CN210327578U - Different-wavelength single-fiber bidirectional optical module capable of integrating OTDR function - Google Patents

Abstract

A single-fiber bidirectional optical module with different wavelengths capable of integrating OTDR function. The optical module comprises an optical transmitter (20), a three-way device (30), a small-angle filter (401), an optical receiver (50), an OTDR detection interface (61), a control unit (60) and a PCB (printed Circuit Board), wherein the optical transmitter, the three-way device (30), the small-angle filter (401) and the optical receiver are sequentially connected, the band-pass wavelength range of the small-angle filter (401) isolates a downlink optical signal lambda of a first wavelength₁And through the upstream optical signal of the second wavelengthNumber lambda₂The optical circulator (30') is matched with the small-angle filter (401) to use, so that the defect that the uplink and downlink wavelength interval is overlarge when the traditional single-fiber bidirectional optical module is in bidirectional communication can be overcome. And simultaneously, the utility model discloses in integrating the two-way optical module of single fiber with OTDR, the OTDR detection method who adopts makes the optical module switch in two-way communication mode and OTDR detection mode, compares in like product, both can carry out normal communication service, can carry out the optical fiber link in needs and detect, is applicable to the occasion of supervisory channel in the trunk communication very much.

Description

Different-wavelength single-fiber bidirectional optical module capable of integrating OTDR function

Technical Field

The application relates to the field of optical fiber communication, in particular to a different-wavelength single-fiber bidirectional optical module capable of integrating OTDR function and an OTDR detection method thereof.

Background

With the continuous development of optical fiber communication technology, the complexity of an optical fiber network is increased day by day, and in order to ensure the smoothness and stability of an optical communication line, the daily management and maintenance work of the optical fiber line are indispensable. When a break point or other faults occur in an Optical fiber line, because the distance between an Optical fiber and another node is often long, detection and positioning of the fault point are often completed by means of Optical Time Domain Reflection (OTDR).

At present, most single-fiber bidirectional optical modules adopt different-wavelength technology, but the optical modules do not have OTDR function, and when the OTDR is needed to be used for detecting optical fiber lines, switching to external professional OTDR equipment is often needed. Because the cost of the equipment used by the external OTDR is high, the line structure is complex when the device is used, and the fault can not be judged and positioned in the shortest time of fault occurrence, thereby prolonging the time required by maintenance and fault removal and influencing the normal communication.

The optical module with OTDR function usually requires that the wavelength of the optical signal emitted from the laser emitter is completely consistent with the wavelength of the optical signal entering the optical receiving end 33, so that the optical signal reflected by the optical fiber can be received by the optical receiving end 33 and processed. However, due to crosstalk between the optical transmitter and the receiving end 33, when the optical path implementing the OTDR function transmits the communication optical signal, the sensitivity performance of the receiving end 33 is greatly reduced, which is not favorable for implementing long-distance optical fiber communication.

SUMMERY OF THE UTILITY MODEL

In view of the foregoing problems, a primary object of the present invention is to provide a single-fiber bidirectional optical module with different wavelengths, which can integrate an OTDR function, and can implement the OTDR function on the basis of ensuring a normal single-fiber bidirectional communication function with different wavelengths.

The secondary objective of the present application is to provide a different-wavelength single-fiber bidirectional optical module, which reduces the wavelength interval of uplink and downlink optical signals by improving the optical structure.

Another object of the present application is to provide an OTDR detection method applied to a single-fiber bidirectional optical module with different wavelengths, which has the advantages of performing both communication service and optical fiber link detection.

The first embodiment of the present application provides a dual-wavelength single-fiber bidirectional optical module capable of integrating OTDR function, which comprises an optical transmitter, a three-way device, a filter device and an optical receiver connected in sequence,

in the bidirectional communication mode, the optical transmitter is used for transmitting a downlink optical signal lambda of a first wavelength₁(ii) a The optical receiver is used for receiving an uplink optical signal lambda of a second wavelength₂(ii) a The band-pass wavelength range of the filter device isolates the optical signal λ of the first wavelength₁And passing an optical signal λ of said second wavelength₂；

The three ports of the three-way device are respectively a transmitting end, a public end and a receiving end, the transmitting end is connected with the optical transmitter, the public end is connected with an optical fiber socket, and the optical fiber socket is connected with an optical network port; the receiving end of the optical receiver is connected with the optical transmitter so that the downstream optical signal lambda of the first wavelength emitted from the optical transmitter₁Transmitting the upstream optical signal λ of the second wavelength from the optical network port into the optical network through the optical fiber jack of the common port₂The light is transmitted from the public end to the receiving end through the three-way device, and is received by the light receiver after passing through the filter device.

Further, in the first embodiment of the present application, in the different-wavelength single-fiber bidirectional optical module capable of integrating the OTDR function, in the OTDR detection mode, the optical transmitter is configured to transmit an OTDR detection optical signal; the band-pass wavelength range of the filter device detects the optical signal through the OTDR; the OTDR detection optical signal emitted from the optical emitter is transmitted into a public end through the emitting end of the three-way device and sent to an optical network port, and an OTDR feedback optical signal with the same wavelength as the OTDR detection optical signal from the optical network port is emitted from the receiving end of the three-way device after passing through the three-way device from the public end and reaches the optical receiver after passing through the filter device; the optical receiver is used for receiving the OTDR feedback optical signal.

The further improvement of the different-wavelength single-fiber bidirectional optical module capable of integrating OTDR function in the first embodiment of the present application further includes: the filter device is a small-angle filter, and the included angle between the small-angle filter and the vertical surface of the emergent light path of the receiving end is 0-15 degrees, preferably 0 degree.

Further, in the OTDR detection mode, the optical transmitter transmits an uplink optical signal λ having the second wavelength according to the first wavelength, and the optical transmitter transmits an uplink optical signal λ having the second wavelength according to the second wavelength₂The OTDRs of the same wavelength detect the optical signal.

Further, in the different-wavelength single-fiber bidirectional optical module capable of integrating the OTDR function, the filter device is a tunable filter having a tunable bandpass wavelength range.

A second embodiment of the present application provides a hetero-wavelength single-fiber bidirectional optical module capable of integrating OTDR functions, wherein, in OTDR detection mode,

the optical transmitter transmits an upstream optical signal lambda of the second wavelength₂OTDR detecting optical signals with different wavelengths;

the bandpass wavelength range of the tunable filter is tuned to transmit the OTDR detection optical signal and isolate the optical signal λ of the second wavelength₂。

In a second embodiment of the present application, in the different-wavelength single-fiber bidirectional optical module capable of integrating OTDR function, a further improvement is that the optical transmitter transmits a downlink optical signal wavelength λ corresponding to the first wavelength₁The same OTDR detects the optical signal.

Further, in the heterowavelength single-fiber bidirectional optical module capable of integrating the OTDR function of the present application, the three-way device is an optical circulator.

Further, in the single-fiber bidirectional optical module with different wavelengths capable of integrating OTDR function of the present application, the optical signal λ of the first wavelength₁And a secondOptical signal λ of wavelength₂The wavelength difference of (2) is less than or equal to 8 nm.

The application further improves the different-wavelength single-fiber bidirectional optical module capable of integrating the OTDR function: the light emitter adopts a laser with adjustable wavelength; in the bidirectional communication mode, the laser is used for emitting a downlink optical signal lambda of a first wavelength₁(ii) a In the OTDR detection mode, the wavelength of the pulsed laser is adjusted such that the optical transmitter emits an OTDR feedback optical signal.

Furthermore, the different-wavelength single-fiber bidirectional optical module capable of integrating the OTDR function also comprises an OTDR detection interface and a control unit,

the OTDR detection interface is connected with a board card of an optical communication system;

after receiving the OTDR feedback optical signal, the optical receiver converts the optical signal into an electrical signal;

the control unit is connected to the OTDR detection interface, the optical receiver, and the optical transmitter, and configured to send a control command to the optical transmitter and/or the tunable filter according to an OTDR detection command received from the OTDR detection interface, process the electrical signal of the optical receiver, and send the processed data to the board card of the optical communication system through the OTDR detection interface.

According to the technical scheme, the optical structure of the single-fiber bidirectional optical module is improved, the wavelength interval of uplink and downlink optical signals is reduced, the purpose of integrating the OTDR function into the optical module is achieved, meanwhile, the optical module can carry out communication service and detection of an optical fiber link, and the optical module is very suitable for occasions of monitoring channels in trunk communication; and the OTDR signal and the optical signal for normal data communication are separated from each other by a filter device such as a 0-degree filter without mutual influence.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments described in the embodiments of the present application, and other drawings can be obtained by those skilled in the art according to the drawings.

Fig. 1 is a schematic diagram of a single-fiber bidirectional optical module with different wavelengths in the prior art.

Fig. 2 is a schematic diagram of an operating principle of an optical module integrated with an OTDR function in an embodiment of the present invention;

fig. 3 is a schematic diagram of the operation of the optical circulator 30' according to the embodiment of the present invention;

fig. 4 is a schematic diagram illustrating an optical module operating in a digital signal communication mode according to a first embodiment of the present invention;

fig. 5 is a schematic diagram illustrating an optical module operating in an OTDR mode according to a first embodiment of the present invention;

fig. 6 is a schematic diagram of an optical module operating in a digital signal communication mode according to a second embodiment of the present invention;

fig. 7 is a schematic diagram illustrating an optical module operating in an OTDR mode according to a second embodiment of the present invention;

fig. 8 is a schematic perspective view of an optical module according to another embodiment of the present invention.

Reference numerals

1 single-fiber bidirectional optical module integrated with OTDR function

20 light emitter

21 driver

22 laser

30 three-way device

30' light circulator

31 transmitting terminal

32 common terminal

33 receiving end

301 optical fiber socket

40 filter device

401 small angle filter

402 tunable filter

50 light receiver

51 Detector

52 Amplifier

53 digital-to-analog converter

60 control unit

61 OTDR detection interface

70 optical network

71 optical network port

72 board card of optical communication system

λ₁Downstream optical signals of a first wavelength

λ₂Upstream optical signals at a second wavelength

Detailed Description

In order to make those skilled in the art better understand the technical solutions in the embodiments of the present application, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, but not all embodiments. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments in the present application shall fall within the scope of the protection of the embodiments in the present application.

A common single-fiber bidirectional optical module is shown in fig. 1, and generally adopts a TO-CAN packaging form, and is composed of a single-channel transmitter 01, a single-channel receiver 02, an optical filter 03, an optical interface 04 with an integrated pin, and a round and square tube body 05. However, when the optical filter is used as a light splitting element, the requirement on position accuracy is high, the processing technology is complex, and batch production is not easy to realize; and the optical module is not suitable for the occasions of small-interval different-wavelength transceiving due to the processing technology of the optical filter. Meanwhile, such an optical module does not have an OTDR function, and when optical fiber line detection needs to be performed by using OTDR, switching to an external professional OTDR device is often required.

Please refer to fig. 2, which is a schematic diagram illustrating an operating principle of a single-fiber bidirectional optical module 1 with a different wavelength integrated with an OTDR function according to an embodiment of the present application. The optical module in this embodiment includes an optical transmitter 20, a three-way device, a small-angle filter 401, an optical receiver 50, a control unit 60 for controlling the operation of the optical module, and an optical fiber socket 301 for connecting with an optical network port 71, where a collimating lens may be disposed between the optical fiber socket 301 and a receiving end 33 of the three-way device.

The three-way device 30 includes a first port, a second port, and a third port. The first port is connected with the light emitter 20, also called as the emitting end 31; the second port is connected to an optical fiber jack 301, also called a common port 32, and the third port is connected to an optical receiver 50, also called a receiving port 33. Generally, the three-way device 30 is generally referred to as a transflective sheet or light circulator 30'. The typical transflective sheet allows 50% transmission of the incident light intensity while reflecting 50% of the incident light intensity, thus completing the three-way propagation of the optical path with 6dB (75%) of light intensity loss. The function of the transflective sheet is substantially the same as that of the optical circulator 30 ', except that the transflective sheet has about 6dB more attenuation than the optical circulator 30'. The optical circulator 30' is illustrated in the embodiment of fig. 3, but it is understood that a semi-reflective and semi-transparent plate may be used as the three-way device 30 in embodiments of the present invention.

Fig. 3 shows the working principle of the optical circulator 30 ', in the embodiment of the present invention, the optical circulator 30 ' includes three ports, i.e., a transmitting end 31, a common end 32 and a receiving end 33, and the function of the optical circulator 30 ' is to enable the transmitting end 31 to enter the downlink optical signal λ₁Upstream optical signals λ capable of being transmitted into common port 32, through optical circulator 30₂Can be transmitted into the receiving end 33 through the optical circulator 30' to complete the three-way propagation of the optical path. Moreover, if a 45-degree filter is adopted to realize the separation of the uplink and downlink optical signals, the process limitation of the 45-degree filter requires that the interval between the uplink wavelength and the downlink wavelength is larger than 40nm at present, and if small-interval different-wavelength transceiving is realized, the technology becomes stranded.

The preferred embodiment of the utility model provides a but two-way optical module of different wavelength single fiber 1 of integrated OTDR function, the structure chart is shown in fig. 2, and this optical module is including consecutive optical transmitter 20, small-size optical circulator, small-angle filter 401 and optical receiver 50 for control unit 60 of optical module work, and be used for the optical fiber socket 301 of being connected with optical network port 71. The small optical circulator has three ports, which are a transmitting end 31, a common end 32, and a receiving end 33.

In the preferred embodiment shown in fig. 2, the optical transmitter 20 comprises a driver 21 and a laser 22. The laser 22 is driven by the control unit 60 via the driver 21 to emit a downstream optical signal lambda by sending a corresponding command to the driver 21₁The laser of the laser 22 is directly opposite to the transmitting end 31 of the optical circulator, and the laser signal is emitted from the common end 32 through the optical circulator and coupled into the signal transmission optical fiber through the collimating lens.

The optical receiver 50 includes a detector 51, an amplifier 52 and an analog-to-digital converter. Upstream optical signal lambda in a signal transmitting optical fiber₂The light is transmitted from the common end 32 through the three-way device 30 through the optical network port 71 via the optical fiber socket 301, enters the common end 32 of the optical circulator through the collimating lens of the receiving end 33, is emitted from the receiving end 33, passes through the filter device 40, such as the small-angle filter 401, and is captured by the detector 51. Wherein the filter device 40, e.g. the bandpass wavelength range of the low-angle filter 401, is capable of isolating the optical signal λ of said first wavelength₁And can pass an optical signal λ of said second wavelength₂。

Specifically, the optical receiver 50 includes a photodetector 51, an amplifier 52, and an analog-to-digital converter. The detector 51 is electrically connected with the amplifier 52, the amplifier 52 is electrically connected with an analog-to-digital converter, and the analog-to-digital converter is electrically connected with the control unit 60. The detector 51 is connected with the receiving end 33 of the optical circulator, the signal light and the reflected light transmitted by the optical fiber are opposite to the common end 32, the receiving end 33 is connected with the detector 51, the signal light and the reflected light enter the optical circulator through the common end 32, are emitted from the receiving end 33, and enter the detector 51 after passing through the small-angle filter 401. In the detector 51, the optical signal is converted into an electrical signal, amplified by the amplifier 52, converted into a digital signal by the analog-to-digital converter, and transmitted to the control unit 60. Those skilled in the art can understand that, in the optical module of the present embodiment, the optical transmitter 20, the three-way device 30, the small-angle filter 401, the optical receiver 50, and the control unit 60 are integrally designed, and the three-way device 30 and the small-angle filter 401 are designed to implement transceiving of optical signals in the same optical module, so as to solve the problem of miniaturization, facilitate integration, and reduce cost. In addition, some of the control functions of the optical transmitter 20 and the optical receiver 50 may be integrated into the control unit 60 for integrated design and manufacture. Moreover, when the input signal is a digital signal, the analog-to-digital converter does not have to perform analog-to-digital conversion.

Fig. 4 is a schematic diagram of an embodiment of the optical module in the first embodiment of the present invention in the digital signal communication mode, in the first embodiment, the filter device 40 employs a small-angle filter 401, preferably a 0-degree filter, that is, the included angle between the small-angle filter 401 and the vertical plane of the emergent light path of the receiving end 33 is 0 degree. Downstream optical signal lambda of 1550nm wavelength emitted by laser 22 of optical transmitter 20₁Transmitted to the public end 32 through the transmitting end 31 of the optical circulator 30', and coupled into the optical network port 71 through the optical fiber socket 301; and an uplink optical signal λ with a wavelength of 1555nm transmitted from the communication optical fiber₂Transmitted by the optical network port 71 to its receiving end 33 via the common end 32 of the optical circulator 30', and passed through the 0 degree filter to be received and processed by the detector 51 of the optical receiver 50. In this embodiment, the bandpass wavelength range of the 0-degree filter can isolate the downstream optical signal λ of 1550nm₁And can pass through 1555nm uplink optical signal lambda₂And thus the downstream optical signal λ emitted from the laser 22 at a wavelength of 1550nm₁Is blocked by a 0-degree filter plate and cannot enter the detector 51, so that the optical module outputs a downlink optical signal lambda with the wavelength of 1550nm from the common end 32 to the communication optical fiber₁And receives upstream optical signal lambda with 1555nm wavelength from communication optical fiber by receiving terminal 33₂Detected by detector 51.

In the above embodiments of the present invention, the light emitter 20 emits1550nm wavelength downlink optical signal lambda₁Uplink optical signal lambda with 1555nm wavelength transmitted by communication optical fiber₂The wavelength difference of (3) is 5nm, and if the three-way device 30 adopts a 45-degree filter, since the current process limits that the interval between the upstream wavelength and the downstream wavelength must be larger than 40nm, in the embodiment shown in fig. 4, the optical circulator 30' as the three-way device 30 can be applied to the optical network 70 with small interval and different wavelength transceiving. It can be understood by those skilled in the art that the single-fiber bidirectional optical module 1 with different wavelengths according to the present embodiment can also be applied to the optical network 70 with a wavelength difference between the uplink and downlink wavelengths smaller than 5nm, and can also meet the optical communication requirement with a larger wavelength interval between the uplink and downlink wavelengths, such as 8nm, 12nm, or even 20 nm. In addition, in the above embodiment, the included angle between the small-angle filter 401 and the vertical plane of the outgoing light path of the receiving end 33 is 0 degree, and in the design and manufacture of the device, the included angle between 0 degree and 15 degrees may be selected, for example, the included angle is 8 degrees or 13.5 degrees, as long as the band-pass wavelength range is satisfied, and the optical signal λ of the first wavelength can be isolated₁And can pass an optical signal λ of said second wavelength₂Are within the scope of embodiments contemplated by the present invention.

Preferably, the different-wavelength single-fiber bidirectional optical module 1 downloads the optical signal λ in a conventional bidirectional communication mode₁After being emitted by the laser 22, light enters the optical circulator from the emission end 31 and exits from the common end 32 through the optical circulator into the signal transmission fiber, and a coupling lens may be disposed between the fiber socket 301 and the optical circulator 30'. While the signal light λ emitted by the other end optical module of the optical network 70₂The signal transmission optical fiber sequentially passes through the optical network port 71 and the optical fiber socket 301, is incident into the optical circulator from the common end 32, is emitted from the receiving end 33 through the optical circulator, and is transmitted through the small-angle filter 401 arranged in front of the optical detector 51 and finally captured by the detector 51. At the same time, the downlink optical signal λ₁The resulting crosstalk light and reflected light cannot pass through the 0-degree filter, and do not affect the sensitivity of the detector 51.

Fig. 5 shows the working schematic diagram of the optical module in the OTDR detection mode in the first embodiment, and is different from the present dual-directional optical module 1 with single fiber with different wavelengths, the embodiment of the present invention provides an optical module that can also detect the optical fiber line without switching the external OTDR device except the above-mentioned dual-directional communication mode. OTDR uses rayleigh scattering and fresnel reflection to characterize the fiber. Rayleigh scattering is caused by the irregular scattering of an optical signal along an optical fiber. The OTDR measures a portion of the scattered light back to the OTDR port. These backscattered signals indicate the degree of attenuation (loss/distance) caused by the fiber. The OTDR test method is performed by launching optical pulses into the fiber and then receiving the returned information at the OTDR port. When light pulses are transmitted within an optical fiber, scattering and reflection may occur due to the nature of the fiber itself, connectors, joints, bends or other similar events. A part of the scatter and reflections will be returned to the OTDR device. The useful information returned is measured by the detector 51 of the OTDR as time or curve segments at different positions in the fibre. The distance can be calculated from the time taken to transmit the signal to return the signal and then determine the speed of the light in the glass mass to determine the location of the event.

In the optical module of the present invention shown in fig. 5, the dual-fiber optical module 1 with different wavelengths, which can integrate the OTDR function, further includes an OTDR detection interface 61 and a control unit 60, wherein the OTDR detection interface 61 is connected to a board 72 of the optical communication system; the optical receiver 50 converts the optical signal into an electrical signal after receiving the optical signal with the second wavelength; the control unit 60 is connected to the OTDR detection interface 61, the optical receiver 50, and the optical transmitter 20, and is configured to send a control command to the optical transmitter 20 according to the OTDR detection command received from the OTDR detection interface 61, process the electrical signal of the optical receiver 50, and send the processed data to the board 72 of the optical communication system through the OTDR detection interface 61. In addition, the optical transmitter 20 in the present embodiment employs a wavelength tunable laser 22; in the bidirectional communication mode, the optical transmitter 20 is used for transmitting a downlink optical signal λ of a first wavelength₁(ii) a In OTDR detection mode, control commands are sent by control unit 60 to optical transmitter 20, conditioning the pulsesThe wavelength of the laser 22 being such that the upstream optical signal λ is of a second wavelength₂The OTDRs of the same wavelength detect the optical signal.

Therefore, the utility model discloses under preferred embodiment's OTDR detection mode, when needs examine optical fiber line, optical communication system coordinates ascending optical signal lambda₂Stopping sending, and meanwhile, according to the OTDR detection command from the board 72 of the optical communication system received from the OTDR detection interface 61, the control unit 60 sends a control command to the optical transmitter 20, adjusts the wavelength of the pulse laser signal sent by the laser 22, and uses λ as the wavelength₁Is adjusted to lambda₂And then enters the optical fiber to be measured through the optical circulator 30'. The pulse signal is emitted from the optical fiber to be measured after rayleigh back scattering and fresnel reflection, enters the optical circulator and finally is emitted from the receiving end 33, and transmits through the 0-degree filter or the replaced small-angle filter 401 with 8 degrees or 13.5 degrees, and the detector 51 of the optical receiver 50 captures the signal with the second wavelength lambda₂The OTDR of (1) feeds back the optical signal and converts it into an electrical signal. The electrical signal is finally transmitted to the control unit 60 after passing through the amplifier 52 and the analog-to-digital converter, and the control unit 60 calculates information such as the state of the optical fiber circuit and the position of a fault point.

For example, the control unit 60 sends a control command to the optical transmitter 20, tunes the OTDR pulse optical wavelength emitted by the laser 22, and controls the laser 22 to emit an uplink optical signal λ associated with the optical network 70₂The OTDR detection pulse light signal with the same wavelength and the wavelength of 1555nm, which is emitted from the laser 22 of the optical transmitter 20, is transmitted through the emitting end 31 of the optical circulator 30 'to enter the common end 32 thereof, and is sent to the optical network port 71 to be coupled into the communication fiber to be detected, the pulse signal is reflected from the communication fiber to be detected back to the optical module after rayleigh backscattering and fresnel reflection, and the wavelength of the pulse signal is consistent with the pulse light, so that the OTDR feedback light signal with the wavelength of 1555nm from the optical network port 71 is transmitted from the common end 32 through the optical circulator 30' to enter the receiving end 33 thereof, and is received by the optical receiver 50 through the 0-degree filter, so that the optical receiver 50 receives the uplink optical signal λ of the optical network 70, and the optical receiver 50 receives the uplink optical signal λ₂1555nm OTDR feedback optical signal with same wavelength. The optical transmitter 20 described herein transmits an upstream optical signal λ at a second wavelength₂The term "identical" in the case of optical signals detected by OTDRs of the same wavelength means that, numerically, the wavelength range falls within λ₂+7/20*(λ₂-λ₁) And λ₂-7/20*(λ₂-λ₁) For example, in the previous embodiments of the present invention, the two wavelengths 1555nm and 1555.1nm may be considered to be the same. It will be readily appreciated that in alternative embodiments, part of the control functions of the control unit 60 may be implemented by the optical transmitter 20 and the optical receiver 50, respectively, and part of the control functions of the optical transmitter 20 and the optical receiver 50 may be integrated into the control unit 60 for integrated design and manufacture.

The optical module provided in this embodiment utilizes the three-way device 30 to achieve the purpose of optical path multiplexing, which not only solves the problem of miniaturization, but also achieves the purpose of coexistence and non-interference of long-distance transmission and OTDR functions, where it is to be noted that the signal transmission function and the OTDR function cannot be performed simultaneously.

Fig. 6 and 7 show a second embodiment of the optical module of the present invention, which is different from the first embodiment in that the second embodiment replaces the small-angle filter 401 in the first embodiment with a tunable filter 402, and the tunable filter 402 has a characteristic that the band-pass range of the filter can be tuned, and optical signals with different wavelengths are transmitted through the filter as required. As shown in FIG. 6, in the two-way communication mode, the passband of tunable filter 402 is set at λ₂Nearby, when the bandpass wavelength range of the tunable filter 402 isolates the optical signal λ of the first wavelength₁And transmits the optical signal λ of the second wavelength₂. Downstream optical signal lambda emitted by laser 22 of optical transmitter 20₁Transmitted to the public end 32 through the transmitting end 31 of the optical circulator 30', and coupled to the optical network port 71 through the optical fiber jack 301 to enter the communication optical fiber; and the upstream optical signal lambda transmitted from the communication optical fiber₂Transmitted from the optical network port 71 to the receiving end 33 via the common end 32 of the optical circulator 30' and detected by the optical receiver 50 via the tunable filter 402And received and processed by the processor 51. In this embodiment, the bandpass wavelength range of the tunable filter 402 is capable of isolating the downstream optical signal λ₁And can pass through the upstream optical signal lambda₂And thus the downstream optical signal λ emitted from the laser 22₁The tunable filter 402 is configured to block the optical signal from entering the detector 51, so that the optical module outputs a downstream optical signal λ from the common port 32 to the optical communication fiber₁And an upstream optical signal lambda received by the receiving terminal 33 from the communication fiber₂。

As shown in fig. 7, in a second embodiment of the optical module of the present invention, in the OTDR detection mode, when the optical fiber line needs to be detected, according to the OTDR detection command received from the OTDR detection interface 61 and coming from the board 72 of the optical communication system, the control unit 60 sends a control command to the tunable filter 402, so as to adjust the pass band of the filter to λ₁When the band-pass wavelength range of the tunable filter 402 transmits the optical signal λ of the first wavelength₁And isolating the optical signal λ of the second wavelength₂. The control unit 60 then sends a control command to the light emitter 20 to emit a laser pulse laser signal having a wavelength λ₁And then enters the optical fiber to be measured through the optical circulator 30'. The pulse signal is emitted from the optical fiber to be measured after rayleigh backscattering and fresnel reflection, enters the optical circulator, is finally emitted from the receiving end 33, transmits the pulse signal through the tunable filter 402, and is captured by the detector 51 of the optical receiver 50 to have a second wavelength lambda₁The OTDR of (1) feeds back the optical signal and converts it into an electrical signal. The electrical signal is finally transmitted to the control unit 60 after passing through the amplifier 52 and the analog-to-digital converter, and the control unit 60 calculates information such as the state of the optical fiber circuit and the position of a fault point. As previously mentioned, by "the same", it is meant that, numerically, the wavelength range falls within λ₂+7/20*(λ₂-λ₁) And λ₂-7/20*(λ₂-λ₁) For example, in the embodiments described below, the two wavelengths 1550nm and 1550.1nm may be considered to be the same.

In the preferred embodiment of the present invention, after receiving the OTDR detection command, the control unit 60 sends a control command to the OTDR deviceTuning the filter 402 to adjust the passband of the filter to 1550nm of the downstream optical signal λ₁The bandpass wavelength range of the tunable filter 402 still transmits an optical signal λ of 1550nm in the vicinity of, for example, 1550.1nm at the bandpass center₁And isolating uplink optical signal lambda with 1555nm wavelength₂. In the OTDR detection mode, the control unit 60 sends a control command to the optical transmitter 20 to transmit a laser pulse signal λ with a wavelength of 1550nm₁And after passing through the optical circulator 30', the optical fiber is incident into the optical fiber to be detected as an OTDR detection optical signal. Pulse signals with the wavelength of 1550nm are emitted from the optical fiber to be measured after Rayleigh back scattering and Fresnel reflection, enter an optical circulator as OTDR feedback optical signals with the wavelength of 1550nm, are emitted from a receiving end 33 finally, transmit a tunable filter 402, and are captured by a detector 51 of an optical receiver 50 to form a signal with the wavelength of 1550nm and lambda₁The OTDR of (1) feeds back the optical signal and converts it into an electrical signal.

The second embodiment of the present invention may have other different alternatives as long as satisfying the requirement that in the OTDR detection mode, the optical transmitter 20 transmits the uplink optical signal λ having the second wavelength₂The OTDR detection optical signals of different wavelengths, and the bandpass wavelength range of tunable filter 402 is tuned to transmit the OTDR detection optical signal and isolate the optical signal λ of the second wavelength₂. For example, after receiving the OTDR detection command, the control unit 60 instructs the tunable filter 402 to adjust the pass band of the filter to be near the 1545nm optical signal, so that the bandpass wavelength range of the tunable filter 402 transmits the 1545nm optical signal and isolates the upstream optical signal λ having a 1555nm wavelength₂. In the OTDR detection mode, the control unit 60 sends a control command to the optical transmitter 20, adjusts the wavelength of the laser 22, adjusts the wavelength from 1550nm in the bidirectional communication mode to 1545nm, and transmits a laser pulse signal with a wavelength of 1545nm, and after passing through the optical circulator 30', the OTDR detection optical signal with a wavelength of 1545nm is incident on the optical fiber to be detected. The pulse signal is emitted from the optical fiber to be measured after Rayleigh back scattering and Fresnel reflection, enters the optical circulator as an OTDR feedback optical signal with the wavelength of 1545nm, is finally emitted from the receiving end 33 and is transmitted throughA tunable filter 402 received by the optical receiver 50.

Fig. 8 shows that the preferred embodiment of the optical module of the present invention further includes a housing 100, and the three-way device 30 (not shown in the figure), the small-angle filter 401 (not shown in the figure), the control unit 60 (not shown in the figure), the driver 21 (not shown in the figure), the laser 22 (not shown in the figure), the detector 51 (not shown in the figure), the amplifier 52 (not shown in the figure), and the analog-to-digital converter (not shown in the figure) are all packaged in the housing.

Preferably, the optical module in fig. 8 further includes an electromagnetic interference (EMI) dome 500, and the EMI dome 500 seals the gap of the housing 100. The EMI elastic sheet 500 has an anti-radiation function, enhances the safety of the OTDR optical module, and reduces the harm to the body of a user.

Preferably, as shown in fig. 8, the LC optical interface 600 further comprises an unlocking tab movably blocking the LC optical interface 600, and the unlocking tab 700 is mounted on the housing 100. The unlocking tab 700 may protect the LC optical interface 600 from water and dust.

The utility model also provides a be applied to the OTDR detection method in the two-way optical module of different wavelength single fiber 1, the two-way optical module of different wavelength single fiber 1 that this OTDR detection method adopted can switch in two-way optical communication mode and OTDR detection mode.

In the bidirectional optical communication mode, the optical transmitter 20 is caused to transmit a downlink optical signal λ of a first wavelength₁After passing through the three-way device 30, the signal is transmitted to the optical network port 71 from the common end 32; upstream optical signal λ of a second wavelength from optical network port 71₂After passing through the three-way device 30, the light beam is emitted from the receiving end 33 of the three-way device 30, and is received by the light receiver 50 after passing through the filter device 40, such as a small-angle filter 401, and the band-pass wavelength range of the small-angle filter 401 isolates the optical signal λ of the first wavelength₁And passing an optical signal λ of said second wavelength₂. Preferably, the different-wavelength single-fiber bidirectional optical module 1 downloads the optical signal λ in the bidirectional communication mode₁After being emitted by the laser 22, the light enters the optical circulator from the emission end 31 and is emitted from the common end 32 through the optical circulator to enter the signal transmission optical fiber, and the light can be transmitted in the optical fiberA coupling lens is provided between the socket 301 and the optical circulator 30'. While the signal light λ emitted by the other end optical module of the optical network 70₂The signal transmission optical fiber sequentially passes through the optical network port 71 and the optical fiber socket 301, is incident into the optical circulator from the common end 32, is emitted from the receiving end 33 through the optical circulator, and is transmitted through the small-angle filter 401 arranged in front of the optical detector 51 and finally captured by the detector 51. At the same time, the downlink optical signal λ₁The resulting crosstalk light and reflected light cannot pass through the 0-degree filter, and do not affect the sensitivity of the detector 51.

According to an embodiment of the present invention, filter device 40 adopts small angle filter 401, and in OTDR detection mode, OTDR detection command from optical communication system's integrated circuit board 72 received by OTDR detection interface 61 on the optical module switches the optical module from optical communication mode to OTDR detection mode, to optical transmitter 20 sends control command, and the wavelength of pulse laser 22 is from the downstream optical signal λ of first wavelength₁Is adjusted to lambda₂The optical transmitter 20 is made to transmit the uplink optical signal λ with the second wavelength₂The OTDR detection pulse optical signals with the same wavelength pass through the three-way device 30 and are transmitted to the optical network port 71 from the common end 32; after passing through the three-way device 30, the OTDR feedback optical signal of the second wavelength from the optical network port 71 exits from the receiving end 33 of the three-way device, and after passing through the small-angle filter 401, is received by the optical receiver 50; when the detector 51 of the optical receiver 50 captures the light having the second wavelength λ₂After feeding back the optical signal, the electrical signal of the optical receiver 50 is processed. The electrical signal is finally transmitted to the control unit 60 after passing through the amplifier 52 and the analog-to-digital converter, and information such as the state of the optical fiber line and the position of a fault point can be calculated by the control unit 60, and the processed data is sent to the board card 72 of the optical communication system through the OTDR detection interface 61; in an alternative embodiment, the control unit 60 transmits the electrical signal of the optical receiver 50 directly to the board 72 of the optical communication system connected to the OTDR detection interface 61, and the board 72 of the optical communication system performs processing, including data processing and mathematical processing, to form the number of optical intensity and distance changesAccordingly, an OTDR detection curve is obtained.

As another embodiment of the present invention, the filter device 40 employs the tunable filter 402 to serve as an alternative to the OTDR detection method applied to the dual-fiber optical module 1 with different wavelengths. According to the utility model discloses detection method in OTDR detection mode includes, according to OTDR detection interface 61 on this optical module received from optical communication system's integrated circuit board 72 OTDR detection command, to optical transmitter 20 and/or tunable filter 402 sends control command. The optical transmitter 20 is made to transmit a downstream optical signal wavelength lambda corresponding to said first wavelength₁The same OTDR detects the optical signal; tuning the bandpass wavelength range of the tunable filter 402 such that the bandpass wavelength range transmits the OTDR detection optical signal and isolates the optical signal λ of the second wavelength₂(ii) a Then, the OTDR detection optical signal emitted by the optical transmitter 20 is transmitted into the common port 32 through the emitting end 31 of the three-way device 30 and sent to the optical network port 71; the OTDR detection optical signal is incident into the optical fiber to be detected, the pulse signal is emitted from the optical fiber to be detected after rayleigh backscattering and fresnel reflection, the OTDR feedback optical signal having the same wavelength as the OTDR detection optical signal and reaching the optical network port 71 passes through the three-way device 30 from the common end 32, is emitted from the receiving end 33 of the three-way device 30, passes through the filter device 40, and reaches the optical receiver 50; the optical receiver 50 is configured to convert the optical signal into an electrical signal after receiving the OTDR feedback optical signal.

In another preferred embodiment employing tunable filter 402, the wavelength of pulsed laser 22 is adjusted such that optical transmitter 20 transmits an upstream optical signal λ at the second wavelength₂OTDR detecting optical signals with different wavelengths; tuning the bandpass wavelength range of the tunable filter 402 such that the bandpass wavelength range transmits the OTDR detection optical signal and isolates an optical signal λ of a second wavelength₂(ii) a Processing the electrical signal of the optical receiver 50, and sending the processed data to the board 72 of the optical communication system through the OTDR detection interface 61; or transmits the electrical signal of the optical receiver 50 toThe board 72 of the optical communication system connected to the OTDR detection interface 61 is processed by the board 72 of the optical communication system.

It should be noted by those skilled in the art that the OTDR detection method described in this embodiment cannot simultaneously implement a signal transmission function and an OTDR function, but needs to switch between a bidirectional optical communication mode and an OTDR detection mode.

While the invention has been particularly shown and described with reference to a preferred embodiment, it will be understood by those skilled in the art that the invention is not limited to the details of the foregoing illustrative examples, but is capable of other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned. Furthermore, it is obvious that the word "comprising" does not exclude other elements or steps, and the singular does not exclude the plural. A plurality of units or means recited in the apparatus claims may also be implemented by one unit or means in software or hardware. The terms first, second, etc. are used to denote names, but not any particular order.

Finally, it should be noted that: the above embodiments are only used for illustrating the technical solutions of the embodiments of the present application, and are not limited thereto; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions in the embodiments of the present application.

Claims (9)

1. A different wavelength single fiber bidirectional optical module capable of integrating OTDR function is characterized in that: comprises a light emitter (20), a three-way device (30), a filter device (40) and a light receiver (50) which are connected in sequence,

the three ports of the three-way device (30) are respectively a transmitting end (31), a public end (32) and a receiving end (33), the transmitting end (31) is connected with the optical transmitter (20), the public end (32) is connected with an optical fiber socket (301), and the optical fiber socket (301) is connected with an optical network port (71); the receiving end (33) of which is connected to the optical receiver (50) such that a downstream optical signal λ of a first wavelength is emitted from the optical transmitter₁An optical fiber jack (301) for transmission into the common port (32) through the transmitting end (31) thereof into the optical network (70), and an upstream optical signal λ of a second wavelength from the optical network port (71)₂Transmitted from a common terminal (32) through a three-way device (30) into a receiving terminal (33), and received by the optical receiver (50) after passing through the filter device (40);

in the two-way communication mode, the communication device,

the optical transmitter (20) is used for transmitting a downstream optical signal lambda of a first wavelength₁；

The optical receiver (50) is used for receiving an uplink optical signal lambda of a second wavelength₂；

The band-pass wavelength range of the filter device (40) isolates the optical signal λ of the first wavelength₁And passing an optical signal λ of said second wavelength₂。

2. A heterowavelength single-fiber bidirectional optical module integratable with OTDR functionality according to claim 1, characterized in that:

in the OTDR detection mode, the detection mode,

the optical transmitter (20) is for transmitting an OTDR detection optical signal;

the band-pass wavelength range of the filter device (40) is used for detecting optical signals through the OTDR;

-said OTDR test optical signal emitted from said optical transmitter (20) is transmitted through the emitting terminal (31) of said three-way device (30) into the common terminal (32) and sent to the optical network port (71), while the OTDR feedback optical signal from the optical network port (71) having the same wavelength as the OTDR test optical signal passes through the three-way device (30) from the common terminal (32), exits from the receiving terminal (33) of the three-way device (30), passes through said filter device (40) and reaches said optical receiver (50);

the optical receiver (50) is configured to receive the OTDR feedback optical signal.

3. The hetero-wavelength single-fiber bidirectional optical module integratable with OTDR functions of claim 1 or 2, wherein:

the filter device (40) is a small-angle filter (401), and the included angle between the small-angle filter (401) and the vertical surface of the emergent light path of the receiving end (33) is 0 degree to 15 degrees, preferably 0 degree.

4. A heterowavelength single-fiber bidirectional optical module integratable with OTDR functionality according to claim 3, characterized in that:

in the OTDR detection mode, the detection mode,

the optical transmitter (20) transmits an upstream optical signal λ with the second wavelength₂The OTDRs of the same wavelength detect the optical signal.

5. The hetero-wavelength single-fiber bidirectional optical module integratable with OTDR functions of claim 1 or 2, wherein:

the filter device (40) is a tunable filter (402) having a tunable band-pass wavelength range.

6. The hetero-wavelength single-fiber bidirectional optical module integrable with OTDR function of claim 5, characterized in that:

in the OTDR detection mode, the detection mode,

the optical transmitter (20) transmits an upstream optical signal λ with the second wavelength₂Different in wavelengthDetecting the optical signal by OTDR;

the bandpass wavelength range of the tunable filter (402) is tuned to transmit the OTDR detection optical signal and isolate the optical signal λ of the second wavelength₂。

7. The hetero-wavelength single-fiber bidirectional optical module integrable with OTDR functionality of claim 6, wherein: the optical transmitter (20) transmits a downstream optical signal wavelength λ corresponding to the first wavelength₁The same OTDR detects the optical signal.

8. The hetero-wavelength single-fiber bidirectional optical module integrable with OTDR function of any of claims 1, 2, 4, 6 or 7, characterized in that: the three-way device is an optical circulator (30').

9. The hetero-wavelength single-fiber bidirectional optical module integrable with OTDR functionality of claim 8, wherein: an optical signal λ of the first wavelength₁With optical signal λ of a second wavelength₂The wavelength difference of (2) is less than or equal to 8 nm.

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