CN217112799U

CN217112799U - Branch type cladding optical fiber

Info

Publication number: CN217112799U
Application number: CN202122499386.3U
Authority: CN
Inventors: 徐杰; 绪海波; 方洋
Original assignee: O Net Communications Shenzhen Ltd
Current assignee: O Net Technologies Shenzhen Group Co Ltd
Priority date: 2021-10-15
Filing date: 2021-10-15
Publication date: 2022-08-02
Anticipated expiration: 2031-10-15

Abstract

The utility model relates to the field of fiber laser amplifiers, in particular to a branch type cladding fiber, which comprises a trunk cladding fiber and a plurality of branch cladding fibers; the plurality of branch cladding fibers are welded on the side wall of the trunk cladding fiber at intervals along the length direction of the trunk cladding fiber. By welding a plurality of branch cladding fibers at intervals on the side surface of the trunk cladding fiber, residual pump light, amplified spontaneous emission light and high-order mode signals in the trunk cladding fiber can be guided out from the fiber cladding of the trunk cladding fiber in a directional mode, so that the heat accumulation on the trunk cladding fiber is avoided while the signal laser power in the fiber core of the trunk cladding fiber is not reduced, and the overhigh temperature during working is prevented; the device has the characteristics of simple structure, low production cost, convenience for batch production and the like.

Description

Branch type cladding optical fiber

Technical Field

The utility model relates to a fiber laser amplifier field, concretely relates to branch type cladding optic fibre.

Background

Dense wavelength division multiplexing and medium-short distance relay transmission, the transmission loss of each optical relay section needs to be compensated by using an erbium-doped fiber amplifier. Since the transmission loss is different for each hop, several EDFAs (erbium doped fiber amplifiers) of different gains need to be matched and complicated setup and tuning is required. The variable gain optical amplifier is capable of supporting different loss segments.

With the wider application of high-power laser, the method for stripping the cladding of the optical fiber double-clad optical fiber is an important technology required for developing a high-power optical fiber laser, and can improve the beam quality and the performance reliability of the high-power optical fiber laser. The method for stripping the cladding light of the optical fiber at present is to roughen the surface of an inner cladding layer by using a double-cladding optical fiber high-refractive-index coating liquid or high-refractive-index light-guiding glue or other physical and chemical means, and the common characteristics of the two methods are that the residual pumping light is irradiated on a heat sink, the light energy is converted into heat energy, the heat on the heat sink is taken away in a water cooling mode, and the stable operation and the safe work of the cladding light stripper are realized.

However, the existing optical fiber cladding stripper has the problems of high temperature and difficult heat dissipation.

Accordingly, the prior art is yet to be improved and developed.

SUMMERY OF THE UTILITY MODEL

The to-be-solved technical problem of the utility model lies in providing a branching type cladding optic fibre to the above-mentioned defect to prior art to solve current optic fibre cladding stripper during operation temperature height, the difficult scheduling problem of heat dissipation.

The utility model provides a technical scheme that its technical problem adopted is: providing a branch type cladding optical fiber, which comprises a trunk cladding optical fiber and a plurality of branch cladding optical fibers; the plurality of branch cladding fibers are welded on the side wall of the trunk cladding fiber at intervals along the length direction of the trunk cladding fiber.

The utility model discloses a further preferred scheme is: the trunk cladding optical fiber is a three-cladding optical fiber, and the refractive indexes of three optical fiber claddings of the three-cladding optical fiber are gradually reduced from inside to outside.

The utility model discloses a further preferred scheme is: the branch cladding optical fiber is a double-cladding optical fiber, and the refractive indexes of two optical fiber claddings of the double-cladding optical fiber are gradually reduced from inside to outside.

The utility model discloses a still further preferred scheme is: the branch type cladding optical fiber further comprises a high-temperature-resistant and low-refractive-index glue layer wrapped on the outer side of the joint of the trunk cladding optical fiber and the branch cladding optical fiber.

The utility model discloses a further preferred scheme is: the fiber core of the trunk cladding fiber and the fiber core of the branch cladding fiber form an angle a; wherein the value range of a is 0-10 degrees.

The utility model discloses a further preferred scheme is: the plurality of branch cladding fibers are uniformly arranged at intervals along the length direction of the trunk cladding fiber.

The utility model discloses a still further preferred scheme is: and a plurality of welding avoiding gaps for welding the branch cladding optical fibers are arranged on the trunk cladding optical fiber.

The utility model discloses a further preferred scheme is: the end of the branch cladding fiber is tapered.

The utility model has the advantages that the pump light, the amplified spontaneous emission light and the high-order mode signal which are remained in the trunk cladding optical fiber can be directionally led out from the optical fiber cladding of the trunk cladding optical fiber by welding a plurality of branch cladding optical fibers at the side intervals of the trunk cladding optical fiber, so that the heat accumulation on the trunk cladding optical fiber is avoided while the signal laser power in the fiber core of the trunk cladding optical fiber is not reduced, and the working temperature is prevented from being overhigh; the device has the characteristics of simple structure, low production cost, convenience for batch production and the like.

Drawings

The invention will be further explained with reference to the drawings and examples, wherein:

FIG. 1 is a schematic structural view of a branched clad optical fiber according to the present invention;

FIG. 2 is an enlarged schematic view of portion A of FIG. 1;

FIG. 3 is a schematic diagram of the connection between the trunk clad fiber and the branch clad fiber according to the present invention;

FIG. 4 is a first schematic diagram of the pump transmission of the branched cladding fiber of the present invention (main cladding fiber to branch cladding fiber);

fig. 5 is a second schematic diagram of pump transmission of the branched cladding fiber of the present invention (from the branch cladding fiber to the trunk cladding fiber);

fig. 6 is a schematic diagram illustrating the pump gain classification of the branched cladding fiber according to the present invention.

Detailed Description

The utility model provides a branch type cladding optic fibre, for making the utility model discloses a purpose, technical scheme and effect are clearer, clear and definite, and it is right that the embodiment is lifted to follow reference to the attached drawing the utility model discloses further detailed description. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

The branch-type clad fiber according to the preferred embodiment of the present invention, referring to fig. 1 to 6, includes a trunk clad fiber 1 and a plurality of branch clad fibers 2; the plurality of branch cladding fibers 2 are welded to the side wall of the trunk cladding fiber 1 at intervals along the length direction of the trunk cladding fiber 1.

By welding a plurality of branch cladding fibers 2 at intervals on the side surface of the trunk cladding fiber 1, the pumping light, the amplified spontaneous emission light and the high-order mode signal which are remained in the trunk cladding fiber 1 can be directionally led out from the cladding of the trunk cladding fiber 1, so that the heat accumulation on the trunk cladding fiber 1 is avoided while the signal laser power in the fiber core of the trunk cladding fiber 1 is not reduced, and the overhigh temperature during working is prevented; the plurality of branch cladding fibers 2 are arranged at intervals along the length direction of the trunk cladding fiber 1, so that the welding difficulty of the plurality of branch cladding fibers 2 can be effectively reduced; the branch type cladding optical fiber has the characteristics of simple structure, low production cost, convenience for batch production and the like.

In addition, referring to fig. 4 and 6, the branch-type clad fiber may also use the branch clad fiber 2 to introduce multiple stages of pump light into the trunk clad fiber 1, so that the gain level of the amplification system can be adjusted by the multi-stage fusion of the branch clad fiber 2.

The number of the branch cladding fibers 2 can be adjusted according to the length of the trunk cladding fiber 1, and when the trunk cladding fiber 1 is longer, the number of the branch cladding fibers 2 can be increased appropriately; when the trunk clad fiber 1 is short, the number of branch clad fibers 2 can be reduced appropriately.

The trunk clad fiber 1 is a triple clad fiber (not shown in the figure), and the refractive indexes of three fiber claddings of the triple clad fiber gradually decrease from inside to outside. The main cladding fiber 1 is set to be a triple cladding fiber, so that the limiting effect on cladding light can be effectively improved. In other embodiments, the trunk clad fiber 1 may be a double clad fiber, but the confinement effect of the clad light is weaker than that of a triple clad fiber.

The branch clad fiber 2 is a double-clad fiber (not shown in the figure), and the refractive indexes of two fiber claddings of the double-clad fiber gradually decrease from inside to outside. Wherein, the limit requirement of the branch cladding fiber 2 on the cladding light is not as high as that of the main cladding fiber 1; therefore, on the premise of meeting the cladding light limitation, the branch cladding fiber 2 is set as a double-cladding fiber, so that the production cost can be effectively controlled.

Further, referring to fig. 1 and 2, the branch-type clad fiber further includes a glue layer 3 covering the outside of the joint between the trunk clad fiber 1 and the branch clad fiber 2 and having high temperature resistance and low refractive index. Wherein the working temperature of the glue layer 3 is-40 ℃ to 120 ℃; the refractive index of the glue layer is 1.370 +/-0.005 at the wavelength of 852 nm. The refractive index of the glue layer 3 is smaller than that of the optical fiber cladding of the trunk cladding optical fiber 1, and the refractive index of the glue layer 3 is smaller than that of the optical fiber cladding of the branch cladding optical fiber 2. Through increasing glue layer 3 of high temperature resistant and low refracting index, can be used for protecting trunk circuit covering optic fibre 1 and branch road covering optic fibre 2 junction, prevent that trunk circuit covering optic fibre 1 or branch road covering optic fibre 2's fiber covering from exposing, prevent the light leak, guarantee branch type covering optic fibre's normal use.

Further, referring to fig. 1 and fig. 2, a fiber core of the trunk clad fiber 1 and a fiber core of the branch clad fiber 2 form an angle a; wherein the value range of a is 0-10 degrees; when a is larger than 10 degrees, the occupied area of the branch type clad fiber consisting of the branch clad fiber 2 and the trunk clad fiber 1 is increased, the branch type clad fiber is inconvenient to store, and the branch type clad fiber 2 is easy to break; the occupied area of the branch type cladding optical fiber can be effectively reduced by limiting the value range of a to be 0-10 degrees; in addition, when the value of a is small, the branch cladding optical fiber 2 can be close to the trunk cladding optical fiber 1, the branch cladding optical fiber 2 is effectively prevented from being collided with the outside and damaged due to the protrusion of the branch cladding optical fiber 2, and the service life of the branch cladding optical fiber is ensured.

Further, the plurality of branch clad fibers 2 are uniformly spaced along the length direction of the trunk clad fiber 1. Through the even setting with branch road cladding optic fibre 2 on trunk road cladding optic fibre 1, can make branch type cladding optic fibre have better physique uniformity, convenient production and accomodate.

Further, referring to fig. 1, 2, and 3, the trunk clad fiber 1 is provided with a plurality of welding avoidance notches 11 for welding the branch clad fiber 2. The avoiding gap 11 is arranged on the optical fiber cladding, hydrofluoric acid solution can corrode the optical fiber cladding on the trunk cladding optical fiber 1, the concentration and the etching duration of the corrosive solution are controlled, or femtosecond laser and retrograde cutting are performed; the avoidance gap 11 is arranged, so that the core of the trunk cladding fiber 1 and the core of the branch cladding fiber 2 can be avoided from being welded; meanwhile, positioning can be provided for the fusion welding of the fiber core of the branch cladding fiber 2, and the accuracy of the fusion welding position is ensured.

Further, referring to fig. 1, 2 and 3, the end of the branch clad fiber 2 is tapered. In this embodiment, trunk cladding optical fiber 1 fibre core and branch road cladding optical fiber 2 fibre core become less contained angle butt fusion, through setting up 2 tip of branch road cladding optical fiber for the toper, can improve the splice surface, make things convenient for going on of butt fusion, improve the intensity of connecting.

It should be understood that the above embodiments are only used for illustrating the technical solutions of the present invention, and not for limiting the same, and those skilled in the art can modify the technical solutions described in the above embodiments, or make equivalent substitutions for some technical features; and all such modifications and alterations should fall within the scope of the appended claims.

Claims

1. A branch type cladding optical fiber is characterized by comprising a trunk cladding optical fiber and a plurality of branch cladding optical fibers; the plurality of branch cladding fibers are welded on the side wall of the trunk cladding fiber at intervals along the length direction of the trunk cladding fiber.

2. The branched clad optical fiber according to claim 1, wherein the trunk clad optical fiber is a triple clad optical fiber, and the three fiber claddings of the triple clad optical fiber have gradually decreasing refractive indices from the inside to the outside.

3. The branched clad optical fiber according to claim 2, wherein the branched clad optical fiber is a double clad optical fiber, and both fiber claddings of the double clad optical fiber have gradually decreasing refractive indices from inside to outside.

4. The branched clad fiber of claim 1, further comprising a high temperature resistant and low refractive index glue layer wrapped outside the junction of the trunk clad fiber and the branch clad fiber.

5. The branched cladding fiber according to any of claims 1 to 4, wherein the core of the trunk cladding fiber is disposed at an angle a with respect to the core of the branch cladding fiber; wherein the value range of a is 0-10 degrees.

6. The branched clad optical fiber according to claim 5, wherein the plurality of branched clad optical fibers are disposed at regular intervals along the length of the trunk clad optical fiber.

7. The branched clad optical fiber according to claim 1, wherein the trunk clad optical fiber is provided with a plurality of fusion splice avoidance notches for fusion splicing the branch clad optical fibers.

8. The branched cladding fiber of claim 7, wherein the end of the branched cladding fiber is tapered.