CN203193637U

CN203193637U - OTDR control circuit of OLT optical module

Info

Publication number: CN203193637U
Application number: CN 201320233074
Authority: CN
Inventors: 谢怀堂; 杨进松
Original assignee: Shenzhen Neo Photonic Technology Co Ltd
Current assignee: Shenzhen Apat Opto Electronics Components Co ltd
Priority date: 2013-05-02
Filing date: 2013-05-02
Publication date: 2013-09-11
Anticipated expiration: 2023-05-02

Abstract

The utility model provides an OTDR control circuit of an OLT optical module. The OTDR control circuit comprises an OLT optical assembly, an uplink optical signal strength unit, a module microprocessor, an OTDR control processing unit and a power switch. The assembly comprises a light emitting device emitting a downlink-to-ONU optical signal lambda 1 and an OTDR fault detection signal lambda 1', a first optical receiver receiving uplink optical signals lambda 2 from an ONU, and a second optical receiver receiving a reflected OTDR fault detection signal lambda 1" from a network fault point. An input end of the uplink optical signal strength unit is connected with the first optical receiver, and an output end of the uplink optical signal strength unit is connected with an input end of the module microprocessor. The OTDR control processing unit comprises an OTDR signal generator connected with the light emitting device, and an OTDR signal microprocessor with an input end connected with the second optical receiver. An output end of the power switch is connected with a power supply of the second optical receiver. Because the OLT module has low power consumption when a network is normal, and the power consumption of the OLT module is only increased by small power consumption produced by the OTDR function module when a fault occurs in the network, working stability of the OLT optical module cannot be affected.

Description

A kind of OTDR control circuit of OLT optical module

Technical field

The utility model relates to a kind of OLT optical module of PON passive optical network, relates in particular to a kind of OTDR control circuit of OLT optical module.

Background technology

Along with popularizing and large-scale application of Fibre Optical Communication Technology, the maintenance of fiber optic network becomes a problem.Particularly develop rapidly, expand at PON (Passive Optical Network is called for short PON) network, when forming large-scale application gradually, the maintenance issues of optical fiber cable comes out gradually, and has become one of main problem of restriction industry development.If optical fiber fractures, at first the breakpoint location determination of optical fiber is exactly the thing that bothers very much.Need send the technical staff to the scene, take hand-hold type optical time domain reflectometer OTDR(Optical Time-Domain Reflectometer, hereinafter to be referred as OTDR), this equipment is the equipment that can effectively judge fiber failure point up to now, launch light pulse in optical fiber by equipment itself during work, the echo information that receives according to the OTDR port is come localization of faults distance then.When light pulse is transmitted, if occurred discontinuity point on the optical fiber transport channel, will produce reflection, scattered light signal in optical fiber.Wherein Yi Bufen reflection, scattered light will turn back to the pick-up probe of OTDR equipment.The useful information that returns is exactly the corresponding transmission time on the interior diverse location of optical fiber.Transmit signals to the used time of fiber failure point inverse signal from test point, according to the transmission speed of light in glass medium, just can calculate the fault point distance again, thereby the fiber failure point is effectively located.Because hand-hold type OTDR equipment, expensive, have at present the OTDR functional module is integrated in the OLT optical module, yet such OLT optical module carrying out the shortcoming that fiber failure when test exist is: the OTDR detection signal that module is emitted to the fault point can produce the interference of light with the OTDR detection signal that fault point reflection, scattering are returned, thereby influences the OTDR detection performance of OLT optical module.For this reason, Chinese patent application number: 201210337938.3, patent name: a kind of method of improving optical fiber OTDR test performance, the OLT optical module that discloses a kind of integrated OTDR function in this patent documentation solves aforesaid drawbacks, namely by in the module laser, increasing by a heater block, when network breaks down, the heater block heating, the people raises the temperature of laser, impel its wavelength to fluctuate, reduce the interference of light that OTDR sensed light signal that the OTDR sensed light signal of launching and reflection or scattering return produces between the two with this, thereby improve the detectability of OTDR network failure.The defective that this patented method exists: when the OLT optical module starts the OTDR measuring ability, owing to increased a heater block, at this moment whole OLT optical module power consumption is except normal module operation power consumption, also can increase two-part power consumption: the power consumption that OTDR functional module power consumption and heater block produce, whole OLT optical module power consumption increased suddenly when network failure took place, and can cause the job insecurity of whole OLT optical module.

Summary of the invention

For overcoming above shortcoming, the utility model provides a kind of OTDR control circuit of OLT optical module of good stability.

For realizing above goal of the invention, the invention provides a kind of OTDR control circuit of OLT optical module, comprising: an OLT optical assembly, this assembly comprises: light emitting devices emission one comes downwards to ONU light signal λ 1 and OTDR fault detection signal λ 1 '; One first optical receiver receives from ONU uplink optical signal λ 2; The described OTDR fault detection signal λ 1 ' that the reception of one second optical receiver is returned from the network failure point reflection; The input of one uplink optical signal intensity detection is connected with described first optical receiver, and its output connects the input of a module microprocessor; One OTDR controlled processing unit, this unit comprises: an OTDR signal generator connects described light emitting devices, and the input of an OTDR signal microprocessor connects described second optical receiver; Also comprise a mains switch, its output connects the power supply of described second optical receiver.

The output of described module microprocessor connects described mains switch input and is switched on or switched off to control it.

The input of described OTDR signal microprocessor is connected with the output of described module microprocessor, and the output of described OTDR signal microprocessor connects described mains switch input and is switched on or switched off to control it.

The OTDR control circuit of above-mentioned OLT optical module, be provided with a mains switch owing to be used for second optical receiver of reception OTDR fault detection signal, optical-fiber network just often, the light emitting devices emission comes downwards to ONU light signal λ 1 and OTDR fault detection signal λ 1 ', first optical receiver receives from ONU uplink optical signal λ 2, it is normal that uplink signal strength detects the signal that exports module microprocessor to, no signal out-put supply switch, and second optical receiver is not worked.When optical fiber link breaks down, because uplink signal strength detects the weak output signal that exports module microprocessor to, module microprocessor makes mains switch connect the power supply of second optical receiver, to carry out the OTDR test, after second optical receiver is started working, conduct heat to the laser in the light emitting devices, temperature raises the OTDR fault detection signal λ 1 ' wavelength of back laser LD output with respect to the OTDR fault detection signal λ 1 that returns from fault point reflection or scattering " wavelength is different; reduce the interference of light between the OTDR signal that sends out and also return with this, thereby improve the job stability of OLT optical module greatly.Just often the OLT module dissipation is little owing to network, and when network broke down, the power consumption of OLT module only can increase the small power consumption that the OTDR functional block produces, and therefore can not influence the job stability of whole OLT optical module.

Description of drawings

Fig. 1 represents OTDR control circuit first embodiment of a kind of OLT optical module of the present utility model;

Fig. 2 represents OTDR control circuit second embodiment of a kind of OLT optical module of the present utility model.

Embodiment

Describe the utility model most preferred embodiment in detail below in conjunction with accompanying drawing.

The OTDR control circuit of OLT optical module as shown in Figure 1 comprises: an OLT optical assembly 10, and this assembly comprises: a light emitting devices 11 emissions one come downwards to ONU light signal λ 1 and OTDR fault detection signal λ 1 '; One first optical receiver 12 receives from ONU uplink optical signal λ 2; The described OTDR fault detection signal λ 1 that 13 receptions of one second optical receiver are returned from the network failure point reflection ".The input of one uplink optical signal intensity detection 20 is connected with described first optical receiver 12, and its output connects the input of a module microprocessor 30; One OTDR controlled processing unit 40, this unit comprises: the input that an OTDR signal generator 41 connects described light emitting devices 11, one OTDR signal microprocessors 42 connects described second optical receiver 13.Also comprise a mains switch 50, its output connects the power supply of described second optical receiver 13, and the input that the output of module microprocessor 30 connects mains switch 50 is switched on or switched off to control it.

The operation principle of foregoing circuit: optical-fiber network just often, light emitting devices 11 emission downlink optical signal λ 1 export the ONU reception through the WDM device transmission of OLT optical assembly 10 to by single fiber, be converted to uplink electrical signals output by single fiber input back by 12 receptions of first optical receiver from ONU uplink optical signal λ 2, the signal that uplink optical signal intensity detection 20 inputs to module microprocessor 30 is normal, and module microprocessor 30 did not start the power supply that mains switch 50 connects second optical receiver 13 and made it be in closed condition this moment.When optical fiber link breaks down, the light signal λ 2 that uplink optical signal intensity detection 20 detects 12 receptions of first optical receiver is faint, this moment, module microprocessor 30 will make mains switch 50 connect the power supply of second optical receiver 13, OTDR controlled processing unit 40 is started working, carry out the OTDR functional test.Second optical receiver, 13 power supply openings, because conduction of heat, laser temperature in the light emitting devices raises, the OTDR fault detection signal λ 1 ' wavelength of laser LD output is with respect to the OTDR fault detection signal λ 1 that returns from fault point reflection or scattering " wavelength different, reduced the interference of light between the OTDR signal that sends out and also return with this.Just often the OLT module dissipation is little owing to network, and when network broke down, the power consumption of OLT module only can increase the small power consumption that the OTDR functional block produces, and therefore can not influence the job stability of whole OLT optical module.

The OTDR control circuit of OLT optical module as shown in Figure 2 comprises: an OLT optical assembly 10, and this assembly comprises: a light emitting devices 11 emissions one come downwards to ONU light signal λ 1 and OTDR fault detection signal λ 1 '; One first optical receiver 12 receives from ONU uplink optical signal λ 2; One second optical receiver 13 is used for the described fault detection signal λ 1 that reception is returned from the network failure point reflection ".The input of one uplink optical signal intensity detection 20 is connected with described first optical receiver 12, and its output connects the input of a module microprocessor 30; One OTDR controlled processing unit 40, this unit comprises: the input that an OTDR signal generator 41 connects described light emitting devices 11, one OTDR signal microprocessors 42 connects the output of described second optical receiver 13 and module microprocessor 30.Also comprise a mains switch 50, its output connects the power supply of described second optical receiver 13, and the input that the output of OTDR signal microprocessor 42 connects mains switch 50 is switched on or switched off to control it.The difference of the operation principle of second embodiment and first embodiment: the mains switch 50 in first embodiment is directly to be switched on or switched off by module microprocessor 30 controls, and the mains switch 50 among second embodiment is to be switched on or switched off by 42 controls of OTDR signal microprocessor by module microprocessor 30.Other parts are identical.

Claims

1. the OTDR control circuit of an OLT optical module comprises: an OLT optical assembly, and this assembly comprises: light emitting devices emission one comes downwards to ONU light signal λ 1 and OTDR fault detection signal λ 1 '; One first optical receiver receives from ONU uplink optical signal λ 2; The described OTDR fault detection signal λ 1 ' that the reception of one second optical receiver is returned from the network failure point reflection; The input of one uplink optical signal intensity detection is connected with described first optical receiver, and its output connects the input of a module microprocessor; One OTDR controlled processing unit, this unit comprises: an OTDR signal generator connects described light emitting devices, and the input of an OTDR signal microprocessor connects described second optical receiver; It is characterized in that also comprise a mains switch, its output connects the power supply of described second optical receiver.

2. the OTDR control circuit of a kind of OLT optical module according to claim 1 is characterized in that, the output of described module microprocessor connects described mains switch input and is switched on or switched off to control it.

3. the OTDR control circuit of a kind of OLT optical module according to claim 1, it is characterized in that, the input of described OTDR signal microprocessor is connected with the output of described module microprocessor, and the output of described OTDR signal microprocessor connects described mains switch input and is switched on or switched off to control it.