CN218940304U - Laser output device and fiber laser - Google Patents

Abstract

The embodiment of the application provides a laser output device and an optical fiber laser, wherein the laser output device comprises an output optical fiber, at least two mode stripper and at least one mode scrambler, the output optical fiber is provided with an input end and an output end, and the output optical fiber is used for being connected with a laser generating device so as to transmit laser beams output by the laser generating device; at least two stripper devices are arranged at intervals in the direction from the input end to the output end, the stripper devices are arranged on the output optical fiber, and a mode scrambler is arranged on the output optical fiber between the adjacent stripper devices.

Description

Laser output device and fiber laser

technical field

The application belongs to the field of laser technology, and in particular relates to a laser output device and a fiber laser.

Background technique

Fiber lasers have the advantages of high conversion rate, high conversion efficiency, good beam quality, compact structure and high reliability. Fiber lasers are widely used in industrial processing fields such as laser welding, cladding, cutting, and drilling.

The pump source of the fiber laser couples the pump light into the inner cladding of the active fiber through the beam combiner to provide energy for the active fiber, and the signal light is generated in the fiber core, and then amplified through the resonant cavity feedback mode selection, and then output. However, due to the limited length of the active fiber, the pump light in the cladding cannot be completely absorbed, and part of the pump light in the cladding exists in the form of helical light. Therefore, the cladding contains pump light. In addition, due to the imperfection of optical fiber fusion and the defects of the optical fiber itself, part of the signal light may leak into the cladding, which will also cause signal light in the cladding. The existence of signal light in the cladding will lead to unstable laser energy, and the beam quality of the fiber laser is poor, which seriously affects the performance of the fiber laser and even damages the fiber laser. In the prior art, the cladding light is generally removed by setting a stripper, but the small-angle cladding light cannot be removed, and the cladding light will still affect the beam quality along with the transmission of the optical path. In addition, due to the small resistivity, smooth surface, and absorption rate of near-infrared light of metal materials, when using fiber lasers to process metal materials, the metal material surface reflects laser light to form return light, and the return light enters the laser again through the processing head. Damage to the processing head and the laser itself.

Utility model content

Embodiments of the present application provide a laser output device and a fiber laser to solve the existing problem of poor beam quality due to the existence of cladding light and return light, which affects the performance of the fiber laser.

In the first aspect, the embodiment of the present application provides a laser output device, including:

An output optical fiber has an input end and an output end, and the output optical fiber is used for connecting with the laser generating device to transmit the laser beam output by the laser generating device;

At least two mold strippers, in the direction from the input end to the output end, the at least two mold strippers are arranged at intervals, and the mold strippers are arranged on the output optical fiber;

At least one mode scrambler, one mode scrambler is arranged on the output optical fiber between adjacent mode strippers.

Optionally, the output fiber at least includes:

The first sub-fiber has an input end and a second end, and the first sub-fiber is provided with a stripper;

The second sub-fiber has a third end, the second end is docked with the third end, the second sub-fiber is provided with a mode stripper, and the mode scrambler on the first sub-fiber The mode scrambler is disposed between the mode scrambler and the second end or the mode scrambler is disposed between the third end and the mode scrambler on the second sub-fiber.

Optionally, the output optical fiber further includes a third sub-fiber, the third sub-fiber has a fifth end and the output end, the second sub-fiber has a fourth end, and the fourth end is connected to the The fifth end is fused, and the core diameter of the third sub-fiber is larger than the core diameter of the second sub-fiber.

Optionally, the first sub-fiber, the second sub-fiber and the third sub-fiber are arranged coaxially.

Optionally, the core diameters of the first sub-fiber, the second sub-fiber, and the third sub-fiber increase sequentially.

Optionally, both the second sub-fiber and the third sub-fiber are passive fibers.

Optionally, the core diameter of the second sub-fiber is larger than the core diameter of the first sub-fiber.

Optionally, the core diameter of the second sub-fiber is more than 1.2 times the core diameter of the first sub-fiber.

In the second aspect, the embodiment of the present application also provides a fiber laser, including:

A laser generating device for generating a laser beam;

In the laser output device described in any one of the above, the input end of the output fiber is connected to the laser emitting device, and the laser beam is transmitted through the laser output device and emitted from the output end.

Optionally, a casing is also included, and the laser generating device, the mold stripper and the mold scrambler are fixed in the casing.

The laser output device and the fiber laser provided in the embodiment of the present application are provided with at least two mode strippers and at least one mode scrambler on the output fiber, and the mode scrambler is located between the two mode strippers. When the laser generating device outputs When the laser beam is used, the laser beam is transmitted along the output fiber, and the stripper close to the laser generator strips part of the cladding light in the output fiber, and the small-angle cladding light that cannot be stripped by the stripper enters the mode scrambler. After being increased by the mode scrambler, it enters another mode stripper, which further strips the cladding light. When the laser reflected by the workpiece, that is, the return light, enters the laser output device from the output end and is located in the output fiber package. After the return light in the layer is stripped by the stripper near the output end, the return light with a small angle that cannot be stripped by the stripper passes through the scrambler to increase the divergence angle and then enters the stripper near the laser generator for stripping , a large amount of cladding light and return light are stripped by at least two mode strippers, which overcomes the existing problems of poor beam quality and affecting the performance of fiber lasers due to the existence of cladding light and return light, and reduces the cladding light And the impact of returning light on the laser and the beam improves the stability of the laser and the quality of the beam.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings that need to be used in the description of the embodiments. Apparently, the drawings in the following description are only some embodiments of the present application, and those skilled in the art can obtain other drawings according to these drawings without creative efforts.

For a more complete understanding of the present application and its beneficial effects, the following will be described in conjunction with the accompanying drawings. Wherein, the same reference numerals denote the same parts in the following description.

Fig. 1 is a diagram of the first optical path system of the fiber laser provided by the embodiment of the present application.

Fig. 2 is a second optical path system diagram of the fiber laser provided by the embodiment of the present application.

Fig. 3 is a third optical path system diagram of the fiber laser provided by the embodiment of the present application.

Detailed ways

The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Apparently, the described embodiments are only some of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without making creative efforts belong to the scope of protection of this application.

Embodiments of the present application provide a laser output device and a fiber laser to solve the existing problem of poor beam quality due to the existence of cladding light and return light, which affects the performance of the fiber laser. It will be described below in conjunction with the accompanying drawings.

Referring to Fig. 1 and Fig. 2, Fig. 1 is the first optical path system diagram of the fiber laser provided by the embodiment of the present application, and Fig. 2 is the second optical path system diagram of the fiber laser provided by the embodiment of the present application.

The embodiment of the present application provides a laser output device, which is suitable for fiber lasers. The fiber lasers can be continuous fiber lasers or pulsed fiber lasers. The laser output device includes an output fiber 100, at least two mode strippers 200 and at least one mode scrambler 300, the output fiber 100 has an input end 111 and an output end 132, the input end of the output fiber 100 is connected with the laser generator, and the output fiber is used to transmit the laser beam output by the laser generator, from the input end 111 to the direction of the output end 132 , at least two strippers 200 are arranged at intervals, the stripper 200 is arranged on the output optical fiber 100, the stripper 200 is used to strip the cladding light and the return light in the cladding, and the strippers between adjacent strippers 200 A mode scrambler 300 is arranged on the output optical fiber 100 .

It can be understood that a plurality of strippers 200 and at least one scrambler 300 can be arranged along the length direction of the output optical fiber 100, such as N sets of strippers 200, N-1 sets of scramblers 300, and N-1 sets of strippers 200 Alternately arranged with the mode scrambler 300, and the output fiber 100 is provided with a mode stripper 200 near the side of the laser generating device, and a mode stripper 200 is provided near the side of the output end 132, and the cladding light entering the output fiber 100 passes from the input end During the transmission process of 111 to the output terminal 132, it is successively stripped by multiple strippers 200, wherein, the low NA (core vertical aperture) in the cladding that cannot be stripped by the N-1 stripper 200 After passing through the N-1th mode scrambler 300, the divergence angle of the beam increases, and it is transmitted into the Nth mode stripper 200, and is stripped by the Nth mode stripper 200, and the mode stripper 200 acts on the output fiber 100, make the output fiber 100 produce micro-bending stress, enhance the coupling mode of the laser beam in the fiber, increase the beam divergence angle, and achieve the purpose of homogenizing the energy distribution of the spot, reduce the density of the laser so as to improve the SRS of the specific laser (subjected to Excited Raman scattering) threshold, after a plurality of strippers 200 cooperate with the mode scrambler 300, remove the cladding light in the output fiber 100 as much as possible, output the laser beam from the output end 132, reduce the cladding light to the laser beam The effect of beam quality improves the beam quality of the laser beam. And the laser light reflected from the workpiece to be processed is the return light, the return light enters the output optical fiber 100 from the output end 132 of the output optical fiber 100, and is transmitted to the direction of the input end 111, and the return light is stripped by the Nth mold stripping device 200, without The stripped part enters the N-1th mold scrambler 300. After passing through the N-1th mold scrambler 300, the divergence angle of the return light increases, and then enters the N-1th mold stripper 200 to remove the package as much as possible. The return light in the layer reduces the return light entering the laser generating device, reduces the influence of the return light on the laser, and improves the performance of the laser.

The number of mode strippers 200 and mode scramblers 300 can be set according to the length of the output optical fiber 100. The more the number of mode strippers 200 and mode scramblers 300, the better the effect of stripping cladding light and return light. performance and cost.

Referring to Fig. 2, in the embodiment of the present application, along the length direction of the output optical fiber 100, two strippers 200 and one scrambler 300 are set, which are respectively the first stripper 210 and the second stripper 220 , the first mold stripper 210 is close to the input end 111, the second mold stripper 220 is close to the output end 132, a scrambler 300 is set between the first mold stripper 210 and the second mold stripper 220, the first mold stripper 210 The structure is the same as that of the second stripper 220 .

As a variant, along the length direction of the output optical fiber 100, three mold strippers 200 and two mold scramblers 300 are set, which are respectively the first mold stripper 210, the second mold stripper 220 and the third mold stripper. A mode scrambler and a second mode scrambler, along the length direction of the output optical fiber 100, from the input end 111 to the output end 132, the first mode stripper 210, the second mode stripper 220 and the third mode stripper are sequentially arranged at intervals , the first mold scrambler is located between the first mold stripper 210 and the second mold stripper 220, and the second mold scrambler is located between the second mold stripper 220 and the third mold stripper. Multiple mode scramblers 300 and multiple mode strippers 200 are provided to strip cladding light and return light as much as possible to improve the beam quality of the laser.

The above-mentioned stripper 200 is prepared from a part of the output optical fiber 100. A stripping method such as a mechanical stripping method, a chemical stripping method or a thermal stripping method is used to make a bare fiber section, and at least one layer is coated on the bare fiber section. Coating material, the coating material includes and is not limited to photosensitive glue whose refractive index is higher than that of the cladding of the output optical fiber 100 , the cladding light is refracted from the coating layer, and the cladding light is stripped or returned light. The mode stripper 200 is prepared from the output optical fiber 100, which reduces the number of welds of the output optical fiber 100, reduces the generation of cladding light, and improves the beam quality.

Referring to FIG. 3 , FIG. 3 is a third optical path system diagram of the fiber laser provided by the embodiment of the present application.

In some embodiments, the output optical fiber 100 at least includes a first sub-fiber 110 and a second sub-fiber 120, the first sub-fiber 110 has an input end 111 and a second end 112, and a mode stripper 200 is provided on the first sub-fiber 110 That is, the first mode stripper 210 and the second sub-optical fiber 120 have a third end 121, the second end 112 is connected to the third end 121, and the second sub-optical fiber 120 is provided with a mode stripper 200, that is, a second mode stripper 220 A mode scrambler 300 is provided between the first mold stripper 210 and the second end 112 or a mode scrambler 300 is provided between the third terminal 121 and the second mold stripper 220 .

The above-mentioned first sub-fiber 110 and second sub-fiber 120 can be the same type of optical fiber, and can also be different optical fibers, such as the first sub-fiber 110 has a cladding and a core, the cladding wraps the core, and the second sub-fiber 120 has a core, a cladding and a coating layer, the cladding wraps the core, the coating wraps the cladding, the mode scrambler 300 and the second mode stripper 220 are arranged on the second sub-optical fiber 120, the second sub-optical fiber 120 The high structural strength is beneficial to the installation of the mode scrambler 300 and ensures the performance of the mode scrambler 300 .

In the above embodiment, referring to FIG. 2, the output optical fiber 100 also includes a third sub-fiber 130, the third sub-fiber 130 has a fifth end 131 and an output end 132, the second sub-fiber 120 has a fourth end 122, and the third sub-fiber 130 has a fifth end 131 and an output end 132. The four ends 122 are welded to the fifth end 131 , and the core diameter of the third sub-fiber 130 is larger than the core diameter of the second sub-fiber 120 .

It can be understood that when the laser beam is transmitted along the output direction, the core diameter of the second sub-fiber 120 is smaller than the core diameter of the third sub-fiber 130, and all the core light of the second sub-fiber 120 enters the third sub-fiber 130 from The output end 132 outputs to ensure the quality of the laser beam. When the return light is transmitted, the return light is transmitted from the third sub-fiber 130 to the second sub-fiber 120 side, and the diameter of the third sub-fiber 130 is greater than the diameter of the second sub-fiber 120. All the returning light in the cladding of the third sub-fiber 130 enters the cladding of the second sub-fiber 120, and part of the returning light in the core of the third sub-fiber 130 enters the cladding of the second sub-fiber 120, and passes through the stripper 200 stripping, the core diameter of the second sub-fiber 120 and the core diameter of the third sub-fiber 130 are designed differently, which can strip off a part of the return light in the core, and prevent the return light from entering the laser beam along the reverse transmission of the laser beam. The laser device is damaged or the gain fiber is burned in the resonant cavity of the laser, which ensures the normal operation of the internal components of the laser and the laser.

On the basis of the above embodiments, referring to FIG. 2 , the first optical fiber sub 110 , the second optical fiber sub 120 and the third optical fiber sub 130 are arranged coaxially.

It can be understood that the first sub-fiber 110 , the second sub-fiber 120 and the third sub-fiber 130 are coaxially arranged to avoid decentering of the laser beam and improve the beam quality of the laser beam.

On the basis of the above embodiments, as shown in FIG. 2 , the core diameters of the first sub-fiber 110 , the second sub-fiber 120 and the third sub-fiber 130 increase sequentially.

It can be understood that the core diameter of the first sub-fiber 110 is smaller than the core diameter of the second sub-fiber 120, and the core diameter of the second sub-fiber 120 is smaller than the core diameter of the third sub-fiber 130. When returning light transmission, Part of the returned light in the core of the third sub-fiber 130 enters the cladding of the second sub-fiber 120, and is stripped by the second mode stripper 220, and part of the returned light in the core of the second sub-fiber 120 enters the first sub-fiber The cladding of the optical fiber 110 is stripped by the first mode stripper 210, so as to strip the return light in the core of the output optical fiber 100 as much as possible, and reduce the impact of the return light on the laser.

The core diameters of the first sub-fiber 110, the second sub-fiber 120, and the third sub-fiber 130 are sequentially designed, which is conducive to the coaxial arrangement of the first sub-fiber 110, the second sub-fiber 120, and the third sub-fiber 130, which is convenient Processing, to avoid the decentering of the laser beam, while reducing the return light, improve the beam quality of the laser.

On the basis of the above embodiments, both the second sub-fiber 120 and the third sub-fiber 130 are passive fibers.

It can be understood that the above-mentioned second sub-fiber 120 and third sub-fiber 130 are both passive optical fibers, which have a core, a cladding and a coating layer, the cladding wraps the core, the coating wraps the cladding, and the second sub-fiber The operation of fusing the optical fiber 120 and the third sub-optical fiber 130 is simple, and the optical fiber structure has high strength.

On the basis of the above embodiments, referring to FIG. 3 , the core diameter of the second sub-fiber 120 is larger than the core diameter of the first sub-fiber 110 .

It can be understood that the core diameter of the first sub-fiber 110 is smaller than the core diameter of the second sub-fiber 120, but the core diameter of the second sub-fiber 120 is smaller than the core diameter of the third sub-fiber 130, or the second The fiber core diameter of sub-fiber 120 is equal to the fiber core diameter of the 3rd sub-fiber 130, and when the return light is transmitted, part of the return light in the fiber core of the second sub-fiber 120 enters the cladding layer of the first sub-fiber 110, and passes through the first sub-fiber 110. The mode stripper 210 strips, thereby stripping the return light in the fiber core of the output fiber 100 as much as possible, and reducing the influence of the return light on the laser.

On the basis of the above embodiments, as shown in FIG. 3 , the core diameter of the second sub-fiber 120 is more than 1.2 times the core diameter of the first sub-fiber 110 .

It can be understood that the cladding diameter of the first sub-fiber 110 is the same as that of the second sub-fiber 120, but the core diameter of the second sub-fiber 120 is larger than the core diameter of the first sub-fiber 110, and the second sub-fiber The core diameter of the optical fiber 120 is more than 1.2 times the core diameter of the first sub-fiber 110, the difference between the core diameters of the first sub-fiber 110 and the second sub-fiber 120 is increased as much as possible, and the output fiber is stripped as much as possible. 100 of the return light in the fiber core reduces the influence of the return light on the laser.

As the deformation is large, referring to Fig. 2, when the third sub-fiber 130 is set, the core diameter of the second sub-fiber 120 is more than 1.2 times the core diameter of the first sub-fiber 110, and the third sub-fiber 130 The core diameter is more than 1.2 times the core diameter of the second sub-fiber 120, the cladding diameter of the first sub-fiber 110, the cladding diameter of the second sub-fiber 120 can be the same as the cladding diameter of the third sub-fiber 130, The output optical fiber 100 has a beautiful appearance and is convenient for processing.

Referring to Fig. 1, Fig. 2 and Fig. 3, the embodiment of the present application also provides a fiber laser, including: a laser generating device 400 and a laser output device described in any one of the above, and the laser generating device 400 is used to generate a laser beam The input end 111 of the output fiber 100 of the laser output device is connected to the laser generator 400, and the laser beam is transmitted from the output end through the laser output device.

It can be understood that the light in the cladding and the returning light entering the cladding can be stripped simultaneously by the laser output device, which improves the quality of the beam output by the laser and prolongs the service life of the laser.

In some embodiments, the fiber laser further includes a housing, and the laser generating device 400, the mold stripper 200 and the mode scrambler 300 are fixed in the housing.

It can be understood that in the embodiment of the present application, the laser generating device 400, the mold stripper 200 and the mode scrambler 300 are all integrated in the housing, and the fiber laser also includes a heat dissipation mechanism, a monitoring module and a control module, etc. The device 300 can share the heat dissipation mechanism of the fiber laser without a separate heat dissipation design, reducing equipment investment and cost.

In the foregoing embodiments, the descriptions of each embodiment have their own emphases, and for parts not described in detail in a certain embodiment, reference may be made to relevant descriptions of other embodiments.

In the description of the present application, the terms "first" and "second" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of indicated technical features. Thus, features defined as "first" and "second" may explicitly or implicitly include one or more features.

The laser output device and the fiber laser provided by the embodiment of the present application have been introduced in detail above. In this paper, specific examples are used to illustrate the principle and implementation of the present application. The description of the above embodiment is only used to help understand the application. method and its core idea; at the same time, for those skilled in the art, according to the idea of this application, there will be changes in the specific implementation and application scope. In summary, the content of this specification should not be construed as limiting the application .

Claims (10)

1. A laser output device, comprising:

the output optical fiber is provided with an input end and an output end and is used for being connected with the laser generating device so as to transmit the laser beam output by the laser generating device;

the at least two stripper devices are arranged at intervals in the direction from the input end to the output end, and the stripper devices are arranged on the output optical fiber;

at least one mode scrambler, one mode scrambler is arranged on the output optical fiber between the adjacent mode stripper.

2. The laser output device of claim 1, wherein the output fiber comprises at least:

the first sub-optical fiber is provided with an input end and a second end, and the first sub-optical fiber is provided with the mode stripper;

the second sub optical fiber is provided with a third end, the second end is in butt joint with the third end, the second sub optical fiber is provided with a mode stripper, the mode scrambler is arranged between the mode scrambler on the first sub optical fiber and the second end, or the mode scrambler is arranged between the third end and the mode scrambler on the second sub optical fiber.

3. The laser output device of claim 2 wherein the output fiber further comprises a third sub-fiber having a fifth end and the output end, the second sub-fiber having a fourth end, the fourth end being fused to the fifth end, the core diameter of the third sub-fiber being greater than the core diameter of the second sub-fiber.

4. A laser output device as claimed in claim 3 wherein the first sub-optical fibre, the second sub-optical fibre and the third sub-optical fibre are coaxially arranged.

5. A laser output device as claimed in claim 3, wherein the core diameters of the first sub-optical fiber, the second sub-optical fiber and the third sub-optical fiber are sequentially increased.

6. A laser output device as claimed in claim 3 wherein the second and third sub-fibres are both passive fibres.

7. A laser output device as claimed in claim 2 or claim 3, wherein the core diameter of the second sub-fibre is greater than the core diameter of the first sub-fibre.

8. The laser output device as claimed in claim 7, wherein the core diameter of the second sub-fiber is 1.2 times or more the core diameter of the first sub-fiber.

9. A fiber laser, comprising:

a laser generating device for generating a laser beam;

a laser output apparatus according to any one of claims 1 to 8, wherein an input end of an output optical fiber is connected to the laser generating apparatus, and the laser beam is transmitted through the laser output apparatus to be emitted from the output end.

10. The fiber laser of claim 9, further comprising a housing, wherein the laser generating device, mode stripper and mode scrambler are secured within the housing.

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