Optical fiber sensing integrated signal transmission system and method

Abstract

The invention provides an optical fiber sensing integrated signal transmission system and method, and relates to the technical field of optical communication, and the system comprises a first laser, a first signal transmitting module, a first signal receiving module, an annular transmission module, a second laser, a second signal transmitting module, and a second signal receiving module. The first laser is connected with the first signal transmitting module and the second signal receiving module; the second laser is connected with the second signal transmitting module and the first signal receiving module; the annular transmission module is connected with the first signal transmitting module, the first signal receiving module, the second signal transmitting module and the second signal receiving module. Through Rayleigh scattering of the optical fiber in the annular transmission module and different output ends of the circulator, communication signals and sensing signals with different frequencies are received on the same coherent optical receiver, and efficient transmission of communication and sensing integrated signals is realized under the condition that the communication signals and the sensing signals with different frequencies do not interfere with each other.

Description

Technical Field

[0001] The present invention relates to the field of optical communication technology, and in particular to an optical fiber interaural integrated signal transmission system and method. Background Art

[0002] Driven by an unprecedented surge in global network traffic, information technology has developed rapidly in recent years. As mobile communication technology evolves from the fifth generation (5G) to the sixth generation (6G), the large-scale deployment of fiber optic infrastructure as the backbone of wireless service transmission has become increasingly critical. In addition, the advent of the fifth generation fixed network (F5G) era will further expand the application scope of fiber optics, allowing it to penetrate into all levels of society and provide ultra-broadband connections. These ubiquitous optical fibers will support a coordinated global network to realize a wide range of future smart applications, such as smart cities and smart manufacturing.

[0003] In order to meet the growing demand for high throughput in future optical networks, the adoption of coherent solutions is becoming an inevitable trend, even in the data center field. Single-span technology based on coherent digital subcarrier multiplexing (DSCM) has emerged as a new paradigm that can cope with highly dynamic traffic patterns. In the new architecture, the coherent system based on digital subcarrier (DSC) splits the information into several narrower intermediate digital carriers, and then modulates these carriers onto the optical carrier. The inherent flexibility in defining and allocating frequency channels enables DSCM-based optical transceivers to be seamlessly integrated into existing data center networks. In addition, in order to enhance the experience of optical fiber links in smart applications and open up additional revenue sources, research in academia and industry is turning its focus to integrating smart sensing functions into existing networks. As the most forward-looking candidate medium, the widely deployed optical fiber infrastructure will not only serve as a communication network, but also as a distributed sensor to provide continuous monitoring for the entire system.

[0004] In the field of distributed fiber optic sensing, phase-sensitive distributed fiber optic sensing, also known as phase-sensitive optical time-domain reflectometer (Φ-OTDR), has attracted widespread attention due to its excellent monitoring capabilities. By detecting the phase of the Rayleigh backscatter (RBS) signal through interferometric phase beat frequency, Φ-OTDR can show advantages in high strain sensitivity, high spatial resolution, fast response, and fully distributed measurement, thereby efficiently realizing distributed acoustic sensing. Using existing fiber optic networks, Φ-OTDR has been used for deep ground and deep sea seismic wave detection, traffic flow monitoring, and geological monitoring. However, these solutions only utilize dark fiber resources and focus on the independent operation of sensing functions. In order to further optimize resource utilization, Φ-OTDR has been integrated into coherent optical communication networks to achieve simultaneous data transmission and distributed vibration detection through wavelength division multiplexing. However, these solutions only share the same fiber medium within two independent sensing and communication transceivers, and a dedicated transmission channel must be reserved for distributed fiber optic sensing, which reduces transmission efficiency and significantly increases the complexity and cost of the system. The challenge of integrating Φ-OTDR solutions with communication systems remains that the sensing and communication functions rely on independent transceivers. Therefore, it is necessary to integrate communication and sensing functions on the existing transmitter at the same time to achieve true synaesthesia. Summary of the invention

[0005] In view of this, the purpose of the present invention is to provide an optical fiber intersensory integrated signal transmission system and method to solve the technical problems of low transmission efficiency, high complexity and high cost of existing optical fiber networks.

[0006] The present invention provides an optical fiber interaceptive integrated signal transmission system, comprising: a first laser, a first signal transmitting module, a first signal receiving module, a ring transmission module, a second laser, a second signal transmitting module and a second signal receiving module;

[0007] The first laser is connected to the first signal transmitting module and the second signal receiving module;

[0008] The second laser is connected to the second signal transmitting module and the first signal receiving module;

[0009] The ring transmission module is connected with the first signal transmitting module, the first signal receiving module, the second signal transmitting module and the second signal receiving module.

[0010] Preferred:

[0011] The first signal transmission module includes: a first digital-to-analog converter, a first dual-polarization IQ modulator and a first optical fiber amplifier;

[0012] The first laser is connected to the first dual polarization IQ modulator;

[0013] The first digital-to-analog converter is connected to the first dual-polarization IQ modulator;

[0014] The first dual-polarization IQ modulator is connected to the input end of the first optical fiber amplifier.

[0015] Preferred:

[0016] The first signal receiving module includes: a first dual-polarization coherent optical receiver and a first analog-to-digital converter;

[0017] The first laser, the first dual-polarization coherent optical receiver and the first analog-to-digital converter are connected in sequence.

[0018] Preferred:

[0019] The second signal transmission module includes: a second digital-to-analog converter, a second dual-polarization IQ modulator and a second optical fiber amplifier;

[0020] The second laser is connected to the second dual polarization IQ modulator;

[0021] The second digital-to-analog converter is connected to the second dual-polarization IQ modulator;

[0022] The second dual-polarization IQ modulator is connected to the input end of the second optical fiber amplifier.

[0023] Preferred:

[0024] The second signal receiving module includes: a second dual-polarization coherent optical receiver and a second analog-to-digital converter;

[0025] The second laser, the second dual-polarization coherent optical receiver and the second analog-to-digital converter are connected in sequence.

[0026] Preferred:

[0027] The ring transmission module includes: a first circulator, a first optical fiber, a third optical fiber amplifier, a second circulator, a second optical fiber, and a fourth optical fiber amplifier;

[0028] The output end of the first optical fiber amplifier is connected to the input end 1 of the first circulator;

[0029] The output ends of the first optical fiber and the third optical fiber amplifier are connected to the first dual-polarization coherent optical receiver;

[0030] The output end of the second optical fiber amplifier is connected to the input end 1 of the second circulator;

[0031] The output ends of the second optical fiber and the fourth optical fiber amplifier are connected to the second dual-polarization coherent optical receiver;

[0032] The output end 2 of the first circulator, the first optical fiber, the output end of the third optical fiber amplifier, the input end of the third optical fiber amplifier, the output end 3 of the second circulator, the output end 2 of the second circulator, the second optical fiber, the output end of the fourth optical fiber amplifier, the input end of the fourth optical fiber amplifier and the output end 3 of the first circulator are connected in sequence to form a ring structure.

[0033] An optical fiber synaesthesia integrated signal transmission method is implemented based on the optical fiber synaesthesia integrated signal transmission system, comprising the steps of:

[0034] S1: At the same time, the first laser outputs the first signal light and the first local oscillator light through the coupler, and the second laser outputs the second signal light and the second local oscillator light through the coupler;

[0035] S2: The first signal light is modulated by the first signal transmitting module to generate a first synaesthesia integrated light signal, which includes: a first communication signal and a first sensor signal; the second signal light is modulated by the second signal transmitting module to generate a second synaesthesia integrated light signal, which includes: a second communication signal and a second sensor signal; the first synaesthesia integrated light signal and the second synaesthesia integrated light signal are input into the ring transmission module;

[0036] S3: The first signal receiving module receives the second local oscillation light, the first synaesthesia light signal and the second sensor signal for signal analysis; at the same time, the second signal receiving module receives the first local oscillation light, the second synaesthesia light signal and the first sensor signal for signal analysis.

[0037] Preferably, step S3 specifically comprises:

[0038] The second local oscillator light is directly input into the first dual-polarization coherent optical receiver; the first inter-sensing optical signal is sequentially input into the first dual-polarization coherent optical receiver after passing through the output end 2 of the first circulator and the first optical fiber; the second inter-sensing optical signal generates Rayleigh scattering through the second optical fiber, and the second sensing signal is reflected to the second circulator, and the second sensing signal is output from the output end 3 of the second circulator, and is input into the first dual-polarization coherent optical receiver after passing through the third optical fiber amplifier; the first analog-to-digital converter converts the analog signal output by the first dual-polarization coherent optical receiver into a digital signal and then performs digital signal analysis;

[0039] At the same time, the first local oscillator light is directly input into the second dual-polarization coherent optical receiver; the second inter-sensing optical signal passes through the output end 2 of the second circulator and the second optical fiber in sequence and then is input into the second dual-polarization coherent optical receiver; the first inter-sensing optical signal generates Rayleigh scattering through the first optical fiber, and reflects the first sensing signal to the first circulator, and the first sensing signal is output from the output end 3 of the first circulator, and then is input into the second dual-polarization coherent optical receiver after passing through the fourth optical fiber amplifier; the second analog-to-digital converter converts the analog signal output by the second dual-polarization coherent optical receiver into a digital signal and then performs digital signal analysis.

[0040] Preferred:

[0041] The frequencies of the first communication signal, the first sensing signal, the second communication signal and the second sensing signal are all different.

[0042] The present invention has the following beneficial effects:

[0043] An optical fiber synaesthesia signal transmission system with a bidirectional optical transmission architecture is constructed through a ring transmission module. Through the Rayleigh scattering of the optical fiber in the ring transmission module and the different output ends of the circulator, communication signals and perception signals of different frequencies are received on the same coherent optical receiver. In the case that communication signals and perception signals of different frequencies do not interfere with each other, efficient transmission of synaesthesia signals is achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 This is a structural diagram of the optical fiber interaceptive integrated signal transmission system;

[0045] Figure 2 Schematic diagram of the spectrum of the signal light loaded into the dual-polarization IQ modulator;

[0046] Figure 3 A schematic diagram of a spectrum of a signal received by a first dual-polarization coherent optical receiver;

[0047] Figure 4 is a vibration point location map of the second sensing signal;

[0048] Figure 5 is a transmission performance diagram of a first communication signal;

[0049] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0050] It should be understood that the specific embodiments described herein are only used to explain the present invention, and are not used to limit the present invention.

[0051] Reference Figure 1, the present invention provides an optical fiber interaceptive integrated signal transmission system, comprising: a first laser, a first signal transmitting module, a first signal receiving module, a ring transmission module, a second laser, a second signal transmitting module and a second signal receiving module;

[0052] The first laser is connected to the first signal transmitting module and the second signal receiving module;

[0053] The second laser is connected to the second signal transmitting module and the first signal receiving module;

[0054] The ring transmission module is connected with the first signal transmitting module, the first signal receiving module, the second signal transmitting module and the second signal receiving module.

[0055] As an example:

[0056] The first signal transmission module includes: a first digital-to-analog converter, a first dual-polarization IQ modulator and a first optical fiber amplifier;

[0057] The first laser is connected to the first dual polarization IQ modulator;

[0058] The first digital-to-analog converter is connected to the first dual-polarization IQ modulator;

[0059] The first dual-polarization IQ modulator is connected to the input end of the first optical fiber amplifier.

[0060] As an example:

[0061] The first signal receiving module includes: a first dual-polarization coherent optical receiver and a first analog-to-digital converter;

[0062] The first laser, the first dual-polarization coherent optical receiver and the first analog-to-digital converter are connected in sequence.

[0063] As an example:

[0064] The second signal transmission module includes: a second digital-to-analog converter, a second dual-polarization IQ modulator and a second optical fiber amplifier;

[0065] The second laser is connected to the second dual polarization IQ modulator;

[0066] The second digital-to-analog converter is connected to the second dual-polarization IQ modulator;

[0067] The second dual-polarization IQ modulator is connected to the input end of the second optical fiber amplifier.

[0068] As an example:

[0069] The second signal receiving module includes: a second dual-polarization coherent optical receiver and a second analog-to-digital converter;

[0070] The second laser, the second dual-polarization coherent optical receiver and the second analog-to-digital converter are connected in sequence.

[0071] As an example:

[0072] The ring transmission module includes: a first circulator, a first optical fiber, a third optical fiber amplifier, a second circulator, a second optical fiber, and a fourth optical fiber amplifier;

[0073] The output end of the first optical fiber amplifier is connected to the input end 1 of the first circulator;

[0074] The output ends of the first optical fiber and the third optical fiber amplifier are connected to the first dual-polarization coherent optical receiver;

[0075] The output end of the second optical fiber amplifier is connected to the input end 1 of the second circulator;

[0076] The output ends of the second optical fiber and the fourth optical fiber amplifier are connected to the second dual-polarization coherent optical receiver;

[0077] The output end 2 of the first circulator, the first optical fiber, the output end of the third optical fiber amplifier, the input end of the third optical fiber amplifier, the output end 3 of the second circulator, the output end 2 of the second circulator, the second optical fiber, the output end of the fourth optical fiber amplifier, the input end of the fourth optical fiber amplifier and the output end 3 of the first circulator are connected in sequence to form a ring structure.

[0078] Specifically, for ease of description, the first laser is called the west laser, and the second laser is called the east laser. Here, the bidirectional transmission is divided into two types: west-to-east transmission and east-to-west transmission. Here, taking the west-to-east transmission as an example, after the west laser is divided into two paths by the coupler, one of them is used as the local oscillator light to receive the coherent beat frequency with the communication signal transmitted from the east to the west and the reflected sensor signal, and the other path enters the dual-polarization IQ modulator to generate a communication and sensing integrated optical signal (abbreviated as: inter-sensory integrated optical signal). The inter-sensory integrated optical signal is then amplified by the optical fiber amplifier and enters the optical fiber link through the circulator. After the inter-sensory integrated optical signal is transmitted through the optical fiber, it is received by the dual-polarization coherent receiver at the receiving end, and subsequent analog-to-digital conversion and digital signal processing are performed. After the sensor signal emitted from the west is reflected in the optical fiber link, it passes through the circulator and the optical fiber amplifier and is received in the coherent optical receiver at the same time as the inter-sensory integrated signal transmitted from the east to the west, and subsequent analog-to-digital conversion and digital signal processing are performed.

[0079] The present invention provides an optical fiber synaesthesia integrated signal transmission method, which is implemented based on the optical fiber synaesthesia integrated signal transmission system, and comprises the steps of:

[0080] S1: At the same time, the first laser outputs the first signal light and the first local oscillator light through the coupler, and the second laser outputs the second signal light and the second local oscillator light through the coupler;

[0081] S2: The first signal light is modulated by the first signal transmitting module to generate a first synaesthesia integrated light signal, which includes: a first communication signal and a first sensor signal; the second signal light is modulated by the second signal transmitting module to generate a second synaesthesia integrated light signal, which includes: a second communication signal and a second sensor signal; the first synaesthesia integrated light signal and the second synaesthesia integrated light signal are input into the ring transmission module;

[0082] S3: The first signal receiving module receives the second local oscillation light, the first synaesthesia light signal and the second sensor signal for signal analysis; at the same time, the second signal receiving module receives the first local oscillation light, the second synaesthesia light signal and the first sensor signal for signal analysis.

[0083] As an example:

[0084] Step S3 is specifically as follows:

[0085] The second local oscillator light is directly input into the first dual-polarization coherent optical receiver; the first inter-sensing optical signal is sequentially input into the first dual-polarization coherent optical receiver after passing through the output end 2 of the first circulator and the first optical fiber; the second inter-sensing optical signal generates Rayleigh scattering through the second optical fiber, and the second sensing signal is reflected to the second circulator, and the second sensing signal is output from the output end 3 of the second circulator, and is input into the first dual-polarization coherent optical receiver after passing through the third optical fiber amplifier; the first analog-to-digital converter converts the analog signal output by the first dual-polarization coherent optical receiver into a digital signal and then performs digital signal analysis;

[0086] At the same time, the first local oscillator light is directly input into the second dual-polarization coherent optical receiver; the second inter-sensing optical signal passes through the output end 2 of the second circulator and the second optical fiber in sequence and then is input into the second dual-polarization coherent optical receiver; the first inter-sensing optical signal generates Rayleigh scattering through the first optical fiber, and reflects the first sensing signal to the first circulator, and the first sensing signal is output from the output end 3 of the first circulator, and then is input into the second dual-polarization coherent optical receiver after passing through the fourth optical fiber amplifier; the second analog-to-digital converter converts the analog signal output by the second dual-polarization coherent optical receiver into a digital signal and then performs digital signal analysis.

[0087] As an example:

[0088] The frequencies of the first communication signal, the first sensing signal, the second communication signal and the second sensing signal are all different.

[0089] Specifically, at the signal transmitting end, the communication signal and the sensor signal are multiplexed together in the frequency domain through subcarrier multiplexing technology. After the communication signal is transmitted through the optical fiber, it is received by the receiver at the receiving end in a coherent manner. Under the architecture of bidirectional optical transmission, the sensor signal is reflected and then enters the coherent receiver at the receiving end together with the communication signal transmitted from the other side for demodulation, completing the simultaneous reception of the communication and sensor signals. It should be pointed out that since the communication and sensor signals are in different frequency bands, they will not interfere with each other. For a bidirectional transmission link, the bidirectional sensor signals can also be allocated in different frequency bands, thereby avoiding mutual interference between the sensor signals in the bidirectional transmission scenario.

[0090] Figure 2 Figure 1 is a schematic diagram of the spectrum of the signal light loaded into the dual-polarization IQ modulator. It can be seen that the spectrum emitted from west to east and from east to west does not overlap at all. This ensures that the sensing and communication signals can be demodulated simultaneously through a coherent receiver.

[0091] Figure 3 It is a schematic diagram of the electrical signal spectrum of the received optical signal after coherent reception. It can be seen that the signal received by the first dual-polarization coherent optical receiver in the west includes the communication and sensing optical signals transmitted from the transmitter in the east, and also includes the low-power optical signal received after the transmission signal of the first signal transmission module in the west is Rayleigh reflected. As mentioned above, since the transmission signals in the two directions are completely separated in the spectrum, no interference will be generated.

[0092] Figure 4 This is a vibration point location map obtained after the sensing signal received by the first dual-polarization coherent optical receiver in the example of the present invention is processed by the digital signal of the first analog-to-digital converter. It can be seen that the position of the vibration point can be clearly identified.

[0093] Figure 5 This is a transmission performance diagram obtained after the communication signal received by the first dual-polarization coherent optical receiver in the example of the present invention has been processed by the digital signal of the first analog-to-digital converter. It can be seen that after the received optical power is greater than -22dBm, the bit error rate of the communication signal can be below the threshold of 0.01, meeting the transmission requirements of the communication system.

[0094] It should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or system including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or system. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the existence of other identical elements in the process, method, article or system including the element.

[0095] The serial numbers of the embodiments of the present invention are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments. In a unit claim that lists several means, several of these means may be embodied by the same hardware item. The use of the words first, second, and third, etc. does not indicate any order and these words may be interpreted as identifiers.

[0096] The above are only preferred embodiments of the present invention, and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. An optical fiber interoception integrated signal transmission system, characterized in that: include: A first laser, a first signal transmitting module, a first signal receiving module, a ring transmission module, a second laser, a second signal transmitting module, and a second signal receiving module; The first laser is connected to the first signal transmitting module and the second signal receiving module; The second laser is connected to the second signal transmitting module and the first signal receiving module; The ring transmission module is connected with the first signal transmitting module, the first signal receiving module, the second signal transmitting module and the second signal receiving module.

2. The optical fiber interaceptive integrated signal transmission system according to claim 1, characterized in that: The first signal transmission module includes: a first digital-to-analog converter, a first dual-polarization IQ modulator and a first optical fiber amplifier; The first laser is connected to the first dual polarization IQ modulator; The first digital-to-analog converter is connected to the first dual-polarization IQ modulator; The first dual-polarization IQ modulator is connected to the input end of the first optical fiber amplifier.

3. The optical fiber interaceptive integrated signal transmission system according to claim 1, characterized in that: The first signal receiving module includes: a first dual-polarization coherent optical receiver and a first analog-to-digital converter; The first laser, the first dual-polarization coherent optical receiver and the first analog-to-digital converter are connected in sequence.

4. The optical fiber interaceptive integrated signal transmission system according to claim 1, characterized in that: The second signal transmission module includes: a second digital-to-analog converter, a second dual-polarization IQ modulator and a second optical fiber amplifier; The second laser is connected to the second dual polarization IQ modulator; The second digital-to-analog converter is connected to the second dual-polarization IQ modulator; The second dual-polarization IQ modulator is connected to the input end of the second optical fiber amplifier.

5. The optical fiber interaceptive integrated signal transmission system according to claim 1, characterized in that: The second signal receiving module includes: a second dual-polarization coherent optical receiver and a second analog-to-digital converter; The second laser, the second dual-polarization coherent optical receiver and the second analog-to-digital converter are connected in sequence.

6. The optical fiber interaceptive integrated signal transmission system according to any one of claims 2 to 5, characterized in that: The ring transmission module includes: a first circulator, a first optical fiber, a third optical fiber amplifier, a second circulator, a second optical fiber, and a fourth optical fiber amplifier; The output end of the first optical fiber amplifier is connected to the input end 1 of the first circulator; The output ends of the first optical fiber and the third optical fiber amplifier are connected to the first dual-polarization coherent optical receiver; The output end of the second optical fiber amplifier is connected to the input end 1 of the second circulator; The output ends of the second optical fiber and the fourth optical fiber amplifier are connected to the second dual-polarization coherent optical receiver; The output end 2 of the first circulator, the first optical fiber, the output end of the third optical fiber amplifier, the input end of the third optical fiber amplifier, the output end 3 of the second circulator, the output end 2 of the second circulator, the second optical fiber, the output end of the fourth optical fiber amplifier, the input end of the fourth optical fiber amplifier and the output end 3 of the first circulator are connected in sequence to form a ring structure.

7. An optical fiber synaesthesia integrated signal transmission method, implemented based on the optical fiber synaesthesia integrated signal transmission system according to any one of claims 1 to 6, characterized in that: Includes steps: S1: At the same time, the first laser outputs the first signal light and the first local oscillator light through the coupler, and the second laser outputs the second signal light and the second local oscillator light through the coupler; S2: The first signal light is modulated by the first signal transmitting module to generate a first synaesthesia integrated light signal, which includes: a first communication signal and a first sensor signal; the second signal light is modulated by the second signal transmitting module to generate a second synaesthesia integrated light signal, which includes: a second communication signal and a second sensor signal; the first synaesthesia integrated light signal and the second synaesthesia integrated light signal are input into the ring transmission module; S3: The first signal receiving module receives the second local oscillation light, the first synaesthesia light signal and the second sensor signal for signal analysis; at the same time, the second signal receiving module receives the first local oscillation light, the second synaesthesia light signal and the first sensor signal for signal analysis.

8. The optical fiber interaceptive integrated signal transmission method according to claim 7, characterized in that: Step S3 is specifically as follows: The second local oscillator light is directly input into the first dual-polarization coherent optical receiver; the first intersensory integrated optical signal is sequentially input into the first dual-polarization coherent optical receiver after passing through the output end 2 of the first circulator and the first optical fiber; The second intersensory optical signal generates Rayleigh scattering through the second optical fiber, and reflects the second sensing signal to the second circulator. The second sensing signal is output from the output end 3 of the second circulator, and is input into the first dual-polarization coherent optical receiver after passing through the third optical fiber amplifier. The first analog-to-digital converter converts the analog signal output by the first dual-polarization coherent optical receiver into a digital signal and then performs digital signal analysis; At the same time, the first local oscillator light is directly input into the second dual-polarization coherent optical receiver; the second inter-sensory integrated optical signal is sequentially input into the second dual-polarization coherent optical receiver after passing through the output end 2 of the second circulator and the second optical fiber; The first intersensory optical signal generates Rayleigh scattering through the first optical fiber, and reflects the first sensing signal to the first circulator. The first sensing signal is output from the output end 3 of the first circulator, and is input into the second dual-polarization coherent optical receiver after passing through the fourth optical fiber amplifier. The second analog-to-digital converter converts the analog signal output by the second dual-polarization coherent optical receiver into a digital signal and then performs digital signal analysis.

9. The optical fiber interacuity signal transmission method according to claim 7, characterized in that: The frequencies of the first communication signal, the first sensing signal, the second communication signal and the second sensing signal are all different.

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