Combined energy transfer type high temperature resistant multi-core optical fiber

Abstract

The application provides a combined energy transmission type high-temperature-resistant multi-core optical fiber, which comprises a first light guiding core, a second light guiding core, a third light guiding core and a fourth light guiding core which are different in shape; a first doped inner cladding, a second doped inner cladding, a third doped inner cladding and a fourth doped inner cladding which are respectively arranged on the outer circumferential surfaces of the first light guiding core, the second light guiding core, the third light guiding core and the fourth light guiding core; a doped outer cladding which is arranged on the outer circumferential surfaces of the first doped inner cladding, the second doped inner cladding, the third doped inner cladding and the fourth doped inner cladding; a polymer coating layer which is arranged on the outer circumferential surface of the doped outer cladding; and a fluoroplastic layer which is arranged on the outer circumferential surface of the polymer coating layer. The optical fiber core layer energy transmission light guiding layer of the application is composed of square, circular, triangular and octagonal light guiding cores, can simultaneously meet the laser energy distribution requirements of different laser processing requirements, and enhances the flexibility of laser transmission.

Description

Technical Field

[0001] This invention relates to the field of optical fiber technology, specifically to a combined-state energy transfer type high-temperature resistant multi-core optical fiber. Background Technology

[0002] In the field of laser energy transfer, high-power semiconductor lasers have developed rapidly driven by the continuous development of laser processing applications. Their high output power and brightness have made them a focus of attention worldwide. Compared with other lasers, semiconductor lasers have many significant advantages and can be directly used in laser manufacturing fields such as laser welding, cladding, and surface treatment. Semiconductor laser fiber energy combiners can efficiently improve the output power of semiconductor lasers. Compared with other semiconductor laser combining systems, they have advantages of high efficiency, low cost, and simple structure, making them one of the latest hot topics in semiconductor laser combining research. However, the optical fibers in semiconductor laser fiber energy combiners are generally traditional optical fibers with a circular core structure. This results in poor mode matching with the output end of the semiconductor laser, making it difficult to improve coupling efficiency. Consequently, they cannot meet the performance requirements of laser spot for various processing functions such as transmission homogenization, limiting transmission capacity and restricting the application range of semiconductor lasers.

[0003] Existing technologies include some research on polygonal optical core designs. For example, Chinese patent application CN108975675A discloses a square-core optical fiber and its fabrication method. This fiber has a single polygonal core, and the cladding uses a fluorine-doped liner with a refractive index lower than that of the core material. The preform is fabricated by inserting a core rod into the fluorine-doped liner. The core is made of quartz substrate doped with germanium dioxide, and its refractive index is 1.4570-1.4750. This single-core square-core structure can only handle the needs of flat-head homogenized laser processing, and its transmission function for other processing planes such as laser welding and cutting is not significantly improved. Furthermore, it cannot achieve laser transmission with multiple operating modes. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a combined-mode energy transfer type high-temperature resistant multi-core optical fiber that can achieve laser transmission with multiple working modes.

[0005] To achieve the above and other objectives, the present invention is implemented through the following technical solution: The present invention proposes a combined-state energy transfer type high-temperature resistant multi-core optical fiber, characterized in that it includes a first light guide core, a second light guide core, a third light guide core, and a fourth light guide core with different shapes; a first doped inner cladding layer, a second doped inner cladding layer, a third doped inner cladding layer, and a fourth doped inner cladding layer, respectively surrounding the outer peripheral surfaces of the first light guide core, the second light guide core, the third light guide core, and the fourth light guide core; and a doped outer cladding layer surrounding the first doped inner cladding layer, the second doped inner cladding layer, the third doped inner cladding layer, and the fourth doped inner cladding layer. The outer peripheral surface of the doped inner cladding layer; a polymer coating layer surrounding the outer peripheral surface of the doped outer cladding layer; a fluoroplastic layer surrounding the outer peripheral surface of the polymer coating layer; the refractive indices of the first, second, third, and fourth light guide cores are respectively greater than the refractive indices of the first, second, third, and fourth doped inner cladding layers; the refractive indices of the first, second, third, and fourth doped inner cladding layers are all greater than the refractive indices of the doped outer cladding layer; the refractive index of the doped outer cladding layer is greater than the refractive index of the polymer coating layer.

[0006] Furthermore, the minimum side spacing between each pair of the first doped inner cladding layer, the second doped inner cladding layer, the third doped inner cladding layer, and the fourth doped inner cladding layer is ∈ [0.02mm, 0.04mm].

[0007] Furthermore, the material of the first light guide core is doped quartz glass, the doping element is fluorine, and the refractive index after doping is ∈ [1.4566, 1.4571]; the cross-sectional shape of the first light guide core is square, and the side length is ∈ [0.21mm, 0.86mm]; the material of the first doped inner cladding layer is doped quartz glass, the doping element is fluorine, and the refractive index after doping is ∈ [1.433, 1.456]; the outer contour shape of the first doped inner cladding layer is square, and the thickness is ∈ [0.012mm, 0.025mm].

[0008] Furthermore, the material of the second light guide core is doped quartz glass, the doping element is fluorine, and the refractive index after doping is ∈ [1.4566, 1.4571]; the cross-sectional shape of the second light guide core is circular, and the diameter is ∈ [0.30mm, 0.80mm]; the material of the second doped inner cladding is doped quartz glass, the doping element is fluorine, and the refractive index after doping is ∈ [1.433, 1.456]; the outer contour shape of the second doped inner cladding is circular, and the thickness is ∈ [0.012mm, 0.025mm].

[0009] Furthermore, the material of the third light guide core is doped quartz glass, the doping element is fluorine, and the refractive index after doping is ∈ [1.4566, 1.4571]; the cross-sectional shape of the third light guide core is an equilateral triangle, and the side length is ∈ [0.25mm, 0.75mm]; the material of the third doped inner cladding is doped quartz glass, the doping element is fluorine, and the refractive index after doping is ∈ [1.433, 1.456]; the outer contour shape of the third doped inner cladding is an equilateral triangle, and the thickness is ∈ [0.012mm, 0.025mm].

[0010] Furthermore, the material of the fourth light guide core is doped quartz glass, the doping element is fluorine, and the refractive index after doping is ∈ [1.4566, 1.4571]; the cross-sectional shape of the fourth light guide core is a regular octagon, and the side length is ∈ [0.18mm, 0.72mm]; the material of the fourth doped inner cladding is doped quartz glass, the doping element is fluorine, and the refractive index after doping is n8 ∈ [1.433, 1.456]; the outer contour shape of the fourth doped inner cladding is a regular octagon, and the thickness is ∈ [0.012mm, 0.025mm].

[0011] Furthermore, the material of the doped outer cladding layer is doped quartz glass, and the doping elements are fluorine and boron, with a refractive index of [1.420, 1.432] after doping; the doped outer cladding layer adopts a square structure; the minimum edge distance between the doped outer cladding layer and the first doped inner cladding layer, the second doped inner cladding layer, the third doped inner cladding layer and the fourth doped inner cladding layer is [0.05mm, 0.09mm].

[0012] Furthermore, the polymer coating layer is made of fluorinated acrylic resin, the refractive index of the polymer coating layer is ∈ [1.370, 1.420], the modulus is ∈ [210 MPa, 450 MPa], the outer contour shape of the polymer coating layer is square, and the thickness is ∈ [0.025 mm, 0.065 mm].

[0013] Furthermore, the fluoroplastic layer is made of ethylene-tetrafluoroethylene copolymer; the outer contour of the fluoroplastic layer is square, and the thickness is [0.030 mm, 0.080 mm].

[0014] Furthermore, a positioning quartz strip is also provided within the polymer coating layer, and the positioning quartz strip is located at the top corner of the polymer coating layer adjacent to the first light guide core; the material of the positioning quartz strip is pure quartz glass, the cross-sectional shape is circular, and the diameter is ∈ [0.012mm, 0.024mm].

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0016] 1. The optical fiber core energy transmission and light guiding layer of the present invention is composed of light guiding cores of four shapes: square, circular, equilateral triangle and regular octagon, which can simultaneously meet the laser energy distribution requirements of different laser processing applications and enhance the flexibility of laser transmission.

[0017] 2. By wrapping a shallowly depressed refractive index quartz-doped inner cladding layer around the outer layer of the optical fiber core energy transmission and light guiding layer, and then wrapping a deeply depressed refractive index quartz-doped outer cladding layer around the outer layer of the doped inner cladding layer, the high-order mode laser is further constrained, thereby enhancing the light guiding efficiency.

[0018] 3. By coating the outer layer of the doped outer layer with a low-refractive-index, high-modulus, and high-temperature resistant polymer coating, a stable triple-layer structure can be formed, further improving the stability of laser transmission power. At the same time, the high-modulus polymer coating provides high-strength protection and has a high-temperature resistance of up to 145℃, effectively preventing damage from high-power lasers.

[0019] 4. By wrapping the outer layer of the polymer coating with an extruded high-temperature resistant fluoroplastic layer, the high temperature resistance can reach 155℃, which can further protect all the structural layers of the inner layer.

[0020] 5. By embedding a positioning quartz strip within the polymer coating layer, and with the positioning quartz strip located at the top corner of the polymer coating layer adjacent to the first light guide core, it is possible to easily switch and position different energy-transmitting light guide cores. Attached Figure Description

[0021] Figure 1 The diagram shown is a structural schematic of a combined-state energy transfer type high-temperature resistant multi-core optical fiber according to the present invention. Detailed Implementation

[0022] Please see Figure 1 The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification.

[0023] It should be noted that the structures, proportions, sizes, etc., illustrated in the accompanying drawings of this specification are only used to complement the content disclosed in the specification for those skilled in the art to understand and read, and are not intended to limit the conditions under which the present invention can be implemented. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportional relationships, or adjustments to the size, without affecting the effects and objectives that the present invention can produce, should still fall within the scope of the technical content disclosed in the present invention.

[0024] Unless otherwise defined, technical or scientific terms used herein should be understood in their ordinary sense by one of ordinary skill in the art to which this invention pertains. The terms “first,” “second,” “third,” and “fourth,” as used herein, are used to distinguish different objects and not to describe a particular order, quantity, or importance. Similarly, words such as “an,” “a,” or “the” do not indicate a quantity limitation but simply indicate the presence of at least one. Terms such as “comprising” or “including” mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. The term “connection” as used herein, unless otherwise specified, includes both direct and indirect connections.

[0025] like Figure 1 As shown, the present invention provides a combined-state energy transfer type high-temperature resistant multi-core optical fiber, comprising a first light guide core 11, a second light guide core 12, a third light guide core 13, and a fourth light guide core 14 with different shapes; a first doped inner cladding layer 21, a second doped inner cladding layer 22, a third doped inner cladding layer 23, and a fourth doped inner cladding layer 24 respectively surrounding the outer peripheral surfaces of the first doped inner cladding layer 11, the second doped inner cladding layer 22, the third doped inner cladding layer 23, and the fourth doped inner cladding layer 24; a doped outer cladding layer 30 surrounding the outer peripheral surfaces of the first doped inner cladding layer 21, the second doped inner cladding layer 22, the third doped inner cladding layer 23, and the fourth doped inner cladding layer 24; a polymer coating layer 40 surrounding the outer peripheral surface of the doped outer cladding layer 30; and a fluoroplastic layer 50 surrounding the outer peripheral surface of the polymer coating layer 40.

[0026] The first light guide core 11 can be made of doped quartz glass, and the doping element can be fluorine. The refractive index after doping is n1∈[1.4566, 1.4571]; the cross-sectional shape of the first light guide core 11 is square, and the side length L1∈[0.21mm, 0.86mm]. The first doped inner cladding layer 21 can be made of doped quartz glass, and the doping element can be fluorine. The refractive index after doping is n5<n1, specifically, n5∈[1.433, 1.456]; the outer contour shape of the first doped inner cladding layer 21 is square, and the thickness T5∈[0.012mm, 0.025mm].

[0027] The material of the second light guide core 12 can be doped quartz glass, and the doping element can be fluorine. The refractive index after doping is n2∈[1.4566, 1.4571]; the cross-sectional shape of the second light guide core 12 is circular, and the diameter D2∈[0.30mm, 0.80mm]. The material of the second doped inner cladding layer 22 can be doped quartz glass, and the doping element can be fluorine. The refractive index after doping is n6<n2, specifically, n6∈[1.433, 1.456]; the outer contour shape of the second doped inner cladding layer 22 is circular, and the thickness T6∈[0.012mm, 0.025mm].

[0028] The material of the third light guide core 13 can be doped quartz glass, and the doping element can be fluorine. The refractive index after doping is n3∈[1.4566, 1.4571]. The cross-sectional shape of the third light guide core 13 is an equilateral triangle with a side length L3∈[0.25mm, 0.75mm]. The material of the third doped inner cladding layer 23 can be doped quartz glass, and the doping element can be fluorine. The refractive index after doping is n7<n3, specifically, n7∈[1.433, 1.456]. The outer contour shape of the third doped inner cladding layer 23 is an equilateral triangle with a thickness T7∈[0.012mm, 0.025mm].

[0029] The fourth light guide core 14 can be made of doped quartz glass, and the doping element can be fluorine. The refractive index after doping is n4 ∈ [1.4566, 1.4571]. The cross-sectional shape of the fourth light guide core 14 is a regular octagon, and the side length L4 ∈ [0.18 mm, 0.72 mm]. The fourth doped inner cladding layer 24 can be made of doped quartz glass, and the doping element can be fluorine. The refractive index after doping is n8 < n4, specifically, n8 ∈ [1.433, 1.456]. The outer contour shape of the fourth doped inner cladding layer 24 is a regular octagon, and the thickness T8 ∈ [0.012 mm, 0.025 mm].

[0030] The minimum side spacing MinL between each pair of the first doped inner cladding layer 21, the second doped inner cladding layer 22, the third doped inner cladding layer 23, and the fourth doped inner cladding layer 24 (5-6、5-7、5-8、6-7、6-8、7-8) The range is [0.02mm, 0.04mm], which ensures good crosstalk performance between light guide cores of different shapes.

[0031] The doped outer cladding layer 30 is used to protect the high-power laser transmission of the multi-core optical guide core. The material of the doped outer cladding layer 30 can be doped quartz glass, and the doping elements can be fluorine and boron. The refractive index n9 after doping is less than n5, n6, n7, and n8 to further constrain higher-order modes; specifically, n9 ∈ [1.420, 1.432]. The doped outer cladding layer 30 can adopt a square structure design to facilitate docking and coupling. The minimum margin MinL between the doped outer cladding layer 30 and the first doped inner cladding layer 21, the second doped inner cladding layer 22, the third doped inner cladding layer 23, and the fourth doped inner cladding layer 24 is... 9-(5、6、7、8) The thickness is ∈ [0.05mm, 0.09mm], which has a certain edge thickness to constrain the transmission of laser light.

[0032] The polymer coating layer 40 can be made of fluorinated acrylic resin, which has the characteristics of low refractive index, high modulus, and high temperature resistance. The refractive index of the polymer coating layer 40 is n10 < n9, specifically, n10 ∈ [1.370, 1.420]. The modulus of the polymer coating layer 40 is M10 ∈ [210 MPa, 450 MPa]. The high modulus coating design can provide high-strength protection for the fiber optic quartz glass layer. At the same time, the high temperature resistance of the polymer coating layer 40 reaches 145℃, which can prevent damage from high-power lasers. The outer contour shape of the polymer coating layer 40 can be square, matching the structural design of the doped outer cladding layer 30. The thickness T10 of the polymer coating layer 40 ∈ [0.025 mm, 0.065 mm] can form a stable three-layer structure design together with the doped inner cladding layer outside the optical guide core and the doped outer cladding layer 30, enhancing the stability of transmitted laser power.

[0033] Furthermore, a positioning quartz strip 60 may be provided within the polymer coating layer 40. The positioning quartz strip 60 may be located at the apex of the polymer coating layer 40 adjacent to the first light guide core 11 to facilitate the positioning of the starting functional position, thereby enabling the switching of positions of light guide cores of different shapes for different application requirements. The material of the positioning quartz strip 60 may be pure quartz glass, and the cross-sectional shape may be circular with a diameter D12 ∈ [0.012 mm, 0.024 mm].

[0034] The fluoroplastic layer 50 can be made of ethylene-tetrafluoroethylene copolymer, which has high temperature resistance. The outer contour of the fluoroplastic layer 50 can be square, with a thickness T11 ∈ [0.030mm, 0.080mm], and a high temperature resistance of up to 155℃, which can fully protect all the structural layers of its inner layer.

[0035] Table 1 below shows the design parameters of Examples 1 to 8 of the combined-state energy transfer type high-temperature resistant multi-core optical fiber. Table 2 below shows the test results of the light guide core performance of Examples 1 to 8 of the combined-state energy transfer type high-temperature resistant multi-core optical fiber. By referring to Tables 1 and 2, you can understand the superior performance of the combined-state energy transfer type high-temperature resistant multi-core optical fiber provided by the present invention.

[0036] Table 1 Design parameters for Examples 1 to 8

[0037]

[0038]

[0039] Table 2 Performance parameters of the light guide core in Examples 1 to 8

[0040]

[0041] In summary, the energy transmission and light guiding layer of the present invention employs four different shapes of the first light guiding core 11, the second light guiding core 12, the third light guiding core 13, and the fourth light guiding core 14, which can meet the laser energy distribution requirements of different laser processing applications, such as conventional applications, laser cleaning, laser cladding, and laser welding. The first doped inner cladding layer 21, the second doped inner cladding layer 22, the third doped inner cladding layer 23, and the fourth doped inner cladding layer 24 are quartz doped cladding layers with a shallow refractive index design, which can realize the optical waveguide energy transmission design; the doped outer cladding layer 30 is a quartz doped outer cladding layer with a deep refractive index design, which can further confine the high-order mode laser and enhance the light guiding efficiency; the polymer coating layer 40 is a low refractive index, high modulus, and high temperature resistant polymer coating layer, which can form a stable three-cladding structure design together with the doped inner cladding layer outside the light guide core and the doped outer cladding layer 30, further improving the stability of laser transmission power; the fluoroplastic layer 50 is an extruded high temperature resistant fluoroplastic layer, which can enhance the high temperature resistance of the optical fiber and provide industrial-grade protective coating.

[0042] Therefore, this invention effectively overcomes the various shortcomings of the prior art and has high industrial applicability. The above embodiments are merely illustrative of the principles and effects of this invention and are not intended to limit the invention. Any person skilled in the art can modify or change the above embodiments without departing from the spirit and scope of this invention. Therefore, all equivalent modifications or changes made by those skilled in the art without departing from the spirit and technical concept disclosed in this invention should still be covered by the claims of this invention.

Claims

1. A combination-state energy transfer type high-temperature resistant multi-core optical fiber, characterized in that, include A first light guide core, a second light guide core, a third light guide core, and a fourth light guide core, each with a different shape; The first doped inner cladding layer, the second doped inner cladding layer, the third doped inner cladding layer, and the fourth doped inner cladding layer respectively surround the outer peripheral surfaces of the first light guide core, the second light guide core, the third light guide core, and the fourth light guide core. A doped outer cladding layer surrounds the outer peripheral surfaces of the first doped inner cladding layer, the second doped inner cladding layer, the third doped inner cladding layer, and the fourth doped inner cladding layer; A polymer coating layer surrounds the outer peripheral surface of the doped outer layer; A fluoroplastic layer surrounds the outer peripheral surface of the polymer coating layer; The refractive indices of the first, second, third, and fourth light guide cores are greater than those of the first, second, third, and fourth doped inner cladding layers, respectively; the refractive indices of the first, second, third, and fourth doped inner cladding layers are all greater than those of the doped outer cladding layer; and the refractive index of the doped outer cladding layer is greater than that of the polymer coating layer.

2. The combined-state energy transfer type high-temperature resistant multi-core optical fiber according to claim 1, characterized in that, The minimum side spacing between each pair of the first doped inner cladding layer, the second doped inner cladding layer, the third doped inner cladding layer, and the fourth doped inner cladding layer is ∈ [0.02 mm, 0.04 mm].

3. The combined-state energy transfer type high-temperature resistant multi-core optical fiber according to claim 2, characterized in that, The first light guide core is made of doped quartz glass, with fluorine as the doping element, and the refractive index after doping is ∈ [1.4566, 1.4571]; the cross-sectional shape of the first light guide core is square, with a side length ∈ [0.21mm, 0.86mm]; the first doped inner cladding layer is made of doped quartz glass, with fluorine as the doping element, and the refractive index after doping is ∈ [1.433, 1.456]; the outer contour shape of the first doped inner cladding layer is square, with a thickness ∈ [0.012mm, 0.025mm].

4. The combined-state energy transfer type high-temperature resistant multi-core optical fiber according to claim 3, characterized in that, The second light guide core is made of doped quartz glass, with fluorine as the doping element, and the refractive index after doping is ∈ [1.4566, 1.4571]; the cross-sectional shape of the second light guide core is circular, with a diameter ∈ [0.30mm, 0.80mm]; the material of the second doped inner cladding is doped quartz glass, with fluorine as the doping element, and the refractive index after doping is ∈ [1.433, 1.456]; the outer contour shape of the second doped inner cladding is circular, with a thickness ∈ [0.012mm, 0.025mm].

5. The combined-state energy transfer type high-temperature resistant multi-core optical fiber according to claim 4, characterized in that, The third light guide core is made of doped quartz glass, with fluorine as the dopant element, and the refractive index after doping is ∈ [1.4566, 1.4571]. The cross-sectional shape of the third light guide core is an equilateral triangle with a side length ∈ [0.25mm, 0.75mm]. The third doped inner cladding is made of doped quartz glass, with fluorine as the dopant element, and the refractive index after doping is ∈ [1.433, 1.456]. The outer contour shape of the third doped inner cladding is an equilateral triangle with a thickness ∈ [0.012mm, 0.025mm].

6. The combined-state energy transfer type high-temperature resistant multi-core optical fiber according to claim 5, characterized in that, The fourth light guide core is made of doped quartz glass, with fluorine as the dopant element, and the refractive index after doping is ∈ [1.4566, 1.4571]. The cross-sectional shape of the fourth light guide core is a regular octagon, with a side length ∈ [0.18 mm, 0.72 mm]. The fourth doped inner cladding is made of doped quartz glass, with fluorine as the dopant element, and the refractive index n8 after doping is ∈ [1.433, 1.456]. The outer contour shape of the fourth doped inner cladding is a regular octagon, with a thickness ∈ [0.012 mm, 0.025 mm].

7. The combined-state energy transfer type high-temperature resistant multi-core optical fiber according to claim 6, characterized in that, The doped outer cladding is made of doped quartz glass, and the doping elements are fluorine and boron. The refractive index after doping is ∈ [1.420, 1.432]. The doped outer cladding adopts a square structure. The minimum distance between the doped outer cladding and the first, second, third, and fourth doped inner claddings is ∈ [0.05 mm, 0.09 mm].

8. The combined-state energy transfer type high-temperature resistant multi-core optical fiber according to claim 7, characterized in that, The polymer coating layer is made of fluorinated acrylic resin, with a refractive index of [1.370, 1.420] and a modulus of [210 MPa, 450 MPa]. The outer contour of the polymer coating layer is square, and the thickness is [0.025 mm, 0.065 mm].

9. The combined-state energy transfer type high-temperature resistant multi-core optical fiber according to claim 8, characterized in that, The fluoroplastic layer is made of ethylene-tetrafluoroethylene copolymer; the outer contour of the fluoroplastic layer is square, and the thickness is [0.030 mm, 0.080 mm].

10. The combined-state energy transfer type high-temperature resistant multi-core optical fiber according to claim 8, characterized in that, The polymer coating layer is further provided with a positioning quartz strip, which is located at the top corner of the polymer coating layer adjacent to the first light guide core; the positioning quartz strip is made of pure quartz glass, has a circular cross-section, and a diameter ∈ [0.012mm, 0.024mm].

Images