Multi-channel spiral winding type multi-core optical fiber distributed sensing sensibilization device

Abstract

The utility model discloses a multi-channel spiral winding type multi-core optical fiber distributed sensing sensitization device which comprises a multi-channel multi-core optical fiber, an elastic sensitization structure, a fan-in and fan-out module, a transmission optical fiber group and a signal demodulation system, the multi-channel multi-core optical fiber senses an external sensing signal and loads the external sensing signal to back reflected light of each channel, and a single fiber core of each multi-core optical fiber is a sensing optical channel; the elastic sensitization structure has a good sensitization sensing effect, deformation resistance and stress damage resistance, and realizes constant-amplitude sensitization on the multichannel multi-core optical fibers which are uniformly and spirally wound on the elastic sensitization structure side by side with the same prestress; according to the signal demodulation system, the sensing response sensitivity and the output signal-to-noise ratio of the multi-channel multi-core optical fiber are improved by accumulating phase difference signals of a plurality of independent fiber cores of a plurality of optical fibers in a corresponding optical fiber interval; the overall improvement effect of the distributed sensing sensitization device is approximate to the product of the number of the multi-core optical fibers and the number of fiber cores in each multi-core optical fiber.

Description

TECHNICAL FIELD

[0001] The utility model belongs to optical fiber sensing technical field, especially relate to a kind of multi-channel spiral winding type multicore optical fiber distributed sensing sensitization device. BACKGROUND

[0002] Multicore optical fiber is the optical fiber with multiple cores in a single cladding, and the space division multiplexing of the multicore optical fiber is to divide the light beam into multiple sensing channels along the space in one optical fiber. Through the space division multiplexing, each point on the optical fiber link serves as a sensing element, and the sensing length can reach tens of kilometers. The environmental parameters distributed along the length of the optical fiber can be continuously measured to realize distributed optical fiber sensing.

[0003] The conventional distributed sensing technology obtains sensing information by processing backscattered light, and has the following disadvantages: using optical fiber with a single core, only one set of sensing data can be obtained at the same time for a certain event; in long-distance sensing, the amount of single sensing information is insufficient due to the influence of noise, which may cause misjudgment, and multiple measurements may miss the capture of the change of environmental parameters due to delay in the middle, the reliability is poor, the sensing sensitivity is limited, and in the process of large-scale networking, the system as a whole may have a large range of blind spots in the spatial domain for sensing external acoustic signals. SUMMARY

[0004] The utility model provides a kind of multi-channel spiral winding type multicore optical fiber distributed sensing sensitization device to solve the problem of limited sensitivity of optical fiber distributed sensing.

[0005] To solve the above problems, the technical scheme provided by the utility model is as follows:

[0006] The utility model embodiment provides a kind of multi-channel spiral winding type multicore optical fiber distributed sensing sensitization device, including multi-channel multicore optical fiber (1), elastic sensitization structure (2), fan-in fan-out module (3), transmission optical fiber group (4) and signal demodulation system (5);Wherein, the multi-channel multicore optical fiber (1) is uniformly and side by side spiral wound on the elastic sensitization structure (2), and the tail fiber of the multi-channel multicore optical fiber (1) is connected by the fan-in fan-out module (3) and the transmission optical fiber group (4), and the transmission optical fiber group (4) is used to transmit sensing optical signal to the signal demodulation system (5);

[0007] The multi-channel multicore optical fiber (1) includes a plurality of multicore optical fibers with the same optical structure, and a plurality of cores in each multicore optical fiber independently exist in a common cladding region. A single core is a sensing optical channel, and the total number of channels of the multi-channel multicore optical fiber (1) is the product of the number of multicore optical fibers and the number of cores of each multicore optical fiber.

[0008] The utility model discloses a preferred embodiment, the multichannel multicore optical fiber (1) is even and side by side spiral winding with same pre -stress on same the elastic sensitization structure (2), realizes the equal amplitude enhancement of sensing signal in multichannel multicore optical fiber, not only the sensitization amplitude of sensing signal in each fiber core channel of every multicore optical fiber is close to equal, and the sensing signal in each fiber core channel of different channel multicore optical fiber also obtains almost same sensitization effect.

[0009] The utility model discloses a preferred embodiment, the signal demodulation system (5) demodulates the phase difference signal between the back reflection light of each independent fiber core of the multichannel multicore optical fiber (1) winding on the elastic sensitization structure (2) two different positions, and the multichannel multicore optical fiber winding on the elastic sensitization structure (2) between two points, the sensing response sensitivity and output signal noise ratio of the multichannel multicore optical fiber (1) are improved through the accumulation phase difference signal of independent fiber core in corresponding optical fiber interval.

[0010] The utility model discloses a preferred embodiment, the elastic sensitization structure (2) includes but is not limited to single or composite material cylinder shell sensitization structure, or high polymer / multilayer elastomer sensitization structure, and the elastic sensitization structure (2) can be the core shaft of the whole distributed sensitization cable, also can be the sensitization unit of separation type.

[0011] The utility model discloses a preferred embodiment, the signal demodulation system (5) can adopt but is not limited to the structure homodyne or heterodyne type interference demodulation system of Mach - Zehnder interferometer, michelson interferometer, fizeau interferometer.

[0012] Beneficial effect: the utility model embodiment provides a kind of multichannel spiral winding type multicore optical fiber distributed sensing sensitization device, including multichannel multicore optical fiber, elastic sensitization structure, fan-in fan-out module, transmission optical fiber group and signal demodulation system;Multichannel multicore optical fiber perceives external sensing signal, and load it in the back reflection light of each channel, and the single fiber core of each multicore is a sensing optical channel;Elastic sensitization structure has good sensitization sensing effect and the ability of anti-deformation, stress damage, realizes equal amplitude sensitization to the multichannel multicore optical fiber evenly and side by side spiral winding on it with same pre -stress;Signal demodulation system is accumulated the phase difference signal of multiple independent fiber cores in corresponding optical fiber interval, and the sensing response sensitivity and output signal noise ratio of multichannel multicore optical fiber are improved, and compared with single channel, the overall improvement effect of this distributed sensing sensitization device is approximately the product of the number of multicore optical fiber and the number of fiber core in each multicore optical fiber. BRIEF DESCRIPTION OF DRAWINGS

[0013] In order to more clearly illustrate the technical solutions in the embodiments or the prior art, the following will briefly introduce the drawings needed to be used in the description of the embodiments or the prior art. Obviously, the drawings described below are only some embodiments of the utility model, and for those skilled in the art, other drawings can also be obtained without creative labor on the basis of these drawings.

[0014] Figure 1 A multi-channel spiral winding multi-core optical fiber distributed sensing sensitization device provided by the embodiment of the application is shown in a schematic diagram. DETAILED DESCRIPTION

[0015] The technical solutions in the embodiments of the application will be described clearly and completely in the following with reference to the drawings in the embodiments of the application. Obviously, the described embodiments are only some embodiments of the application, not all the embodiments. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor are within the protection scope of the application.

[0016] As Figure 1 shown, the embodiment of the utility model provides a kind of multi-channel spiral winding multi-core optical fiber distributed sensing sensitization device to solve the problem of limited sensitivity of optical fiber distributed sensing, it can be applied to the field of underwater acoustic sensing and distributed vibration sensing field.A kind of multi-channel spiral winding multi-core optical fiber distributed sensing sensitization device includes multi-channel multi-core optical fiber 1, elastic sensitization structure 2, fan-in fan-out module 3, transmission optical fiber group 4 and signal demodulation system 5;Wherein, multi-channel multi-core optical fiber 1 is uniformly and side by side spiral wound on elastic sensitization structure 2, and the tail fiber of multi-channel multi-core optical fiber 1 is connected by fan-in fan-out module 3 and transmission optical fiber group 4, and transmission optical fiber group 4 is used to transmit sensing optical signal to signal demodulation system 5.Multi-channel multi-core optical fiber 1 includes a plurality of multi-core optical fibers with the same optical structure, a plurality of fiber cores in each multi-core optical fiber independently exist in common cladding region, and a single fiber core is a sensing optical channel, and the total number of channels of multi-channel multi-core optical fiber 1 is the product of the number of multi-core optical fibers and the number of fiber cores of each multi-core optical fiber.

[0017] The multi-channel multi-core optical fiber 1 realizes equal-amplitude enhancement of sensing signals in the multi-channel multi-core optical fiber by being uniformly and side-by-side spirally wound on the same elastic enhancement structure 2, so that the enhancement amplitudes of sensing signals in each core channel of each multi-core optical fiber are close to equal, and the sensing signals in each core channel of different multi-channel multi-core optical fibers also obtain almost the same enhancement effect. The elastic enhancement structure 2 has an axially homogenous structural design, the size, material and structure at different axial positions are completely the same, and the overall enhancement effect obtained by the multi-channel multi-core optical fiber 1 by being side-by-side spirally wound on the same elastic enhancement structure 2 is approximately the product of the enhancement multiple obtained by a single-core optical fiber in the same spiral winding manner on the elastic enhancement structure and the total number of channels of the multi-channel multi-core optical fiber.

[0018] The signal demodulation system 5 demodulates the phase difference signals between the backscattered light of each independent core of the multi-channel multi-core optical fiber 1 wound on the elastic enhancement structure 2 at two different positions, and the multi-channel multi-core optical fiber is contained between the two positions, and the sensing response sensitivity and output signal-to-noise ratio of the multi-channel multi-core optical fiber 1 are improved by accumulating the phase difference signals of the independent cores in the corresponding optical fiber interval.

[0019] The multi-channel multi-core optical fiber 1 realizes enhancement by being side-by-side spirally wound on the same elastic enhancement structure 2, and the side-by-side spiral winding manner can be close side-by-side or sparse side-by-side with a certain winding gap. In addition to being side-by-side spirally wound on the elastic enhancement structure 2, the multi-channel multi-core optical fiber 1 can also be enhanced in a secondary coating manner.

[0020] The sensing optical signals in the multi-channel multi-core optical fiber 1 can use, but are not limited to, backscattered Rayleigh scattering light of the multi-core optical fiber or backscattered enhanced scattering light of the multi-core optical fiber, or backscattered light generated by grating written on the multi-core optical fiber. The elastic enhancement structure 2 includes, but is not limited to, a single or composite material cylindrical shell enhancement structure, or a high polymer / multi-layer elastomer enhancement structure; the elastic enhancement structure 2 can be a separate enhancement unit, or a core shaft of the entire distributed enhancement cable. The signal demodulation system 5 can use, but is not limited to, a homodyne or heterodyne interference demodulation system based on a Mach-Zehnder interferometer, a Michelson interferometer, a Fizeau interferometer and the like.

[0021] Although the utility model has disclosed as above with preferred embodiments, the above preferred embodiments are not used to limit the utility model, ordinary skilled in the art can make various modifications and modifications without departing from the spirit and scope of the utility model, therefore the protection scope of the utility model is the range defined by claims.

Claims

1. A multi-channel, helically-wound, multicore optical fiber distributed sensing enhancement device, characterized in that, The application relates to a multi-channel multi-core optical fiber sensing system, which comprises a multi-channel multi-core optical fiber (1), an elastic sensitization structure (2), a fan-in fan-out module (3), a transmission optical fiber group (4) and a signal demodulation system (5); wherein the multi-channel multi-core optical fiber (1) is uniformly and side-by-side spirally wound on the elastic sensitization structure (2), tail fibers of the multi-channel multi-core optical fiber (1) are connected by the fan-in fan-out module (3) and the transmission optical fiber group (4), and the transmission optical fiber group (4) is used for transmitting sensing optical signals to the signal demodulation system (5). The multi-channel multi-core optical fiber (1) comprises a plurality of multi-core optical fibers with the same optical structure, a plurality of fiber cores in each multi-core optical fiber independently exist in a common cladding region, a single fiber core is a sensing optical channel, and the total number of channels of the multi-channel multi-core optical fiber (1) is the product of the number of multi-core optical fibers and the number of fiber cores of each multi-core optical fiber.

2. A multi-channel, helically-wound multicore optical fiber distributed sensing apparatus according to claim 1, wherein, The multi-channel multi-core optical fiber (1) is uniformly and side-by-side spirally wound on the same elastic sensitization structure (2) with the same pre-tightening force, equal-amplitude enhancement of sensing signals in the multi-channel multi-core optical fiber is realized, the sensitization amplitudes of sensing signals in each fiber core channel of each multi-core optical fiber are close to equal, and the sensitization effects of sensing signals in each fiber core channel of different multi-core optical fibers are almost the same.

3. A multi-channel, helically-wound multicore optical fiber distributed sensing apparatus according to claim 1, wherein, The signal demodulation system (5) demodulates phase difference signals between back-reflection lights of independent fiber cores at two different positions of the multi-channel multi-core optical fiber (1) wound on the elastic sensitization structure (2), the multi-channel multi-core optical fiber is contained between the two positions, the sensing response sensitivity and output signal-to-noise ratio of the multi-channel multi-core optical fiber (1) are improved by accumulating the phase difference signals of independent fiber cores in corresponding optical fiber intervals.

4. A multi-channel, helically-wound multicore optical fiber distributed sensing apparatus according to claim 1, wherein, The elastic sensitization structure (2) comprises but is not limited to a single or composite material cylindrical shell sensitization structure, or a high polymer / multi-layer elastomer sensitization structure; the elastic sensitization structure (2) can be a separate sensitization unit or a core shaft of a whole distributed sensitization cable.

5. A multi-channel, helically-wound multicore optical fiber distributed sensing apparatus according to claim 1, wherein, The signal demodulation system (5) can adopt but is not limited to a homodyne or heterodyne interference demodulation system based on a Mach-Zehnder interferometer, a Michelson interferometer and a Fizeau interferometer structure.

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