An integrated structure of a mode scrambler and a cladding light filter and a fiber laser

Abstract

The utility model discloses an integration structure of scrambler and cladding light filter and optical fiber laser, wherein the integration structure includes optical fiber, and the optical fiber includes core and cladding, the cladding is wrapped in the outside of core, and the outer circumference of cladding forms the roughened section of the destroyed total reflection characteristic, and the core in roughened section forms the blemish section for changing the refractive index distribution of core, and a plurality of blemishes are equipped in blemish section. The integration structure can realize two functions of cladding light stripping and scrambler, and has the advantages of simple structure, small size, high reliability and good structure integrity.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the technical field of laser, especially relates to a kind of integration structure of mode scrambler and cladding light filter and fiber laser. BACKGROUND

[0002] Fiber laser is widely used in industrial processing field with its compact structure, high stability, flexible transmission laser and other characteristics.In the welding application scene, the beam energy of high beam quality fiber laser output is too concentrated, so that the welding assembly gap tolerance is smaller, and it is not suitable for special joint form needing fusion width larger;At the same time, in laser deep penetration welding, the welding process is more complex, local area excessive evaporation, easy to occur spoon hole collapse and molten pool violent fluctuation, so as to cause the poor quality of weld forming, and easy to produce pore defect.In this market demand background, mode scrambler is invented and applied to fiber laser, for realizing low beam quality laser output.

[0003] At present, existing mode scrambler is divided into two kinds:one kind of mode scrambler is formed by single-mode fiber and multimode fiber misregistration fusion, the incidence angle of light entering multimode fiber in single-mode fiber is changed by misregistration fusion, so as to excite high-order mode in fiber;Although the mode scrambler has the advantages of small size, simple production, low cost, mode stability and the like, since it is prepared by misregistration fusion, it will bring laser energy loss, and since laser leakage is easy to cause fusion place burning, the reliability is low.Another kind of mode scrambler is formed by extruding transmission fiber through mechanical device, the mode in fiber is coupled with each other by extrusion, so as to control the mode of fiber output laser, i.e.to change beam quality;The mode scrambler is complex in structure, depends on high-precision adjustment of mechanical mechanism, and the precision requirement of mechanical device is higher, so that the cost is higher. UTILITY MODEL CONTENTS

[0004] In view of the above problems, the utility model discloses a kind of integration structure of mode scrambler and cladding light filter and fiber laser, to overcome the above problems or at least partially solve the above problems.

[0005] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0006] The utility model discloses a kind of integration structure of mode scrambler and cladding light filter on one side, including fiber, the fiber includes core and cladding;

[0007] The cladding is wrapped in the outside of the core, the outer circumference of the cladding is formed with roughened section that full reflection characteristic is destroyed, the core in the roughened section is formed with spot mark section for changing core refractive index distribution, multiple spot marks are equipped in the spot mark section.

[0008] Further, the plurality of the spots are uniformly distributed in the core.

[0009] Further, the roughened section is formed by a femtosecond laser.

[0010] Further, the spots are formed by a femtosecond laser.

[0011] Further, the inner part of the cladding in the roughened section is formed with a plurality of cavities.

[0012] Further, the plurality of the cavities are of different sizes and have different interval distances in the axial direction of the cladding.

[0013] Further, the roughened section has a length of 5mm-80mm, and the spot section has a length of 5mm-80mm.

[0014] Further, when the area of the roughened section around the cladding is less than a semicircle of the cladding, the chord length of the circular arc formed by the roughened section is not less than one fifth of the diameter of the cladding.

[0015] Further, the utility model discloses a glass tube cover.

[0016] The glass tube cover is sleeved on the outside of the roughened section.

[0017] The utility model discloses a kind of optical fiber lasers on another aspect, including output optical fiber and the integration structure of above-mentioned mode scrambler and cladding light filter;

[0018] The integration structure is formed on the output optical fiber.

[0019] The utility model has the advantages and beneficial effects that:

[0020] In the integration structure of the utility model, the spot section for changing the refractive index distribution of the core is formed on the core, and a plurality of spots are arranged in the spot section, to form a mode scrambler, so that the coupling of the core transmission laser mode is realized, the mode scrambler has simple structure, higher reliability and better integrity; in addition, the roughened section with the full reflection characteristic being destroyed is formed on the outer circumference of the cladding outside the mode scrambler, to form a cladding light filter, which can effectively remove the cladding light in the cladding, and realize the two functions of cladding light removal and mode scrambling in the same optical fiber device, so that the mode scrambler does not occupy the volume of laser additionally, and is more miniaturized. BRIEF DESCRIPTION OF DRAWINGS

[0021] Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments with reference made to the accompanying drawings. The drawings are for purposes of illustration only and are not intended to limit the present application thereto. Like reference numerals are used to indicate like elements throughout the several views. In the drawings:

[0022] Figure 1 FIG. 1 is a structural schematic diagram of an integrated structure of a mode scrambler and a cladding light filter according to an embodiment of the present application.

[0023] In the figure: 1, fiber core; 2, cladding; 3, roughened section; 4, blemish section. DETAILED DESCRIPTION

[0024] In order to make the objectives, technical solutions and advantages of the present application clearer, the following will make a clear and complete description of the technical solutions of the present application with reference to the embodiments of the present application and the corresponding drawings. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of protection of the present application.

[0025] The following will make a detailed description of the technical solutions provided by the embodiments of the present application with reference to the drawings.

[0026] An embodiment of the present application provides an integrated structure of a mode scrambler and a cladding light filter, as shown in the figure, the integrated structure comprises an optical fiber, and the optical fiber comprises a fiber core 1 and a cladding 2. Figure 1

[0027] Specifically, the cladding 2 is wrapped outside the fiber core 1, and a roughened section 3 with a destroyed total reflection characteristic is formed on the outer circumference of the cladding 2, which constitutes a cladding light filter, so that the cladding light is emitted from the cladding 2 at the roughened section 3, and the cladding light is stripped, and the setting of the roughened section 3 does not destroy the overall structure of the cladding 2, so that the cladding 2 still has good mechanical properties; in addition, a blemish section 4 for changing the refractive index distribution of the fiber core 1 is formed on the fiber core 1 in the roughened section 3, and a plurality of blemishes (not shown in the figure) are arranged in the blemish section 4, which constitutes a mode scrambler, and the coupling of the fiber core 1 transmission laser mode is realized. The blemish section can be one section or multiple sections arranged at intervals; the blemish can be a dot mark or a line mark, or a combination of a dot mark and a line mark.

[0028] In the integrated structure, the cladding light filter is sleeved outside the mode scrambler, that is, the two are arranged in structural overlap, so that the two functions of stripping the cladding light and scrambling the mode are realized, and the structure is more compact.

[0029] ​In summary, in the integrated structure of the embodiment, the scar section for changing the refractive index distribution of the fiber core is formed on the fiber core, and a plurality of scars are arranged in the scar section to form a mode scrambler, so that the coupling of the laser mode transmitted in the fiber core is realized. The mode scrambler has simple structure, higher reliability and better integrity. In addition, the roughened area with the destroyed total reflection characteristic is formed on the outer circumference of the cladding outside the mode scrambler to form a cladding light filter, which can effectively remove the cladding light in the cladding. The cladding light removal and mode scrambling functions are realized in the same optical fiber device, and the mode scrambler does not occupy the volume of the laser device, so that the mode scrambler is more miniaturized.

[0030] In the embodiment, the plurality of scars are uniformly distributed in the fiber core, so that the mode scrambling effect is better.

[0031] In addition, the roughened section is formed by femtosecond laser sintering. The uniform roughened structure can be formed on the outer wall of the cladding by femtosecond laser, so as to ensure the uniformity of the overall cladding structure. Of course, the roughened section can also be processed by other processing methods, and is not limited to being formed by femtosecond laser sintering.

[0032] In addition, the scars are formed by femtosecond laser etching. The preparation of the mode scrambler by femtosecond laser has the advantages of simple operation, good repeatability and low cost. In the process of forming the scars, the structure of the optical fiber is not damaged, so as to ensure the integrity of the optical fiber structure.

[0033] Further, the length of the roughened section is 5mm-80mm, the length of the scar section is 5mm-80mm, and when the area of the roughened section around the cladding is less than half of the cladding, the chord length of the arc formed by the roughened section is not less than one fifth of the diameter of the cladding. The above-mentioned dimensions make the mode scrambling effect and the cladding light filtering effect of the integrated structure better.

[0034] In other embodiments, a plurality of cavities are formed in the cladding in the roughened section.

[0035] In this way, part of the cladding light transmitted in the cladding is emitted through the roughened section when reflected to the roughened section, so as to realize the stripping of the cladding light. Another part of the cladding light transmitted in the cladding is scattered when being incident on the cavity, and the scattered light is emitted through the roughened section, so as to realize the stripping of the cladding light, and further to make the stripping degree of the cladding light higher. In addition, through the arrangement of the cavities, the length of the roughened section required in the axial direction can be reduced, so as to make the volume of the cladding light filter smaller. Similarly, the arrangement of the cavities does not damage the overall structure of the cladding, so that the cladding still has good mechanical properties.

[0036] Further, the plurality of cavities are different in size, so that the scattering angles of the cladding light in the cladding passing through the different cavities are different, and then the scattering range of the scattered light is larger, so that the scattered light generated by the cladding light is better emitted through the roughened area, and the stripping effect of the cladding light is better. The interval distances of the plurality of cavities in the axial direction of the cladding are different; in this way, the cladding light with different reflection angles in the cladding can be scattered and stripped, so that the stripping degree of the cladding light is improved. Of course, the interval distances of the plurality of cavities in the axial direction of the cladding can be equal, which is also within the protection scope of the utility model.

[0037] In addition, the integrated structure of the mode scrambler and the cladding light filter further comprises a glass tube cover.

[0038] The glass tube cover is sleeved on the outer side of the roughened section, is used for protecting the roughened section, prevents dust particles from affecting the stripping of the cladding light, and enables the cladding light to pass through the glass tube cover.

[0039] In another embodiment of the utility model, a fiber laser is provided, which comprises an output fiber and the integrated structure of the mode scrambler and the cladding light filter in the above embodiment, and the integrated structure is formed on the output fiber. The fiber laser can realize the mode scrambling effect and the cladding light filtering effect, has a small size, a compact structure and low manufacturing cost.

[0040] The above is only a specific embodiment of the utility model, and other improvements or deformations can be made on the basis of the above embodiment under the above teaching of the utility model. It should be understood by those skilled in the art that the above specific description is only for better explaining the purpose of the utility model, and the protection scope of the utility model should be subject to the protection scope of the claims.

Claims

1. An integrated structure of a mode scrambler and a cladding optical filter, characterized in that, The optical fiber comprises a core and a cladding. The cladding is wrapped outside the core, and a roughened section with destroyed total reflection characteristics is formed on the outer circumference of the cladding, and a scar section for changing the core refractive index distribution is formed on the core in the roughened section, and a plurality of scars are arranged in the scar section.

2. The integrated mode scrambler and cladding light filter according to claim 1, wherein The plurality of scars are uniformly distributed in the core.

3. The integrated mode scrambler and cladding light filter according to claim 1, wherein The roughened section is formed by femtosecond laser sintering.

4. The integrated mode scrambler and cladding light filter according to claim 1, wherein The scars are formed by femtosecond laser etching.

5. The integrated mode scrambler and cladding light filter of claim 1, wherein An inner part of the cladding in the roughened section is formed with a plurality of cavities.

6. The integrated mode scrambler and cladding light filter according to claim 5, wherein The plurality of cavities are different in size and unequal in interval distance in the axial direction of the cladding.

7. The integrated mode scrambler and cladding light filter of claim 1, wherein The length of the roughened section is 5mm-80mm, and the length of the scar section is 5mm-80mm.

8. The integrated mode scrambler and cladding light filter of claim 1, wherein, When the area of the roughened section around the cladding is less than half of the cladding, the chord length of the circular arc formed by the roughened section is not less than one fifth of the diameter of the cladding.

9. The integrated mode scrambler and cladding light filter according to any one of claims 1 to 8, wherein The glass tube cover is further included. The glass tube cover is sleeved outside the roughened section.

10. A fiber laser, characterized by, The integrated structure comprises an output optical fiber and the mode scrambler and the cladding optical filter in any one of claims 1-9. The integrated structure is formed on the output optical fiber.

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