A few-mode fiber amplifier structure

Abstract

The application discloses a few-mode fiber amplifier structure, comprising: a first few-mode spatial isolator coupler, a second few-mode spatial isolator coupler, a first photodetector, a few-mode spatial combiner, a laser and a second photodetector; the few-mode spatial combiner is arranged between the first few-mode spatial isolator coupler and the second few-mode spatial isolator coupler, the first photodetector is arranged adjacent to the first few-mode spatial isolator coupler, the second photodetector is arranged adjacent to the second few-mode spatial isolator coupler, the laser is arranged adjacent to the few-mode spatial combiner and outside the few-mode spatial combiner, the first photodetector is arranged adjacent to the first few-mode spatial isolator coupler and outside the first few-mode spatial isolator coupler, and the second photodetector is arranged adjacent to the second few-mode spatial isolator coupler and outside the second few-mode spatial isolator coupler.

Description

Technical Field

[0001] This invention relates to the field of optical fiber technology, and in particular to a few-mode fiber amplifier structure. Background Technology

[0002] With the continuous upgrading of Internet communication technology and the development of technologies such as big data and cloud computing, the amount of data in communication networks has exploded. The communication capacity of ordinary single-mode optical fiber is gradually approaching its limit as communication technology advances, leading to an increasing demand for the communication capacity of single-core optical fibers. To improve communication capacity in single-core fibers, a new communication system has been proposed – few-mode fiber communication. In few-mode fiber communication, each mode acts as an independent channel carrying optical signals. One mode is equivalent to one single-mode fiber. Depending on the fiber design, a single few-mode fiber can carry 2, 4, 6, 8, or other different numbers of modes.

[0003] Compared to conventional fiber optic communication systems, few-mode communication systems will add the following key components: few-mode fiber (replacing single-mode fiber as the signal transmission medium), mode multiplexer (multiplexing single-mode signals onto few-mode fiber or separating different modes of signals from a few-mode fiber onto a single-mode fiber), and few-mode fiber amplifier (optical signal relay amplification, extending optical communication distance). While the components involved in the optical path structure of a few-mode fiber amplifier are the same as those in a conventional amplifier, the tapered components used in traditional fiber optic amplifiers are unsuitable for few-mode devices because they require stable transmission of different modes within the fiber.

[0004] Therefore, it is necessary to provide a novel few-mode fiber amplifier structure to overcome the above-mentioned defects. Summary of the Invention

[0005] The purpose of this invention is to provide a few-mode fiber amplifier structure that is simple to manufacture and can achieve good gain amplification and gain flatness for optical signals, ensuring stable output of the optical fiber.

[0006] To achieve the above objectives, the present invention provides a few-mode fiber amplifier structure, comprising: a first few-mode spatial isolator coupler, a second few-mode spatial isolator coupler, a first photodetector, a few-mode spatial multiplexer, a laser, and a second photodetector.

[0007] The few-mode spatial multiplexer is disposed between the first few-mode spatial isolator coupler and the second few-mode spatial isolator coupler. The first photodetector is disposed adjacent to the first few-mode spatial isolator coupler, and the second photodetector is disposed adjacent to the second few-mode spatial isolator coupler.

[0008] The laser is disposed adjacent to and outside the few-mode spatial multiplexer. The first photodetector is disposed adjacent to and outside the first few-mode spatial isolator coupler. The second photodetector is disposed adjacent to and outside the second few-mode spatial isolator coupler.

[0009] Preferably, the first few-mode spatial isolator coupler includes a first few-mode fiber, a first few-mode fiber collimator, a first reflective beam splitter, a first isolator, a second few-mode fiber collimator, a second few-mode fiber, and a first single-mode fiber; the first few-mode fiber and the first few-mode fiber collimator are arranged adjacent to each other, the first few-mode fiber collimator, the first reflective beam splitter, the first isolator, and the second few-mode fiber collimator are arranged in sequence at intervals, and the second few-mode fiber and the second few-mode fiber collimator are arranged adjacent to each other.

[0010] Preferably, the first few-mode spatial isolator coupler includes a first transparent tube, and the first few-mode fiber collimator, the first reflective beam splitter, the first isolator, and the second few-mode fiber collimator are all housed within the first transparent tube.

[0011] Preferably, the second few-mode spatial isolator coupler includes a third few-mode fiber, a third few-mode fiber collimator, a second reflective beam splitter, a second isolator, a fourth few-mode fiber collimator, a fourth few-mode fiber, a second transparent tube, and a second single-mode fiber; the third few-mode fiber and the third few-mode fiber collimator are arranged adjacent to each other, the third few-mode fiber collimator, the second reflective beam splitter, the second isolator, and the fourth few-mode fiber collimator are arranged sequentially at intervals and housed in the second transparent tube, and the fourth few-mode fiber and the fourth few-mode fiber collimator are arranged adjacent to each other.

[0012] Preferably, the second few-mode spatial isolator coupler includes a second transparent tube, and the third few-mode fiber collimator, the second reflective beam splitter, the second isolator, and the fourth few-mode fiber collimator are all housed within the second transparent tube.

[0013] Preferably, the few-mode spatial multiplexer includes a fifth few-mode fiber, a fifth few-mode fiber collimator, a multiplexing diaphragm, a sixth few-mode fiber collimator, a sixth few-mode fiber, and a third transparent tube; the fifth few-mode fiber and the fifth few-mode fiber collimator are arranged adjacent to each other, the fifth few-mode fiber collimator, the multiplexing diaphragm, the sixth few-mode fiber collimator, and the sixth few-mode fiber are arranged sequentially and housed within the third transparent tube, and the sixth few-mode fiber and the sixth few-mode fiber collimator are arranged adjacent to each other.

[0014] Preferably, the fifth few-mode fiber collimator, the multiplexing diaphragm, the sixth few-mode fiber collimator, and the sixth few-mode fiber are all housed within the third transparent tube.

[0015] Compared with existing technologies, the advantages are as follows: by adjusting the positions of the fifth and sixth few-mode collimators to form aligned beams, and by adjusting the distance and angle of the combining diaphragm, the laser emitted by the laser, the signal light of the second few-mode fiber of the first few-mode spatial isolator coupler, and the signal light of the fourth few-mode fiber of the second few-mode spatial isolator coupler are coupled into the sixth few-mode fiber. The few-mode fiber amplifier structure constructed in this way is simple to manufacture and can achieve good gain amplification and gain flatness for optical signals, ensuring stable output of the fiber. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the few-mode fiber amplifier structure provided by the present invention.

[0018] Figure 2 for Figure 1 The schematic diagram shows the structure of the first few-mode spatial isolator coupler in the few-mode fiber amplifier structure shown.

[0019] Figure 3 for Figure 1 The schematic diagram shows the structure of the second few-mode spatial isolator coupler in the few-mode fiber amplifier structure shown.

[0020] Figure 4 for Figure 1 The diagram shows the structure of a few-mode space combiner with a few-mode fiber amplifier structure.

[0021] 1. First few-mode spatial isolator coupler; 11. First few-mode fiber; 12. First few-mode fiber collimator; 13. First reflective beam splitter diaphragm; 14. First isolator; 15. Second few-mode fiber collimator; 16. Second few-mode fiber; 17. First transparent tube; 18. First single-mode fiber; 2. Second few-mode spatial isolator coupler; 21. Third few-mode fiber; 22. Third few-mode fiber collimator; 23. Second reflective beam splitter diaphragm; 24. 25. Second isolator; 26. Fourth few-mode fiber collimator; 27. Fourth few-mode fiber; 28. Second transparent tube; 29. ​​Second single-mode fiber; 20. First photodetector; 21. Few-mode spatial combiner; 22. Fifth few-mode fiber; 23. Combiner diaphragm; 24. Sixth few-mode fiber collimator; 25. Sixth few-mode fiber; 26. Third transparent tube; 27. Laser; 28. Second photodetector; 29. ​​Few-mode erbium-doped fiber. Detailed Implementation

[0022] To make the objectives, technical solutions, and beneficial effects of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described in this specification are merely for explaining the invention and are not intended to limit the invention.

[0023] It should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention.

[0024] It should also be noted that, unless otherwise explicitly specified and limited, terms such as "installation," "connection," "joining," "fixing," and "setting" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to a connection within two components or an interaction between two components. Those skilled in the art will understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0025] Furthermore, features specified as "first" or "second" may explicitly or implicitly include one or more of those features; "multiple" or "several" means two or more, unless otherwise explicitly specified.

[0026] Please see Figures 1 to 4The present invention provides a few-mode fiber amplifier structure, comprising: a first few-mode spatial isolator coupler 1, a second few-mode spatial isolator coupler 2, a first photodetector 3, a few-mode spatial multiplexer 4, a laser 5, and a second photodetector 6;

[0027] The few-mode spatial combiner 4 is disposed between the first few-mode spatial isolator coupler 1 and the second few-mode spatial isolator coupler 2. The first photodetector 3 is disposed adjacent to the first few-mode spatial isolator coupler 1, and the second photodetector 6 is disposed adjacent to the second few-mode spatial isolator coupler 2.

[0028] The first few-mode spatial isolator coupler 1 and the second few-mode spatial isolator coupler 2 serve to split and isolate light. The laser 5 is arranged adjacent to and outside the few-mode spatial multiplexer 4. The first photodetector 3 is arranged adjacent to and outside the first few-mode spatial isolator coupler 1. The second photodetector 6 is arranged adjacent to and outside the second few-mode spatial isolator coupler 2.

[0029] The few-mode spatial combiner 4 is used to adjust the angle of beam transmission in the first few-mode spatial isolator coupler 1, the second few-mode spatial isolator coupler 2, and the few-mode spatial combiner 4. The laser 5 emits laser light. The first photodetector 3 detects the direction of the beam in the first few-mode spatial isolator coupler 1. The second photodetector 6 detects the direction of the beam in the second few-mode spatial isolator coupler 2.

[0030] In one embodiment, the first few-mode spatial isolator coupler 1 includes a first few-mode fiber 11, a first few-mode fiber collimator 12, a first reflective beam splitter 13, a first isolator 14, a second few-mode fiber collimator 15, a second few-mode fiber 16, a first transparent tube 17, and a first single-mode fiber 18; the first few-mode fiber 11 is disposed adjacent to the first few-mode fiber collimator 12, the first few-mode fiber collimator 12, the first reflective beam splitter 13, the first isolator 14, and the second few-mode fiber collimator 15 are arranged sequentially at intervals and housed within the first transparent tube 17, and the second few-mode fiber 16 is disposed adjacent to the second few-mode fiber collimator 15. Thus, by adjusting the positions of the first few-mode fiber collimator 12 and the second few-mode fiber collimator 15, the optical signal input from the first few-mode fiber 11 passes through the first few-mode fiber collimator 12, the first reflective beam splitter 13, the first isolator 14, and the first and second few-mode fiber collimators 15. The angle and position of the first reflective beam splitter 13 and the first isolator 14 are adjusted so that the transmitted light is transmitted to the second few-mode fiber 16. The first reflective beam splitter 13 reflects part of the light into the first single-mode fiber 18, and the first photodetector 3 detects the optical signal in the first single-mode fiber 18.

[0031] In one embodiment, the second few-mode spatial isolator coupler 2 includes a third few-mode fiber 21, a third few-mode fiber collimator 22, a second reflective beam splitter 23, a second isolator 24, a fourth few-mode fiber collimator 25, a fourth few-mode fiber 26, a second transparent tube 27, and a second single-mode fiber 28; the third few-mode fiber 21 is arranged adjacent to the third few-mode fiber collimator 22, the third few-mode fiber collimator 22, the second reflective beam splitter 23, the second isolator 24, and the fourth few-mode fiber collimator 25 are arranged sequentially at intervals and housed within the second transparent tube 27, and the fourth few-mode fiber 26 is arranged adjacent to the fourth few-mode fiber collimator 25. Thus, by adjusting the positions of the third few-mode fiber collimator 22 and the fourth few-mode fiber collimator 25, the optical signal input from the first few-mode fiber 11 passes through the third few-mode fiber collimator 22, the second reflective beam splitter 23, the second isolator 24, and the fourth few-mode fiber collimator 25. The angles and positions of the second reflective beam splitter 23 and the second isolator 24 are adjusted so that the transmitted light is transmitted to the fourth few-mode fiber 26. The second reflective beam splitter 23 reflects part of the light into the second single-mode fiber 28, and the second photodetector 6 detects the optical signal in the second single-mode fiber 28.

[0032] In one embodiment, the few-mode spatial combiner 4 includes a fifth few-mode fiber 41, a fifth few-mode fiber collimator 42, a combiner diaphragm 43, a sixth few-mode fiber collimator 44, a sixth few-mode fiber 45, and a third transparent tube 46; the fifth few-mode fiber 41 is arranged adjacent to the fifth few-mode fiber collimator 42, the fifth few-mode fiber collimator 42, the combiner diaphragm 43, the sixth few-mode fiber collimator 44, and the sixth few-mode fiber 45 are arranged sequentially and housed within the third transparent tube 46, and the sixth few-mode fiber 45 is arranged adjacent to the sixth few-mode fiber collimator 44.

[0033] In one embodiment, the few-mode fiber amplifier structure further includes a few-mode erbium-doped fiber 7, which is located between the few-mode spatial combiner 4 and the second few-mode spatial isolator coupler 2.

[0034] By adjusting the positions of the fifth and sixth few-mode collimators, the beams are aligned. The distance and angle of the combining diaphragm 43 are adjusted so that the laser emitted by the laser 5, the signal light of the second few-mode fiber 16 of the first few-mode spatial isolator coupler 1, and the signal light of the fourth few-mode fiber 26 of the second few-mode spatial isolator coupler 2 are coupled into the sixth few-mode fiber 45. The few-mode fiber amplifier structure constructed in this way is simple to manufacture and can achieve good gain amplification and gain flatness for optical signals, ensuring stable output of the fiber.

[0035] The present invention is not limited to the description in the specification and embodiments, and thus other advantages and modifications can be readily realized by those skilled in the art. Therefore, the present invention is not limited to the specific details, representative devices and examples shown and described herein without departing from the spirit and scope of the general concept defined by the claims and their equivalents.

Claims

1. A few-mode fiber amplifier structure, characterized in that, include: The system comprises a first few-mode spatial isolator coupler (1), a second few-mode spatial isolator coupler (2), a first photodetector (3), a few-mode spatial combiner (4), a laser (5), and a second photodetector (6). The few-mode spatial combiner (4) is disposed between the first few-mode spatial isolator coupler (1) and the second few-mode spatial isolator coupler (2). The first photodetector (3) is disposed adjacent to the first few-mode spatial isolator coupler (1), and the second photodetector (6) is disposed adjacent to the second few-mode spatial isolator coupler (2). The laser (5) is arranged adjacent to the few-mode space combiner (4) and located outside the few-mode space combiner (4); the first photodetector (3) is arranged adjacent to the first few-mode space isolator coupler (1) and located outside the first few-mode space isolator coupler (1); the second photodetector (6) is arranged adjacent to the second few-mode space isolator coupler (2) and located outside the second few-mode space isolator coupler (2). The few-mode spatial combiner (4) includes a fifth few-mode fiber (41), a fifth few-mode fiber collimator (42), a combiner diaphragm (43), a sixth few-mode fiber collimator (44), a sixth few-mode fiber (45), and a third transparent tube (46); the fifth few-mode fiber (41) and the fifth few-mode fiber collimator (42) are arranged adjacent to each other, the fifth few-mode fiber collimator (42), the combiner diaphragm (43), the sixth few-mode fiber collimator (44), and the sixth few-mode fiber (45) are arranged sequentially and housed in the third transparent tube (46), and the sixth few-mode fiber (45) and the sixth few-mode fiber collimator (44) are arranged adjacent to each other; By adjusting the positions of the fifth few-mode fiber collimator (42) and the sixth few-mode fiber collimator (44), the aligned beams are formed. The distance and angle of the combining diaphragm (43) are adjusted so that the laser emitted by the laser (5), the signal light of the first few-mode spatial isolator coupler (1) and the signal light of the second few-mode spatial isolator coupler (2) are coupled into the sixth few-mode fiber (45).

2. The few-mode fiber amplifier structure as described in claim 1, characterized in that, The first few-mode spatial isolator coupler (1) includes a first few-mode fiber (11), a first few-mode fiber collimator (12), a first reflective beam splitter (13), a first isolator (14), a second few-mode fiber collimator (15), a second few-mode fiber (16), and a first single-mode fiber (18). The first few-mode fiber (11) is arranged adjacent to the first few-mode fiber collimator (12), and the first few-mode fiber collimator (12), the first reflective beam splitter (13), the first isolator (14), and the second few-mode fiber collimator (15) are arranged in sequence at intervals. The second few-mode fiber (16) is arranged adjacent to the second few-mode fiber collimator (15).

3. The few-mode fiber amplifier structure as described in claim 2, characterized in that, The first few-mode spatial isolator coupler (1) includes a first transparent tube (17), and the first few-mode fiber collimator (12), the first reflective beam splitter (13), the first isolator (14) and the second few-mode fiber collimator (15) are all housed in the first transparent tube (17).

4. The few-mode fiber amplifier structure as described in claim 1, characterized in that, The second few-mode spatial isolator coupler (2) includes a third few-mode fiber (21), a third few-mode fiber collimator (22), a second reflective beam splitter (23), a second isolator (24), a fourth few-mode fiber collimator (25), a fourth few-mode fiber (26), a second transparent tube (27), and a second single-mode fiber (28). The third few-mode fiber (21) is arranged adjacent to the third few-mode fiber collimator (22). The third few-mode fiber collimator (22), the second reflective beam splitter (23), the second isolator (24), and the fourth few-mode fiber collimator (25) are arranged in sequence at intervals and housed in the second transparent tube (27). The fourth few-mode fiber (26) is arranged adjacent to the fourth few-mode fiber collimator (25).

5. The few-mode fiber amplifier structure as described in claim 4, characterized in that, The second few-mode spatial isolator coupler (2) includes a second transparent tube (27), and the third few-mode fiber collimator (22), the second reflective beam splitter (23), the second isolator (24) and the fourth few-mode fiber collimator (25) are all housed in the second transparent tube (27).

6. The few-mode fiber amplifier structure as described in claim 1, characterized in that, The fifth few-mode fiber collimator (42), the wave combiner diaphragm (43), the sixth few-mode fiber collimator (44), and the sixth few-mode fiber (45) are all housed within the third transparent tube (46).

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