Optical fiber sensing and signal transmission integrated system and method

Abstract

The application provides an optical fiber sensing integrated signal transmission system and method, and relates to the technical field of optical communication.The system comprises 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 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 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.The application realizes efficient transmission of the sensing integrated signal by Rayleigh scattering of the optical fiber in the ring transmission module and different output ends of the circulator, and the communication signal and the sensing signal of different frequencies are received on the same coherent light receiver without interference.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of optical communication technology, and in particular to an optical fiber sensing integrated signal transmission system and method. BACKGROUND

[0002] Driven by the unprecedented surge in global network traffic, information technology has developed rapidly in recent years. With the evolution of mobile communication technology from the fifth generation (5G) to the sixth generation (6G), the large-scale deployment of optical fiber infrastructure as the backbone network for wireless service transmission has become increasingly important. In addition, the advent of the fifth generation fixed network (F5G) era will further expand the application range of optical fibers, enabling them to penetrate into all aspects of society and provide ultra-wideband connections. These ubiquitous optical fibers will support a coordinated global network to realize a wide range of future intelligent applications, such as smart cities and intelligent 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 field of data centers. 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, a coherent system based on digital subcarriers (DSC) divides information into several narrower intermediate digital carriers, which are then combined and modulated onto an 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 intelligent applications and open up additional revenue sources, research in academia and industry is focusing on integrating intelligent 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 sensing, phase-sensitive distributed fiber sensing, also known as phase-sensitive optical time domain reflectometer (Φ-OTDR), has attracted extensive attention due to its excellent monitoring capability. By detecting the phase of Rayleigh backscattering (RBS) signal through interference phase beat frequency, Φ-OTDR can exhibit advantages in high strain sensitivity, high spatial resolution, fast response and full-distributed measurement, thereby efficiently realizing distributed acoustic sensing. By utilizing existing optical fiber networks, Φ-OTDR has been used for deep earth and deep sea seismic wave detection, traffic flow monitoring and geological monitoring. However, these schemes only utilize dark fiber resources and focus on the independent operation of sensing function. In order to further optimize resource utilization, Φ-OTDR has been integrated into a coherent optical communication network to realize simultaneous data transmission and distributed vibration detection through wavelength division multiplexing. However, these schemes only share the same fiber medium in two independent sensing and communication transceivers, and a dedicated transmission channel must be reserved for distributed fiber sensing, thereby reducing transmission efficiency and significantly increasing system complexity and cost. The challenge of integrating Φ-OTDR scheme with communication system is still that sensing and communication functions rely on independent transceivers. Therefore, it is necessary to integrate communication and sensing functions on the existing transmitter to realize true sense of all-in-one. SUMMARY

[0005] Therefore, the present application aims to provide an optical fiber all-in-one signal transmission system and method, which can solve the technical problems of low transmission efficiency, high complexity and high cost of existing optical fiber networks.

[0006] The present application provides an optical fiber all-in-one signal transmission system, comprising: a first laser, a first signal transmission module, a first signal receiving module, a ring transmission module, a second laser, a second signal transmission module and a second signal receiving module.

[0007] The first laser is connected with the first signal transmission module and the second signal receiving module.

[0008] The second laser is connected with the second signal transmission module and the first signal receiving module.

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

[0010] Preferably,

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

[0012] The first laser is connected with the first dual-polarization IQ modulator.

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

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

[0015] Preferably,

[0016] The first signal receiving module comprises 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 sequentially connected.

[0018] Preferably,

[0019] The second signal transmitting module comprises a second digital-to-analog converter, a second dual-polarization IQ modulator and a second fiber amplifier.

[0020] The second laser is connected with the second dual-polarization IQ modulator.

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

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

[0023] Preferably,

[0024] The second signal receiving module comprises 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 sequentially connected.

[0026] Preferably,

[0027] The ring transmission module comprises a first circulator, a first optical fiber, a third fiber amplifier, a second circulator, a second optical fiber and a fourth fiber amplifier.

[0028] An output end of the first fiber amplifier is connected with an input end 1 of the first circulator.

[0029] The first optical fiber and an output end of the third fiber amplifier are connected with the first dual-polarization coherent optical receiver.

[0030] An output end of the second fiber amplifier is connected with an input end 1 of the second circulator.

[0031] The second optical fiber and an output end of the fourth fiber amplifier are connected with 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 fiber amplifier, the input end of the third 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 fiber amplifier, the input end of the fourth fiber amplifier and the output end 3 of the first circulator are sequentially connected to form a ring structure.

[0033] An optical fiber sensing and communication integrated signal transmission method is realized based on the optical fiber sensing and communication integrated signal transmission system, and includes the following steps:

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

[0035] S2: The first signal light generates first sensing and communication integrated light signal after being modulated by the first signal transmitting module, and the first sensing and communication integrated light signal includes first communication signal and first sensing signal; the second signal light generates second sensing and communication integrated light signal after being modulated by the second signal transmitting module, and the second sensing and communication integrated light signal includes second communication signal and second sensing signal; the first sensing and communication integrated light signal and the second sensing and communication integrated light signal are input into the ring transmission module;

[0036] S3: The first signal receiving module receives the second local oscillator light, the first sensing and communication integrated light signal and the second sensing signal for signal analysis; at the same time, the second signal receiving module receives the first local oscillator light, the second sensing and communication integrated light signal and the first sensing signal for signal analysis.

[0037] Preferably, the step S3 is specifically as follows:

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

[0039] Meanwhile, the first local oscillator light is directly input into the second dual-polarization coherent optical receiver; the second sensing-integrated optical signal is sequentially input into the second dual-polarization coherent optical receiver through the output end 2 of the second circulator and the second optical fiber; the first sensing-integrated optical signal generates Rayleigh scattering through the first optical fiber, and the first sensing signal is reflected to the first circulator, and the first sensing signal is output by the output end 3 of the first circulator and input into the second dual-polarization coherent optical receiver 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] Preferably,

[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 application has the following beneficial effects:

[0043] The optical fiber sensing-integrated signal transmission system with the bidirectional optical transmission structure is constructed by the ring transmission module, the communication signals and the sensing signals with different frequencies are received on the same coherent optical receiver through Rayleigh scattering of the optical fiber in the ring transmission module and different output ends of the circulator, and the efficient transmission of the sensing-integrated signal is realized without interference between the communication signals and the sensing signals with different frequencies. BRIEF DESCRIPTION OF DRAWINGS

[0044] Figure 1 It is a structure diagram of the optical fiber sensing-integrated signal transmission system;

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

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

[0047] Figure 4 It is a vibration point positioning diagram of the second sensing signal;

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

[0049] The implementation, functional features and advantages of the application will be further described with reference to the embodiments and the accompanying drawings. DETAILED DESCRIPTION

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

[0051] Reference Figure 1The present invention provides an integrated optical fiber sensing 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 to the first signal transmitting module, the first signal receiving module, the second signal transmitting module, and the second signal receiving module.

[0055] As one example:

[0056] The first signal transmitting module includes: a first digital-to-analog converter, a first dual-polarization IQ modulator, and a first 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 of the first fiber amplifier.

[0060] As one 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 one example:

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

[0068] As one 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 sequentially connected.

[0071] As an embodiment:

[0072] The ring-shaped transmission module comprises 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 with 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 with the first dual-polarization coherent optical receiver.

[0075] The output end of the second optical fiber amplifier is connected with 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 with 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 sequentially connected to form a ring-shaped structure.

[0078] Specifically, in order to facilitate description, the first laser is referred to as a west laser, and the second laser is referred to as an east laser. Here, the bidirectional transmission is divided into west-to-east transmission and east-to-west transmission. Taking the west-to-east transmission as an example, after the west laser is divided into two paths through the coupler, one path is used as a local light to perform coherent frequency mixing reception together with a communication signal and a reflected sensing signal transmitted from the east to the west, and the other path enters a dual-polarization IQ modulator to generate a communication and sensing integrated optical signal (referred to as a communication and sensing integrated optical signal). After the communication and sensing integrated optical signal is amplified through the optical fiber amplifier, it enters the optical fiber link through the circulator. After the communication and sensing 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 sensing signal transmitted from the west is reflected through the optical fiber link, it is received together with the communication and sensing integrated signal transmitted from the east to the west in the coherent optical receiver through the circulator and the optical fiber amplifier, and subsequent analog-to-digital conversion and digital signal processing are performed.

[0079] The application provides a kind of optical fiber communication and sensing integrated signal transmission method, based on the optical fiber communication and sensing integrated signal transmission system implementation, comprising steps:

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

[0081] S2: The first signal light generates the first sensing and communication integrated light signal after being modulated by the first signal transmitting module, and the first sensing and communication integrated light signal includes the first communication signal and the first sensing signal; the second signal light generates the second sensing and communication integrated light signal after being modulated by the second signal transmitting module, and the second sensing and communication integrated light signal includes the second communication signal and the second sensing signal; the first sensing and communication integrated light signal and the second sensing and communication integrated light signal are input into the ring transmission module;

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

[0083] As an embodiment:

[0084] Step S3 is specifically:

[0085] The second local light is directly input into the first dual-polarization coherent light receiver; the first sensing and communication integrated light signal is input into the first dual-polarization coherent light receiver after passing through the output end 2 of the first circulator and the first optical fiber in sequence; the second sensing and communication integrated light signal generates Rayleigh scattering after passing through the second optical fiber, and the second sensing signal is reflected to the second circulator, and the second sensing signal is output by the output end 3 of the second circulator and input into the first dual-polarization coherent light 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 light receiver into a digital signal and then performs digital signal analysis;

[0086] At the same time, the first local light is directly input into the second dual-polarization coherent light receiver; the second sensing and communication integrated light signal is input into the second dual-polarization coherent light receiver after passing through the output end 2 of the second circulator and the second optical fiber in sequence; the first sensing and communication integrated light signal generates Rayleigh scattering after passing through the first optical fiber, and the first sensing signal is reflected to the first circulator, and the first sensing signal is output by the output end 3 of the first circulator and input into the second dual-polarization coherent light 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 light receiver into a digital signal and then performs digital signal analysis.

[0087] As an embodiment:

[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 sensing signal are multiplexed together in the frequency domain by the sub-carrier multiplexing technology. After the communication signal is transmitted through the optical fiber, it is received by the receiver of the receiving end in a coherent manner. Under the architecture of bidirectional optical transmission, the sensing signal is demodulated after entering the coherent receiver together with the communication signal transmitted from the other side after reflection, completing the simultaneous reception of the communication and sensing signals. It should be noted that the communication and sensing signals will not interfere with each other because they are in different frequency bands. For the bidirectional transmission link, the bidirectional sensing signals can also be allocated in different frequency bands, thereby avoiding the mutual interference of the sensing signals in the bidirectional transmission scenario.

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

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

[0092] Figure 4 is a vibration point positioning map obtained after the sensing signal received by the first dual-polarization coherent optical receiver on the west side of the present application is processed by the digital signal processing 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 is a transmission performance map obtained after the communication signal received by the first dual-polarization coherent optical receiver on the west side of the present application is processed by the digital signal processing of the first analog-to-digital converter. It can be seen that when 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 the present document, the terms "comprising", "comprising" or any other variant thereof are intended to cover non-exclusive inclusions, so that a process, method, article or system that includes a list of elements not only includes those elements, but also includes other elements not explicitly listed, or inherent to such a process, method, article or system. Without more limitations, the element defined by the statement "comprising a" does not exclude the presence of other identical elements in the process, method, article or system that includes the element.

[0095] The above-mentioned embodiment numbers of the present application are only for description, and do not represent the advantages and disadvantages of the embodiments. In the unit claims of several devices, several of these devices can be embodied by the same hardware item. The use of the words first, second, and third does not represent any order, and these words can be interpreted as identification.

[0096] The above is only the preferred embodiment of the present application, and does not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation, or direct or indirect application in other related technical fields, is also included in the patent protection scope of the present application.

Claims

1. A fiber optic inductive 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 to the first signal transmitting module, the first signal receiving module, the second signal transmitting module, and the second signal receiving module; The first signal transmitting module includes: a first digital-to-analog converter, a first dual-polarization IQ modulator, and a first fiber amplifier; the first signal receiving module includes: a first dual-polarization coherent optical receiver and a first analog-to-digital converter; the second signal transmitting module includes: a second digital-to-analog converter, a second dual-polarization IQ modulator, and a second fiber amplifier; the second signal receiving module includes: a second dual-polarization coherent optical receiver and a second analog-to-digital converter. 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 of the first fiber amplifier is connected to the input 1 of the first circulator; The outputs of the first and third fiber amplifiers are connected to the first dual-polarization coherent optical receiver. The output of the second fiber amplifier is connected to the input 1 of the second circulator; The outputs of the second and fourth fiber amplifiers are connected to the second dual-polarization coherent optical receiver. The output terminal 2 of the first circulator, the first optical fiber, the output terminal of the third optical fiber amplifier, the input terminal of the third optical fiber amplifier, the output terminal 3 of the second circulator, the output terminal 2 of the second circulator, the second optical fiber, the output terminal of the fourth optical fiber amplifier, the input terminal of the fourth optical fiber amplifier, and the output terminal 3 of the first circulator are connected in sequence to form a ring structure.

2. The fiber optic inductive integrated signal transmission system according to claim 1, characterized in that: 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 of the first fiber amplifier.

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

4. The fiber optic induction integrated signal transmission system according to claim 1, characterized in that: 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 of the second fiber amplifier.

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

6. A fiber optic inductive integrated signal transmission method, implemented based on the fiber optic inductive integrated signal transmission system according to any one of claims 1-5, characterized in that, Including the following 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 integrated sensing optical signal, which includes a first communication signal and a first sensing signal; the second signal light is modulated by the second signal transmitting module to generate a second integrated sensing optical signal, which includes a second communication signal and a second sensing signal; the first integrated sensing optical signal and the second integrated sensing optical signal are input into the ring transmission module. S3: The first signal receiving module receives the second local oscillator light, the first integrated sensing light signal, and the second sensing signal for signal analysis; at the same time, the second signal receiving module receives the first local oscillator light, the second integrated sensing light signal, and the first sensing signal for signal analysis.

7. The fiber optic induction integrated signal transmission method according to claim 6, characterized in that, Step S3 is as follows: The second local oscillator is directly input to the first dual-polarization coherent optical receiver; the first integrated sensing optical signal passes sequentially through the output terminal 2 of the first circulator and the first optical fiber before being input to the first dual-polarization coherent optical receiver. The second sensing integrated optical signal is Rayleigh scattered through the second optical fiber, reflecting the second sensing signal to the second circulator. The second sensing signal is output from the output terminal 3 of the second circulator, and after passing through the third optical fiber amplifier, it is input to the first dual polarization coherent optical receiver. The first analog-to-digital converter converts the analog signal output from the first dual-polarization coherent optical receiver into a digital signal and then performs digital signal analysis. Simultaneously, the first local oscillator light is directly input into the second dual-polarization coherent optical receiver; the second integrated sensing optical signal passes sequentially through the output terminal 2 of the second circulator and the second optical fiber before being input into the second dual-polarization coherent optical receiver. The first sensing integrated optical signal is Rayleigh scattered through the first optical fiber, reflecting the first sensing signal to the first circulator. The first sensing signal is output from the output terminal 3 of the first circulator, and after passing through the fourth optical fiber amplifier, it is input to the second dual polarization coherent optical receiver. The second analog-to-digital converter converts the analog signal output from the second dual-polarization coherent optical receiver into a digital signal, which is then analyzed by the digital signal converter.

8. The fiber optic induction integrated signal transmission method according to claim 6, 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.

Images