Variable light attenuation FIFO (First In First Out) device for multi-core optical fiber

Abstract

The utility model provides a variable optical attenuation FIFO device used for a multi-core optical fiber, comprising a multi-core optical fiber, an aspherical lens, a variable optical attenuation array and a single-fiber collimator array which are sequentially arranged along an optical axis, an optical fiber lens is formed on the output end face of the multi-core optical fiber, the variable optical attenuation array comprises a plurality of variable optical attenuators, and the single-fiber collimator array comprises a single-fiber collimator array. The plurality of variable optical attenuators are rotationally and symmetrically arranged around an optical axis; the single-fiber collimator array comprises a plurality of single-fiber collimators, and light of one fiber core is output from the optical fiber lens, sequentially passes through the aspherical lens and one variable optical attenuator and then is input into one single-fiber collimator. Through the independently adjusted variable optical attenuator, the loss of an independent channel can be continuously adjusted, and the loss can be received through a plurality of independent single-fiber collimators at an emergent end, so that fan-in and fan-out are realized, and the scheme does not need to corrode optical fibers, so that the reliability of the device is greatly improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to optical communication technical field especially relates to a kind of variable optical attenuation's FIFO device for multicore optical fiber. BACKGROUND

[0002] With the rapid growth of optical communication services, intelligent optical networks enter the practical stage of rapid development, among which the application of multicore fiber (MCF) is more common, and space multiplexer / demultiplexer (referred to as fan-in / fan-out (FIFO) device) is used to effectively couple light from a single single-mode fiber to a multicore fiber.

[0003] Currently, common multicore optical fibers on the market include 2-core, 4-core, 7-core, 8-core, 19-core, etc. Different multicore optical fibers are applied in various occasions. For example, the core distance of a four-core optical fiber is relatively small (e.g., 43 um). The conventional FIFO method is to corrode four separate single-core optical fibers to 43 um, and then assemble them into a four-core optical fiber head with a core distance of 43 um using a burr tube to achieve coupling.

[0004] However, the corroded optical fiber is extremely thin, and it is easy to damage the optical fiber during threading and curing. Micro cracks exist in the cladding, which affects the device yield and reliability. On the other hand, after collimation by the lens, the four beams of light of the four-core optical fiber almost overlap, and the walk-off is too small, making it difficult to achieve independent attenuation of the coupling efficiency of each light path, and the communication of each channel will affect each other. SUMMARY

[0005] The utility model aims to provide a kind of variable optical attenuation's FIFO device for multicore optical fiber.

[0006] To achieve the purpose of the utility model, the utility model provides a kind of variable optical attenuation's FIFO device for multicore optical fiber, including the multicore optical fiber, aspheric lens, adjustable optical attenuation array and single fiber collimator array arranged in sequence along the optical axis;The multicore optical fiber includes a cladding and a plurality of cores, the cladding is arranged as a cylinder along the optical axis, the plurality of cores is arranged in the cladding parallel to the optical axis, the plurality of cores is arranged rotationally symmetric around the optical axis, and the output end face of the multicore optical fiber is formed with an optical fiber lens, the optical fiber lens faces the aspheric lens, and the curved surface of the optical fiber lens is arranged rotationally symmetric around the optical axis;The adjustable optical attenuation array includes a plurality of adjustable optical attenuators, and the plurality of adjustable optical attenuators is arranged rotationally symmetric around the optical axis;The light of a core is output from the optical fiber lens, sequentially passes through the aspheric lens and an adjustable optical attenuator, and is input to a single fiber collimator.

[0007] Further, the optical fiber lens is formed by ball-burning or grinding process.

[0008] Further, the fiber lens is directly formed on the end of the cladding and the end of the multiple cores.

[0009] Further, the tunable optical attenuator is a mechanical VOA, a magneto-optic VOA, a liquid crystal VOA, a thermo-optic VOA or a MEMS VOA.

[0010] Further, the number of cores, the number of tunable optical attenuators and the number of single-fiber collimators are equal.

[0011] Further, the number of cores, the number of tunable optical attenuators and the number of single-fiber collimators are four.

[0012] Further, the distance between the aspheric lens and the tunable optical attenuator array is between 10mm and 30mm.

[0013] The beneficial effect of the utility model is that the fiber lens is directly formed on the end of the cladding and the end of the core by using a ball burning or grinding process, and the multiple cores and the fiber lens curved surface are rotationally symmetrically distributed, so that the light beam is emitted at a large angle, the multiple collimated light beams are quickly separated in space after collimation by the aspheric lens, are completely separated after a certain working distance and pass through the corresponding tunable optical attenuator respectively, the tunable optical attenuator is independently adjusted, the loss of the independent channel is continuously adjustable, and the multiple collimated light beams are separated after transmission through a working distance of about 10mm to 30mm, so that the multiple single-fiber collimators can receive the light beams at the exit end, thereby realizing fan-in and fan-out between the multi-core fiber and the multiple single-fiber, and the utility model does not need to corrode the fiber, so the reliability of the device is greatly improved. BRIEF DESCRIPTION OF DRAWINGS

[0014] Fig. 1 Fig. 1 is a 3D view of the optical path of the FIFO device embodiment of the utility model.

[0015] Fig. 2 Fig. 2 is a side view of the optical path of the FIFO device embodiment of the utility model.

[0016] Fig. 3 Fig. 3 is a structural schematic view of the multi-core fiber in the FIFO device embodiment of the utility model.

[0017] Fig. 4 Fig. 4 is a sectional schematic view of the VOA array in the FIFO device embodiment of the utility model.

[0018] The utility model will be further described below in combination with the drawings and embodiments. DETAILED DESCRIPTION

[0019] Reference Figs. 1 to 4The variable optical attenuation FIFO device comprises a multicore optical fiber 1, an aspheric lens 2, an adjustable optical attenuation array 3 and a single-fiber collimator array 4 arranged in sequence along an optical axis L0, the multicore optical fiber 1 comprises a cladding 11 and four cores 12, the cladding 11 is arranged in a cylinder along the optical axis L0, the four cores 12 are arranged in the cladding 11 parallel to the optical axis L0, the four cores 12 are arranged rotationally symmetrically around the optical axis L0, an optical fiber lens 13 is formed at an output end face of the multicore optical fiber 1, the optical fiber lens 13 faces the aspheric lens 2, specifically, the optical fiber lens 13 is processed by a ball burning process or a grinding process, the optical fiber lens 13 is directly processed on the end of the cladding 11 and the end of the multiple cores 12, the curved surface of the optical fiber lens 13 is arranged outwardly convex, and the curved surface of the optical fiber lens 13 is arranged rotationally symmetrically around the optical axis L0.

[0020] The input end face of the aspheric lens 2 is arranged in a plane and faces the optical fiber lens 13, the output end face of the aspheric lens 2 is arranged in an arc shape outwardly convex and faces the adjustable optical attenuation array 3. The adjustable optical attenuation array 3 comprises a mounting bracket 31 and four adjustable optical attenuators 32, the four adjustable optical attenuators 32 are arranged on the mounting bracket 31, the four adjustable optical attenuators 32 are arranged rotationally symmetrically around the optical axis L0, the adjustable optical attenuator 32 adopts a mechanical VOA, a magneto-optical VOA, a liquid crystal VOA, a thermo-optic VOA or a MEMS VOA, and in the embodiment, a MEMS VOA is preferably adopted, which is a MEMS free space VOA (FS-VOA). The distance between the aspheric lens 2 and the adjustable optical attenuation array 3 is between 10 mm and 30 mm, and is preferably 20 mm. The single-fiber collimator array 4 comprises four single-fiber collimators 41, and the four single-fiber collimators 41 are arranged rotationally symmetrically around the optical axis L0.

[0021] The light of one core 12 is output from the optical fiber lens 13, and the light beam is emitted with a large angle, and the specific emission angle depends on the curvature selection of the optical fiber lens 12, and then passes through the aspheric lens 2, and after collimation by the aspheric lens 2, the four collimated lights are quickly separated in space, and are completely separated after a certain working distance,

[0022] and each is incident on a corresponding adjustable optical attenuator 32, and the loss of the independent channel can be continuously adjusted by adjusting the MEMS voltage, and after transmission through a working distance of about 20 mm, the four collimated lights are separated by about 1 mm, and finally the light output from the adjustable optical attenuator is correspondingly input into a single-fiber collimator 41, thereby realizing the fan-out of the four-core optical fiber to four single-fiber optical fibers. Of course, according to the reversibility of the optical path, that is, the light is input from the single-fiber collimator 41 in the single-fiber collimator array 4, passes through the adjustable optical attenuation array 3 and the aspheric lens 2, and can be incident on the corresponding core 12 in the multicore optical fiber 1, thereby realizing the fan-in function of the optical signal.

[0023] Of course, the above embodiments are only the preferred embodiments of the present application, and in specific applications, the number of fiber cores, the number of adjustable optical attenuators, and the number of single-fiber collimators can be correspondingly selected, and the number can be two or more, and the number can be equal or unequal arrangement.

[0024] As can be seen from the above, the present application forms a fiber lens by directly using a burning ball or a grinding process on the end of the cladding and the core, and then using the rotationally symmetrical distribution on each core and the curved surface of the fiber lens to make the light beam exit with a large angle, and after collimation by the aspherical lens, the multiple collimated light beams are quickly separated in space, completely separated after a certain working distance, and pass through the corresponding adjustable optical attenuators respectively, the loss of the independent channels can be continuously adjustable through the independently adjustable adjustable optical attenuators, and finally at the exit end, multiple independent single-fiber collimators can be used for receiving, thereby realizing the fan-in and fan-out between the multi-core fiber and multiple single-fiber fibers, and the present application does not need to corrode the fiber, thereby greatly improving the reliability of the device.

Claims

1. A FIFO device for variable optical attenuation of a multi-core fiber, characterized by, The FIFO device comprises a multicore optical fiber, an aspherical lens, an adjustable optical attenuation array and a single-fiber collimator array arranged in sequence along an optical axis. The multicore optical fiber comprises a cladding and a plurality of cores, the cladding is arranged in a cylinder along the optical axis, the plurality of cores are arranged in the cladding parallel to the optical axis, the plurality of cores are arranged rotationally symmetrically around the optical axis, an output end face of the multicore optical fiber is formed with an optical fiber lens, the optical fiber lens faces the aspherical lens, and the curved surface of the optical fiber lens is arranged rotationally symmetrically around the optical axis. The adjustable optical attenuation array comprises a plurality of adjustable optical attenuators, and the plurality of adjustable optical attenuators are arranged rotationally symmetrically around the optical axis. The single-fiber collimator array comprises a plurality of single-fiber collimators, and the plurality of single-fiber collimators are arranged rotationally symmetrically around the optical axis. Light of one of the cores is output from the optical fiber lens, sequentially passes through the aspherical lens and one of the adjustable optical attenuators, and is input to one of the single-fiber collimators.

2. The FIFO device according to claim 1, wherein: The optical fiber lens is processed by a ball-burning process or a grinding process.

3. The FIFO device according to claim 2, wherein: The optical fiber lens is directly processed on the end of the cladding and the ends of the plurality of cores.

4. The FIFO device according to claim 1, wherein: The adjustable optical attenuator is a mechanical VOA, a magneto-optical VOA, a liquid crystal VOA, a thermo-optic VOA or a MEMS VOA.

5. The FIFO device according to claim 1, wherein: The number of cores, the number of adjustable optical attenuators and the number of single-fiber collimators are equal.

6. The FIFO device according to claim 5, wherein: The number of cores, the number of adjustable optical attenuators and the number of single-fiber collimators are four.

7. The FIFO device according to any one of claims 1 to 6, wherein: The distance between the aspherical lens and the adjustable optical attenuation array is between 10 mm and 30 mm.

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