A different-wavelength single-fiber bidirectional optical module capable of integrating OTDR function and a detection method thereof

Abstract

A different-wavelength single-fiber bidirectional optical module capable of integrating an OTDR function and an OTDR detection method thereof. The optical module comprises an optical transmitter (20), a three-way device (30), a small-angle filter (401) and an optical receiver (50) connected in sequence, and also comprises an OTDR detection interface (61), a control unit (60) and a PCB board. The passband wavelength range of the small-angle filter (401) isolates a downlink optical signal λ of a first wavelength. 1 , and transmits the upstream optical signal λ via the second wavelength 2 The use of an optical circulator (30) in conjunction with a small-angle filter (401) can overcome the disadvantage of a conventional single-fiber bidirectional optical module that the uplink and downlink wavelength intervals are too large during bidirectional communication. At the same time, the present invention integrates an OTDR into a single-fiber bidirectional optical module, and the OTDR detection method used enables the optical module to switch between a bidirectional communication mode and an OTDR detection mode. Compared with similar products, the optical module can perform normal communication services and perform optical fiber link detection when needed, and is very suitable for monitoring channels in trunk communications.

Description

Technical Field

[0001] The present application relates to the field of optical fiber communication, and in particular to a different-wavelength single-fiber bidirectional optical module capable of integrating an OTDR function and an OTDR detection method thereof. Background Art

[0002] With the continuous development of optical fiber communication technology, the complexity of optical fiber networks is increasing. In order to ensure the smooth and stable operation of optical communication lines, daily management and maintenance of optical fiber lines are essential. When a breakpoint or other fault occurs in an optical fiber line, since the distance between one node and another is often very long, the detection and location of the fault point often needs to rely on optical time domain reflectometer (OTDR).

[0003] At present, most of the single-fiber bidirectional optical modules adopt different wavelength technology, and such optical modules do not have OTDR function. When OTDR is needed for optical fiber line detection, it is often necessary to switch to external professional OTDR equipment. Since the equipment used by the external OTDR is expensive and the line structure is complex when used, it is impossible to judge and locate the fault in the shortest time after the fault occurs, thus prolonging the time required for maintenance and troubleshooting, affecting normal communication.

[0004] At present, optical modules with OTDR function usually require that the wavelength of the optical signal emitted by the laser transmitter and the wavelength entering the optical receiving end 33 are completely consistent, so that the optical signal reflected by the optical fiber can be received and processed by the optical receiving end 33. However, due to the existence of crosstalk between the optical transmitter and the receiving end 33, when the optical path for realizing the OTDR function transmits the communication optical signal, the sensitivity performance of the receiving end 33 will be greatly reduced, which is not conducive to the implementation of long-distance optical fiber communication. Summary of the invention

[0005] In view of the above problems, the main purpose of this application is to provide a different-wavelength single-fiber bidirectional optical module with integrated OTDR function, which can ensure the realization of OTDR function on the basis of normal different-wavelength single-fiber bidirectional communication function.

[0006] The secondary purpose of the present application is to provide a single-fiber bidirectional optical module with different wavelengths, which reduces the wavelength interval between uplink and downlink optical signals by improving the optical structure.

[0007] Another object of the present application is to provide an OTDR detection method applied to a different-wavelength single-fiber bidirectional optical module, which has the advantages of being able to perform both communication services and optical fiber link detection.

[0008] The first embodiment of the present application provides a different-wavelength single-fiber bidirectional optical module capable of integrating an OTDR function, comprising an optical transmitter, a three-way device, a filter device and an optical receiver connected in sequence,

[0009] In a bidirectional communication mode, the optical transmitter is used to transmit a downlink optical signal λ1 of a first wavelength; the optical receiver is used to receive an uplink optical signal λ2 of a second wavelength; the passband wavelength range of the filter device isolates the optical signal λ1 of the first wavelength and passes the optical signal λ2 of the second wavelength;

[0010] The three ports of the three-way device are respectively a transmitting end, a common end and a receiving end, wherein the transmitting end is connected to the optical transmitter, the common end is connected to the optical fiber socket, and the optical fiber socket is connected to the optical network port; the receiving end is connected to the optical receiver, so that the downlink optical signal λ1 of the first wavelength emitted from the optical transmitter is transmitted through the transmitting end to enter the optical fiber socket of the common end and then enter the optical network, while the uplink optical signal λ2 of the second wavelength from the optical network port is transmitted from the common end through the three-way device to enter the receiving end, and is received by the optical receiver after passing through the filter device.

[0011] Furthermore, in the first embodiment of the present application, the heterogeneous single-fiber bidirectional optical module with integrated OTDR function, in the OTDR detection mode, the optical transmitter is used to transmit the OTDR detection optical signal; the passband wavelength range of the filter device passes through the OTDR detection optical signal; the OTDR detection optical signal emitted from the optical transmitter enters the common end through the transmitting end of the three-way device and is sent to the optical network port, and the OTDR feedback optical signal from the optical network port with the same wavelength as the OTDR detection optical signal passes through the three-way device from the common end, is emitted from the receiving end of the three-way device, and reaches the optical receiver after passing through the filter device; the optical receiver is used to receive the OTDR feedback optical signal.

[0012] Further improvements to the different-wavelength single-fiber bidirectional optical module with integrated OTDR function of the first embodiment of the present application also include: the filter device is a small-angle filter, and the angle between the small-angle filter and the vertical plane of the output light path of the receiving end is 0 degrees to 15 degrees, preferably 0 degrees.

[0013] Furthermore, in the different-wavelength single-fiber bidirectional optical module capable of integrating an OTDR function, in an OTDR detection mode, the optical transmitter emits an OTDR detection optical signal having the same wavelength as the second wavelength uplink optical signal λ2.

[0014] Furthermore, in the different-wavelength single-fiber bidirectional optical module capable of integrating OTDR function, the filter device is a tunable filter having a tunable bandpass wavelength range.

[0015] The second embodiment of the present application provides a different-wavelength single-fiber bidirectional optical module capable of integrating an OTDR function, wherein in an OTDR detection mode,

[0016] The optical transmitter transmits an OTDR detection optical signal having a wavelength different from that of the uplink optical signal λ2 of the second wavelength;

[0017] The passband wavelength range of the tunable filter is tuned to transmit the OTDR detection optical signal and isolate the second wavelength optical signal λ2.

[0018] A further improvement of the different-wavelength single-fiber bidirectional optical module capable of integrating an OTDR function in the second embodiment of the present application is that the optical transmitter emits an OTDR detection optical signal having the same wavelength λ1 as the first wavelength of the downlink optical signal.

[0019] Furthermore, in the different-wavelength single-fiber bidirectional optical module capable of integrating OTDR function of the present application, the three-way device is an optical circulator.

[0020] Furthermore, in the different-wavelength single-fiber bidirectional optical module capable of integrating OTDR function of the present application, the wavelength difference between the first wavelength optical signal λ1 and the second wavelength optical signal λ2 is less than or equal to 8 nm.

[0021] A further improvement of the heterogeneous single-fiber bidirectional optical module with integrated OTDR function of the present application is that: the optical transmitter adopts a wavelength-adjustable laser; in the bidirectional communication mode, the laser is used to transmit a downlink optical signal λ1 of a first wavelength; in the OTDR detection mode, the wavelength of the pulse laser is adjusted so that the optical transmitter transmits an OTDR feedback optical signal.

[0022] Furthermore, the heterogeneous wavelength single-fiber bidirectional optical module capable of integrating OTDR function also includes an OTDR detection interface and a control unit.

[0023] The OTDR detection interface is connected to a board of the optical communication system;

[0024] After receiving the OTDR feedback optical signal, the optical receiver converts the optical signal into an electrical signal;

[0025] The control unit is connected to the OTDR detection interface, the optical receiver and the optical transmitter respectively, and is used to send a control command to the optical transmitter and / or the tunable filter according to the OTDR detection command received from the OTDR detection interface, and is also used to process the electrical signal of the optical receiver and send the processed data to the board of the optical communication system through the OTDR detection interface.

[0026] The present application also provides an OTDR detection method, which is applied to a single-fiber bidirectional optical module with different wavelengths, including:

[0027] In two-way communication mode,

[0028] The optical transmitter emits a downlink optical signal λ1 of the first wavelength, which is transmitted from the common end of the three-way device to the optical network port;

[0029] An uplink optical signal λ2 of a second wavelength from an optical network port passes through a three-way device, is emitted from a receiving end of the three-way device, and is received by the optical receiver after passing through a filter device, wherein a passband wavelength range of the filter device isolates the optical signal λ1 of the first wavelength and passes the optical signal λ2 of the second wavelength;

[0030] In OTDR detection mode,

[0031] Allowing the passband wavelength range of the filter device to pass through the OTDR to detect the optical signal;

[0032] The OTDR detection optical signal emitted by the optical transmitter is transmitted through the transmitting end of the three-way device into the common end and sent to the optical network port;

[0033] The OTDR feedback optical signal from the optical network port having the same wavelength as the OTDR detection optical signal is emitted from the receiving end of the three-way device after passing through the common end, and reaches the optical receiver after passing through the filter device;

[0034] The optical receiver is used to convert the optical signal into an electrical signal after receiving the optical signal fed back by the OTDR.

[0035] In one embodiment of the OTDR detection method of the present application,

[0036] When the filter device adopts a small-angle filter, the detection method in the OTDR detection mode further includes:

[0037] Sending a control command to the optical transmitter according to an OTDR detection command received by the OTDR detection interface on the optical module from a board of the optical communication system;

[0038] Adjusting the wavelength of the pulse laser so that the optical transmitter emits an OTDR detection optical signal having the same wavelength as the uplink optical signal λ2 of the second wavelength;

[0039] Processing the electrical signal of the optical receiver, and sending the processed data to the board of the optical communication system through the OTDR detection interface;

[0040] Alternatively, the electrical signal of the optical receiver is transmitted to a board of an optical communication system connected to an OTDR detection interface, and is processed by the board of the optical communication system.

[0041] In another embodiment of the OTDR detection method of the present application,

[0042] When the filter device adopts a tunable filter, the detection method in the OTDR detection mode further includes:

[0043] Sending a control command to the optical transmitter (20) and / or the tunable filter according to an OTDR detection command received by the OTDR detection interface on the optical module from a board of the optical communication system;

[0044] The optical transmitter emits an OTDR detection optical signal having the same wavelength λ1 as the downlink optical signal of the first wavelength;

[0045] or adjusting the wavelength of the pulse laser so that the optical transmitter emits an OTDR detection optical signal having a wavelength different from that of the uplink optical signal λ2 of the second wavelength;

[0046] Tuning the passband wavelength range of the tunable filter so that the passband wavelength range transmits the OTDR detection optical signal and isolates the second wavelength optical signal λ2;

[0047] Processing the electrical signal of the optical receiver, and sending the processed data to the board of the optical communication system through the OTDR detection interface;

[0048] Alternatively, the electrical signal of the optical receiver is transmitted to a board of an optical communication system connected to an OTDR detection interface, and is processed by the board of the optical communication system.

[0049] The OTDR detection method of the present application further includes: the optical module or the board of the optical communication system connected to the optical module processes the electrical signal, specifically including digital processing and mathematical processing to form data of light intensity and distance change.

[0050] It can be seen from the above technical solutions that the embodiment of the present application improves the optical structure of the single-fiber bidirectional optical module and reduces the wavelength interval of the uplink and downlink optical signals, thereby achieving the purpose of integrating the OTDR function into the optical module. At the same time, the optical module can perform both communication services and optical fiber link detection, which is very suitable for monitoring channels in trunk communications. Moreover, filter devices such as 0-degree filters are used to separate the OTDR signal and the normal data communication optical signal without affecting each other. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the embodiments of the present application. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0052] Figure 1 The figure is a schematic diagram of a single-fiber bidirectional optical module with different wavelengths in the prior art.

[0053] Figure 2 A schematic diagram of the working principle of an optical module with an integrated OTDR function in an embodiment of the present invention;

[0054] Figure 3 This is a working principle diagram of an optical circulator 30' according to an embodiment of the present invention;

[0055] Figure 4 It is a schematic diagram of the principle of the optical module working in the digital signal communication mode in the first embodiment of the present invention;

[0056] Figure 5 It is a schematic diagram of the principle of the optical module working in the OTDR mode in the first embodiment of the present invention;

[0057] Figure 6 A schematic diagram of the principle of the optical module in the second embodiment of the present invention working in the digital signal communication mode;

[0058] Figure 7 It is a schematic diagram of the principle of the optical module working in the OTDR mode in the second embodiment of the present invention;

[0059] Figure 8 FIG. 4 is a schematic diagram of the three-dimensional structure of an optical module in another embodiment of the present invention.

[0060] Fig. 9 The present invention is a flow chart of an OTDR detection method applied to a heterogeneous wavelength single-fiber bidirectional optical module.

[0061] Reference numerals

[0062] 1 Single-fiber bidirectional optical module with integrated OTDR function

[0063] 20 Light Transmitter

[0064] 21 Drive

[0065] 22 Laser

[0066] 30 Three-way device

[0067] 30' Optical Circulator

[0068] 31 Transmitter

[0069] 32 Public terminal

[0070] 33 Receiver

[0071] 301 Fiber Optic Socket

[0072] 40 filter devices

[0073] 401 Small Angle Filter

[0074] 402 Tunable Filter

[0075] 50 Optical Receiver

[0076] 51 Detector

[0077] 52 Amplifier

[0078] 53 Digital to Analog Converter

[0079] 60 Control Unit

[0080] 61 OTDR detection interface

[0081] 70 Optical Network

[0082] 71 optical network ports

[0083] 72 Optical communication system board

[0084] λ1 Downlink optical signal of the first wavelength

[0085] λ2 Uplink optical signal of the second wavelength DETAILED DESCRIPTION

[0086] In order to enable those skilled in the art to better understand the technical solutions in the embodiments of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments in the embodiments of the present application should fall within the scope of protection of the embodiments of the present application.

[0087] Commonly used single-fiber bidirectional optical modules such as Figure 1As shown, it generally adopts the TO-CAN packaging form, which consists of a single-channel transmitter 01, a single-channel receiver 02, a filter 03, an integrated pin optical interface 04 and a round square tube body 05. This structure uses a single or multiple filters as the splitter element of the transmitter and receiver, and uses a single optical fiber to simultaneously complete the transmission of a wavelength optical signal and the reception of another wavelength optical signal. However, when using filters as splitter elements, the position accuracy requirements are high, the processing technology is complex, and it is not easy to mass produce; and due to the processing technology of the filters, this optical module is not suitable for occasions of small-interval different-wavelength transmission and reception. At the same time, such an optical module does not have the OTDR function. When OTDR is needed to perform optical fiber line detection, it is often necessary to switch to an external professional OTDR device.

[0088] Please refer to Figure 2 , which is a schematic diagram of the working principle of a different-wavelength single-fiber bidirectional optical module 1 with an integrated OTDR function in one 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 and an optical receiver 50 connected in sequence, a control unit 60 for controlling the operation of the optical module, and an optical fiber socket 301 for connecting to an optical network port 71, and a collimating lens may be provided between the optical fiber socket 301 and the receiving end 33 of the three-way device.

[0089] The three-way device 30 includes a first port, a second port, and a third port. The first port is connected to the optical transmitter 20, also known as the transmitting end 31; the second port is connected to the optical fiber socket 301, also known as the common end 32, and the third port is connected to the optical receiver 50, also known as the receiving end 33. Generally speaking, the three-way device 30 generally refers to a semi-reflective and semi-transparent film or an optical circulator 30'. A general semi-reflective and semi-transparent film allows 50% of the intensity of the incident light to be transmitted, while reflecting 50% of the intensity, thereby completing the three-way propagation of the optical path with a loss of 6dB (75%) of the intensity of the light. The function of the semi-reflective and semi-transparent film is basically the same as that of the optical circulator 30', the difference being that the semi-reflective and semi-transparent film has an attenuation of about 6dB more than the optical circulator 30'. In the present invention, Figure 3 In the embodiment of the present invention, an optical circulator 30' is used for illustration, but it can be understood that a semi-reflective and semi-transparent sheet can also be used as the three-way device 30 in the embodiment of the present invention.

[0090] Figure 3The working principle of the optical circulator 30' is shown. The optical circulator 30' in the embodiment of the present invention includes three ports, namely, a transmitting end 31, a common end 32 and a receiving end 33. The function of the optical circulator 30' is to allow the downlink optical signal λ1 entering the transmitting end 31 to be transmitted through the optical circulator 30' to enter the common end 32, and the uplink optical signal λ2 of the common end 32 to be transmitted through the optical circulator 30' to enter the receiving end 33, thus completing the three-way propagation of the optical path. Moreover, if a 45-degree filter is used to separate the uplink and downlink optical signals, due to the process limitation of the 45-degree filter, the interval between the uplink and downlink wavelengths must be greater than 40nm. If small interval different wavelength transmission and reception are to be achieved, this technology will become helpless.

[0091] The preferred embodiment of the present invention provides a different wavelength single fiber bidirectional optical module 1 with integrated OTDR function, the structure diagram of which is shown in FIG. Figure 2 As shown, the optical module includes an optical transmitter 20, a small optical circulator, a small angle filter 401 and an optical receiver 50 connected in sequence, a control unit 60 for controlling the operation of the optical module, and an optical fiber socket 301 for connecting to an optical network port 71. The small optical circulator has three ports, namely a transmitting end 31, a common end 32, and a receiving end 33.

[0092] exist Figure 2 In the preferred embodiment shown, the optical transmitter 20 includes a driver 21 and a laser 22. The control unit 60 sends a corresponding instruction to the driver 21, and the driver 21 drives the laser 22 to emit a downlink optical signal λ1. The laser of the laser 22 is directly facing the transmitting end 31 of the optical circulator. The laser signal is emitted from the common end 32 through the optical circulator and is coupled into the signal transmission optical fiber through the collimating lens.

[0093] The optical receiver 50 includes a detector 51, an amplifier 52, and an analog-to-digital converter. The uplink optical signal λ2 in the signal transmission optical fiber passes through the optical network port 71 and the optical fiber jack 301, and is transmitted from the common end 32 through the three-way device 30 to the collimating lens of the receiving end 33, enters the common end 32 of the optical circulator, and is emitted from the receiving end 33, and is captured by the detector 51 after passing through the filter device 40, such as the small-angle filter 401. The passband wavelength range of the filter device 40, such as the small-angle filter 401, can isolate the optical signal λ1 of the first wavelength, and can pass the optical signal λ2 of the second wavelength.

[0094] Specifically, the optical receiver 50 includes an optical detector 51, an amplifier 52, and an analog-to-digital converter. The detector 51 is electrically connected to the amplifier 52, the amplifier 52 is electrically connected to the analog-to-digital converter, and the analog-to-digital converter is electrically connected to the control unit 60. The detector 51 is connected to the receiving end 33 of the optical circulator, and the signal light and reflected light transmitted by the optical fiber are directly opposite to the common end 32. The receiving end 33 is connected to the detector 51. The signal light and reflected light enter the optical circulator through the common end 32 and are emitted from the receiving end 33, and after passing through the small-angle filter 401, they enter the detector 51. In the detector 51, the optical signal is converted into an electrical signal, and after being amplified by the amplifier 52, it is converted into a digital signal through the analog-to-digital converter and transmitted to the control unit 60. It can be understood by those skilled in the art 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 designed in an integrated manner. The design of the three-way device 30 and the small-angle filter 401 enables the transmission and reception of optical signals to be realized in the same optical module, and solves the problem of miniaturization, and is easy to integrate and low in cost. In addition, some control functions in the optical transmitter 20 and the optical receiver 50 here can also be integrated into the control unit 60 for integrated design and manufacturing. Moreover, when the input signal is a digital signal, the analog-to-digital converter does not have to perform analog-to-digital conversion.

[0095] Figure 4 1 is a schematic diagram of an embodiment of an optical module in a digital signal communication mode in the first embodiment of the present invention. In the first embodiment, the filter device 40 adopts a small-angle filter 401, preferably a 0-degree filter, that is, the angle between the small-angle filter 401 and the vertical plane of the output light path of the receiving end 33 is 0 degrees. The 1550nm wavelength downlink optical signal λ1 emitted by the laser 22 of the optical transmitter 20 is transmitted to the common end 32 through the transmitting end 31 of the optical circulator 30', and is coupled to the optical network port 71 into the communication optical fiber through the optical fiber socket 301; and the 1555nm wavelength uplink optical signal λ2 transmitted from the communication optical fiber is transmitted from the optical network port 71 to the receiving end 33 through the common end 32 of the optical circulator 30', and is received and processed by the detector 51 of the optical receiver 50 through the 0-degree filter. In this embodiment, the passband wavelength range of the 0-degree filter can isolate the downlink optical signal λ1 of 1550nm, and can pass the uplink optical signal λ2 of 1555nm. Therefore, the downlink optical signal λ1 with a wavelength of 1550nm emitted from the laser 22 is blocked by the 0-degree filter and cannot enter the detector 51. In this way, the optical module outputs the downlink optical signal λ1 with a wavelength of 1550nm from the common end 32 to the communication optical fiber, and the uplink optical signal λ2 with a wavelength of 1555nm is received from the communication optical fiber by the receiving end 33 and detected by the detector 51.

[0096] In the above embodiment of the present invention, the wavelength difference between the 1550nm wavelength downlink optical signal λ1 emitted by the optical transmitter 20 and the 1555nm wavelength uplink optical signal λ2 transmitted by the communication optical fiber is 5nm. If the three-way device 30 uses a 45-degree filter, the interval between the uplink and downlink wavelengths must be greater than 40nm due to the current process restrictions. Figure 4 In the embodiment shown, the optical circulator 30' is used as the three-way device 30 and can be applied to the optical network 70 with small interval different wavelengths for transmission and reception. It can be understood by those skilled in the art that the different wavelength single-fiber bidirectional optical module 1 conceived by the present embodiment can also be applied to the optical network 70 with the wavelength difference of the uplink and downlink wavelengths less than 5nm, and can also meet the optical communication requirements with larger wavelength intervals of the uplink and downlink wavelengths, such as 8nm, 12nm or even 20nm. In addition, in the above embodiment, the angle between the small-angle filter 401 and the vertical plane of the outgoing optical path of the receiving end 33 is 0 degrees. In the design and manufacture of the device, an angle setting of 0 degrees to 15 degrees can also be selected, for example, an angle of 8 degrees or an angle of 13.5 degrees. As long as the passband wavelength range can isolate the optical signal λ1 of the first wavelength and can pass the optical signal λ2 of the second wavelength, it is within the scope of the embodiments conceived by the present invention.

[0097] Preferably, in the conventional bidirectional communication mode, after the downlink optical signal λ1 is emitted by the laser 22, it enters the optical circulator from the transmitting end 31, and is emitted from the common end 32 through the optical circulator, enters the signal transmission optical fiber, and a coupling lens can be arranged between the optical fiber jack 301 and the optical circulator 30'. At the same time, the signal light λ2 emitted by the optical module at the other end of the optical network 70 passes through the optical network port 71 and the optical fiber jack 301 in sequence through the signal transmission optical fiber, enters the optical circulator from the common end 32, is emitted from the receiving end 33 through the optical circulator, transmits through the small-angle filter 401 placed in front of the optical detector 51, and is finally captured by the detector 51. At the same time, the crosstalk light and reflected light caused by the downlink optical signal λ1 cannot pass through the 0-degree filter, and will not affect the sensitivity of the detector 51.

[0098] Figure 5The working principle diagram of the optical module in the first embodiment under the OTDR detection mode is shown. Different from the current different-wavelength single-fiber bidirectional optical module 1, the optical module provided in the embodiment of the present invention can directly detect the optical fiber line without switching the external OTDR device in addition to the above-mentioned bidirectional communication mode. OTDR uses Rayleigh scattering and Fresnel reflection to characterize the characteristics of the optical fiber. Rayleigh scattering is formed due to the irregular scattering of the optical signal along the optical fiber. The OTDR measures a part of the scattered light returned to the OTDR port. These backscattered signals indicate the degree of attenuation (loss / distance) caused by the optical fiber. The OTDR test method is to transmit a light pulse into the optical fiber and then receive the returned information at the OTDR port. When the light pulse is transmitted in the optical fiber, scattering and reflection will be generated due to the properties of the optical fiber itself, connectors, joints, bends or other similar events. Part of the scattering and reflection will be returned to the OTDR device. The returned useful information is measured by the detector 51 of the OTDR, and they are used as time or curve fragments at different positions in the optical fiber. By determining the time it takes for a signal to be transmitted and returned, and determining the speed of light in the glass material, the distance can be calculated to determine where the event occurred.

[0099] exist Figure 5 In the optical module of the present invention shown, the heterogeneous single-fiber bidirectional optical module 1 with integrated OTDR function also includes an OTDR detection interface 61 and a control unit 60. The OTDR detection interface 61 is connected to the board 72 of the optical communication system; after receiving the optical signal of the second wavelength, the optical receiver 50 converts the optical signal into an electrical signal; the control unit 60 is respectively connected to the OTDR detection interface 61, the optical receiver 50 and the optical transmitter 20, and is used to send a control command to the optical transmitter 20 according to the OTDR detection command received from the OTDR detection interface 61, and is also used to 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 this embodiment adopts a wavelength-adjustable laser 22; in the bidirectional communication mode, the optical transmitter 20 is used to transmit a downlink optical signal λ1 of a first wavelength; in the OTDR detection mode, the control unit 60 sends a control command to the optical transmitter 20 to adjust the wavelength of the pulse laser 22 so that the OTDR detection optical signal has the same wavelength as the uplink optical signal λ2 of the second wavelength.

[0100] Therefore, in the OTDR detection mode of the preferred embodiment of the present invention, when it is necessary to detect the optical fiber line, the optical communication system coordinates the uplink optical signal λ2 to stop sending, and at the same time, according to the OTDR detection command received from the board 72 of the optical communication system through 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 emitted by the laser 22 from λ1 to λ2, and is incident on the optical fiber to be tested through the circulator 30'. After Rayleigh backscattering and Fresnel reflection, the pulse signal is emitted from the optical fiber to be tested, enters the optical circulator, and finally emitted from the receiving end 33, passes through the 0-degree filter, or replaces the 8-degree or 13.5-degree small-angle filter 401, and the detector 51 of the optical receiver 50 captures the OTDR feedback optical signal with the second wavelength λ2 and converts it into an electrical signal. After passing through the amplifier 52 and the analog-to-digital converter, the electrical signal is finally transmitted to the control unit 60, and the control unit 60 calculates and obtains information such as the optical fiber line status and the fault point location.

[0101] For example, the control unit 60 sends a control command to the optical transmitter 20 to tune the wavelength of the OTDR pulse light emitted by the laser 22, and control the laser 22 to emit an OTDR detection pulse light signal with a wavelength of 1555 nm, which is the same as the wavelength of the uplink optical signal λ2 of the optical network 70. The OTDR detection pulse light signal with a wavelength of 1555 nm emitted by the laser 22 of the optical transmitter 20 is transmitted through the transmitting end 31 of the optical circulator 30' into its common end 32, and is sent to the optical network port 71 to be coupled into the communication optical fiber to be tested. The pulse signal is reflected from the communication optical fiber to be tested back to the optical module after Rayleigh backscattering and Fresnel reflection, and its wavelength is consistent with the pulse light. Therefore, the 1555 nm OTDR feedback light signal from the optical network port 71 is transmitted from the common end 32 through the optical circulator 30' into its receiving end 33, and is received by the optical receiver 50 after passing through the 0-degree filter, so that the optical receiver 50 receives the 1555 nm OTDR feedback light signal with the same wavelength as the uplink optical signal λ2 of the optical network 70. The optical transmitter 20 mentioned here transmits an OTDR detection optical signal having the same wavelength as the second wavelength of the uplink optical signal λ2. The so-called "same" in terms of numerical value means that the wavelength range falls between λ2+7 / 20*(λ2-λ1) and λ2-7 / 20*(λ2-λ1). For example, in the aforementioned embodiment of the present invention, the two wavelengths of 1555nm and 1555.1nm can be regarded as the same. It is easy to understand that in an alternative embodiment, part of the control functions of the control unit 60 can also be implemented by the optical transmitter 20 and the optical receiver 50 respectively, and part of the control functions in the optical transmitter 20 and the optical receiver 50 can also be integrated into the control unit 60 for integrated design and manufacturing.

[0102] The optical module provided in this embodiment utilizes a three-way device 30 to achieve the purpose of optical path multiplexing, which not only solves the problem of miniaturization, but also realizes the purpose of long-distance transmission and OTDR functions coexisting without interfering with each other. It should be noted here that the signal transmission function and the OTDR function cannot be performed at the same time.

[0103] Figure 6 and Figure 7 The second embodiment of the optical module of the present invention is shown. The difference from the first embodiment is that the second embodiment uses a tunable filter 402 to replace the small-angle filter 401 in the first embodiment. The tunable filter 402 is characterized in that the bandpass range of the filter can be tuned, and optical signals of different wavelengths can be selected to pass through the filter as needed. Figure 6 As shown, in the bidirectional communication mode, the passband of the tunable filter 402 is set near λ2. At this time, the passband wavelength range of the tunable filter 402 isolates the optical signal λ1 of the first wavelength and transmits the optical signal λ2 of the second wavelength. The downlink optical signal λ1 emitted by the laser 22 of the optical transmitter 20 is transmitted to the common end 32 through the transmitting end 31 of the circulator 30', and enters the communication optical fiber through the optical fiber socket 301 coupling optical network port 71; and the uplink optical signal λ2 transmitted from the communication optical fiber is transmitted from the optical network port 71 through the common end 32 of the circulator 30' to its receiving end 33, and passes through the set tunable filter 402, and is received and processed by the detector 51 of the optical receiver 50. In this embodiment, the bandpass wavelength range of the tunable filter 402 can isolate the downlink optical signal λ1 and can pass the uplink optical signal λ2. Therefore, the downlink optical signal λ1 emitted from the laser 22 is blocked by the set tunable filter 402 and cannot enter the detector 51. In this way, the optical module outputs the downlink optical signal λ1 from the common end 32 to the communication optical fiber, and the uplink optical signal λ2 is received from the communication optical fiber by the receiving end 33.

[0104] like Figure 7In the second embodiment of the optical module of the present invention shown, in the OTDR detection mode, when it is necessary to detect the optical fiber line, according to the OTDR detection command received from the board 72 of the optical communication system through the OTDR detection interface 61, the control unit 60 sends a control command to the tunable filter 402 to adjust the passband of the filter to near λ1. At this time, the passband wavelength range of the tunable filter 402 transmits the optical signal λ1 of the first wavelength and isolates the optical signal λ2 of the second wavelength. Then the control unit 60 sends a control command to the optical transmitter 20 to emit a laser pulse laser signal wavelength λ1, which is incident on the optical fiber to be tested through the circulator 30'. After Rayleigh backscattering and Fresnel reflection, the pulse signal is emitted from the optical fiber to be tested, enters the optical circulator, and finally emitted from the receiving end 33, transmitted through the tunable filter 402, and the OTDR feedback optical signal with the second wavelength λ1 is captured by the detector 51 of the optical receiver 50 and converted into an electrical signal. After passing through the amplifier 52 and the analog-to-digital converter, the electrical signal is finally transmitted to the control unit 60, and the control unit 60 calculates information such as the optical fiber line status and the location of the fault point. As mentioned above, the so-called "same" in terms of numerical value means that the wavelength range falls between λ2+7 / 20*(λ2-λ1) and λ2-7 / 20*(λ2-λ1). For example, in the following embodiment, the two wavelengths of 1550nm and 1550.1nm can be regarded as the same.

[0105] In a preferred embodiment of the present invention, after receiving the OTDR detection command, the control unit 60 sends a control command to the tunable filter 402 to adjust the passband of the filter to the vicinity of the downstream optical signal λ1 of 1550nm. For example, when the passband center is 1550.1nm, the passband wavelength range of the tunable filter 402 still transmits the optical signal λ1 of 1550nm and isolates the upstream optical signal λ2 of 1555nm. In the OTDR detection mode, the control unit 60 sends a control command to the optical transmitter 20 to emit a laser pulse signal λ1 of 1550nm, which is incident on the optical fiber to be tested as an OTDR detection optical signal after passing through the circulator 30'. The pulse signal with a wavelength of 1550nm is emitted from the optical fiber to be tested after Rayleigh backscattering and Fresnel reflection, enters the optical circulator as an OTDR feedback optical signal with a wavelength of 1550nm, and finally emits from the receiving end 33, transmits through the tunable filter 402, and is captured by the detector 51 of the optical receiver 50 with a wavelength λ1 of 1550nm and converted into an electrical signal.

[0106] The second embodiment of the present invention may have other different replacement modes, as long as it satisfies that in the OTDR detection mode, the optical transmitter 20 transmits an OTDR detection optical signal having a different wavelength from the uplink optical signal λ2 having a second wavelength, and the bandpass wavelength range of the tunable filter 402 is tuned to transmit the OTDR detection optical signal and isolate the optical signal λ2 having the second wavelength. For example, after receiving the OTDR detection command, the control unit 60 instructs the tunable filter 402 to adjust the filter passband to near the optical signal of 1545nm, so that the bandpass wavelength range of the tunable filter 402 transmits the optical signal of 1545nm and isolates the uplink optical signal λ2 having a wavelength of 1555nm. In the OTDR detection mode, the control unit 60 sends a control command to the optical transmitter 20 to adjust the wavelength of the laser 22 from 1550nm in the bidirectional communication mode to 1545nm, and emits a laser pulse signal having a wavelength of 1545nm. After passing through the circulator 30', the OTDR detection optical signal having a wavelength of 1545nm is incident on the optical fiber to be tested. The pulse signal is emitted from the optical fiber to be tested after Rayleigh backscattering and Fresnel reflection, enters the optical circulator as an OTDR feedback optical signal with a wavelength of 1545 nm, and finally emitted from the receiving end 33, transmitted through the tunable filter 402, and received by the optical receiver 50.

[0107] Figure 8 The preferred embodiment of the optical module of the present invention shown in the figure also 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 encapsulated in the housing.

[0108] Preferably, Figure 8 The optical module in the embodiment further includes an electromagnetic interference EMI shrapnel 500, which seals the gap of the housing 100. The EMI shrapnel 500 has a radiation protection function, enhances the safety of the OTDR optical module, and reduces the harm to the user's body.

[0109] Preferably, Figure 8 As shown, it also includes an unlocking pull ring that can movably block the LC optical interface 600, and the unlocking pull ring 700 is installed on the housing 100. The unlocking pull ring 700 can protect the LC optical interface 600 from water and dust.

[0110] The present invention also provides an OTDR detection method applied to a different wavelength single-fiber bidirectional optical module 1, such as Fig. 9As shown, the different-wavelength single-fiber bidirectional optical module 1 used in the OTDR detection method shown in the figure can be switched between the bidirectional optical communication mode and the OTDR detection mode.

[0111] In the bidirectional optical communication mode, the optical transmitter 20 emits a first wavelength downlink optical signal λ1, which is transmitted to the optical network port 71 from its common end 32 after passing through the three-way device 30; the uplink optical signal λ2 of the second wavelength from the optical network port 71 passes through the three-way device 30, and is emitted from the receiving end 33 of the three-way device 30, and is received by the optical receiver 50 after passing through the filter device 40, such as the small-angle filter 401. The passband wavelength range of the small-angle filter 401 isolates the first wavelength optical signal λ1 and passes the second wavelength optical signal λ2. Preferably, in the bidirectional communication mode of the hetero-wavelength single-fiber bidirectional optical module 1, after the downlink optical signal λ1 is emitted by the laser 22, it enters the optical circulator from the transmitting end 31, and is emitted from the common end 32 through the optical circulator, and enters the signal transmission optical fiber, and a coupling lens can be provided between the optical fiber jack 301 and the circulator 30'. At the same time, the signal light λ2 emitted by the optical module at the other end of the optical network 70 passes through the optical network port 71 and the optical fiber jack 301 in sequence through the signal transmission optical fiber, enters the optical circulator from the common end 32, is emitted from the receiving end 33 after passing through the optical circulator, passes through the small-angle filter 401 placed in front of the optical detector 51, and is finally captured by the detector 51. At the same time, the crosstalk light and reflected light caused by the downlink optical signal λ1 cannot pass through the 0-degree filter, and will not affect the sensitivity of the detector 51.

[0112] According to one embodiment of the present invention, the filter device 40 adopts a small-angle filter 401. In the OTDR detection mode, the OTDR detection interface 61 on the optical module receives an OTDR detection command from a board 72 of the optical communication system, switches the optical module from the optical communication mode to the OTDR detection mode, sends a control command to the optical transmitter 20, adjusts the wavelength of the pulse laser 22 from the first wavelength of the downlink optical signal λ1 to λ2, so that the optical transmitter 20 emits an OTDR detection pulse optical signal with the same wavelength as the second wavelength of the uplink optical signal λ2, and transmits it to the optical network port 71 from its 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 passes through the three-way device 30, is emitted from the receiving end 33 of the three-way device, and is received by the optical receiver 50 after passing through the small-angle filter 401; when the detector 51 of the optical receiver 50 captures the OTDR feedback optical signal with the second wavelength λ2, the electrical signal of the optical receiver 50 is processed. After passing through the amplifier 52 and the analog-to-digital converter, the electrical signal is finally transmitted to the control unit 60, and the control unit 60 can calculate information such as the optical fiber line status and the fault point location, and send the processed data to the board card 72 of the optical communication system through the OTDR detection interface 61; in an alternative embodiment, the control unit 60 directly transmits the electrical signal of the optical receiver 50 to the board card 72 of the optical communication system connected to the OTDR detection interface 61, and the board card 72 of the optical communication system processes it, including data processing and mathematical processing, to form data on light intensity and distance changes, and obtain an OTDR detection curve.

[0113] As another embodiment of the present invention, the filter device 40 adopts a tunable filter 402 as an alternative to the OTDR detection method applied to the different-wavelength single-fiber bidirectional optical module 1. The detection method in the OTDR detection mode according to the embodiment of the present invention includes sending a control command to the optical transmitter 20 and / or the tunable filter 402 according to the OTDR detection command received by the OTDR detection interface 61 on the optical module from the board 72 of the optical communication system. The optical transmitter 20 is made to emit an OTDR detection optical signal having the same wavelength λ1 as the downlink optical signal of the first wavelength; the bandpass wavelength range of the tunable filter 402 is tuned so that the bandpass wavelength range transmits the OTDR detection optical signal and isolates the optical signal λ2 of the second wavelength; then the OTDR detection optical signal emitted by the optical transmitter 20 is transmitted through the transmitting end 31 of the three-way device 30 into the common end 32 and sent to the optical network port 71; the OTDR detection optical signal is incident on the optical fiber to be tested, the pulse signal is emitted from the optical fiber to be tested after Rayleigh backscattering and Fresnel reflection, and the OTDR feedback optical signal having the same wavelength as the OTDR detection optical signal that reaches the optical network port 71 is then emitted from the receiving end 33 of the three-way device 30 after passing through the three-way device 30 from the common end 32, and reaches the optical receiver 50 after passing through the filter device 40; the optical receiver 50 is used to convert the optical signal into an electrical signal after receiving the OTDR feedback optical signal.

[0114] In another preferred embodiment using the tunable filter 402, the wavelength of the pulse laser 22 is adjusted so that the optical transmitter 20 emits an OTDR detection optical signal having a wavelength different from that of the second wavelength uplink optical signal λ2; the passband wavelength range of the tunable filter 402 is tuned so that the passband wavelength range transmits the OTDR detection optical signal and isolates the second wavelength optical signal λ2; the electrical signal of the optical receiver 50 is processed, and the processed data is sent to the board card 72 of the optical communication system through the OTDR detection interface 61; or the electrical signal of the optical receiver 50 is transmitted to the board card 72 of the optical communication system connected to the OTDR detection interface 61, and is processed by the board card 72 of the optical communication system.

[0115] It should be noted by those skilled in the art that the OTDR detection method described in this embodiment cannot realize the signal transmission function and the OTDR function at the same time, but needs to switch between the bidirectional optical communication mode and the OTDR detection mode. The advantage is that the OTDR detection method can perform normal communication services and perform optical fiber link detection when necessary, which is very suitable for monitoring channels in trunk communications.

[0116] Although the present invention has been specifically shown and described in conjunction with the preferred embodiments, it is obvious to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-restrictive, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present invention. Any figure mark in the claims should not be regarded as limiting the claims involved. In addition, it is obvious that the word "comprising" does not exclude other units or steps, and the singular does not exclude the plural. Multiple units or devices stated in the device claim can also be implemented by one unit or device through software or hardware. The words first, second, etc. are used to indicate names, and do not indicate any particular order.

[0117] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the embodiments of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A different-wavelength single-fiber bidirectional optical module with integrated OTDR function, characterized in that: It comprises an optical transmitter (20), a three-way device (30), a filter device (40) and an optical receiver (50) which are connected in sequence, wherein the optical transmitter (20) adopts a wavelength-adjustable pulse laser (22); In two-way communication mode, The optical transmitter (20) is used to transmit a downlink optical signal λ1 of a first wavelength; The optical receiver (50) is used to receive an uplink optical signal λ2 of a second wavelength; The passband wavelength range of the filter device (40) isolates the optical signal λ1 of the first wavelength and passes the optical signal λ2 of the second wavelength; In an OTDR detection mode, adjusting the wavelength-adjustable pulse laser (22) so that the optical transmitter (20) transmits an OTDR detection optical signal; The three ports of the three-way device (30) are respectively a transmitting end (31), a common end (32) and a receiving end (33); the transmitting end (31) is connected to the optical transmitter (20); the common end (32) is connected to the optical fiber socket (301); and the optical fiber socket (301) is connected to the optical network port (71); Its receiving end (33) is connected to the optical receiver (50), so that a downlink optical signal λ1 of a first wavelength emitted from the optical transmitter is transmitted through its transmitting end (31) into the optical fiber socket (301) of the common end (32) and thus enters the optical network (70), while an uplink optical signal λ2 of a second wavelength from the optical network port (71) is transmitted from the common end (32) through the three-way device (30) into the receiving end (33), and is received by the optical receiver (50) after passing through the filter device (40).

2. The different-wavelength single-fiber bidirectional optical module with integrated OTDR function as claimed in claim 1, characterized in that: In OTDR detection mode, The optical transmitter (20) is used to transmit an OTDR detection optical signal; The passband wavelength range of the filter device (40) detects the optical signal through the OTDR; The OTDR detection optical signal emitted from the optical transmitter (20) is transmitted through the transmitting end (31) of the three-way device (30) into the common end (32) and is 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 detection optical signal 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), and reaches the optical receiver (50) after passing through the filter device (40); The optical receiver (50) is used to receive the OTDR feedback optical signal.

3. The different-wavelength single-fiber bidirectional optical module with integrated OTDR function as claimed in claim 1 or 2, characterized in that: The filter device (40) is a small-angle filter (401), and the included angle between the small-angle filter (401) and a vertical plane of the outgoing light path of the receiving end (33) is 0 to 15 degrees, preferably 0 degrees.

4. The different-wavelength single-fiber bidirectional optical module with integrated OTDR function as claimed in claim 3, characterized in that: In OTDR detection mode, The optical transmitter (20) transmits an OTDR detection optical signal having the same wavelength as the uplink optical signal λ2 of the second wavelength.

5. The different-wavelength single-fiber bidirectional optical module with integrated OTDR function as claimed in claim 1 or 2, characterized in that: The filter device (40) is a tunable filter (402) having a tunable bandpass wavelength range.

6. The different-wavelength single-fiber bidirectional optical module with integrated OTDR function as claimed in claim 5, characterized in that: In OTDR detection mode, The optical transmitter (20) transmits an OTDR detection optical signal having a wavelength different from that of the second wavelength uplink optical signal λ2; The passband wavelength range of the tunable filter (402) is tuned to transmit the OTDR detection optical signal and isolate the optical signal λ2 of the second wavelength.

7. The different-wavelength single-fiber bidirectional optical module with integrated OTDR function as claimed in claim 6, characterized in that: The optical transmitter (20) transmits an OTDR detection optical signal having the same wavelength λ1 as the first wavelength of the downlink optical signal.

8. The different-wavelength single-fiber bidirectional optical module (1) capable of integrating OTDR function according to any one of claims 1, 2, 4, 6 or 7, characterized in that: The three-way device is an optical circulator (30').

9. The different-wavelength single-fiber bidirectional optical module with integrated OTDR function as claimed in claim 8, characterized in that: The wavelength difference between the optical signal λ1 of the first wavelength and the optical signal λ2 of the second wavelength is less than or equal to 8 nm.

10. The different-wavelength single-fiber bidirectional optical module with integrated OTDR function as claimed in claim 7, characterized in that: It also includes an OTDR detection interface (61) and a control unit (60), The OTDR detection interface (61) is connected to a board (72) of an optical communication system; After receiving the OTDR feedback optical signal, the optical receiver (50) converts the optical signal into an electrical signal; The control unit (60) is connected to the OTDR detection interface (61), the optical receiver (50) and the optical transmitter (20) respectively, and is used to send a control command to the optical transmitter (20) and / or the tunable filter (402) according to an OTDR detection command received from the OTDR detection interface (61), and is also used to 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).

11. An OTDR detection method, applied to a different-wavelength single-fiber bidirectional optical module, comprising: In two-way communication mode, The optical transmitter (20) transmits a downlink optical signal λ1 of a first wavelength, which passes through a three-way device and is then transmitted from its common end (32) to an optical network port (71); An uplink optical signal λ2 of a second wavelength from an optical network port (71) passes through a three-way device, is emitted from a receiving end (33) of the three-way device, and is received by an optical receiver (50) after passing through a filter device (40), wherein the passband wavelength range of the filter device (40) isolates the optical signal λ1 of the first wavelength and passes the optical signal λ2 of the second wavelength; In OTDR detection mode, The optical transmitter (20) uses a wavelength-tunable pulse laser (22); Allowing the passband wavelength range of the filter device (40) to pass through the OTDR to detect the optical signal; The OTDR detection optical signal emitted by the optical transmitter (20) is transmitted through the transmitting end (31) of the three-way device to enter the common end (32) and is sent to the optical network port (71); An OTDR feedback optical signal having the same wavelength as the OTDR detection optical signal from the optical network port (71) passes through the three-way device from the common end (32), is emitted from the receiving end (33) of the three-way device, and reaches the optical receiver (50) after passing through the filter device (40); The optical receiver (50) is used for converting the optical signal into an electrical signal after receiving the OTDR feedback optical signal.

12. The OTDR detection method according to claim 11, wherein: When the filter device (40) adopts a small-angle filter (401), the detection method in the OTDR detection mode further comprises: Sending a control command to the optical transmitter (20) according to an OTDR detection command received by the OTDR detection interface (61) on the optical module from a board (72) of the optical communication system; Adjusting the wavelength-adjustable pulse laser (22) so that the optical transmitter (20) transmits an OTDR detection optical signal having the same wavelength as the second wavelength uplink optical signal λ2; 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); Alternatively, the electrical signal of the optical receiver (50) is transmitted to a board card (72) of an optical communication system connected to an OTDR detection interface (61), and is processed by the board card (72) of the optical communication system.

13. The OTDR detection method according to claim 11, wherein: When the filter device (40) adopts a tunable filter (402), the detection method in the OTDR detection mode further includes: Sending a control command to the optical transmitter (20) and / or the tunable filter (402) according to an OTDR detection command received by the OTDR detection interface (61) on the optical module from a board (72) of the optical communication system; The optical transmitter (20) transmits an OTDR detection optical signal having the same wavelength λ1 as the first wavelength of the downlink optical signal; or adjusting the wavelength-adjustable pulse laser (22) so that the optical transmitter (20) transmits an OTDR detection optical signal having a wavelength different from that of the second wavelength uplink optical signal λ2; Tuning the passband wavelength range of the tunable filter (402) so that the passband wavelength range transmits the OTDR detection optical signal and isolates the second wavelength optical signal λ2; 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); Alternatively, the electrical signal of the optical receiver (50) is transmitted to a board card (72) of an optical communication system connected to an OTDR detection interface (61), and is processed by the board card (72) of the optical communication system.

14. The OTDR detection method according to any one of claims 12 or 13, characterized in that: The optical module (1) or a board (72) of an optical communication system connected to the optical module (1) processes the electrical signal, specifically including digital processing and mathematical processing, to form data on light intensity and distance changes.

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