TWI811094B - Distributed fiber sensor for multi-wavelength communication - Google Patents

Abstract

A distributed fiber sensor for multi-wavelength communication is provided, including an interrogator, a first optical add/drop multiplexer (OADM), a second OADM, and an optical amplifier. The interrogator is for transmitting a detect light to a first fiber, wherein the first fiber is for communicate light transmission. The first OADM includes a first common port, a first express port for the communication light transmission, and a first add/drop port for detecting light transmission, wherein the first common port optically coupled to the interrogator through the first fiber. The second OADM includes a second common port, a second express port, and a second add/drop port, wherein the first express port optically coupled to the first express port and the second add/drop port optically coupled to the first add/drop port. The optical amplifier is set between the first express port and the second express port.

Description

Distributed Fiber Optic Sensors for Multiwavelength Communications

The invention relates to a distributed optical fiber sensor for multi-wavelength communication.

Distributed optical fiber sensing technology uses optical fiber as an environmental sensing element, which can inject pulse wave detection light into the optical fiber to generate backscattered light in the optical fiber. Since the characteristics of the backscattered light of the optical fiber change due to the environmental factors of the fiber (such as vibration or temperature change), the environmental conditions near the fiber can be detected by analyzing the characteristic changes of the backscattered light. Since distributed optical fiber sensing technology must detect backscattered light, the optical fiber routing used cannot use communication devices that only allow one-way transmission.

On the other hand, in order to increase the transmission distance of multi-wavelength communication, the optical fiber used for multi-wavelength communication needs to use components such as amplifiers that only need to allow unidirectional transmission. Therefore, optical fibers used for multi-wavelength communication are difficult to implement distributed optical fiber sensing technology. If the user intends to deploy the distributed optical fiber sensor at a specific location, the user needs to re-lay the optical fiber used to implement the distributed optical fiber sensing technology. The existing optical fibers in the telecommunications network will not be available to users.

The invention provides a distributed optical fiber sensor for multi-wavelength communication, which can simultaneously implement multi-wavelength communication technology and distributed optical fiber sensing technology on the same optical fiber.

A distributed optical fiber sensor for multi-wavelength communication of the present invention includes an interrogator, a first optical plug and demultiplexer, a second optical plug and demultiplexer and an optical amplifier. The interrogator is used to send detection light to the first optical fiber, wherein the first optical fiber is used to transmit communication light. The first optical plug and multiplexer includes a first common port, a first through port for transmitting communication light, and a first plug and take port for transmitting detection light, wherein the first common port is optically coupled through a first optical fiber to the interrogator. The second optical plug and multiplexer includes a second common port, a second through port and a second plug port, wherein the second through port is optically coupled to the first through port, and the second through port is optically coupled to the first through port Plug the port. The optical amplifier is arranged between the first through port and the second through port.

In an embodiment of the present invention, the above-mentioned distributed optical fiber sensor further includes a detection light processing module. The detection light processing module is arranged between the first plug port and the second plug port, wherein the optical fiber detection light processing module is used to transmit the detection light from the first plug port to the second plug port, And it is used to transmit the backscattered light corresponding to the detection light from the second light plug port to the first light plug port.

In an embodiment of the present invention, the detection light processing module includes a first optical coupling device, a second optical coupling device and a first optical amplifier. The first optical coupling device includes a first port, a second port and a third port, wherein the first port is optically coupled to the first plug port. The second optical coupling device includes a fourth port, a fifth port and a sixth port, wherein the fourth port is optically coupled to the second port, the fifth port is optically coupled to the second port, and the sixth port is optically coupled to the third port. port. The first optical amplifier is disposed between the second port and the fifth port, wherein the input end of the first optical amplifier is optically coupled to the second port, and the output end of the first optical amplifier is optically coupled to the fifth port.

In an embodiment of the present invention, the above detection light processing module further includes a second optical amplifier. The second optical amplifier is disposed between the third port and the sixth port, wherein the input end of the second optical amplifier is optically coupled to the sixth port, and the output end of the second optical amplifier is optically coupled to the third port.

In an embodiment of the present invention, the above detection light processing module further includes an optical filter. The optical filter is arranged between the output terminal of the first optical amplifier and the fifth port.

In an embodiment of the present invention, the above detection light processing module further includes an optical filter. The optical filter is arranged between the output terminal of the second optical amplifier and the third port.

In an embodiment of the present invention, the detection light processing module includes a first optical coupling device, a second optical coupling device and a second optical amplifier. The first optical coupling device includes a first port, a second port and a third port, wherein the first port is optically coupled to the first plug port. The second optical coupling device includes a fourth port, a fifth port and a sixth port, wherein the fourth port is optically coupled to the second port, the fifth port is optically coupled to the second port, and the sixth port is optically coupled to the third port. port. The second optical amplifier is disposed between the third port and the sixth port, wherein the input end of the second optical amplifier is optically coupled to the sixth port, and the output end of the first optical amplifier is optically coupled to the third port.

In an embodiment of the present invention, the above-mentioned first optical coupling device is an optical splitter, wherein the first port is the common port of the optical splitter, and the second port and the third port are respectively the first branch of the optical splitter port and the second branch port.

In an embodiment of the present invention, the above-mentioned first optical coupling device is an optical circulator.

In an embodiment of the present invention, the above-mentioned second optical coupling device is an optical splitter, wherein the fifth port is the common port of the optical splitter, and the fourth port and the sixth port are respectively the first branch of the optical splitter port and the second branch port.

In an embodiment of the present invention, the above-mentioned second optical coupling device is an optical circulator.

In an embodiment of the present invention, the input end of the optical amplifier is optically coupled to the first through port, and the output end of the optical amplifier is optically coupled to the second through port.

In an embodiment of the present invention, the above-mentioned distributed optical fiber sensor further includes a high-density wavelength division multiplexer. The high-density wavelength division multiplexer includes a first channel port for receiving communication light, a second channel port for receiving detection light, and a common port, wherein the common port is optically coupled to the first common port.

In an embodiment of the present invention, the above-mentioned distributed optical fiber sensor further includes a high-density wavelength division multiplexer. The high-density wavelength division multiplexer includes a common port for receiving communication light and detection light, a first channel port for transmitting communication light, and a second channel port for transmitting detection light, wherein the common port is optically coupled to the second channel port Two common ports.

Based on the above, the present invention can use optical fiber for communication as a distributed optical fiber sensor without affecting the communication quality of multi-wavelength optical communication. In this way, the existing optical fiber in the telecommunication network can be transformed into an optical fiber capable of detecting environmental conditions (such as vibration or temperature), thereby expanding the application of the existing optical fiber network. For example, the present invention can be implemented on existing communication optical fibers to realize homeland security monitoring functions such as traffic condition monitoring, infrastructure health monitoring, underground pipeline safety monitoring, earthquake early warning or landslide early warning.

Distributed optical fiber sensing technology uses the optical fiber itself as the sensing element, and its testing principle is that an interrogator sends pulse detection light to the optical fiber. The interrogator can receive and analyze the backscattered light generated when the pulse wave detection light is transmitted along the optical fiber. The backscattered light is affected by environmental factors (such as vibration or temperature), so the interrogator can measure the environmental vibration or temperature change at each point of the optical fiber through the backscattered light, as shown in Figure 1.

In order to receive backscattered light, the fiber path of traditional distributed fiber optic sensors must not have active/passive components that block backscattered light from returning to the interrogator, such as isolators or erbium-doped optical fiber amplifiers. amplifier, EDFA) and so on. Fiber optic networks have become ubiquitous due to communication needs. Using existing optical fibers as environmental sensing components can not only save the cost of optical fiber construction, but also expand the detection range, so that existing optical fibers can be used in infrastructure health monitoring, homeland security, and traffic control, etc. However, in order to increase the communication distance, current communication systems usually install optical amplifiers that only allow one-way transmission. Due to the restriction that there must be no active/passive elements on the optical fiber path to prevent backscattered light from returning to the interrogator, the use of existing optical fibers in the communication network for environmental sensing elements will be restricted.

In view of this, the present invention proposes a distributed optical fiber sensor for multi-wavelength communication, which can make the transmission of detection light or backscattered light bypass the unidirectional transmission component path for communication. The transmission path of detection light or backscattered light can be equipped with an optical amplifier to increase the measurement distance. The distributed optical fiber sensor of the present invention can use the same optical fiber to realize distributed optical fiber sensing and multi-wavelength communication, thereby expanding the application of the existing optical fiber network.

FIG. 2 is a schematic diagram of a distributed optical fiber sensor 100 for multi-wavelength communication according to an embodiment of the present invention. The distributed optical fiber sensor 100 may include an interrogator 01 , an optical add/drop multiplexer (OADM) 07 , an optical add/drop multiplexer 08 and an optical amplifier 06 . In one embodiment, the distributed optical fiber sensor 100 may further include a detection light processing module 10, a high-density wavelength division multiplexer (dense wavelength division multiplexer, DWDM) 04, a high-density wavelength division multiplexer 11, and an optical router Switch mechanism 12. In the distributed optical fiber sensor 100 , various components can be optically coupled to each other through optical fibers, and these optical fibers (for example: optical fiber 05 or optical fiber 13 ) can simultaneously transmit communication light 03 , detection light 02 and backscattered light 09 .

The HDWDM 04 includes a channel port 41 for receiving the communication light 03 , a channel port 42 for receiving the detection light 02 and transmitting the backscattered light 09 , and a common (common or line) port 43 . The communication light 03 may include a plurality of communication lights having wavelengths λ ₁ , λ ₂ , λ ₃ , . . . , λ _n , respectively. Communication lights of different wavelengths can be input into the HDWDM 04 through different channel ports of the HDWDM 04 .

The interrogator 01 can be optically coupled to the channel port 42 of the HDWDM 04 through optical fiber. The interrogator 01 can transmit the detection light 02 with a wavelength of λ _sf to the HDWDM 04 , and can receive backscattered light 09 with a wavelength of λ _sb corresponding to the detection light 02 from the HDWDM 04 . If used for environmental monitoring, the interrogator 01 can analyze whether the characteristics of the backscattered light 09 change, and then determine whether the environment changes in the area where the optical fiber of the distributed optical fiber sensor 100 passes. If the interrogator 01 detects that the backscattered light 09 changes, the interrogator 01 can output a warning message to notify the user.

The common port 43 of the high-density wavelength multiplexer 04 can be optically coupled to the high-density wavelength multiplexer 11 through the optical fiber 05, and can transmit the detection light 02 or the communication light 03 to the high-density wavelength multiplexer 11 through the optical fiber 05, or through the optical fiber 05 receives the backscattered light 09 from the high-density wavelength division multiplexer 11. On the path of the optical fiber 05 between the high-density wavelength division multiplexer 04 and the high-density wavelength division multiplexer 11, the optical plug and multiplexer 07, the optical plug and multiplexer 08, the optical amplifier 06 and the detection light processing can be configured Module 10.

The optical plug and multiplexer 07 may include a common port 71 , an express port 72 and an add/drop port 73 . The common port 43 of the HDWDM 04 can be optically coupled to the common port 71 through the optical fiber 05 . Accordingly, the interrogator 01 can be optically coupled to the common port 71 through the high-density wavelength division multiplexer 04 and the optical fiber 05 . The high-density wavelength division multiplexer 04 can transmit the communication light 03 from the channel port 41 and the detection light 02 from the channel port 42 to the common port 71 of the optical plug and multiplexer 07 through the optical fiber 05 . The optical plug and multiplexer 07 can distinguish the optical signal received by the common port 71 into the detection light 02 and the communication light 03, and output the detection light 02 and the communication light 03 through different channels, wherein the detection light 02 is controlled by the plug The port 73 is output, and the communication light 03 is output by the through port 72.

The optical plug and multiplexer 08 may include a common port 81 , a through port 82 and a plug port 83 . The through port 72 of the optical plug and multiplexer 07 can be optically coupled to the through port 82 of the optical plug and multiplexer 08 through the optical amplifier 06 . That is to say, the optical amplifier 06 can be disposed between the through port 72 and the through port 82 . The plug port 73 of the optical plug and multiplexer 07 can be optically coupled to the plug port 83 of the optical plug and multiplexer 08 through the detection optical processing module 10 . That is to say, the detection light processing module 10 can be disposed between the plug port 73 and the plug port 83 .

The optical amplifier 06 is, for example, an erbium-doped fiber amplifier. The input of the optical amplifier 06 can be optically coupled to the through port 72 of the optical plug and multiplexer 07 , and the output of the optical amplifier 06 can be optically coupled to the through port 82 of the optical plug and multiplexer 08 . The optical amplifier 06 can transmit optical signals in one direction. The input port of the optical amplifier 06 is connected to the through port 72, and the optical signal from the through port 72 can be transmitted to the through port 82, but the optical signal from the through port 82 cannot be transmitted to the through port 72. Therefore, the path between the through port 72 and the through port 82 can only be used to transmit unidirectionally transmitted light (for example: communication light 03 ), but cannot be used for transmitting reversely transmitted light (for example: anti-scattered light 09 ). The optical amplifier 06 can receive the communication light 03 from the through port 72 of the optical plug-and-multiplexer 07 . The optical amplifier 06 can amplify the communication light 03 and transmit the amplified communication light 03 to the pass-through port 82 of the optical add/demultiplexer 08 .

The optical amplifier 06 is used to amplify the communication light 03 to extend the optical communication distance. The detection light 02 and the multi-wavelength communication light 03 can be transmitted in the same direction or in opposite directions. When the transmission direction of the detection light 02 is opposite to that of the communication light, the detection light 02 cannot pass through the optical amplifier 06 . When the transmission direction of the detection light 02 is the same as that of the communication light, the noise amplified by the optical amplifier 06 will affect the sensing performance of the optical fiber and the backscattered light 09 cannot pass through the optical amplifier 06 . In order to solve the above-mentioned problems, the distributed optical fiber sensor 100 of the present invention can bypass the optical amplifier 06 for the detection light 02 (or the backscattered light 09 ) and transmit it through the detection light processing module 10 instead.

The detection light processing module 10 can bidirectionally transmit light signals. The detection light processing module 10 can transmit the optical signal from the plug port 73 to the plug port 83 , and can also transmit the light signal from the plug port 83 to the plug port 73 . Therefore, the path between the plug port 73 and the plug port 83 can be used to transmit detection light (eg, detection light 02 ) or backscattered light (eg, backscattered light 09 ). Specifically, the detection light processing module 10 can receive the detection light 02 from the plug port 73 of the optical plug and multiplexer 07, and transmit the detection light 02 to the plug port of the optical plug and multiplexer 08. 83. On the other hand, the detection light processing module 10 can receive the backscattered light 09 from the plug port 83 of the optical plug and multiplexer 08, and transmit the back scattered light 09 to the plug port of the optical plug and multiplexer 07 73.

The optical plug and multiplexer 08 can collect the optical signals such as the communication light 03 obtained from the through port 82 and the detection light 02 obtained from the plug port 83, and output the collected optical signals to high-density demultiplexing through the common port 81 Demultiplexer 11. On the other hand, the common port 81 of the optical plug and multiplexer 08 can receive the backscattered light 09 from the side of the high-density wavelength division multiplexer 11 . The plug port 83 of the optical plug and multiplexer 08 can transmit the backscattered light 09 to the plug port 73 of the optical plug and multiplexer 07 through the detection light processing module 10 .

The high-density wavelength division multiplexer 11 includes a common port 115 for receiving the communication light 03 and the detection light 02 The input port 115 of the optical plug and multiplexer 08, wherein the common port 115 is optically coupled to the common port 81 of the optical plug and multiplexer 08. The high-density wavelength division multiplexer 11 can be optically coupled to the high-density wavelength division multiplexer 04 through the common port 115, and can receive the collected communication light 03 and detection light 02 through the common port 115, or transmit the anti-scattered light 09 through the common port 115 To HDDM 04.

The HDWDM 11 may further include one or more channel ports 111 for transmitting communication light 03 , and may include channel ports 112 for receiving backscattered light 09 or transmitting detection light 02 . After obtaining the collected optical signals, the high-density wavelength division multiplexer 11 can distinguish the collected optical signals into communication light 03 and detection light 02 . The communication light 03 may include a plurality of communication lights having wavelengths λ ₁ , λ ₂ , λ ₃ , . . . , λ _n , respectively. The communication lights of different wavelengths can be output through the channel port 111 of the high-density wavelength division multiplexer 11 . The detection light 02 can be output to the optical routing switching mechanism 12 through the channel port 112 of the high-density wavelength division multiplexer 11, wherein the optical routing switching mechanism 12 is used to connect the channel port 112 to another optical fiber 13, so as to extend the distributed optical fiber sensing The detection range of the detector 100. The channel port 112 can receive the backscattered light 09 from the optical fiber 13 through the optical routing switching mechanism 12 , and can transmit the backscattered light 09 to the common port 81 of the optical plug and multiplexer 08 .

FIG. 3 shows a schematic diagram of the detection light processing module 10 according to an embodiment of the present invention. The light processing module 10 can include an optical fiber 23 . The plug port 73 of the optical plug and multiplexer 07 can transmit the detection light 02 to the plug port 83 of the optical plug and multiplexer 08 through the optical fiber 23 . The plug port 83 of the optical plug and multiplexer 08 can transmit the backscattered light 09 to the plug port 73 of the optical plug and multiplexer 07 through the optical fiber 23 .

FIG. 4 shows a schematic diagram of a detection light processing module 10 according to another embodiment of the present invention, wherein the detection light processing module 10 can be used to improve the communication quality of the detection light 02 . The detection light processing module 10 may include an optical coupling device 50 , an optical amplifier 16 , an optical filter 17 and an optical coupling device 60 . The optical coupling device 50 may include a port 51 , a port 52 and a port 53 . The port 51 of the optical coupling device 50 can be optically coupled to the plug port 73 of the optical plug and multiplexer 07 . The optical coupling device 60 may include a port 61 , a port 62 and a port 63 . The port 61 of the optical coupling device 60 can be optically coupled to the plug port 83 of the optical plug and multiplexer 08 . The port 52 of the optical coupling device 50 can be optically coupled to the port 62 of the optical coupling device 60 through the optical fiber 23 , wherein the optical amplifier 16 and the optical filter 17 can be disposed on the optical fiber 23 . The port 53 of the optical coupling device 50 can be optically coupled to the port 63 of the optical coupling device 60 through the optical fiber 20 .

The optical amplifier 16 is provided between the port 52 of the optical coupling device 50 and the port 62 of the optical coupling device 60 . The optical amplifier 16 can transmit optical signals in one direction. Specifically, an input of optical amplifier 16 may be optically coupled to port 52 and an output of optical amplifier 16 may be optically coupled to port 62 . The optical amplifier 16 can amplify the detection light 02 from the port 52 of the optical coupling device 50 and transmit the amplified detection light 02 to the port 62 of the optical coupling device 60 . The optical filter 17 can be disposed between the output end of the optical amplifier 16 and the port 62 of the optical coupling device 60 , and can be used to filter the detection light 02 amplified by the optical amplifier 16 .

FIG. 5 shows a schematic diagram of a detection light processing module 10 according to another embodiment of the present invention, wherein the detection light processing module 10 can be used to improve the communication quality of the backscattered light 09 . The detection light processing module 10 may include an optical coupling device 50 , an optical amplifier 21 , an optical filter 22 and an optical coupling device 60 . The optical coupling device 50 may include a port 51 , a port 52 and a port 53 . The port 51 of the optical coupling device 50 can be optically coupled to the plug port 73 of the optical plug and multiplexer 07 . The optical coupling device 60 may include a port 61 , a port 62 and a port 63 . The port 61 of the optical coupling device 60 can be optically coupled to the plug port 83 of the optical plug and multiplexer 08 . The port 52 of the optical coupling device 50 can be optically coupled to the port 62 of the optical coupling device 60 through the optical fiber 23 . The port 53 of the optical coupling device 50 can be optically coupled to the port 63 of the optical coupling device 60 through the optical fiber 20 , wherein the optical amplifier 21 and the optical filter 22 can be configured on the optical fiber 20 .

The optical amplifier 21 is provided between the port 53 of the optical coupling device 50 and the port 63 of the optical coupling device 60 . The optical amplifier 21 can transmit optical signals in one direction. Specifically, the input of optical amplifier 21 may be optically coupled to port 63 and the output of optical amplifier 21 may be optically coupled to port 53 . The optical amplifier 21 can amplify the backscattered light 09 from the port 53 of the optical coupling device 60 and transmit the amplified backscattered light 09 to the port 53 of the optical coupling device 50 . The optical filter 22 can be disposed between the output terminal of the optical amplifier 21 and the port 53 of the optical coupling device 50 , and can be used to filter the backscattered light 22 amplified by the optical amplifier 21 .

FIG. 6 shows a schematic diagram of a detection light processing module 10 according to another embodiment of the present invention, wherein the detection light processing module 10 can be used to improve the communication quality of the detection light 02 and the backscattered light 09 . The detection light processing module 100 may include an optical coupling device 50 , an optical amplifier 16 , an optical filter 17 , an optical coupling device 60 , an optical amplifier 21 and an optical filter 22 . The optical coupling device 50 may include a port 51 , a port 52 and a port 53 . The port 51 of the optical coupling device 50 can be optically coupled to the plug port 73 of the optical plug and multiplexer 07 . The optical coupling device 60 may include a port 61 , a port 62 and a port 63 . The port 61 of the optical coupling device 60 can be optically coupled to the plug port 83 of the optical plug and multiplexer 08 . The port 52 of the optical coupling device 50 can be optically coupled to the port 62 of the optical coupling device 60 through the optical fiber 23 , wherein the optical amplifier 16 and the optical filter 17 can be disposed on the optical fiber 23 . The port 53 of the optical coupling device 50 can be optically coupled to the port 63 of the optical coupling device 60 through the optical fiber 20 , wherein the optical amplifier 21 and the optical filter 22 can be configured on the optical fiber 20 .

The optical amplifier 16 is provided between the port 52 of the optical coupling device 50 and the port 62 of the optical coupling device 60 . The optical amplifier 16 can transmit optical signals in one direction. Specifically, an input of optical amplifier 16 may be optically coupled to port 52 and an output of optical amplifier 16 may be optically coupled to port 62 . The optical amplifier 16 can amplify the detection light 02 from the port 52 of the optical coupling device 50 and transmit the amplified detection light 02 to the port 62 of the optical coupling device 60 . The optical filter 17 can be disposed between the output end of the optical amplifier 16 and the port 62 of the optical coupling device 60 , and can be used to filter the detection light 02 amplified by the optical amplifier 16 .

The optical amplifier 21 is provided between the port 53 of the optical coupling device 50 and the port 63 of the optical coupling device 60 . The optical amplifier 21 can transmit optical signals in one direction. Specifically, the input of optical amplifier 21 may be optically coupled to port 63 and the output of optical amplifier 21 may be optically coupled to port 53 . The optical amplifier 21 can amplify the backscattered light 09 from the port 53 of the optical coupling device 60 and transmit the amplified backscattered light 09 to the port 53 of the optical coupling device 50 . The optical filter 22 can be disposed between the output terminal of the optical amplifier 21 and the port 53 of the optical coupling device 50 , and can be used to filter the backscattered light 22 amplified by the optical amplifier 21 .

In one embodiment, the optical coupling device 50 is, for example, the optical splitter 14 shown in FIG. The ports 53 and 53 can be respectively the branch port 142 and the branch port 143 of the optical splitter 14 .

In one embodiment, the optical coupling device 60 is, for example, an optical splitter 18 as shown in FIG. The port 63 and the port 63 can be respectively the branch port 182 and the branch port 183 of the optical splitter 18 .

In one embodiment, the optical coupling device 50 is, for example, the optical circulator 15 as shown in FIG. 3rd port 153 and 1st port 151. After the detection light 02 enters the second port 152 of the optical circulator 15 , the optical circulator 15 can output the detection light 02 through the third port 153 . After the backscattered light 09 enters the first port 151 of the optical circulator 15 , the optical circulator 15 can output the backscattered light 09 through the second port 152 .

In one embodiment, the optical coupling device 60 is, for example, an optical circulator 19 as shown in FIG. 1st port 191 and 3rd port 193. After the detection light 02 enters the first port 191 of the optical circulator 19 , the optical circulator 19 can output the detection light 02 through the second port 192 . After the backscattered light 09 enters the second port 192 of the optical circulator 19 , the optical circulator 19 can output the backscattered light 09 through the third port 193 .

In summary, the distributed optical fiber sensor for multi-wavelength communication of the present invention has the following characteristics and effects: the present invention can use the optical fiber used for communication as a sensor without affecting the communication quality of multi-wavelength optical communication. Distributed optical fiber sensors are used to achieve environmental sensing functions. The invention can delay the sensing distance of the distributed optical fiber sensor, and can transform the existing optical fiber in the telecommunication network into a distributed optical fiber sensor capable of detecting various environmental conditions (such as vibration or temperature) , expand the application of existing communication optical fiber to fields such as traffic condition monitoring, underground pipeline safety monitoring, earthquake early warning or landslide flow monitoring; the distributed optical fiber sensor of the present invention is composed of optical plug multiplexer, It consists of optical circulators, optical amplifiers, and optical filters. The components used in the present invention are all mature and inexpensive mass-produced products. Therefore, the present invention can deploy distributed optical fiber sensors for customers with a very small construction cost to increase revenue.

01:Interrogator

02:Detect light

03:Communication light

04: High-density wave division multiplexer

05, 13, 20, 23: optical fiber

06, 16, 21: optical amplifier

07, 08: Optical plug and take multiplexer

09: Anti-scattered light

10: Detection light processing module

100: Distributed fiber optic sensor

11: High-density wave division multiplexer

12: Optical routing switching mechanism

14, 18: Optical splitter

17, 22: Optical filter

15, 19: Optical circulator

41, 42, 111, 112: Channel ports of high-density wave division multiplexer

43, 115: Common port of high density wave division multiplexer

141, 181: common port of optical splitter

142, 143, 182, 183: the branch port of the optical splitter

181, 191: Port 1 of the optical circulator

182, 192: The second port of the optical circulator

183, 193: Optical circulator port 3

50, 60: Optical coupling device

51, 52, 53, 61, 62, 63: ports

71, 81: common port

72, 82: Straight-through port

73, 83: plugging port

FIG. 1 shows a schematic diagram of the laying of distributed optical fiber sensors. FIG. 2 shows a schematic diagram of a distributed optical fiber sensor for multi-wavelength communication according to an embodiment of the present invention. FIG. 3 shows a schematic diagram of a detection light processing module according to an embodiment of the present invention. FIG. 4 is a schematic diagram of a detection light processing module according to another embodiment of the present invention. FIG. 5 is a schematic diagram of a detection light processing module according to another embodiment of the present invention. FIG. 6 is a schematic diagram of a detection light processing module according to another embodiment of the present invention. FIG. 7 shows a schematic diagram of an optical coupling device according to an embodiment of the present invention. FIG. 8 is a schematic diagram of an optical coupling device according to another embodiment of the present invention.

01:Interrogator

02:Detect light

03:Communication light

04, 11: High-density wave division multiplexer

05, 13: Optical fiber

06:Optical Amplifier

07, 08: Optical plug and take multiplexer

09: Anti-scattered light

10: Detection light processing module

100: Distributed fiber optic sensor

12: Optical routing switching mechanism

41, 42, 111, 112: channel port

43, 115: common port

71, 81: common port

72, 82: Straight-through port

73, 83: plugging port

Claims (13)

A distributed optical fiber sensor for multi-wavelength communication, comprising: an interrogator, used to send detection light to a first optical fiber, wherein the first optical fiber is used to transmit communication light; a first optical plug-and-take multiplexer , including a first common port, a first through port for transmitting the communication light, and a first insertion port for transmitting the detection light, wherein the first common port passes through the first optical fiber coupled to the interrogator; a second optical plug-and-take multiplexer, including a second common port, a second through port, and a second plug-and-take port, wherein the second through-port is optically coupled to the first through-port , and the second plug port is optically coupled to the first plug port; and an optical amplifier is disposed between the first through port and the second through port; a detection optical processing module, Set between the first plug port and the second plug port, wherein the detection light processing module is used to transmit the detection light from the first plug port to the second plug port Two plug ports are used for transmitting backscattered light corresponding to the detection light from the second plug port to the first plug port. The distributed optical fiber sensor as described in claim 1, wherein the detection light processing module includes: a first optical coupling device, including a first port, a second port and a third port, wherein the first port Optically coupled to the first plug port; the second optical coupling device includes a fourth port, a fifth port and a sixth port, wherein the fourth port is optically coupled to the second plug port, and the fifth port optically coupled to the second port, and the sixth port is optically coupled to the third port; and A first optical amplifier disposed between the second port and the fifth port, wherein the input end of the first optical amplifier is optically coupled to the second port, and the output end of the first optical amplifier optically coupled to the fifth port. The distributed optical fiber sensor according to claim 2, wherein the detection light processing module further includes: a second optical amplifier, arranged between the third port and the sixth port, wherein the The input of the second optical amplifier is optically coupled to the sixth port, and the output of the second optical amplifier is optically coupled to the third port. The distributed optical fiber sensor as described in claim 2, wherein the detection light processing module further includes: an optical filter disposed between the output end of the first optical amplifier and the fifth port between. The distributed optical fiber sensor as described in claim 3, wherein the detection light processing module further includes: an optical filter disposed between the output end of the second optical amplifier and the third port between. The distributed optical fiber sensor as described in claim 1, wherein the detection light processing module includes: a first optical coupling device, including a first port, a second port and a third port, wherein the first port Optically coupled to the first plug port; the second optical coupling device includes a fourth port, a fifth port and a sixth port, wherein the fourth port is optically coupled to the second plug port, and the fifth port optically coupled to the second port, And the sixth port is optically coupled to the third port; and a second optical amplifier is disposed between the third port and the sixth port, wherein the input end of the second optical amplifier is optically coupled to The sixth port, and the output end of the second optical amplifier is optically coupled to the third port. The distributed optical fiber sensor as claimed in item 2, wherein the first optical coupling device is an optical splitter, wherein the first port is a common port of the optical splitter, and the second port is the same as the optical splitter The third ports are respectively the first branch port and the second branch port of the optical splitter. The distributed optical fiber sensor as claimed in claim 2, wherein the first optical coupling device is an optical circulator. The distributed optical fiber sensor as claimed in item 2, wherein the second optical coupling device is an optical splitter, wherein the fifth port is a common port of the optical splitter, and the fourth port and The sixth ports are respectively the first branch port and the second branch port of the optical splitter. The distributed optical fiber sensor according to claim 2, wherein the second optical coupling device is an optical circulator. The distributed optical fiber sensor as claimed in claim 1, wherein the input end of the optical amplifier is optically coupled to the first through port, and the output end of the optical amplifier is optically coupled to the second through port . The distributed optical fiber sensor as described in claim 1, further comprising: a high-density wavelength division multiplexer, including a first channel port for receiving the communication light, and a second channel for receiving the detection light port and common port, wherein the common port Optically coupled to the first common port. The distributed optical fiber sensor as described in claim 1, further comprising: a high-density wavelength division multiplexer, including a common port for receiving the communication light and the detection light, and a port for transmitting the communication light A first channel port and a second channel port for transmitting the detection light, wherein the common port is optically coupled to the second common port.

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