CN218940304U

CN218940304U - Laser output device and fiber laser

Info

Publication number: CN218940304U
Application number: CN202223501160.3U
Authority: CN
Inventors: 陈明; 张怡静; 王建明; 施建宏; 闫大鹏
Original assignee: Wuhan Raycus Fiber Laser Technologies Co Ltd
Current assignee: Wuhan Raycus Fiber Laser Technologies Co Ltd
Priority date: 2022-12-27
Filing date: 2022-12-27
Publication date: 2023-04-28
Anticipated expiration: 2032-12-27

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 technical field of lasers, and particularly relates to a laser output device and an optical fiber laser.

Background

The fiber laser has the advantages of high conversion efficiency, good beam quality, compact structure, high reliability and the like, and is widely applied to the industrial processing fields of laser welding, cladding, cutting, drilling and the like.

The pumping source of the fiber laser couples the pumping light into the inner cladding of the active fiber through the beam combiner, provides energy for the active fiber, generates signal light in the fiber core, feeds back the mode-selecting amplification through the resonant cavity, and outputs. However, since the active optical fiber has a limited length, the pump light in the cladding cannot be completely absorbed, and the pump light in a part of the cladding exists in a spiral form, the pump light is contained in the cladding. In addition, due to imperfections in fusion splicing of the fibers, and defects in the fibers themselves, some of the signal light may leak into the cladding, also resulting in signal light in the cladding. The presence of signal light in the cladding layer can lead to unstable laser energy, which is poor in beam quality of the fiber laser, seriously affects the performance of the fiber laser, and even damages the fiber laser. In the prior art, the mode stripper is generally arranged to remove the cladding light, but the small-angle cladding light cannot be removed, and the cladding light still can influence the light beam quality along with the transmission of the light path. In addition, because of the characteristics of small resistivity, smooth surface, absorptivity to near infrared light and the like of the metal material, when the fiber laser is used for processing the metal material, the surface of the metal material reflects laser light to form return light, and the return light reenters the laser through the processing head to damage the processing head and the laser.

Disclosure of Invention

The embodiment of the application provides a laser output device and a fiber laser, so as to solve the problem that the performance of the fiber laser is affected due to poor beam quality caused by cladding light and return light in the prior art.

In a first aspect, embodiments of the present application provide a laser output device, including:

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.

Optionally, the output optical fiber includes 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.

Optionally, the output optical fiber further includes a third sub-optical fiber, the third sub-optical fiber having a fifth end and the output end, the second sub-optical fiber having a fourth end, the fourth end being fused to the fifth end, and the core diameter of the third sub-optical fiber being greater than the core diameter of the second sub-optical fiber.

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

Optionally, the core diameters of the first sub-optical fiber, the second sub-optical fiber and the third sub-optical fiber are sequentially increased.

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

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

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

In a second aspect, embodiments of the present application further provide a fiber laser, including:

a laser generating device for generating a laser beam;

the laser output device according to any one of the above claims, wherein an input end of the output optical fiber is connected with the laser emitting device, and the laser beam is transmitted by the laser output device and emitted from the output end.

Optionally, the laser device further comprises a shell, and the laser generating device, the stripper and the scrambler are fixed in the shell.

According to the laser output device and the optical fiber laser, at least two mode stripping devices and at least one mode scrambler are arranged on the output optical fiber, the mode scrambler is located between the two mode stripping devices, when the laser generating device outputs laser beams, the laser beams are transmitted along the output optical fiber, the mode stripping devices close to the laser generating device strip part of cladding light in the output optical fiber, the mode stripping devices cannot strip part of the cladding light, the mode stripping devices enter the mode scrambler, the mode stripping devices are injected into the other mode stripping device after the angle of the mode stripping devices is increased by the mode scrambler, the mode stripping devices further strip the cladding light, when laser reflected by a workpiece, namely return light, is injected into the laser output device from the output end, after the return light located in a cladding layer of the output optical fiber is stripped by the mode stripping devices close to the output end, the return light of the mode stripping devices with the small angle which cannot strip part of the cladding light and the return light after the divergence angle of the mode stripping devices is increased by the mode stripping devices, the existing cladding light and the return light due to the fact that the cladding light and the return light exist are stripped by the mode stripping devices, the quality difference is caused, the performance of the laser beam quality of the laser beam and the laser beam quality of the laser is improved, and the quality of the laser beam is improved.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings that are required to be used in the description of the embodiments will be briefly described below. It is obvious that the drawings in the following description are only some embodiments of the present application, and that other drawings may be obtained from these drawings without inventive effort to a person skilled in the art.

For a more complete understanding of the present application and the advantages thereof, reference is now made to the following descriptions taken in conjunction with the accompanying drawings. Wherein like reference numerals refer to like parts throughout the following description.

Fig. 1 is a first optical path system diagram of a fiber laser according to an embodiment of the present application.

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

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

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. It will be apparent that the described embodiments are only some, but not all, of the embodiments of the present application. All other embodiments, which can be made by those skilled in the art based on the embodiments herein without making any inventive effort, are intended to be within the scope of the present application.

The embodiment of the application provides a laser output device and a fiber laser, so as to solve the problem that the performance of the fiber laser is affected due to poor beam quality caused by cladding light and return light in the prior art. The following description will be given with reference to the accompanying drawings.

Referring to fig. 1 and fig. 2, fig. 1 is a first optical path system diagram of a fiber laser according to an embodiment of the present application, and fig. 2 is a second optical path system diagram of a fiber laser according to an embodiment of the present application.

The embodiment of the application provides a laser output device, be applicable to the fiber laser, the fiber laser can be continuous fiber laser or pulse fiber laser, this laser output device includes output fiber 100, two piece at least shells mould ware 200 and at least one mode scrambler 300, output fiber 100 has input 111 and output 132, output fiber 100's input is connected with laser generating device, output fiber is used for transmitting the laser beam of laser generating device output, from the direction of input 111 to output 132, two piece at least shells mould ware 200 interval settings, shell mould ware 200 and set up on output fiber 100, shell mould ware 200 is used for stripping the return light in cladding light and the cladding, set up one mode scrambler 300 on the output fiber 100 between the adjacent shell mould ware 200.

It will be appreciated that a plurality of stripper 200 and at least one scrambler 300 may be provided along the length of the output optical fiber 100, e.g., N stripper 200 is provided, N-1 scramblers 300 are provided, stripper 200 is alternatively provided with scrambler 300, and stripper 200 is provided on the side of output optical fiber 100 near the laser generating device, stripper 200 is provided on the side near output end 132, and cladding light entering into output optical fiber 100 is sequentially stripped by a plurality of stripper 200 during the transmission from input end 111 to output end 132, wherein light of low NA (core vertical aperture) in the cladding that cannot be stripped by N-1 stripper 200 passes through N-1 scrambler 300, the beam divergence angle is increased, the beam is transmitted into the Nth mode stripper 200 and stripped by the Nth mode stripper 200, the mode stripper 200 acts on the output optical fiber 100 to enable the output optical fiber 100 to generate micro-bending stress, the coupling mode of the laser beam in the optical fiber is enhanced, the beam divergence angle is increased, the purpose of homogenizing the light spot energy distribution is achieved, the density of the laser is reduced, the SRS (stimulated Raman scattering) threshold value of a specific laser is improved, after the mode strippers 200 are matched with the mode scrambler 300, cladding light in the output optical fiber 100 is removed as much as possible, the laser beam is output from the output end 132, the influence of the cladding light on the beam quality of the laser beam is reduced, and the beam quality of the laser beam is improved. The laser reflected from the workpiece to be processed is 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, the return light is stripped by the Nth mould stripper 200, the non-stripped part enters the N-1 mould scrambler 300, after passing through the N-1 mould scrambler 300, the angle of divergence of the return light is increased, and then enters the N-1 mould stripper 200, so that the return light in the cladding layer is removed as much as possible, the influence of the return light on the laser is reduced, and the performance of the laser is improved.

The number of the stripper 200 and the scrambler 300 may be set according to the length of the output optical fiber 100, and the greater the number of the stripper 200 and the scrambler 300, the better the effect of stripping the clad light and the return light, in order to achieve both performance and cost.

Referring to fig. 2, in the embodiment of the present application, two stripper units 200 and one scrambler 300 are disposed along the length direction of the output optical fiber 100, which are respectively a first stripper unit 210 and a second stripper unit 220, the first stripper unit 210 is close to the input end 111, the second stripper unit 220 is close to the output end 132, the scrambler 300 is disposed between the first stripper unit 210 and the second stripper unit 220, and the first stripper unit 210 has the same structure as the second stripper unit 220.

As a variant, three stripper 200 and two scramblers 300 are provided along the length direction of the output optical fiber 100, namely, a first stripper 210, a second stripper 220 and a third stripper, respectively, the first scramblers and the second scramblers are provided at intervals in sequence from the input end 111 to the output end 132 along the length direction of the output optical fiber 100, the first scramblers are located between the first stripper 210 and the second stripper 220, and the second scramblers are located between the second stripper 220 and the third stripper. The plurality of scramblers 300 and the plurality of stripper 200 are provided to strip cladding light and return light as much as possible, thereby improving the beam quality of the laser.

The stripper 200 is prepared from a portion of the output optical fiber 100, and a bare fiber segment is manufactured by a stripping method, such as a mechanical stripping method, a chemical stripping method, or a thermal stripping method, and at least one layer of coating material is coated on the bare fiber segment, wherein the coating material includes, but is not limited to, a photosensitive paste having a refractive index greater than that of the cladding layer of the output optical fiber 100, the cladding light is refracted out from the coating layer, and the cladding light or the return light is stripped. The mode stripper 200 is prepared from the output optical fiber 100, so that the welding position of the output optical fiber 100 is reduced, the generation of cladding light is reduced, and the beam quality is improved.

Referring to fig. 3, fig. 3 is a third optical path system diagram of the fiber laser according to the embodiment of the present application.

In some embodiments, the output optical fiber 100 at least includes a first sub-optical fiber 110 and a second sub-optical fiber 120, where the first sub-optical fiber 110 has an input end 111 and a second end 112, a mode stripper 200, i.e., a first mode stripper 210, is disposed on the first sub-optical fiber 110, the second sub-optical fiber 120 has a third end 121, the second end 112 is in butt joint with the third end 121, a mode stripper 200, i.e., a second mode stripper 220, is disposed on the second sub-optical fiber 120, and a mode scrambler 300 is disposed between the first mode stripper 210 and the second end 112 or between the third end 121 and the second mode stripper 220.

The first sub-optical fiber 110 and the second sub-optical fiber 120 may be the same type of optical fiber, or may be different optical fibers, for example, the first sub-optical fiber 110 has a cladding and a core, the cladding wraps the core, the second sub-optical fiber 120 has a core, a cladding and a coating, the cladding wraps the core, the coating wraps the cladding, the mode scrambler 300 and the second mode stripper 220 are disposed on the second sub-optical fiber 120, and the second sub-optical fiber 120 has high structural strength, which 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 further includes a third sub-optical fiber 130, the third sub-optical fiber 130 has a fifth end 131 and an output end 132, the second sub-optical fiber 120 has a fourth end 122, the fourth end 122 is fused to the fifth end 131, and the core diameter of the third sub-optical fiber 130 is larger than the core diameter of the second sub-optical fiber 120.

It can be understood that, when the laser beam is transmitted along the output direction, the core diameter of the second sub-optical fiber 120 is smaller than the core diameter of the third sub-optical fiber 130, the core light of the second sub-optical fiber 120 enters the third sub-optical fiber 130 and is output from the output end 132, so as to ensure the quality of the laser beam, when the return light is transmitted, the return light is transmitted from the third sub-optical fiber 130 to the second sub-optical fiber 120 side, and the diameter of the third sub-optical fiber 130 is larger than the diameter of the second sub-optical fiber 120, so that the return light in the cladding layer of the third sub-optical fiber 130 enters the cladding layer of the second sub-optical fiber 120, part of the return light in the core of the third sub-optical fiber 130 enters the cladding layer of the second sub-optical fiber 120, and is stripped by the stripper 200, so that part of the return light in the core is stripped off, and the return light is prevented from entering the resonant cavity of the laser along the reverse transmission of the laser beam, so as to ensure the normal operation of the laser device and the laser.

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

It can be understood that the first sub-optical fiber 110, the second sub-optical fiber 120 and the third sub-optical fiber 130 are coaxially arranged, so that the eccentricity of the laser beam is avoided and the beam quality of the laser beam is improved.

Based on the above embodiment, as shown in fig. 2, the core diameters of the first sub-optical fiber 110, the second sub-optical fiber 120, and the third sub-optical fiber 130 are sequentially increased.

It will be appreciated that the core diameter of the first sub-optical fiber 110 is smaller than the core diameter of the second sub-optical fiber 120, the core diameter of the second sub-optical fiber 120 is smaller than the core diameter of the third sub-optical fiber 130, and during return light transmission, part of the return light in the core of the third sub-optical fiber 130 enters the cladding of the second sub-optical fiber 120, is stripped by the second stripper 220, part of the return light in the core of the second sub-optical fiber 120 enters the cladding of the first sub-optical fiber 110, and is stripped by the first stripper 210, so that the return light in the core of the output optical fiber 100 is stripped as much as possible, and the influence of the return light on the laser is reduced.

The diameters of the fiber cores of the first sub-optical fiber 110, the second sub-optical fiber 120 and the third sub-optical fiber 130 are sequentially and gradually increased, so that the coaxial arrangement of the first sub-optical fiber 110, the second sub-optical fiber 120 and the third sub-optical fiber 130 is facilitated, the processing is convenient, the eccentricity of a laser beam is avoided, and the quality of the laser beam is improved while the return light is reduced.

In addition to the above embodiments, the second sub-optical fiber 120 and the third sub-optical fiber 130 are both passive optical fibers.

It can be understood that the second sub-optical fiber 120 and the third sub-optical fiber 130 are all passive optical fibers, and have a core, a cladding and a coating layer, the cladding wraps the core, the coating layer wraps the cladding, the welding operation of the second sub-optical fiber 120 and the third sub-optical fiber 130 is simple, and the optical fiber has high structural strength.

Based on the above embodiment, referring to fig. 3, the core diameter of the second sub-optical fiber 120 is larger than that of the first sub-optical fiber 110.

It will be appreciated 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 core diameter of the second sub-fiber 120 is equal to the core diameter of the third sub-fiber 130, and during return light transmission, part of the return light in the core of the second sub-fiber 120 enters the cladding of the first sub-fiber 110 and is stripped by the first stripper 210, so that the return light in the core of the output fiber 100 is stripped as much as possible, and the influence of the return light on the laser is reduced.

Based on the above embodiment, as shown in fig. 3, the core diameter of the second sub-optical fiber 120 is 1.2 times or more the core diameter of the first sub-optical fiber 110.

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

As a modification, referring to fig. 2, when the third sub-optical fiber 130 is provided, the core diameter of the second sub-optical fiber 120 is 1.2 times or more the core diameter of the first sub-optical fiber 110, the core diameter of the third sub-optical fiber 130 is 1.2 times or more the core diameter of the second sub-optical fiber 120, the cladding diameter of the first sub-optical fiber 110 and the cladding diameter of the second sub-optical fiber 120 may be the same as the cladding diameter of the third sub-optical fiber 130, and the output optical fiber 100 has an attractive appearance and is easy to process.

Referring to fig. 1, fig. 2, and fig. 3, an embodiment of the present application further provides a fiber laser, including: the laser generator 400 and the laser output device according to any one of the above, wherein the laser generator 400 is used for generating a laser beam, the input end 111 of the output optical fiber 100 of the laser output device is connected to the laser generator 400, and the laser beam is transmitted through the laser output device and emitted from the output end.

It can be understood that the laser output device can strip the light in the cladding layer and the return light entering the cladding layer at the same time, so that the quality of the light beam output by the laser is improved, and the service life of the laser is prolonged.

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

It can be appreciated that, in this embodiment of the present application, the laser generating device 400, the mode stripper 200 and the mode scrambler 300 are all integrated in the housing, the fiber laser further includes a heat dissipation mechanism, a monitoring module, a control module and the like, and the mode stripper 200 and the mode scrambler 300 can share the heat dissipation mechanism of the fiber laser, so that the heat dissipation design is not required to be separately performed, the equipment investment is reduced, and the cost is reduced.

In the foregoing embodiments, the descriptions of the embodiments are emphasized, and for parts of one embodiment that are not described in detail, reference may be made to related descriptions of other embodiments.

In the description of the present application, the terms "first," "second," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more features.

The laser output device and the fiber laser provided by the embodiments of the present application are described in detail, and specific examples are applied herein to illustrate the principles and embodiments of the present application, and the description of the above embodiments is only used to help understand the method and core idea of the present application; meanwhile, as those skilled in the art will vary in the specific embodiments and application scope according to the ideas of the present application, the contents of the present specification should not be construed as limiting the present application in summary.

Claims

1. A laser output device, comprising:

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

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.