is connected with one or more ONU304, that is, optical time domain detector optical module 303 is connected in series between OLT301 and splitter 302. Specifically, the OLT301 is connected to an optical time domain detector optical module 303 through an optical fiber, the optical time domain detector optical module 303 is connected to an optical splitter 302 through an optical fiber, and the optical splitter 302 is connected to one or more ONUs 304 through an optical fiber.

Preferably, the optical time domain detector optical module 303 is located closer to the OLT301 in the gigabit passive optical network breakpoint detection system.

An OLT301, configured to transmit an optical signal (a downlink communication optical signal) with a first wavelength, enter an optical time domain detector optical module 303 through an optical fiber, and transmit the optical signal to an optical splitter 302 through the optical time domain detector optical module 303; receiving an optical signal (uplink communication optical signal) with a second wavelength transmitted by the optical time domain detector optical module 303 through an optical fiber, and processing the optical signal;

in the embodiment of the present invention, OLT301 transmits an optical signal with a first wavelength to an uplink optical fiber interface of optical time domain detector optical module 303 through an optical fiber, and enters the optical fiber through a downlink optical fiber interface of optical time domain detector optical module 303, and after transmitting in the optical fiber, the optical signal reaches optical splitter 302; and receiving the optical signal with the second wavelength transmitted by the uplink optical fiber interface of the optical time domain detector optical module 303 through an optical fiber, and processing the optical signal.

In the embodiment of the present invention, a specific processing flow of the OLT301 for the optical signal is the same as that in the prior art, and reference may be specifically made to related technical documents, which is not described herein again.

An optical time domain detector optical module 303, configured to receive an optical signal with a first wavelength output by OLT301, and transmit the optical signal to optical splitter 302; receiving the optical signal with the second wavelength output by the ONU304, and transmitting the optical signal to the OLT 301; generating an optical signal with a third wavelength, outputting the optical signal, receiving the optical signal with the third wavelength returned by Rayleigh scattering and Fresnel reflection, processing the signal, and acquiring breakpoint information according to a signal processing result;

in the embodiment of the present invention, the optical time domain detector optical module 303 determines the received optical signal to determine whether the received optical signal is an optical signal with a first wavelength, an optical signal with a second wavelength, or an optical signal with a third wavelength.

The optical signal of the third wavelength returned by rayleigh scattering and fresnel reflection may be an optical signal returned by rayleigh scattering and fresnel reflection on a communication link between the optical time domain detector optical module 303 and the optical splitter 302, an optical signal returned by rayleigh scattering and fresnel reflection on a communication link between the optical splitter 302 and the ONU304, or an optical signal returned by rayleigh scattering and fresnel reflection on the ONU 304.

The optical splitter 302 is configured to receive an optical signal output by the optical time domain detector optical module 303, perform optical splitting, and output the optical signal to one or more ONUs 304 connected to the optical splitter; receiving the optical signal with the second wavelength generated by the ONU304, performing a confluence process, and outputting the converged optical signal to the optical time domain detector optical module 303; receiving an optical signal of a third wavelength, which is reflected by rayleigh scattering and fresnel, performing convergence processing, and outputting the optical signal to the optical time domain detector optical module 303;

in the embodiment of the present invention, the optical splitter 302 is configured to perform optical splitting processing on the downlink optical signal sent to the ONU304, perform convergence processing on the received uplink optical signal, and output the converged uplink optical signal to the optical time domain detector optical module 303.

The ONU304 is configured to receive the optical signal with the first wavelength through an optical fiber, process the optical signal, generate an optical signal with a second wavelength, and output the optical signal to the optical splitter 302; the optical signal of the third wavelength is received, and the optical signal of the third wavelength reflected by rayleigh scattering and fresnel is output to the optical splitter 302 through the optical fiber.

In the embodiment of the present invention, a detailed flow of the ONU304 receiving the optical signal with the first wavelength through the optical fiber, processing the optical signal, and generating the optical signal with the second wavelength belongs to the prior art, and for details, reference may be made to related technical documents.

If the ONU304 receives an optical signal with a third wavelength through the optical fiber, it indicates that the communication link between the optical module 303 of the optical time domain detector and the ONU304 is normal; if the optical time domain detector optical module 303 outputs the optical signal with the third wavelength and the ONU304 does not receive the optical signal with the third wavelength, it indicates that the communication link between the optical time domain detector optical module 303 and the ONU304 is abnormal.

In the embodiment of the present invention, OLT301 transmits an optical signal (downlink communication optical signal) with a first wavelength, enters an optical fiber between OLT301 and optical time domain detector optical module 303, transmits the optical signal in the optical fiber, reaches an uplink optical fiber interface of optical time domain detector optical module 303, transmits the optical signal through optical time domain detector optical module 303, enters the optical fiber between optical time domain detector optical module 303 and optical splitter 302 from the downlink optical fiber interface of optical time domain detector optical module 303, transmits the optical signal through the optical fiber, enters optical splitter 302, performs optical splitting processing on optical splitter 302, enters the optical fiber between optical splitter 302 and ONU304, and finally reaches ONU 304; the ONU304 processes the received optical signal with the first wavelength, transmits an optical signal with a second wavelength (an uplink communication optical signal), enters a downlink optical fiber interface of the optical time domain detector optical module 303 through optical fibers among the optical splitter 302, the optical splitter 302 and the optical time domain detector optical module 303, enters the optical fiber from the uplink optical fiber interface of the optical time domain detector optical module 303 after being transmitted by the optical time domain detector optical module 303, reaches the OLT301 after being transmitted in the optical fiber, the OLT301 receives the optical signal with the second wavelength for processing, transmits the optical signal with the first wavelength (a downlink communication optical signal) according to an optical signal processing result, and repeats the above steps until the process is finished;

when the optical time domain detector optical module 303 performs breakpoint detection, an optical signal of a third wavelength is transmitted through a downlink optical fiber interface thereof, and optical signal transmission is performed through an optical fiber between the optical time domain detector optical module 303 and the optical splitter 302, an optical fiber between the optical splitter 302 and the ONU304, and a link of the ONU304 in sequence, if a breakpoint occurs in the link, the optical signal of the third wavelength is reflected from the breakpoint and reversely passes through the link to reach the downlink optical fiber interface of the optical time domain detector optical module 303, the downlink optical fiber interface of the optical time domain detector optical module 303 receives the reflected optical signal of the third wavelength, converts the reflected optical signal of the third wavelength into an electrical signal, performs sampling and analog-to-digital conversion to obtain a digital signal, and stores and analyzes the sampled digital signal to determine the breakpoint or the position of the fault point.

In practical application, the optical time domain detector optical module 303 starts to perform breakpoint detection, where after transmitting an optical signal with a first wavelength, if an optical signal with a second wavelength responding to the optical signal with the first wavelength is not received within a preset time, the OLT301 sends trigger information to the optical time domain detector optical module 303 to trigger starting of the optical time domain detector optical module 303 to perform breakpoint detection, or the optical time domain detector optical module 303 periodically transmits an optical signal with a third wavelength to perform breakpoint fault detection according to the reflected optical signal with the third wavelength. Of course, the breakpoint detection may also be triggered by other means.

For setting various detection parameters, such as the refractive index n of the optical fiber, the wavelength of the optical pulse, etc., in the optical module 303 of the optical time domain detector, reference may be made to related technical documents, which are not described herein again.

Preferably, after the optical time domain detector optical module 303 analyzes information fed back by the back scattering light at different positions of the optical fiber, a waveform is formed on the liquid crystal display, and the waveform is analyzed, so that the position where the optical fiber fails is obtained.

It should be noted that the third wavelength of the optical signal emitted by the optical time domain detector optical module 303 is only required to be not the same as the optical signal with the first wavelength and the optical signal with the second wavelength (uplink and downlink optical waves), for example, the commonly used 10G downlink optical wavelength is 1577nm, and the 2.5G uplink optical wavelength is 1270 nm; the wavelength of 2.5G downlink light is 1490nm, and the wavelength of 1G uplink light is 1310 nm. The optical wavelength used for OTDR breakpoint detection was chosen to be 1625nm in order not to affect normal traffic.

In the embodiment of the present invention, the transmission means that the optical time domain detector optical module 303 serves as a repeater, and forwards the received optical signal to the next receiving unit without any processing.

As can be seen from the above description, the optical time domain detector optical module 303 serially connected between the OLT301 and the optical splitter 302 can transmit communication signals in the GPON system, for example, a downlink communication optical signal with a first wavelength and an uplink communication optical signal with a second wavelength, so that in a process of detecting a breakpoint, transmission of communication data is implemented, and the existence of the optical time domain detector optical module 303 does not affect communication of the existing GPON system.

Fig. 4 is a schematic structural diagram of an optical module of the optical time domain detector according to the embodiment of the present invention. Referring to fig. 4, the light module includes: optical path component 401, laser transmitter 402, laser detector 403, breakpoint detection module 405, electrical signal sampling circuit 404, wherein,

an optical path component 401, configured to connect to an optical fiber connected to OLT301 through a built-in uplink optical fiber interface, connect to an optical fiber connected to optical splitter 302 through a built-in downlink optical fiber interface, connect to a laser transmitter 402 through a built-in laser transmitting interface, and connect to a laser detector 403 through a built-in laser receiving interface;

specifically, optical path component 401 receives, through an uplink optical fiber interface, an optical signal with a first wavelength output by OLT301 through an optical fiber, transmits to the optical fiber through a downlink optical fiber interface, and transmits to optical splitter 302; receiving an optical signal of a second wavelength output by the ONU304 through an optical fiber through the downlink optical fiber interface, transmitting the optical signal to the optical fiber through the uplink optical fiber interface, and transmitting the optical signal to the OLT 301;

receiving the optical signal with the third wavelength transmitted by the laser transmitter 402 through the laser transmitting interface, outputting the optical signal to the downlink optical fiber interface, and outputting the optical signal by the downlink optical fiber interface; the reflected optical signal with the third wavelength is received by the downlink optical fiber interface, output to the laser receiving interface, and output to the laser detector 403 by the laser receiving interface.

In the embodiment of the present invention, the optical path component 401 includes four interfaces, which are respectively: the optical fiber system comprises an uplink optical fiber interface, a downlink optical fiber interface, a laser transmitting interface and a laser receiving interface, wherein the uplink optical fiber interface and the downlink optical fiber interface are respectively connected with optical fibers, namely the uplink optical fiber interface is connected with an OLT301 through optical fibers, and the downlink optical fiber interface is connected with an optical splitter 302 through optical fibers; the optical path component 401 receives the optical signal with the third wavelength transmitted by the laser transmitter 402 through the laser transmitting interface, and outputs the optical signal with the third wavelength transmitted by the laser transmitter 402 to the optical fiber from the downlink optical fiber interface for transmission after coupling.

In the embodiment of the present invention, the optical signal of the third wavelength is transmitted through the optical fiber of the GPON system, and is reflected at a fault point of the optical fiber or a fault of a device (for example, an optical splitter and an ONU) or other fault places, the reflected optical signal of the third wavelength is transmitted through the optical fiber, and after returning to the optical path module 401, the optical path module 401 receives the reflected optical signal of the third wavelength from the downstream optical fiber interface, performs optical splitting processing, and outputs the reflected optical signal of the third wavelength to the laser detector 403 through the laser receiving interface.

The laser transmitter 402 is configured to generate an optical signal with a third wavelength for detecting a breakpoint when performing breakpoint detection, and output the optical signal to a laser transmission interface of the optical path component 401;

in the embodiment of the present invention, when the laser emitter 402 performs the breakpoint detection, the pulse electrical signal with a fixed period may be subjected to electro-optical conversion to generate and emit an optical signal with a third wavelength.

A laser detector 403, configured to receive the optical signal with the third wavelength output from the laser receiving interface of the optical path component 401, convert the received optical signal with the third wavelength into a corresponding electrical signal, and output the electrical signal;

in the embodiment of the present invention, the optical signal of the third wavelength received by the laser detector 403 is a reflected signal, and the reflected signal can reflect the position of the breakpoint in the network optical fiber, and after the reflected optical signal is converted into an electrical signal and sampled, the sampled digital signal is analyzed to determine the position of the breakpoint or the fault point.

The electrical signal sampling circuit 404 is used for connecting with the laser detector 403, sampling the electrical signal output by the laser detector 403 to obtain a digital signal, and sending the digital signal to the breakpoint detection module 405;

in the embodiment of the present invention, the electrical signal sampling circuit 404 may further amplify and filter the electrical signal output by the laser detector 403, and sample the amplified and filtered electrical signal to output a sampled digital signal.

And the breakpoint detection module 405 is configured to receive the digital signal sent by the electrical signal sampling circuit 404, analyze the digital signal, compare an analysis result with a result obtained by analyzing the sampling without a breakpoint in advance, and obtain a breakpoint or a fault point position.

In this embodiment of the present invention, the breakpoint detection module 405 may further be configured to store the received digital signal sent by the electrical signal sampling circuit 404.

The breakpoint detection module 405 generates a first waveform according to the digital signal received and stored from the electrical signal sampling circuit 404, compares the first waveform with a second waveform that is pre-stored and is generated according to the digital signal sampled when there is no breakpoint, and determines a breakpoint or a fault point position according to a comparison result. Of course, in practical applications, the received digital signal may be compared with a pre-stored digital signal, where the pre-stored digital signal is a sampled digital signal obtained by sampling and analog-to-digital converting the reflected optical signal with the third wavelength under a normal condition, that is, under a condition without a breakpoint or a fault point.

The external pin of the optical time domain detector optical module 303 may specifically include:

SDA pin, namely serial communication line data pin;

an SCL pin, namely a clock pin of the serial communication line;

GND and VCC pins.

Specifically, the SDA pin and the SCL pin are connected to the breakpoint detection module 405, and the control unit 1202 communicates with the external device through the SDA pin and the SCL pin.

The electrical interface of the external pin of the optical module 303 of the optical time domain detector may adopt a 4pin structure of a pin type.

In the embodiment of the present invention, the analysis result is compared with a result obtained by analyzing the pre-obtained sampling without the breakpoint, and the obtained breakpoint or the fault point location is set as the prior art, which may specifically refer to related technical documents, and is not described herein again. The principle is only briefly described here.

Fig. 5 is a schematic diagram of a breakpoint detection system of a gigabit passive optical network according to an embodiment of the present invention. Referring to fig. 5, it is assumed that there is a 10km length of optical fiber between the optical module of the optical time domain detector and the optical splitter, the distance between the optical splitter and the ONU1 is 1km, the distance between the optical splitter and the ONU2 is 2km, and the distance between the optical splitter and the ONU3 is 10km, but an optical fiber break occurs at 7 km.

When the breakpoint detection is performed (communication service can be normally performed), the laser transmitter 402 of the optical module of the optical time domain detector transmits an optical signal with a wavelength of 1625nm to the laser transmitting interface of the optical path component 401, the laser transmitting interface outputs the received optical signal with the wavelength of 1625nm to the downlink optical fiber interface, and output to the optical splitter through the downlink optical fiber interface, output respectively after being subjected to optical splitting processing by the optical splitter, when the optical signal with the wavelength of 1625nm is transmitted to the position, with the distance of 7km, between the optical splitter and the ONU3, the optical fiber is broken, the broken position reflects the optical signal with the wavelength of 1625nm, the optical signal is reflected back to the optical splitter by the optical fiber, the optical splitter is subjected to reflux treatment, transmitting to optical time domain detector optical module, receiving optical signal by optical fiber interface at down link of optical time domain detector optical module, determining that the received optical signal is an optical signal with a wavelength of 1625nm, outputting the optical signal to a laser receiving interface, and outputting the optical signal to the laser detector 403 through the laser receiving interface;

the laser detector 403 converts the received optical signal into an electrical signal, and the electrical signal is sampled by the electrical signal sampling circuit 404 into a digital signal and stored in the breakpoint detection module 405.

Fig. 6 is a schematic diagram of waveforms of digital signals stored in the breakpoint detection module. Referring to fig. 6, the abscissa is time, the ordinate is received optical power (dbm), and assuming that after the optical module emits light, the reflection peaks of the optical signals are received at time points T1 to T4, respectively, the distance between each reflection light and the optical line termination optical module is calculated according to the following formula:

in the formula,

c=3×10⁸m/s is the speed of light;

n is the refractive index of the fiber core;

d is the calculated value, namely the distance from the optical line terminal optical module at the reflected light.

Fig. 7 is a schematic diagram of the digital signal waveform and the distance calculated based on fig. 6. Referring to fig. 7, the abscissa is the distance from the optical line terminal optical module at the reflected light, and the ordinate is the received optical power (dbm), as can be seen from the signal waveform shown in fig. 7, at a distance of 10km from the optical time domain detector optical module, a fresnel reflection peak is detected due to reflection of the optical splitter, at a distance of 11km from the optical time domain detector optical module, a reflection peak of ONU1 is detected, at a distance of 12km from the optical time domain detector optical module, a reflection peak of ONU2 is detected, and at a distance of 17km from the optical time domain detector optical module, a reflection peak at the reflected light (at a broken optical fiber) is detected.

Comparing the system layout, namely the signal waveform of the normal condition, namely the result obtained by analyzing the pre-obtained sampling without the break point: at a distance of 10km from the optical time domain detector optical module, a reflection peak is detected due to reflection of the optical splitter, at a distance of 11km from the optical time domain detector optical module, a reflection peak of an ONU1 is detected due to reflection of an ONU1, at a distance of 12km from the optical time domain detector optical module, a reflection peak of an ONU2 is detected due to reflection of an ONU2, and at a distance of 20km from the optical time domain detector optical module, a reflection peak of an ONU3 is detected due to reflection of an ONU 3.

From this, it can be determined that since the signal waveform shown in fig. 7 does not include the reflection peak of ONU3, a breakpoint is present in the link from the optical splitter to ONU3, and the breakpoint is located 17km away from the optical time domain detector optical module.

Wherein,

the optical path component 401 includes: a Wavelength Division Multiplexer (WDM) 411 and a circulator 412, wherein,

WDM411 has three interfaces, respectively a common interface (COM interface), a transmissive interface (Pass interface) and a reflective interface (reflector interface). The COM interface of the WDM411 is used as a downlink optical fiber interface access optical fiber of the optical path component 401, the Pass interface of the WDM411 is used as an uplink optical fiber interface access optical fiber of the optical path component 401, and the Reflect interface of the WDM411 is connected with the circulator 412;

WDM411 that receives an optical signal of a first wavelength output by OLT301 through an optical fiber via an uplink optical fiber interface, transmits the optical signal to the optical fiber via a downlink optical fiber interface, and transmits the optical signal to optical splitter 302; receiving an optical signal of a second wavelength output by the ONU304 through an optical fiber through the downlink optical fiber interface, transmitting the optical signal to the optical fiber through the uplink optical fiber interface, and transmitting the optical signal to the OLT 301;

receiving the optical signal with the third wavelength output by the circulator 412 through the Reflect interface, outputting the optical signal to the downlink optical fiber interface, and outputting the optical signal by the downlink optical fiber interface; receiving the reflected optical signal with the third wavelength through the downlink optical fiber interface, outputting the optical signal to the reflector interface, and outputting the optical signal to the circulator 412 through the reflector interface;

in the embodiment of the invention, in order to perform optical path coupling on 1490nm downlink light, 1310nm uplink light and 1625nm optical wave, WDM is introduced to realize the function. The downlink optical fiber interface of the WDM411 receives the optical signal with the second wavelength and the optical signal with the third wavelength, and a detailed processing flow of wavelength division multiplexing is performed, which may be specifically referred to in related art documents and is not described herein again.

The circulator 412 has three interfaces, which are a first interface, a second interface, and a third interface;

a second interface of circulator 412 is connected to the Reflect interface of WDM 411; for example, the second interface of circulator 412 and the Reflect interface of WDM411 may be connected by fiber, or the two interfaces may be in direct communication.

A first interface and a third interface of the circulator 412 are respectively used as a laser emitting interface and a laser receiving interface of the optical path component 401;

a circulator 412, configured to receive the optical signal of the third wavelength transmitted by the laser transmitter 402 through the laser transmission interface, and output the optical signal to the reflection interface of the WDM411 through the second interface; the reflected optical signal of the third wavelength output by the reflection interface of WDM411 is received by the second interface and output to laser detector 403 by the laser receiving interface.

In the embodiment of the present invention, the circulator 412 is used to separate the emitted light from the reflected light, i.e. 1625nm laser emitted by the laser emitter 402 is input through the first interface and output through the second interface; the 1625nm probe light (reflected light) input from the second interface is output from the third interface and sent to the laser detector 403.

An optical signal of a third wavelength emitted by the laser emitter 402 enters the circulator 412 of the optical path component 401 through the first interface (first interface) of the circulator 412 and exits from the second interface of the circulator 412; the optical signal of the third wavelength reflected from the optical fiber enters the optical path component 401 through the COM interface of the WDM411 and is output to the circulator 412 from the Reflect interface of the WDM411, and after receiving the optical signal of the third wavelength reflected from the Reflect interface of the WDM411, the second interface of the circulator 412 enters the optical fiber through the third interface of the circulator 412 and is transmitted to the laser detector 403.

Preferably, since the intensity of the reflected light is small, in order to avoid the influence of the system-level stray wavelength on the sensitivity of the OTDR, the optical path component 401 may further include an optical filter 413 disposed between the third interface of the circulator 412 and the laser detector 403, and by adding an optical filter before the laser detector 403, the optical wavelength of 1625nm is increased, and the optical wavelength below 1610nm is blocked.

In this embodiment of the present invention, the optical filter 413 is a third wavelength optical signal transmission increasing plate, and is configured to increase the transmission of the third wavelength optical signal output from the third interface of the circulator 412 and isolate the stray wavelength in the system.

In practical applications, in order to implement the above functions, the COM interface of the WDM411 is an interface capable of transmitting a full-band optical signal, the Pass interface thereof is an interface capable of transmitting optical signals of the first and second wavelengths, and the reflection interface thereof is an interface capable of reflecting optical signals of the third wavelength. For example, the first wavelength is 1490 nm; the second wavelength is 1310 nm; and the third wavelength is 1625nm, the Pass interface is designed to transmit the optical signals with the wavelength less than 1580nm, and the Reflect interface is designed to Reflect the optical signals with the wavelength more than 1610 nm. Specific specifications for WDM411 are shown in table 1 below:

TABLE 1

In Table 1, Pass- > Com indicates that the light wave enters from the PASS port and exits from the COM port; both directions can be achieved by indicating that the light wave can enter from the PASS port and exit from the COM port, and can also enter from the COM port and exit from the PASS port.

The insertion loss is required to be as small as possible so as to reduce the loss of the system to the minimum; the isolation requirement is as high as possible to reduce crosstalk and improve the sensitivity of the system.

The laser transmitter 402 includes: a laser emitting unit, and a driving circuit unit (not shown in the drawings), wherein,

In the embodiment of the present invention, the Laser emission unit may specifically be a 1625nm distributed FeedBack Laser (DFB) emission light source, and converts the optical pulse signal into a burst emission optical signal.

In practical applications, the laser transmitter 402 may further include:

The laser detector 403 includes: a photodiode and a transimpedance Amplifier (TIA) (not shown), wherein,

the TIA is configured to receive the response current, and output a corresponding differential electrical signal to the electrical signal sampling circuit 404 according to the received response current.

In the embodiment of the present invention, the photodiode may be an Avalanche Photodiode (APD) in the optical module.

The electrical signal sampling circuit 404 includes: analog to digital converter (ADC) circuit,

and the ADC circuit is configured to sample the electrical signal output by the laser detector 403, and send a digital signal obtained by sampling to the breakpoint detection module 405 for storage.

In the embodiment of the present invention, preferably, the electrical signal sampling circuit 404 may further include an amplifying circuit, where the amplifying circuit is disposed between the laser detector 403 and the ADC circuit, and amplifies the electrical signal output by the laser detector 403, so that the ADC circuit samples the electrical signal amplified by the amplifying circuit, and sends a digital signal obtained by sampling to the breakpoint detection module 405 for storage.

The breakpoint detection module 405 includes: a detection signal storage unit, a comparison unit, a normal operation signal storage unit, and a breakpoint position determination unit (not shown in the drawings), wherein,

In the embodiment of the present invention, the breakpoint position determining unit may be further configured to output the determined position information of the breakpoint or the fault point to a preset external device.

In practical applications, the breakpoint detection module 405 may be specifically implemented by a Logic Array circuit, for example, a Field Programmable Gate Array (FPGA) circuit, a Programmable Array Logic (PAL) circuit, and the like; or, it can be realized by a computing chip such as a single chip, a processor, a microcontroller, etc. That is, the breakpoint detection module 405 may be an FPGA, a PAL, a single chip, a processor, or a microcontroller.

When breakpoint detection is performed, the FPGA is installed in a Flash memory (Flash) program, and sends a pulse signal (indicated by a dotted line in fig. 4) for breakpoint detection to the driving circuit unit, and the driving circuit unit drives the laser emission unit to convert an electric pulse signal sent by the FPGA into an optical pulse signal of 1625 nm; the optical signal reflected back in the system is converted into a current signal through photoelectric conversion of an APD detector, then is converted into a digital signal through a trans-impedance Amplifier (TIA) and processed by an operational Amplifier, and then is input into an ADC circuit, the analog signal is converted into the digital signal and then is transmitted to an FPGA, and the FPGA analyzes and calculates the received digital signal to determine the breakpoint position.

In practical application, the electrical interface of the optical module 303 of the optical time domain detector may adopt a 10pin structure of a Joint Test Action Group (JTAG) interface, where 4 pins are respectively used for I²SDA, I of C data²SCL of C clock, GND for grounding wire and VCC for providing power supply, in addition 6pin is used for debugging circuit, and communicates with external system analysis equipment through JTAG interface, and system passes through I²The data of the FPGA is read in a C bus communication mode, so that the optical fiber breakpoint is determinedLocation.

Specifically, the method comprises the following steps:

in the GPON system, a 1490nm DFB laser located in the GPON OLT is used as a downlink light source to transmit a continuous 2.488Gbps signal, and a 1310nm APD detector located in the GPON OLT receives an upstream burst optical packet transmitted from an ONU to receive data.

When an OTDR optical module (optical time domain detector optical module) is connected into a system in series, a built-in 1625nm DFB laser transmits a series of burst laser, when the burst laser passes through a breakpoint in an optical fiber link, a part of return loss light is reflected back to an optical fiber due to Rayleigh scattering and Fresnel reflection, and then the return loss light returns to a built-in 1625nm APD detector in the optical time domain detector optical module. The APD detector of 1625nm receives the reflected light, forms a current signal through photoelectric conversion, and then transmits the current signal to the FPGA as a digital signal through operational amplifier processing and ADC sampling. The FPGA compares the received signal with the signal stored in the Flash under the normal condition to find the position of the breakpoint, namely the position corresponding to the peak value is the position of the breakpoint relative to the excessive signal peak value under the normal signal, and the signal I is used for comparing the received signal with the signal stored in the Flash under the normal condition to find the position of the breakpoint²And the C bus reads the data of the FPGA to know the position of the breakpoint.

As can be seen from the above description, in the gigabit passive optical network breakpoint detection system according to the embodiment of the present invention, the optical time domain detector optical module is connected in series between the OLT and the optical splitter in the gigabit passive optical network breakpoint detection system, and the optical time domain detector optical module can transmit communication optical signals (optical signals of the first wavelength and optical signals of the second wavelength), emit a breakpoint detection optical signal (optical signal of the third wavelength), perform breakpoint detection according to the reflected optical signal of the third wavelength, and determine a breakpoint position. When the breakpoint detection is carried out, the OLT in the existing GPON system does not need to be disconnected, so that the normal communication signals in the passive optical network are not influenced, the breakpoint detection flow is simplified, and the normal transmission of the network signals of the system is ensured; furthermore, in the breakpoint analysis of the optical module of the optical time domain detector, the device of the optical time domain reflectometer can be omitted, the circuit cost is lower, and compared with the traditional optical time domain reflectometer, the optical time domain reflectometer has the advantages of low price, simple operation, easy maintenance and the like, thereby realizing the breakpoint detection of the passive optical network system with low cost; in addition, the frequent plugging of the OLT is reduced and the working reliability of the OLT is improved because the frequent operations of disconnecting the OLT and plugging the OLT are not required.

Those skilled in the art will appreciate that all or part of the steps in the method for implementing the above embodiments may be implemented by relevant hardware instructed by a program, and the program may be stored in a computer readable storage medium, such as: ROM/RAM, magnetic disk, optical disk, etc.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that those skilled in the art can make various improvements and modifications without departing from the principle of the present invention, and these improvements and modifications should also be construed as the protection scope of the present invention.

Claims

1. An optical time domain detector optical module, comprising: light path component, laser emitter, laser detector, breakpoint detection module and electric signal sampling circuit,

2. The optical time domain detector optical module of claim 1,

3. The optical time domain detector optical module of claim 2, wherein the electrical signal sampling circuit is further configured to amplify and filter the received electrical signal after receiving the electrical signal output by the laser detector.

4. The optical time domain detector optical module of any one of claims 1 to 3, wherein the optical path assembly comprises: a wavelength division multiplexer, and a circulator, wherein,

5. The optical time domain detector optical module of claim 4, wherein the optical path assembly further comprises an optical filter disposed between the laser receiving interface of the circulator and the laser detector, the optical filter for anti-reflection of the optical signal of the third wavelength output from the laser receiving interface of the circulator.

6. The optical time domain detector optical module of claim 5, wherein the laser transmitter comprises: a laser emitting unit and a driving circuit unit, wherein,

7. The optical time domain detector optical module of claim 6, wherein the laser transmitter further comprises:

8. The optical time domain detector optical module of claim 6, wherein the laser emitting unit is a 1625nm distributed feedback laser emitting light source.

9. The optical time domain detector optical module of claim 8, wherein the laser detector comprises: a photodiode and a transimpedance amplifier TIA, wherein,

10. The optical time domain detector optical module of claim 9, wherein said photodiode is an avalanche photodiode.

11. The optical time domain detector optical module of claim 9, wherein the electrical signal sampling circuit comprises:

12. The optical time domain detector optical module of claim 11, wherein the electrical signal sampling circuit further comprises an amplifying circuit, and the amplifying circuit is disposed between the laser detector and the ADC circuit to amplify the electrical signal output by the laser detector.

13. The optical time domain detector optical module of claim 4, wherein the breakpoint detection module comprises: a detection signal storage unit, a comparison unit, a normal operation signal storage unit and a breakpoint position determination unit, wherein,

14. The optical time domain detector optical module of claim 13, wherein the breakpoint detection module is a field programmable gate array, a programmable array logic, a single chip, a processor, or a microcontroller.

15. A gigabit passive optical network breakpoint detection system, the system comprising: the optical line terminal OLT comprises an optical splitter and an optical network unit ONU, wherein the OLT transmits an optical signal with a first wavelength and receives an optical signal with a second wavelength transmitted by the ONU; characterized in that, the gigabit passive optical network breakpoint detection system further comprises: an optical time domain detector optical module is arranged,

16. The system of claim 15, wherein the optical time domain detector optical module comprises: light path component, laser emitter, laser detector, breakpoint detection module and electric signal sampling circuit,

17. The system of claim 16,

18. The system of any of claims 16 to 17, wherein the optical path component comprises: a wavelength division multiplexer, and a circulator, wherein,

19. The system of claim 18, wherein the optical path assembly further comprises an optical filter disposed between the laser receiving interface of the circulator and the laser detector, the optical filter for anti-reflection of the optical signal at the third wavelength output from the laser receiving interface of the circulator.

20. The system of claim 19, wherein the laser transmitter comprises: a laser emitting unit and a driving circuit unit, wherein,

21. The system of claim 20, wherein the laser transmitter further comprises:

22. The system of claim 21, wherein the laser detector comprises: a photodiode and a transimpedance amplifier TIA, wherein,

23. The system of claim 22, wherein the electrical signal sampling circuit comprises:

24. The system of claim 23, wherein the breakpoint detection module comprises: a detection signal storage unit, a comparison unit, a normal operation signal storage unit and a breakpoint position determination unit, wherein,