Integrated structure of mode scrambler and optical fiber output head and optical fiber laser

Abstract

The utility model discloses an integrated structure of a mode scrambler and an optical fiber output head and an optical fiber laser. Wherein the integrated structure comprises an output end cap, a packaging shell and an energy transmitting optical fiber, and the energy transmitting optical fiber comprises a fiber core, a wrapping layer and a coating layer which are sequentially arranged in a sleeving mode from inside to outside; a through cavity is formed in the packaging shell, the output end cap is fixed to one end of the cavity, the output end of the energy transmission optical fiber penetrates into the cavity from the other end of the cavity and is fixedly connected with the output end cap, a blackspot section used for changing refractive index distribution of a fiber core is formed on the fiber core in the cavity, and a plurality of blackspots are arranged in the blackspot section. According to the integrated structure, the mode disturbing effect can be achieved with the minimum loss on the premise that the complexity and the size of the laser are not increased, and the transmission loss of the laser in the fiber core after mode disturbing can be effectively reduced.

Description

TECHNICAL FIELD

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

[0002] Optical fiber laser in industrial processing field, for example, when cutting thin plate, usually need to change the degree of bending of optical fiber by additional mechanical stress or realize the deterioration of beam quality by adopting misalignment fusion method, to achieve mode scrambling effect, and additional mechanical stress needs to increase additional mechanical structure, resulting in bulky laser structure, and misalignment fusion will cause the waste of laser energy, and the leakage of laser is easy to cause the burning of fusion place.

[0003] And, since the output end of optical fiber laser needs to be provided with optical fiber output head, in the prior art optical fiber laser, the mode scrambler and the optical fiber output head are single devices, thereby resulting in large overall size of the optical fiber laser. UTILITY MODEL CONTENT

[0004] In view of the above problems, the utility model discloses a kind of integration structure of mode scrambler and optical fiber output head and optical 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 optical fiber output head, including output end cap, encapsulation shell and energy transmission optical fiber, the energy transmission optical fiber includes the core, cladding and coating layer that are sequentially sleeved from inside to outside;

[0007] The cavity is formed in the encapsulation shell, the output end cap is fixed at one end of the cavity, the output end of the energy transmission optical fiber is penetrated into the cavity from the other end of the cavity, and is fixedly connected with the output end cap, the core in the cavity is formed with spot mark section for changing core refractive index distribution, and a plurality of spot marks are arranged in the spot mark section.

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

[0009] Further, the spot mark section is 5mm-100mm along the axial length of the energy transmission optical fiber.

[0010] Further, the spot mark is formed by femtosecond laser etching.

[0011] Further, the number of the spot mark section is multiple, and each spot mark section is arranged at intervals.

[0012] Further, a roughened section with destroyed total reflection characteristics is formed on the outer circumference of the cladding outside the spot mark section, and the coating layer outside the roughened section is stripped.

[0013] Further, the packaging shell is made of metal material, and the cavity wall of the cavity is frosted.

[0014] Further, a quartz tube is further included.

[0015] The quartz tube is sleeved outside the roughened section, and two ends of the quartz tube are respectively bonded and fixed with the coating layers on two sides of the roughened section.

[0016] Further, a liquid cooling channel is formed in the packaging shell.

[0017] The utility model discloses a kind of optical fiber lasers on the other hand, including pump source and the integration structure of the mode scrambler and optical fiber output head described above;

[0018] The output end of the pump source is connected with the input end of the energy transmission optical fiber.

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

[0020] In the integration structure, the spot mark section for changing the refractive index distribution of the fiber core is formed on the fiber core, and a plurality of spots are arranged in the spot mark section to form the mode scrambler, so that the coupling of the laser mode transmitted by the fiber core is realized. The mode scrambler has simple structure, higher reliability and better integrity. Moreover, the mode scrambler is formed on the optical fiber output head, so that the mode scrambler and the optical fiber output head are integrated as a whole. The mode scrambler can achieve the mode scrambling effect with minimum loss without increasing the complexity and size of the laser, and can effectively reduce the loss of the laser transmitted in the fiber core after mode scrambling. 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 considered a limitation of the present utility model. Moreover, like reference numerals designate identical components throughout the several views. In the drawings:

[0022] Figure 1 Fig. 1 is an axial sectional view of the integration structure of an embodiment of the present utility model;

[0023] Figure 2 Fig. 2 is an axial sectional view of the integration structure of another embodiment of the present utility model.

[0024] In the figure: 1, output end cap; 2, packaging shell; 3, energy transmission optical fiber; 4, fiber core; 5, cladding; 6, coating layer; 7, cavity; 8, blemish section; 9, roughened section. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical scheme and advantages of the utility model clearer, the following will combine the utility model specific embodiment and corresponding drawings to make the utility model technical scheme clear and complete description. Obviously, the described embodiment is only a part of the embodiment of the utility model, not all the embodiments. Based on the embodiment in the utility model, all other embodiments obtained by the ordinary skilled person in the art without creative labor belong to the scope of the utility model protection.

[0026] The following will combine the drawings to specifically describe the technical scheme provided by each embodiment of the utility model.

[0027] One embodiment of the utility model provides a kind of integration structure of mode scrambler and optical fiber output head, as shown in Figure 1 The integration structure includes output end cap 1, packaging shell 2 and energy transmission optical fiber 3, and energy transmission optical fiber 3 includes fiber core 4, cladding 5 and coating layer 6 which are sequentially sleeved from inside to outside;Wherein, output end cap is quartz material.

[0028] Specifically, through cavity 7 is formed in packaging shell 2, i.e. cavity 7 passes through the entire packaging shell 2, output end cap 1 is fixed at one end of cavity 7, output end cap 1 is at least partially located in cavity 7, and output end cap 1 and packaging shell 2 can be fixedly connected by heat-conducting glue, the output end of energy transmission optical fiber 3 is inserted into cavity 7 from the other end of cavity 7, and is fixedly connected with output end cap 1, and blemish section 8 for changing the refractive index distribution of fiber core 4 is formed on fiber core 4 in cavity 7, a plurality of blemishes are arranged in blemish section 8, to form mode scrambler, to realize the coupling of laser mode transmission of fiber core 4. Wherein, blemish can be dot mark or line mark, or combination of dot mark and line mark.

[0029] In this way, mode scrambling is carried out at the optical fiber output head, which reduces the space occupied by the mode scrambler itself, and also reduces the melting point of device connection and laser loss;And the laser after mode scrambling almost does not transmit in the fiber core, but is output through the optical fiber output head, which can effectively reduce the loss of laser transmission in the fiber core after mode scrambling.

[0030] 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. Moreover, the mode scrambler is formed on the fiber output head, so that the mode scrambler and the fiber output head are integrated as a whole. The mode scrambling effect can be achieved with minimum loss without increasing the complexity and volume of the laser, and the loss of the laser transmitted in the fiber core after mode scrambling can be effectively reduced.

[0031] In the embodiment, the number of the scar section is one, and the axial length of the scar section along the energy transmission fiber is 5mm-100mm, which can ensure better mode scrambling effect. Of course, in other embodiments, the number of the scar section can also be multiple, and each scar section is arranged at intervals, which can further improve the mode scrambling effect.

[0032] Moreover, the scars are formed by femtosecond laser etching. The femtosecond laser has the advantages of simple operation, good repeatability and low cost, and the structure of the energy transmission fiber is not damaged in the formation process of the scars, which ensures the integrity of the structure of the energy transmission fiber. The fiber core is etched by femtosecond laser to achieve the purpose of beam quality degradation, without using external mechanical structure, and avoiding the problem of energy loss caused by misalignment fusion.

[0033] In another embodiment, as shown in Figure 2 The outer circumference of the cladding 5 outside the scar section 8 is formed with a roughened section 9 with the total reflection characteristic being destroyed, and the coating layer 6 outside the roughened section 9 is stripped. In this way, the roughened section 9 constitutes a cladding light filter, so that the cladding light is emitted from the cladding 5 at the roughened section 9, the cladding light is stripped, and the fiber output head has both the mode scrambling function and the cladding light stripping function. Moreover, the setting of the roughened section 9 does not damage the overall structure of the cladding 5, so that the cladding 5 still has good mechanical properties.

[0034] In the embodiment, the roughened section is formed by femtosecond laser burning. 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 burning, for example, chemical etching method.

[0035] In other embodiments, a plurality of cavities are formed in the cladding in the roughened section.

[0036] In this way, part of the cladding light transmitted in the cladding is emitted through the roughened section when being reflected to the roughened section, so that the stripping of the cladding light is realized; another part of the cladding light transmitted in the cladding is scattered when being emitted to the cavity, and the scattered light generated is emitted through the roughened section, so that the stripping of the cladding light is realized, and the stripping degree of the cladding light is higher. In addition, the length of the roughened section required in the axial direction can be reduced by arranging the cavity, so that the volume of the cladding light filter is smaller. In addition, the arrangement of the cavity does not damage the overall structure of the cladding, so that the cladding still has good mechanical properties.

[0037] Further, the sizes of the plurality of cavities are different, so that the angles of the cladding light in the cladding scattered through different cavities are different, so that the range of the scattered light is larger, so that the scattered light generated by the cladding light is better emitted through the roughened section, 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.

[0038] In other embodiments, the packaging shell is made of metal, and the cavity wall of the cavity is a frosted surface, so that the cladding light emitted through the roughened section can be quickly absorbed, and the heat generated by absorbing the cladding light can be conducted out.

[0039] In addition, the integrated structure further comprises a quartz tube.

[0040] The quartz tube is sleeved outside the roughened section, and the two ends of the quartz tube are respectively bonded and fixed to the coating layers on the two sides of the roughened section. The quartz tube is used for protecting the roughened section, preventing dust particles from affecting the stripping of the cladding light, and enabling the cladding light to pass through the quartz tube.

[0041] In addition, the liquid cooling channel is formed in the packaging shell, and the cooling liquid flows in the liquid cooling channel, so that the cooling and heat dissipation effect of the packaging shell is better.

[0042] Another embodiment of the utility model provides an optical fiber laser, which comprises a pump source and the integrated structure of the mode scrambler and the optical fiber output head in the above-mentioned embodiments.

[0043] Specifically, the output end of the pump source is connected with the input end of the energy transmission optical fiber, so that the optical fiber laser can realize the mode scrambling effect at the optical fiber output head, and has the advantages of small size, compact structure, low manufacturing cost and small laser loss.

[0044] The above merely illustrates the specific implementation of the present application, and based on the above teaching, those skilled in the art can make other improvements or modifications on the basis of the above examples. Those skilled in the art should understand that the above specific description is only for better explaining the purpose of the present application, and the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. An integrated structure of a mode scrambler and a fiber output head, characterized by comprising: a mode scrambler; and a fiber output head, wherein the mode scrambler and the fiber output head are integrated. The output end cap, the packaging shell and the energy transmission fiber, the energy transmission fiber comprising a core, a cladding and a coating layer which are sequentially sleeved from inside to outside; The packaging shell is internally formed with a through cavity, the output end cap is fixed at one end of the cavity, the output end of the energy transmission fiber is penetrated into the cavity from the other end of the cavity and is fixedly connected with the output end cap, the core in the cavity is formed with a scar segment for changing the refractive index distribution of the core, and a plurality of scars are arranged in the scar segment.

2. The integrated structure of a mode scrambler and a fiber output head according to claim 1, wherein The plurality of scars are uniformly distributed in the core.

3. The integrated structure of a mode scrambler and a fiber output head according to claim 1, wherein The axial length of the scar segment along the energy transmission fiber is 5mm-100mm.

4. The integrated structure of a mode scrambler and a fiber output head according to claim 1, wherein The scars are formed by femtosecond laser etching.

5. The integrated structure of a mode scrambler and a fiber output head according to claim 1, wherein The number of the scar segments is a plurality, and each of the scar segments is arranged at intervals.

6. The integrated structure of a mode scrambler and a fiber output head according to claim 1, wherein An outer circumference of the cladding outside the scar segment is formed with a roughened segment with the total reflection characteristic being destroyed, and the coating layer outside the roughened segment is stripped.

7. The integrated structure of a mode scrambler and a fiber output head according to claim 6, wherein The packaging shell is made of metal, and the cavity wall of the cavity is frosted.

8. The integrated structure of a mode scrambler and a fiber output head according to claim 6, wherein A quartz tube is further included; The quartz tube is sleeved outside the roughened segment, and two ends of the quartz tube are respectively adhesively fixed with the coating layers on two sides of the roughened segment.

9. The integrated structure of a mode scrambler and a fiber output head according to any one of claims 1 to 8, wherein The packaging shell is internally formed with a liquid cooling channel.

10. A fiber laser, characterized by, An integrated structure comprising a pump source and the mode scrambler and the fiber output head according to any one of claims 1-9; The output end of the pump source is connected with the input end of the energy transmission fiber.

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