Homologous zero-difference self-coherent optical fiber communication and sensing integrated device and method

Abstract

The application provides a homologous zero-difference self-coherent optical fiber communication and sensing integrated device and method, wherein a first transmitting end transmits first probe light and first communication light to a second communication receiving end through a first fiber core and a second fiber core of a multi-core optical fiber respectively; the second communication receiving end performs zero-difference self-correlation detection according to the first communication light and the first probe light; a second transmitting end transmits second probe light and second communication light to a first communication receiving end through a third fiber core and a fourth fiber core of the multi-core optical fiber respectively; the first communication receiving end performs zero-difference self-correlation detection according to the second communication light and the second probe light; a first sensing receiving end and a second sensing end are respectively used for demodulating disturbance phases of the second probe light and the first probe light, so as to obtain a disturbance position; the communication light and the probe light are transmitted through multiple fiber cores in the same optical fiber, so that the communication light and the probe light are subjected to consistent external interference, thereby improving the communication demodulation performance and the sensing demodulation performance of the zero-difference self-correlation detection.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of optical communication technology, in particular to a homologous homodyne self-coherent optical fiber communication and sensing integrated device and method. BACKGROUND

[0002] At present, in most of the optical fiber communication and sensing integrated systems, the corresponding communication optical signals and local reference lights are usually transmitted by different optical fibers, which causes the communication optical signals and the local reference lights to be affected by different external interferences, resulting in relatively poor performance of the homodyne self-correlation detection of the communication optical signals and the local reference lights, and further resulting in poor demodulation performance of the communication optical signals.

[0003] In view of this, overcoming the defects of the prior art is an urgent problem to be solved in the technical field. SUMMARY

[0004] The technical problem to be solved by the present application is how to improve the demodulation performance of the communication optical signals of the sensing integrated optical fiber communication.

[0005] The present application adopts the following technical solutions:

[0006] In a first aspect, a homologous homodyne self-coherent optical fiber communication and sensing integrated device is provided, comprising: a first transmitting end, a first communication receiving end, a multi-core transmission optical fiber, a second transmitting end and a second communication receiving end;

[0007] The first transmitting end is configured to send first probe light to the second communication receiving end through a first core in the multi-core transmission optical fiber, and is further configured to send first communication light to the second communication receiving end through a second core in the multi-core transmission optical fiber; the second communication receiving end is configured to perform homodyne self-correlation detection according to the first communication light and the first probe light; wherein the first probe light and the first communication light are generated by the same laser;

[0008] The second transmitting end is configured to send second probe light to the first communication receiving end through a third core in the multi-core transmission optical fiber, and is further configured to send second communication light to the first communication receiving end through a fourth core in the multi-core transmission optical fiber; the first communication receiving end is configured to perform homodyne self-correlation detection according to the second communication light and the second probe light; wherein the second probe light and the second communication light are generated by the same laser.

[0009] Preferably, the device further comprises a first sensing receiving end and a second sensing receiving end.

[0010] The first sensing receiving end is configured to receive the first reference light from the first transmitting end and the second probe light from the second transmitting end, and to perform phase demodulation according to the first reference light and the second probe light, so as to obtain the disturbed phase of the second probe light.

[0011] The second sensing receiving end is configured to receive the second reference light from the second transmitting end and the first probe light from the first transmitting end, and to perform phase demodulation according to the second reference light and the first probe light, so as to obtain the disturbed phase of the first probe light.

[0012] Preferably, the first transmitting end comprises a first laser, a first coupler and a first modulator.

[0013] The first laser is configured to emit first laser light, the first coupler is configured to divide the first laser light into three paths, the first path laser signal is used as the first reference light, the second path laser signal is used as the first probe light, and the third path laser signal is used as the first communication light after being modulated by the first modulator.

[0014] The second transmitting end comprises a second laser, a second coupler and a second modulator.

[0015] The second laser is configured to emit second laser light, the second coupler is configured to divide the second laser light into three paths, the first path laser signal is used as the second reference light, the second path laser signal is used as the second probe light, and the third path laser signal is used as the second communication light after being modulated by the second modulator.

[0016] Preferably, the first transmitting end further comprises a third coupler and a fourth coupler.

[0017] The third coupler is configured to divide the first probe light into two paths, one of which is transmitted to the second communication receiving end, and the other of which is transmitted to the second sensing receiving end.

[0018] The fourth coupler is configured to divide the second probe light into two paths, one of which is transmitted to the first communication receiving end, and the other of which is transmitted to the first sensing receiving end.

[0019] In a second aspect, a homologous zero-difference self-coherent optical fiber communication and sensing integrated method is provided, which is applied to the homologous zero-difference self-coherent optical fiber communication and sensing integrated device, and comprises the following steps:

[0020] The first transmitting end sends first probe light to the second communication receiving end through a first fiber core in the multi-core transmission optical fiber; the first transmitting end also sends first communication light to the second communication receiving end through a second fiber core in the multi-core transmission optical fiber; the second communication receiving end performs homodyne self-correlation detection according to the first communication light and the first probe light, thereby obtaining corresponding I-channel signal current and Q-channel signal current of the first communication light;

[0021] The second transmitting end sends second probe light to the first communication receiving end through a third fiber core in the multi-core transmission optical fiber; the second transmitting end also sends second communication light to the first communication receiving end through a fourth fiber core in the multi-core transmission optical fiber; the first communication receiving end performs homodyne self-correlation detection according to the second communication light and the second probe light, thereby obtaining corresponding I-channel signal current and Q-channel signal current of the second communication light.

[0022] Preferably, the second communication receiving end performs homodyne self-correlation detection according to the first communication light and the first probe light, thereby obtaining corresponding I-channel signal current and Q-channel signal current of the first communication light, and specifically includes:

[0023] The phase and optical power of the first communication light are obtained by the second communication receiving end;

[0024] The I-channel signal current and the Q-channel signal current corresponding to the first communication light are obtained according to the phase of the first communication light, the optical power of the first communication light, and the optical power and phase of the first probe light.

[0025] Preferably, the second communication receiving end performs homodyne self-correlation detection according to the first communication light and the first probe light, thereby obtaining corresponding I-channel signal current and Q-channel signal current of the first communication light, and specifically includes:

[0026] The calculation formula of the corresponding I-channel signal current in the first communication light is:

[0027] ;

[0028] The calculation formula of the corresponding Q-channel signal current in the first communication light is:

[0029] ;

[0030] wherein R is a coefficient related to the responsivity of the photodetector, the splitting ratio of the coupler, the fiber loss, and the polarization and frequency mismatch, is the phase of the first communication light received by the second communication receiving end, ​​optical power after square root of product of optical power of first communication light and optical power of first probe light.

[0031] Preferably, the homologous homodyne self-coherent optical fiber communication and sensing integrated device further comprises a first sensing receiving end and a second sensing receiving end; the homologous homodyne self-coherent optical fiber communication and sensing integrated method further comprises:

[0032] The first sensing receiving end receives first reference light from the first transmitting end and second probe light from the second transmitting end; the first sensing receiving end performs coherent detection phase demodulation according to the first reference light and the second probe light, thereby obtaining the disturbed phase of the second probe light;

[0033] The second sensing receiving end receives second reference light from the second transmitting end and first probe light from the first transmitting end; the second sensing receiving end performs coherent detection phase demodulation according to the second reference light and the first probe light, thereby obtaining the disturbed phase of the first probe light;

[0034] The disturbed position on the multi-core transmission optical fiber is obtained according to the disturbed phase of the second probe light and the disturbed phase of the first probe light.

[0035] Preferably, the first sensing receiving end performs coherent detection phase demodulation according to the first reference light and the second probe light, thereby obtaining the disturbed phase of the second probe light, and specifically comprises:

[0036] The calculation formula of the disturbed phase of the second probe light is:

[0037] ;

[0038] Wherein, is the angular frequency of the laser emitted by the second transmitting end, is the angular frequency of the laser emitted by the first transmitting end, is the phase of the second probe light, n is the core refractive index of the third core, l is the length of the third core, and c is the speed of light in vacuum, is the phase of the first reference light output by the first transmitting end, is the phase noise, is the phase change caused by external disturbance, , is the transmission time of the optical signal from the disturbed position on the third core to the first sensing receiving end, is the transmission distance of the optical signal from the disturbed position on the third core to the first sensing receiving end.

[0039] Preferably, the second sensing receiver performs coherent detection phase demodulation based on the second reference light and the first probe light to obtain the perturbed phase of the first probe light, specifically including:

[0040] The formula for calculating the phase of the first probe light after perturbation is:

[0041] ;

[0042] in, The angular frequency of the laser emitted from the second transmitter is [value missing]. Let be the angular frequency of the laser emitted from the first transmitter. Let be the phase of the first probe light. Where n is the refractive index of the first fiber core, l is the length of the first fiber core, and c is the speed of light in a vacuum. The phase of the second reference light output from the second transmitter. For phase noise, The phase change is caused by external disturbances. , The transmission time of the optical signal from the perturbation position on the first fiber core to the second sensing receiver is denoted as . This is the transmission distance of the optical signal from the disturbance position on the first fiber core to the second sensing receiver.

[0043] This invention provides an integrated device and method for co-source zero-difference autocoherent optical fiber communication and sensing. A first transmitting end transmits a first probe light to a second communication receiving end through a first core of a multi-core transmission optical fiber, and also transmits a first communication light to the second communication receiving end through a second core of the same multi-core transmission optical fiber. The second communication receiving end performs zero-difference autocorrelation detection based on the first communication light and the first probe light. The second transmitting end transmits a second probe light to the first communication receiving end through a third core of the multi-core transmission optical fiber, and also transmits a second communication light to the first communication receiving end through a fourth core of the same multi-core transmission optical fiber. The first communication receiving end performs zero-difference autocorrelation detection based on the second communication light and the second probe light. A first sensing receiving end demodulates the perturbation phase of the second probe light, and a second sensing receiving end demodulates the perturbation phase of the first probe light. By transmitting the communication light and probe light through multiple cores in the same optical fiber, the external interference experienced by the communication light and probe light is consistent, thereby improving the communication demodulation performance and sensing demodulation performance of the zero-difference autocorrelation detection. Attached Figure Description

[0044] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed to be used in the embodiments of the present application will be briefly introduced. Obviously, the drawings described below are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor on the basis of these drawings.

[0045] Figure 1 is a structural schematic diagram of a homologous zero-difference self-coherent optical fiber communication and sensing integrated device provided by an embodiment of the present application;

[0046] Figure 2 is a method flowchart of a homologous zero-difference self-coherent optical fiber communication and sensing integrated method provided by an embodiment of the present application;

[0047] Figure 3 is a demodulation method flowchart corresponding to a first communication light in a homologous zero-difference self-coherent optical fiber communication and sensing integrated method provided by an embodiment of the present application;

[0048] Figure 4 is a demodulation method flowchart corresponding to a second communication light in a homologous zero-difference self-coherent optical fiber communication and sensing integrated method provided by an embodiment of the present application;

[0049] Figure 5 is a demodulation method flowchart of detecting the phase of a sensing light and the position of a fiber disturbance in a homologous zero-difference self-coherent optical fiber communication and sensing integrated method provided by an embodiment of the present application. DETAILED DESCRIPTION

[0050] In order to make the purpose, technical solutions and advantages of the present application more clear, the present application will be further described in detail below in combination with the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application, and are not used to limit the present application.

[0051] In the description of the present application, it should be understood that the terms "center", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only used to facilitate the description of the present disclosure and simplify the description, and therefore cannot be understood as indicating or implying that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present disclosure.

[0052] In the description of the present application, the terms "first", "second", are only for descriptive purpose, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second" can be explicitly or implicitly included one or more of the features. In the description of the embodiments of the present disclosure, unless otherwise specified, the meaning of "a plurality of" is two or more. In addition, for example, in the description, the same type of nouns can also be described as two independent individuals by adding "A", "B" at the end, in which case the features defined with "A", "B" are only used for the purpose of distinguishing the same type of individual description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated.

[0053] The "about", "approximately" or "approximately" used in the present application includes the value stated and the average value within the acceptable deviation range of the specific value, wherein the acceptable deviation range is determined by the person skilled in the art considering the measurement being discussed and the error related to the measurement of the specific quantity, i.e. the limitation of the measurement system.

[0054] Unless the context requires otherwise, throughout the specification and claims, the term "comprising" is interpreted to mean "including, but not limited to". In the description of the specification, the terms "one embodiment", "some embodiments", "exemplary embodiment", "example", "specific example" or "some examples" are intended to mean that the specific feature, structure, material or characteristic associated with that embodiment or example is included in at least one embodiment or example of the present disclosure. The illustrative representation of the above terms does not necessarily mean the same embodiment or example. In addition, the specific features, structures, materials or characteristics described can be included in any one or more embodiments or examples in any appropriate manner, i.e. although they are carried in the embodiments or examples of the above terms due to the order of appearance and position, they are not limited to the combination of one embodiment or example.

[0055] In addition, the technical features involved in each embodiment of the present application described below can be combined with each other as long as there is no conflict.

[0056] Embodiment 1:

[0057] Embodiment 1 of the present application provides a homologous zero-difference self-coherent optical fiber communication and sensing integrated device, as shown in Figure 1 The device comprises a first transmitting end, a first communication receiving end, a multi-core transmission optical fiber, a second transmitting end and a second communication receiving end.

[0058] The first transmitting end is configured to transmit first probe light to the second communication receiving end through a first core of the multi-core transmission optical fiber, and transmit first communication light to the second communication receiving end through a second core of the multi-core transmission optical fiber; the second communication receiving end is configured to perform homodyne self-correlation detection according to the first communication light and the first probe light; wherein the first probe light and the first communication light are generated by the same laser.

[0059] The second transmitting end is configured to transmit second probe light to the first communication receiving end through a third core of the multi-core transmission optical fiber, and transmit second communication light to the first communication receiving end through a fourth core of the multi-core transmission optical fiber; the first communication receiving end is configured to perform homodyne self-correlation detection according to the second communication light and the second probe light; wherein the second probe light and the second communication light are generated by the same laser.

[0060] In the embodiment, the first transmitting end and the first communication receiving end are located at one end of the same-origin homodyne self-coherent optical fiber communication and sensing integrated device, and the second transmitting end and the second communication receiving end are located at the other end of the same-origin homodyne self-coherent optical fiber communication and sensing integrated device, the structures and configurations of the two ends are symmetrically arranged, and optical signals are transmitted between the two ends through the multi-core transmission optical fiber.

[0061] In the embodiment, narrow linewidth lasers are arranged in the first transmitting end and the second transmitting end, and the first probe light and the second probe light can be used as local oscillator light. The second communication receiving end is configured to perform homodyne self-correlation detection on the first communication light and the first probe light as local oscillator light, so as to obtain I-channel signal current and Q-channel signal current corresponding to the first communication light, and realize signal demodulation of the first communication light according to the I-channel signal current and the Q-channel signal current corresponding to the first communication light. The first communication receiving end is configured to perform homodyne self-correlation detection on the second communication light and the second probe light as local oscillator light, so as to obtain I-channel signal current and Q-channel signal current corresponding to the second communication light, and realize signal demodulation of the second communication light according to the I-channel signal current and the Q-channel signal current corresponding to the second communication light.

[0062] In the embodiment, the first core, the second core, the third core and the fourth core are located in the same multicore transmission optical fiber, and the first core, the second core, the third core and the fourth core are of the same model and have consistent performance. In the embodiment, the first probe light and the first communication light are emitted by the same laser in the first transmitting end and are transmitted from the same multicore transmission optical fiber, so that the parameter performance and the external interference of the first communication light and the first probe light received by the second communication receiving end are basically completely consistent. Similarly, the second probe light and the second communication light are emitted by the same laser in the second transmitting end and are transmitted from the same multicore transmission optical fiber, so that the parameter performance and the external interference of the second communication light and the second probe light received by the first communication receiving end are basically completely consistent. Compared with the prior art in which different lasers are used to respectively emit communication light signals and probe light, and different optical fibers are used for transmission, the positions and environments of the two optical fibers are often quite different, resulting in relatively large differences in the disturbances of the light signals transmitted in the two optical fibers, and thus the performance of the homodyne self-correlation detection performed by the communication receiving end is relatively poor. Therefore, the embodiment ensures that the performance of the homodyne self-correlation detection performed by the first communication receiving end and the second communication receiving end is more excellent.

[0063] Further, in the prior art, back Rayleigh scattering light signals are usually generated in an optical fiber for sensing, but the back Rayleigh scattering signals are essentially caused by Rayleigh scattering of light signals in the optical fiber, have weak intensity and cannot be transmitted over a long distance. Even if the sensing receiving end can receive the back Rayleigh scattering light signals, the signal intensity of the back Rayleigh scattering light signals is very weak, which is not conducive to subsequent calculation. Therefore, the embodiment also relates to the following design:

[0064] The same-source homodyne self-coherent optical fiber communication and sensing integrated device further includes a first sensing receiving end and a second sensing receiving end. The first sensing receiving end is configured to receive first reference light from the first transmitting end and second probe light from the second transmitting end. The first sensing receiving end is configured to perform phase demodulation based on the first reference light and the second probe light, so as to obtain a disturbed phase of the second probe light. The second sensing receiving end is configured to receive second reference light from the second transmitting end and first probe light from the first transmitting end. The second sensing receiving end is configured to perform phase demodulation based on the second reference light and the first probe light, so as to obtain a disturbed phase of the first probe light.

[0065] In the embodiment, the disturbed phase of the first probe light and the disturbed phase of the second probe light are obtained, so that the position of the disturbance in the multicore transmission optical fiber is obtained.

[0066] The first probe light and the second probe light are directly emitted by the first emission end and the second emission end respectively, so that the light signal intensity of the first probe light and the second probe light is relatively stronger, the effective transmission can be performed at a farther distance, and the detection distance of the distributed optical fiber sensing can be greatly improved.

[0067] Further, in the embodiment, the first emission end is configured to transmit corresponding light signals of the first fiber core, the second fiber core and the first sensing receiving end, and the second emission end is configured to transmit corresponding light signals of the third fiber core, the fourth fiber core and the second sensing receiving end. The embodiment further relates to the following design:

[0068] As shown in Figure 1 , the first emission end comprises a first laser, a first coupler and a first modulator. The first laser is configured to emit first laser light. The first coupler is configured to divide the first laser light into three paths. The first path laser signal is used as first reference light, and the second path laser signal is used as first probe light. The third path laser signal is used as first communication light after being modulated by the first modulator.

[0069] The second emission end comprises a second laser, a second coupler and a second modulator. The second laser is configured to emit second laser light. The second coupler is configured to divide the second laser light into three paths. The first path laser signal is used as second reference light, and the second path laser signal is used as second probe light. The third path laser signal is used as second communication light after being modulated by the second modulator.

[0070] In the embodiment, the first laser generates narrow linewidth laser with an angular frequency of The expression of the narrow linewidth laser generated by the first laser can be:

[0071] ;

[0072] wherein is the phase of the narrow linewidth laser, is the optical power of the laser emitted by the first laser in the first emission end.

[0073] The first laser light is divided into three paths by the first coupler. The first path can divide 60±5% of the first laser light as first probe light, which is sent to the second communication receiving end and the second sensing receiving end through the first fiber core. The second path can divide 20±5% of the first laser light and modulate it into first communication light by the first modulator, which is sent to the second communication receiving end of the opposite end through the second fiber core. The third path can divide 20±5% of the first laser light as first reference light, and the first reference light is sent to the first sensing receiving end of the local end.

[0074] In the embodiment, the second laser generates a narrow linewidth laser with an angular frequency of The expression of the narrow linewidth laser generated by the second laser can be:

[0075]

[0076] wherein, is the phase of the narrow linewidth laser, is the optical power of the laser emitted by the second laser in the second emission end.

[0077] The second laser is divided into three paths by the second coupler; the first path can divide 60±5% of the second laser as second probe light, which is sent to the first communication receiving end and the first sensing receiving end through the third fiber core; the second path can divide 20±5% of the second laser and modulate it into second communication light by the second modulator, which is sent to the first communication receiving end of the opposite end through the fourth fiber core; the third path can divide 20±5% of the second laser as second reference light, which is sent to the second sensing receiving end of the local end.

[0078] Further, since the first fiber core also needs to be connected with the second sensing receiving end and the second communication receiving end to transmit the first probe light to the second communication receiving end and the second sensing receiving end respectively, and the third fiber core also needs to be connected with the first sensing receiving end and the first communication receiving end to transmit the second probe light to the first communication receiving end and the first sensing receiving end respectively, the embodiment also relates to the following design:

[0079] As shown in Figure 1 The isogenic homodyne self-coherent optical fiber communication and sensing integrated device also includes a third coupler and a fourth coupler; the third coupler is used to divide the first probe light into two paths, one of which is transmitted to the second communication receiving end, and the other of which is transmitted to the second sensing receiving end; the fourth coupler is used to divide the second probe light into two paths, one of which is transmitted to the first communication receiving end, and the other of which is transmitted to the first sensing receiving end.

[0080] In the embodiment, the first probe light is divided into two paths by the third coupler: one of which divides 80±5% of the first probe light as a local oscillator reference light input to the second communication receiving end, which is used for homodyne self-correlation detection with the first communication light to realize demodulation of the first communication light; the other of which divides 20±5% of the first probe light as a sensing probe light input to the second sensing receiving end, which is used for coherent detection and phase demodulation with the second reference light to obtain the disturbance position on the multi-core transmission optical fiber. ​

[0081] The second probe light is split into two paths by the fourth coupler: one path splits 80±5% of the second probe light as a local oscillator reference light input to the first communication receiver, and is used to perform zero-difference autocorrelation detection with the second communication light to achieve demodulation of the second communication light; the other path splits 20±5% of the second probe light as a probe sensing light input to the first sensing receiver, and is used to perform coherent detection and phase demodulation with the first reference light to obtain the disturbance position on the multi-core transmission fiber.

[0082] In this embodiment, the calculation method for the zero-difference autocorrelation detection performed by the second communication receiver is as follows:

[0083] Specifically, the I-channel signal current and Q-channel signal current in the first communication light are obtained based on the phase of the first communication light, the optical power of the first communication light, and the optical power and phase of the first detection light, respectively.

[0084] The I-channel signal current in the first communication optical path The calculation formula is:

[0085] ;

[0086] Q-channel signal current in the first communication optical path The calculation formula is:

[0087] ;

[0088] Where R is a coefficient related to the photodetector responsivity, coupler splitting ratio, fiber loss, and polarization and frequency mismatch. The phase of the first communication light received by the second communication receiver. The optical power is the square root of the product of the optical power of the first communication light and the optical power of the first probe light.

[0089] In this embodiment, the calculation method for the zero-difference autocorrelation detection performed by the first communication receiver is as follows:

[0090] Specifically, the I-channel signal current and Q-channel signal current in the second communication light are obtained based on the phase of the second communication light, the optical power of the second communication light, and the optical power and phase of the second detection light, respectively.

[0091] The I-channel signal current in the second communication optical path The calculation formula is:

[0092] ;

[0093] Q-channel signal current in the second communication optical path The calculation formula is:

[0094] ;

[0095] wherein R is a coefficient related to the photoelectric detector responsivity, the coupler splitting ratio, the fiber loss, and the polarization and frequency mismatch, is a phase of the second communication light received by the first communication receiving end, is an optical power obtained by taking a square root of a product of an optical power of the second communication light and an optical power of the second probe light.

[0096] In the embodiment, a corresponding calculation method for the phase demodulation performed by the second sensing receiving end is as follows:

[0097] A calculation formula of the phase of the first probe light after the disturbance is as follows:

[0098] ;

[0099] wherein, is an angular frequency of the laser light emitted by the second transmitting end, is an angular frequency of the laser light emitted by the first transmitting end, is a phase of the first probe light, n is a core refractive index of the first core, l is a length of the first core, and c is a speed of light in vacuum, is a phase of the second reference light output by the second laser, is a phase noise, is a phase change caused by the external disturbance, , is a transmission time of the optical signal between the disturbance position of the optical fiber on the first core and the second sensing receiving end, is a transmission distance of the optical signal between the disturbance position of the optical fiber on the first core and the second sensing receiving end.

[0100] In the embodiment, a corresponding calculation method for the phase demodulation performed by the first sensing receiving end is as follows:

[0101] A calculation formula of the phase of the second probe light after the disturbance is as follows:

[0102] ;

[0103] wherein, is an angular frequency of the laser light emitted by the second transmitting end, is an angular frequency of the laser light emitted by the first transmitting end, is a phase of the second probe light, n is a core refractive index of the third core, l is a length of the third core, and c is a speed of light in vacuum, a phase of a first reference light output by the first laser, a phase noise, a phase change caused by an external disturbance, , a transmission time of the optical signal between the optical fiber disturbance position on the third core and the first sensing receiving end, a transmission distance of the optical signal between the optical fiber disturbance position on the third core and the first sensing receiving end.

[0104] Embodiment 2:

[0105] The embodiment is based on embodiment 1, and provides a homologous homodyne self-coherent optical fiber communication and sensing integrated method, which is used in the homologous homodyne self-coherent optical fiber communication and sensing integrated device described in embodiment 1, as shown in the figure, comprising: Figure 2

[0106] In step 101, the first transmitting end sends first probe light to the second communication receiving end through the first core in the multi-core transmission optical fiber; the first transmitting end also sends first communication light to the second communication receiving end through the second core in the multi-core transmission optical fiber; the second communication receiving end performs homodyne self-correlation detection according to the first communication light and the first probe light, thereby obtaining the corresponding current of the first communication light.

[0107] In step 102, the second transmitting end sends second probe light to the first communication receiving end through the third core in the multi-core transmission optical fiber; the second transmitting end also sends second communication light to the first communication receiving end through the fourth core in the multi-core transmission optical fiber; the first communication receiving end performs homodyne self-correlation detection according to the second communication light and the second probe light, thereby obtaining the corresponding current of the second communication light.

[0108] Further, the second communication receiving end performs homodyne self-correlation detection according to the first communication light and the first probe light, thereby obtaining the corresponding current of the first communication light, as shown in the figure, the method flow comprises: Figure 3

[0109] In step 201, the phase and optical power of the first communication light are obtained by the second communication receiving end.

[0110] In step 202, the I-channel signal current and Q-channel signal current corresponding to the I-channel communication light signal in the first communication light are obtained according to the phase of the first communication light, the optical power of the first communication light, and the optical power and phase of the first probe light, respectively.

[0111] The calculation formula of the I-channel signal current in the communication light signal is: ​​​

[0112] ;

[0113] Q-path signal current in the communication optical signal The calculation formula is:

[0114] ;

[0115] R is a coefficient related to the photoelectric detector responsivity, the coupler splitting ratio, the optical fiber loss, and the polarization and frequency mismatch, is the phase of the communication optical signal received by the second communication receiving end 2 of the opposite end, is the optical power after the product of the optical power of the first communication light and the optical power of the first probe light is square rooted.

[0116] The first communication receiving end performs homodyne self-correlation detection according to the second communication light and the second probe light, thereby obtaining the corresponding current of the second communication light, as shown in Figure 4 The method flow includes:

[0117] In step 301, the phase and the optical power of the second communication light are obtained by the first communication receiving end.

[0118] In step 302, the I-path signal current and the Q-path signal current in the second communication light are obtained according to the phase of the second communication light, the optical power of the second communication light, and the optical power and the phase of the second probe light, respectively.

[0119] The calculation formula of the I-path signal current in the second communication light is:

[0120] ;

[0121] The calculation formula of the Q-path signal current in the second communication light is:

[0122] ;

[0123] R is a coefficient related to the photoelectric detector responsivity, the coupler splitting ratio, the optical fiber loss, and the polarization and frequency mismatch, is the phase of the second communication light received by the first communication receiving end, is the optical power after the product of the optical power of the second communication light and the optical power of the second probe light is square rooted.

[0124] Further, the homologous homodyne self-coherent fiber communication and sensing integrated device further includes a first sensing receiving end and a second sensing receiving end, and correspondingly, as shown in Figure 5 The sensing optical signal demodulation method of the first sensing receiving end and the second sensing receiving end is:

[0125] In step 401, the first sensing receiving end receives the first reference light from the first transmitting end and the second probe light from the second transmitting end; the first sensing receiving end performs coherent detection phase demodulation according to the first reference light and the second probe light, so as to obtain the disturbed phase of the second probe light.

[0126] In step 402, the second sensing receiving end receives the second reference light from the second transmitting end and the first probe light from the first transmitting end; the second sensing receiving end performs coherent detection phase demodulation according to the second reference light and the first probe light, so as to obtain the disturbed phase of the first probe light.

[0127] In step 403, the disturbed position on the multi-core transmission optical fiber is obtained according to the disturbed phase of the second probe light and the disturbed phase of the first probe light.

[0128] In the embodiment, the corresponding calculation method of the coherent detection phase demodulation performed by the second sensing receiving end is as follows:

[0129] The calculation formula of the disturbed phase of the first probe light is as follows:

[0130] ;

[0131] Wherein, is the angular frequency of the laser emitted by the second transmitting end, is the angular frequency of the laser emitted by the first transmitting end, is the phase of the first probe light, n is the core refractive index of the first core, l is the length of the first core, and c is the speed of light in vacuum, is the phase of the second reference light output by the second laser, is the phase noise, is the phase change caused by external disturbance, , is the transmission time of the optical signal between the optical fiber disturbance position on the first core and the second sensing receiving end, is the transmission distance of the optical signal between the optical fiber disturbance position on the first core and the second sensing receiving end.

[0132] In the embodiment, the corresponding calculation method of the coherent detection phase demodulation performed by the first sensing receiving end is as follows:

[0133] The calculation formula of the disturbed phase of the second probe light is as follows:

[0134] ;

[0135] wherein, is the angular frequency of the laser light emitted by the second transmitting end, is the angular frequency of the laser light emitted by the first transmitting end, is the phase of the second probe light, is the core refractive index of the third core, l is the length of the third core, and c is the speed of light in vacuum, is the phase of the first reference light output by the first laser, is the phase noise, is the phase change caused by external disturbance, , is the transmission time of the optical signal between the fiber disturbance position on the third core and the first sensing receiving end, is the transmission distance of the optical signal between the fiber disturbance position on the third core and the first sensing receiving end.

[0136] In the embodiment, the disturbance position on the multi-core transmission optical fiber is obtained according to the disturbed phase of the second probe light and the disturbed phase of the first probe light, and specifically includes:

[0137] The obtained and are filtered, and is approximated as , is approximated as , and are cross-correlated, and there is a peak at , and since , l is the length of the third core, so the external disturbance position is obtained according to or to obtain the disturbance position on the multi-core transmission optical fiber.

[0138] The above only describes the preferred embodiments of the present application and is not used to limit the present application, and any modification, equivalent replacement and improvement made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. A homodyne self-coherent fiber-optic communication and sensing integrated device, characterized in that, Comprising: a first transmitting end, a first communication receiving end, a multi-core transmission optical fiber, a second transmitting end, a second communication receiving end, a first sensing receiving end and a second sensing receiving end; the first transmitting end is configured to transmit first probe light to the second communication receiving end through a first core of the multi-core transmission optical fiber, and transmit first communication light to the second communication receiving end through a second core of the multi-core transmission optical fiber; the second communication receiving end is configured to perform homodyne self-correlation detection according to the first communication light and the first probe light; wherein the first probe light and the first communication light are generated by the same laser; the second transmitting end is configured to transmit second probe light to the first communication receiving end through a third core of the multi-core transmission optical fiber, and transmit second communication light to the first communication receiving end through a fourth core of the multi-core transmission optical fiber; the first communication receiving end is configured to perform homodyne self-correlation detection according to the second communication light and the second probe light; wherein the second probe light and the second communication light are generated by the same laser; the first sensing receiving end is configured to receive first reference light from the first transmitting end and second probe light from the second transmitting end; the first sensing receiving end is configured to perform phase demodulation according to the first reference light and the second probe light, thereby obtaining the disturbed phase of the second probe light; the second sensing receiving end is configured to receive second reference light from the second transmitting end and first probe light from the first transmitting end; the second sensing receiving end is configured to perform phase demodulation according to the second reference light and the first probe light, thereby obtaining the disturbed phase of the first probe light.

2. The homodyne self-coherent fiber-optic communication and sensing integrated device according to claim 1, wherein, the first transmitting end comprises a first laser, a first coupler and a first modulator; the first laser is configured to emit first laser light, the first coupler is configured to divide the first laser light into three paths, the first path laser signal is used as first reference light, the second path laser signal is used as first probe light; the third path laser signal is used as first communication light after being modulated by the first modulator; the second transmitting end comprises a second laser, a second coupler and a second modulator; the second laser is configured to emit second laser light, the second coupler is configured to divide the second laser light into three paths, the first path laser signal is used as second reference light, the second path laser signal is used as second probe light; the third path laser signal is used as second communication light after being modulated by the second modulator.

3. The homodyne self-coherent fiber-optic communication and sensing integrated device according to claim 1, wherein, further comprising a third coupler and a fourth coupler; the third coupler is configured to divide the first probe light into two paths, one of which is transmitted to the second communication receiving end, and the other is transmitted to the second sensing receiving end; the fourth coupler is configured to divide the second probe light into two paths, one of which is transmitted to the first communication receiving end, and the other is transmitted to the first sensing receiving end.

4. A homologous homodyne self-coherent fiber communication and sensing integrated method, applied to the homologous homodyne self-coherent fiber communication and sensing integrated device as claimed in any one of claims 1-3, characterized in that, Comprising: the first transmitting end transmits first probe light to the second communication receiving end through a first core of the multi-core transmission optical fiber; The first transmitting end also sends first communication light to the second communication receiving end through a second fiber core in the multi-core transmission optical fiber; the second communication receiving end performs homodyne self-correlation detection according to the first communication light and the first probe light, thereby obtaining corresponding I-channel signal current and Q-channel signal current of the first communication light; The second transmitting end sends second probe light to the first communication receiving end through a third fiber core in the multi-core transmission optical fiber; the second transmitting end also sends second communication light to the first communication receiving end through a fourth fiber core in the multi-core transmission optical fiber; the first communication receiving end performs homodyne self-correlation detection according to the second communication light and the second probe light, thereby obtaining corresponding I-channel signal current and Q-channel signal current of the second communication light.

5. The homodyne self-coherent fiber-optic communication and sensing integrated method of claim 4, wherein, The second communication receiving end performs homodyne self-correlation detection according to the first communication light and the first probe light, thereby obtaining corresponding I-channel signal current and Q-channel signal current of the first communication light, specifically comprising: The second communication receiving end obtains the phase and optical power of the first communication light; According to the phase of the first communication light, the optical power of the first communication light, and the optical power and phase of the first probe light, the I-channel signal current and the Q-channel signal current in the first communication light are obtained.

6. The homodyne self-coherent fiber-optic communication and sensing integrated method of claim 5, wherein, The second communication receiving end performs homodyne self-correlation detection according to the first communication light and the first probe light, thereby obtaining corresponding I-channel signal current and Q-channel signal current of the first communication light, specifically comprising: the corresponding I-channel signal current in the first communication light The calculation formula is: ； a corresponding Q-channel signal current in the first communication light The calculation formula is: ； wherein R is a coefficient related to the photo detector responsivity, the coupler splitting ratio, the fiber loss, and the polarization and frequency mismatch, a phase of the first communication light received by the second communication receiving end, an optical power obtained by taking a square root of a product of the optical power of the first communication light and the optical power of the first probe light.

7. The homodyne self-coherent fiber-optic communication and sensing integrated method according to claim 4, wherein, The isogenic homodyne self-coherent optical fiber communication and sensing integrated device further comprises a first sensing receiving end and a second sensing receiving end; The isogenic homodyne self-coherent optical fiber communication and sensing integrated method further comprises: The first sensing receiving end receives first reference light from the first transmitting end and second probe light from the second transmitting end; the first sensing receiving end performs coherent detection phase demodulation according to the first reference light and the second probe light, thereby obtaining the disturbed phase of the second probe light; The second sensing receiving end receives second reference light from the second transmitting end and first probe light from the first transmitting end; the second sensing receiving end performs coherent detection phase demodulation according to the second reference light and the first probe light, thereby obtaining the disturbed phase of the first probe light; According to the disturbed phase of the second probe light and the disturbed phase of the first probe light, the disturbed position on the multi-core transmission optical fiber is obtained.

8. The homodyne self-coherent fiber-optic communication and sensing integrated method of claim 7, wherein, The first sensing receiving end performs coherent detection phase demodulation according to the first reference light and the second probe light, thereby obtaining the disturbed phase of the second probe light, specifically comprising: The calculation formula of the disturbed phase of the second probe light is: ； wherein, is the angular frequency of the laser light emitted by the second emitting end, is the angular frequency of the laser light emitted by the first emitting end, is the phase of the second probe light, is the core refractive index of the third core, l is the length of the third core, and c is the speed of light in vacuum, is the phase of the first reference light output by the first emitting end, is the phase noise, is the phase change caused by the external disturbance, , is the transmission time of the optical signal from the disturbance position on the third core to the first sensing receiving end, is the transmission distance of the optical signal from the disturbance position on the third core to the first sensing receiving end.

9. The homodyne self-coherent fiber-optic communication and sensing integrated method of claim 7, wherein, The second sensing receiving end performs coherent detection phase demodulation according to the second reference light and the first probe light, thereby obtaining the disturbed phase of the first probe light, specifically comprising: The calculation formula of the disturbed phase of the first probe light is: ； wherein, is the angular frequency of the laser light output from the second emitting end, is the angular frequency of the laser light output from the first emitting end, is the phase of the first probe light, is the core refractive index of the first core, l is the length of the first core, c is the speed of light in vacuum, is the phase of the second reference light output from the second emitting end, is the phase noise, is the phase change caused by the external disturbance, , is the transmission time of the optical signal from the disturbance position on the first core to the second sensing receiving end, is the transmission distance of the optical signal from the disturbance position on the first core to the second sensing receiving end.

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