CN112468235A - Relay amplification coupling light path for optical fiber hydrophone array - Google Patents
Relay amplification coupling light path for optical fiber hydrophone array Download PDFInfo
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- CN112468235A CN112468235A CN202011285454.XA CN202011285454A CN112468235A CN 112468235 A CN112468235 A CN 112468235A CN 202011285454 A CN202011285454 A CN 202011285454A CN 112468235 A CN112468235 A CN 112468235A
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- uplink
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
- H04B10/29—Repeaters
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01H—MEASUREMENT OF MECHANICAL VIBRATIONS OR ULTRASONIC, SONIC OR INFRASONIC WAVES
- G01H9/00—Measuring mechanical vibrations or ultrasonic, sonic or infrasonic waves by using radiation-sensitive means, e.g. optical means
- G01H9/004—Measuring mechanical vibrations or ultrasonic, sonic or infrasonic waves by using radiation-sensitive means, e.g. optical means using fibre optic sensors
Abstract
The invention relates to a relay amplification coupling optical path for an optical fiber hydrophone array, which comprises a first uplink optical path, a second uplink optical path, a first downlink optical path, a second downlink optical path, a first pump laser group and a second pump laser group. The first and second uplink optical paths and the first and second downlink optical paths form two pairs of space division optical paths of the optical fiber hydrophone array respectively. The first uplink optical path and the second uplink optical path are connected through a first pump laser group, and the first downlink optical path and the second downlink optical path are connected through a second pump laser group. The invention has the beneficial effects that: the uplink and downlink optical paths separately adopt a double-pump laser parallel coupling distribution mode, so that the problem that the pump lasers are difficult to couple and distribute due to large optical power difference of the uplink and downlink optical paths in the optical fiber hydrophone array is solved; the wavelength division multiplexer is adopted to couple the back scattering light after the relay amplification of the uplink light path into the downlink light path and filter the back scattering light of the laser wavelength for the optical fiber hydrophone array, so that the interference noise introduced into the downlink light path is avoided.
Description
Technical Field
The invention relates to the field of optical fiber sensing, in particular to a relay amplification coupling optical path for an optical fiber hydrophone array.
Background
The optical fiber hydrophone is a new-generation underwater sound sensor taking optical fibers as signal sensing and transmission media, converts underwater sound vibration into optical signals through optical coherent detection, and has the advantages of high sensitivity, frequency response characteristic number, electromagnetic interference resistance and the like. The optical fiber hydrophone forms a hydrophone array through large-scale multiplexing of space division, time division and wavelength division, and has wide application prospect in the fields of marine acoustic environment detection, seabed observation network, underwater security, marine oil exploration, marine geological survey and the like.
In the field of optical communication, optical signals are greatly attenuated after being transmitted by nearly hundreds of kilometers in an undersea optical cable, so that the signal-to-noise ratio of optical signals received by a shore station is reduced, and therefore, an optical repeater is added to a large-capacity and long-distance optical fiber transmission system at a certain distance for repeating, amplifying and compensating optical power. In contrast, the major problems with the introduction of optical repeaters into fiber optic hydrophone arrays for long-range transmission include:
(1) the difference of the uplink and downlink optical power is large. The insertion loss of the optical fiber hydrophone array is generally larger than 20dB, and optical signals of an uplink optical path in a pair of space division optical paths are output to a downlink optical path after passing through the hydrophone array, so that the optical power difference of the uplink and downlink optical paths is more than 20 dB. As shown in fig. 1, a conventional optical repeater dual-pump laser redundancy method performs pump distribution in a pair of uplink and downlink, but it is difficult to implement the dual-pump laser coupling distribution in an optical fiber hydrophone array.
(2) The link couples noise. As shown in fig. 2 and 3, in the optical communication, the optical fiber couplers are added to the submarine optical cable before and after the optical repeater to perform cross coupling on the uplink and downlink, so that unidirectional isolation of the optical repeater on optical transmission is avoided, and detection of the optical cable link at the rear end of the optical repeater is realized. In the optical fiber hydrophone array, the back scattering light of the uplink relay rear-end link enters a downlink light path through the coupler coupling and is superposed with the optical signal returned by the hydrophone array at the same frequency, and interference noise is introduced.
Disclosure of Invention
In order to solve the problems of relay amplification and noise introduction of long-distance transmission of the optical fiber hydrophone array, the invention provides a relay amplification coupling optical path for the optical fiber hydrophone array, which improves the reliability of relay amplification and reduces the noise of the optical fiber hydrophone array system.
The object of the present invention is achieved by the following technical means. A relay amplification coupling optical path for an optical fiber hydrophone array comprises a first uplink optical path, a second uplink optical path, a first downlink optical path, a second downlink optical path, a first pump laser group and a second pump laser group, wherein the first uplink optical path and the second uplink optical path respectively form two pairs of space division optical paths of the optical fiber hydrophone array with the first downlink optical path and the second downlink optical path; the first uplink optical path and the second uplink optical path are connected through a first pump laser group, and the first downlink optical path and the second downlink optical path are connected through a second pump laser group.
The first uplink light path comprises an uplink first isolator, an uplink first wavelength division multiplexer, an uplink first amplification module and an uplink first coupler which are connected in sequence, and the second uplink light path comprises an uplink second isolator, an uplink second wavelength division multiplexer, an uplink second amplification module and an uplink second coupler which are connected in sequence; the first downlink optical path comprises a downlink first amplification module, a downlink first wavelength division multiplexer, a downlink first isolator and a downlink first wavelength division multiplexer, and the second downlink optical path comprises a downlink second wavelength division multiplexer, a downlink second isolator, a downlink second wavelength division multiplexer and a downlink second amplification module; the first uplink optical path is connected with the second input of the downlink first wavelength division multiplexer of the first downlink optical path through the second output of the uplink first coupler; the second uplink optical path is connected with the second input of the downlink second wavelength division multiplexer of the second downlink optical path through the second output of the uplink second coupler, namely, the two optical outputs are respectively connected with the wavelength division multiplexers in the uplink and downlink direction links, so that the back scattering light after the optical relay amplification of the uplink optical path is coupled into the downlink optical path, and the isolator realizes the unidirectional isolation of optical signals.
Preferably, the first pump laser group comprises an uplink coupler and two uplink pump lasers, and the two uplink pump lasers are coupled and output in parallel through the uplink coupler; the second pump laser group comprises a downlink coupler and two downlink pump lasers, and the two downlink pump lasers are coupled and output in parallel through the downlink coupler.
The first pump laser group has a higher output optical power than the second pump laser group.
Preferably, the uplink first amplification module, the uplink second amplification module, the downlink first amplification module and the downlink second amplification module respectively comprise erbium-doped fibers for optical signal gain, and have functions of gain flattening filtering, optical signal input and gain amplification output power detection, and output optical signal unidirectional isolation; the uplink first amplification module and the uplink second amplification module are used in cooperation with the first pump laser group, and the downlink first amplification module and the downlink second amplification module are used in cooperation with the second pump laser group.
Preferably, the second input of the downstream first wavelength division multiplexer of the first downstream optical path and the second input of the downstream second wavelength division multiplexer of the second downstream optical path should be capable of only transmitting a wavelength window for coherent detection of the sea optical cable, that is, the laser wavelength for the fiber optic hydrophone array can be filtered, and the wavelength of the first input should be capable of transmitting the other wavelength windows except for the second input wavelength.
The invention has the beneficial effects that: (1) the upper and lower light paths separately adopt the parallel coupling distribution mode of the double-pump laser, thus avoiding the problem that the pump laser is difficult to couple and distribute due to the large difference of the light power of the upper and lower light paths in the optical fiber hydrophone array. (2) The wavelength division multiplexer is adopted to couple the back scattering light after the relay amplification of the uplink light path into the downlink light path, and the back scattering light of the laser wavelength for the optical fiber hydrophone array is filtered, so that the phenomenon that optical signals returned by the downlink light path and the hydrophone array are overlapped at the same frequency and interference noise is introduced is avoided.
Drawings
FIG. 1 is a schematic diagram of a prior art optical repeater dual pump laser redundancy method;
FIG. 2 is a schematic diagram of a prior art optical repeater uplink and downlink coupling scheme;
FIG. 3 is a schematic diagram of a second uplink and downlink coupling mode of an optical repeater in the prior art;
FIG. 4 is a schematic diagram of a first relay amplification coupling optical path scheme for an optical fiber hydrophone array according to the present invention;
FIG. 5 is a schematic diagram of a second relay amplification coupling optical path scheme for an optical fiber hydrophone array according to the present invention;
description of reference numerals: the optical fiber amplifier comprises a first uplink optical path 11, a second uplink optical path 12, a first downlink optical path 13, a second downlink optical path 14, a first pump laser group 15, a second pump laser group 16, an optical fiber hydrophone array 17, an uplink first isolator 21, an uplink first wavelength division multiplexer 22, an uplink first amplification module 23, an uplink first coupler 24, an uplink pump laser 25, an uplink coupler 26, a downlink first wavelength division multiplexer 27, a downlink first amplification module 28, a downlink pump laser 29, a downlink second wavelength division multiplexer 30, an uplink second isolator 31, an uplink second wavelength division multiplexer 32, an uplink second amplification module 33, an uplink second coupler 34, a downlink first wavelength division multiplexer 35, a downlink first isolator 36, a downlink coupler 37, a downlink second isolator 38, a downlink second wavelength division multiplexer 39 and a downlink second amplification module 40.
Detailed Description
In order to better understand the technical scheme, the technical scheme is described in detail below with reference to the figures and the detailed description of the specification.
The embodiment of the invention provides a relay amplification coupling optical path for an optical fiber hydrophone array, which comprises a first uplink optical path 11, a second uplink optical path 12, a first downlink optical path 13, a second downlink optical path 14, a first pump laser group 15 and a second pump laser group 16, as shown in fig. 4 and 5. The first uplink optical path 11 and the second uplink optical path 12 of the uplink link and the first downlink optical path 13 and the second downlink optical path 14 of the downlink link form two pairs of space division transmission optical paths of the optical fiber hydrophone array 17, respectively. The first uplink optical path 11 and the second uplink optical path 12 are connected through a first pump laser group 15, and the first downlink optical path 13 and the second downlink optical path 14 are connected through a second pump laser group 16. It should be understood that the fiber optic hydrophone array 17 should include a plurality of pairs of space division transmission optical paths, and two pairs are illustrated in detail in the embodiment.
The first group of pump lasers 15 outputs a 980nm window wavelength and includes an upstream coupler 26 and two upstream pump lasers 25. The uplink pump laser 25 selects a higher optical power output, two optical inputs of the uplink coupler 26 are respectively connected with outputs of the two uplink pump lasers 25, and two optical outputs are respectively connected with the first uplink optical path 11 and the second uplink optical path 12.
The second group of pump lasers 16 outputs a 980nm window wavelength and includes two downlink pump lasers 29 and a downlink coupler 37. The downlink pump laser 29 may use a lower optical power output, two optical inputs of the downlink coupler 37 are respectively connected to outputs of the two downlink pump lasers 29, and two optical outputs are respectively connected to the first downlink optical path 13 and the second downlink optical path 14.
The first uplink optical path 11 comprises an uplink first isolator 21, an uplink first wavelength division multiplexer 22, an uplink first amplification module 23 and an uplink first coupler 24 which are connected in sequence, and the second uplink optical path 12 comprises an uplink second isolator 31, an uplink second wavelength division multiplexer 32, an uplink second amplification module 33 and an uplink second coupler 34 which are connected in sequence; the first downlink optical path 13 includes a downlink first amplification module 28, a downlink first wavelength division multiplexer 27, a downlink first isolator 36, and a downlink first wavelength division multiplexer 35, and the second downlink optical path 14 includes a downlink second wavelength division multiplexer 30, a downlink second isolator 38, a downlink second wavelength division multiplexer 39, and a downlink second amplification module 40; the first uplink optical path 11 is connected to the second input of the downlink first wavelength division multiplexer 27 of the first downlink optical path 13 through the second output of the uplink first coupler 24; the second upstream optical path 12 is connected to a second input of the downstream second wavelength division multiplexer 30 of the second downstream optical path 14 via a second output of the upstream second coupler 34. The isolator realizes the unidirectional isolation of the link optical signal.
A first input end of the uplink direction uplink first wavelength division multiplexer 22 is connected to an output end of the uplink first isolator 21, a second input end thereof is connected to an output end of the first pump laser group 15, and an output end thereof is connected to the uplink first amplification module 23. A first input of the downlink direction downlink second wavelength division multiplexer 39 is connected to an output of the downlink second isolator 38, a second input thereof is connected to an output of the second pump laser group 16, and an output thereof is connected to the downlink second amplification module 40.
The uplink first amplification module 23, the uplink second amplification module 33, the downlink first amplification module 28, and the downlink second amplification module 40 each include an erbium-doped fiber for optical signal gain, and have functions of gain flattening filtering, optical signal input and gain amplification output power detection, and output optical signal unidirectional isolation; the upstream first amplification module 23 and the upstream second amplification module 33 are used in cooperation with the first pump laser group 15, and the downstream first amplification module 28 and the downstream second amplification module 40 are used in cooperation with the second pump laser group 16. The input end of the uplink first amplifying module 23 is connected to the output end of the uplink first wavelength division multiplexer 22 of the uplink, and the output end thereof is connected to the input end of the uplink first coupler 24. A first output of the upstream first coupler 24 feeds the optical signal into the fibre optic hydrophone array 17.
In the embodiment of the present invention, two optional implementation schemes are proposed for coupling back-scattered light amplified by an uplink relay into a downlink optical path, including:
the first scheme is as follows:
as shown in fig. 4, the first inputs of the downstream first wavelength division multiplexer 27 and the downstream second wavelength division multiplexer 30 receive optical signals from the fiber optic hydrophone array 17, the second inputs thereof are connected to the second outputs of the upstream first coupler 24 and the upstream second coupler 34, and the outputs thereof are connected to the inputs of the downstream first isolator 36 and the downstream second isolator 38 of the downlink. The outputs of the downlink first isolator 36 and the downlink second isolator 38 are respectively connected with the first inputs of the downlink first wavelength division multiplexer 35 and the downlink second wavelength division multiplexer 39, the second inputs of the downlink first wavelength division multiplexer 35 and the downlink second wavelength division multiplexer 39 in the downlink are connected with the output of the second pump laser group 16, the outputs of the downlink first wavelength division multiplexer and the downlink second wavelength division multiplexer are connected with the inputs of the downlink first amplification module 28 and the downlink second amplification module 40, that is, the optical signal containing the fiber optic hydrophone array 17 and the backscatter optical wave for link detection are combined and then amplified and output to the shore station through the downlink first amplification module 28 and the downlink second amplification module 40.
Scheme II:
as shown in fig. 5, the downlink intermediate downlink first isolator 36 and the downlink second isolator 38 receive the optical signals from the fiber optic hydrophone array 17 at their inputs, and their outputs are connected to the first inputs of the downlink first wavelength division multiplexer 35 and the downlink second wavelength division multiplexer 39, respectively. And the second inputs of the downlink first wavelength division multiplexer 35 and the downlink second wavelength division multiplexer 39 are connected with the output of the second pump laser group 16, and the outputs of the downlink first wavelength division multiplexer and the downlink second wavelength division multiplexer are connected with the inputs of the downlink first amplification module 28 and the downlink second amplification module 40. First inputs of the downlink first wavelength division multiplexer 27 and the downlink second wavelength division multiplexer 30 are connected with outputs of the downlink first amplification module 28 and the downlink second amplification module 40, second inputs of the downlink first wavelength division multiplexer and the downlink second wavelength division multiplexer are connected with second outputs of the uplink first coupler 24 and the uplink second coupler 34, namely, an optical signal containing the optical fiber hydrophone array 17 is amplified and then output to a shore station together with a back scattering optical composite wave for link detection.
Preferably, the second inputs of the downstream first wavelength division multiplexer 27 of the first downstream optical path 13 and the downstream second wavelength division multiplexer 30 of the second downstream optical path 14 should be selected to be permeable only to wavelength windows for coherent detection of the sea optical cable, i.e. to filter the laser wavelength for the fiber optic hydrophone array 17, and the wavelength of the first input should be selected to be permeable to the wavelength windows other than the second input wavelength.
The double-pump laser is coupled and distributed in parallel to enter two uplink light paths, so that the problem that the pump laser is difficult to couple and distribute due to large difference of optical power of the uplink light path and the downlink light path in the optical fiber hydrophone array is solved, meanwhile, the wavelength division multiplexer is adopted to couple the back scattering light amplified by the relay of the uplink light path to enter the downlink light path, the back scattering light of laser wavelength for the optical fiber hydrophone array is filtered, and the same-frequency superposition of optical signals returned by the downlink light path and the hydrophone array and the introduction of interference noise are avoided.
The above embodiments are further described in detail to illustrate the objects, technical solutions and advantages of the present invention, and it should be understood that the above embodiments are only specific examples of the present invention and are not intended to limit the present invention, and any modifications, equivalent substitutions, improvements and the like made on the above embodiments according to the technical spirit of the present invention should be included in the scope of the technical solutions of the present invention.
Claims (6)
1. A relay amplification coupling light path for an optical fiber hydrophone array is characterized in that: the optical fiber hydrophone array comprises a first uplink optical path (11), a second uplink optical path (12), a first downlink optical path (13), a second downlink optical path (14), a first pump laser group (15) and a second pump laser group (16), wherein the first uplink optical path (11) and the second uplink optical path (12) respectively form two pairs of space division optical paths of the optical fiber hydrophone array with the first downlink optical path (13) and the second downlink optical path (14); the first uplink optical path (11) is connected with the second uplink optical path (12) through a first pump laser group (15), and the first downlink optical path (13) is connected with the second downlink optical path (14) through a second pump laser group (16).
2. The relay amplification coupling optical path for a fiber optic hydrophone array as claimed in claim 1, wherein: the first uplink optical path (11) comprises an uplink first isolator (21), an uplink first wavelength division multiplexer (22), an uplink first amplification module (23) and an uplink first coupler (24) which are connected in sequence, and the second uplink optical path (12) comprises an uplink second isolator (31), an uplink second wavelength division multiplexer (32), an uplink second amplification module (33) and an uplink second coupler (34) which are connected in sequence; the first downlink optical path (13) comprises a downlink first amplification module (28), a downlink first wavelength division multiplexer (27), a downlink first isolator (36) and a downlink first wavelength division multiplexer (35), and the second downlink optical path (14) comprises a downlink second wavelength division multiplexer (30), a downlink second isolator (38), a downlink second wavelength division multiplexer (39) and a downlink second amplification module (40); the first uplink optical path (11) is connected with the second input of the downlink first wavelength division multiplexer (27) of the first downlink optical path (13) through the second output of the uplink first coupler (24); the second upstream optical path (12) is connected to a second input of the downstream second wavelength division multiplexer (30) of the second downstream optical path (14) via a second output of the upstream second coupler (34).
3. The relay amplification coupling optical path for a fiber optic hydrophone array as claimed in claim 1, wherein: the first pump laser group (15) comprises an uplink coupler (26) and two uplink pump lasers (25), and the two uplink pump lasers (25) are coupled and output in parallel through the uplink coupler (26); the second pump laser group (16) comprises a downstream coupler (37) and two downstream pump lasers (29), and the two downstream pump lasers (29) are coupled in parallel through the downstream coupler (37) and output.
4. The relay amplification coupling optical path for a fiber optic hydrophone array of claim 3, wherein: the first pump laser group (15) has a higher output optical power than the second pump laser group (16).
5. The relay amplification coupling optical path for a fiber optic hydrophone array as claimed in claim 2, wherein: the uplink first amplification module (23), the uplink second amplification module (33), the downlink first amplification module (28) and the downlink second amplification module (40) respectively comprise erbium-doped optical fibers for optical signal gain, and have functions of gain flattening filtering, optical signal input and gain amplification output power detection and output optical signal one-way isolation; the uplink first amplification module (23) and the uplink second amplification module (33) are used in cooperation with the first pump laser group (15), and the downlink first amplification module (28) and the downlink second amplification module (40) are used in cooperation with the second pump laser group (16).
6. The relay amplification coupling optical path for a fiber optic hydrophone array as claimed in claim 2, wherein: the second input of the downstream first wavelength division multiplexer (27) of the first downstream optical path (13) and the second wavelength division multiplexer (30) of the second downstream optical path (14) should be selected to be permeable only to the wavelength window used for coherent detection of the sea cable, and the wavelength of the first input should be selected to be permeable to the wavelength windows other than the second input wavelength.
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN114526809A (en) * | 2022-02-15 | 2022-05-24 | 南方海洋科学与工程广东省实验室(珠海) | Ultra-long distance distributed optical fiber vibration sensing detection method and device |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114526809A (en) * | 2022-02-15 | 2022-05-24 | 南方海洋科学与工程广东省实验室(珠海) | Ultra-long distance distributed optical fiber vibration sensing detection method and device |
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