Laser and high-brightness fiber laser processing equipment

Abstract

The utility model relates to a laser and high-brightness fiber laser processing equipment, the laser comprises a signal beam combiner, an energy transmission optical cable and N groups of laser modules, N is an odd number greater than or equal to 3; the central wavelengths of lasers output by the laser modules are different, and each laser module comprises a plurality of independent laser units; a group of laser modules with the largest number of laser units is used as a central group; the other groups of laser modules serve as edge groups; and the edge group is positioned at the edge of the central group and is connected with the input end of the signal beam combiner, so that the stimulated Raman scattering intensity of the output laser beam combined by the signal beam combiner is obviously reduced. According to the laser beams output by the laser, the superposed stimulated Raman scattering intensity is far smaller than the stimulated Raman scattering intensity of the combined beams of the laser modules with the same number and the same central wavelength, so that the laser can be transmitted in an energy transmission optical cable with a thinner fiber core and smaller NA, and the laser has higher brightness.

Description

Technical Field

[0001] The utility model relates to the technical field of laser processing, in particular to a laser and a high-brightness fiber laser processing device. Background Technique

[0002] Nowadays, fiber lasers have been widely used in the fields of industry, scientific research, medical treatment, military, etc. For continuous fiber lasers, high power and high brightness are two development directions. In recent years, high-power fiber lasers have developed rapidly, and fiber lasers with more than one hundred thousand watts have emerged in the market. Such high-power fiber lasers are all realized by using large-core fibers to reduce the power density of the laser. In this way, the power density of high-power fiber lasers is even lower than that of some lower-power high-brightness fiber lasers, and in addition, it will cause a decline in beam quality, which greatly reduces the practicability of high-power fiber lasers. Therefore, simply increasing the power of fiber lasers is of little significance. More importantly, it is to improve their brightness. To improve brightness, it is necessary to simultaneously increase the power density of the laser and reduce the divergence angle of the laser under the same power. The biggest difficulty among them is to overcome the nonlinear effect, and for continuous fiber lasers, it is to increase the stimulated Raman scattering threshold.

[0003] Chinese patent document CN216488999U discloses a fiber laser, which includes a first cladding light stripper, a forward combiner, a first reflection grating, a first tilted grating, a gain fiber, a second tilted grating, a second reflection grating, a reverse combiner, and a second cladding light stripper connected in sequence along the optical path. It places the tilted grating between the reflection grating and the gain fiber, so that the Raman light generated in the gain cavity is reflected into the cladding before transmission and amplification, and then stripped by the cladding light stripper, suppressing the influence of stimulated Raman scattering on the laser output power and increasing the threshold of stimulated Raman scattering. The defects and deficiencies of this fiber laser are as follows: This fiber laser increases a tilted grating in the optical path of the fiber laser to achieve an increase in the stimulated Raman scattering threshold. However, the power that the tilted grating can withstand is still relatively low, and the Raman suppression ratio improvement is not high, which results in a relatively limited increase in the stimulated Raman scattering threshold of the fiber laser.

[0004] Therefore, there is an urgent need to provide a laser and a high-brightness fiber laser processing device that can significantly increase the stimulated Raman scattering threshold. Content of the Utility Model

[0005] (1) Technical Problems to be Solved

[0006] In view of the above-mentioned shortcomings and deficiencies of the prior art, the utility model provides a laser and a high-brightness fiber laser processing device, which solve the technical problem that the existing fiber lasers have a limited increase in the stimulated Raman scattering threshold and cannot significantly improve the brightness.

[0007] (2) Technical Solution

[0008] To achieve the above object, the main technical solutions adopted by the present utility model include:

[0009] In a first aspect, an embodiment of the present utility model provides a laser for a high-brightness fiber laser processing device, including: a signal combiner, an energy transmission optical cable, and N sets of laser modules, where N is an odd number greater than or equal to 3; the central wavelengths of the lasers output by each set of laser modules are different, and each set of laser modules includes a plurality of independent laser units;

[0010] The set of laser modules with the largest number of laser units is taken as the central group; the other sets of laser modules are taken as the edge groups;

[0011] The edge groups are located at the edge of the central group and are all connected to the input end of the signal combiner, so that the stimulated Raman scattering intensity of the output laser after the signal combiner combines is lower than the stimulated Raman scattering intensity of the combination of the laser modules composed entirely of the laser units of the central group with the same power;

[0012] The output end of the signal combiner is connected to one end of the energy transmission optical cable, and the other end of the energy transmission optical cable is connected to the laser head of the high-brightness fiber laser processing device.

[0013] Optionally, the 3dB wavelength bandwidths of the fiber lasers output by the N sets of laser modules are the same and are all L, and the wavelength difference between the fiber lasers output by adjacent two sets of laser modules is between L - 10nm.

[0014] Optionally, the laser unit includes a pump source, a pump combiner, a high reflector grating, an active optical fiber, a low reflector grating, and an output optical fiber connected in sequence along the optical path.

[0015] Optionally, the number of arms of the signal combiner is greater than the total number of sets of laser modules, and the power borne by a single arm of the signal combiner is greater than the power of each set of laser modules.

[0016] In a second aspect, an embodiment of the present utility model provides a high-brightness fiber laser processing device, including the above-mentioned laser and a laser head;

[0017] The laser head includes a mirror base, a first moving component, a second moving component, a collimating mirror, a first focusing mirror, and a second focusing mirror;

[0018] An optical path channel is arranged inside the mirror base, and the collimating mirror, the second moving component, and the first moving component are sequentially arranged along the transmission direction of the laser beam in the optical path channel;

[0019] The first focusing mirror is arranged on the first moving component, and the first moving component can drive the first focusing mirror to move along a direction perpendicular to the optical path channel, so as to move into or out of the optical path channel;

[0020] A second focusing mirror is provided on the second moving component, and the second moving component can drive the second focusing mirror to move along a direction perpendicular to the optical path channel, so as to move into or out of the optical path channel.

[0021] Optionally, the collimating mirror and the first focusing mirror form a first collimating and focusing mirror group, and the collimating and focusing ratio of the first collimating and focusing mirror group is greater than 1;

[0022] The collimating mirror and the second focusing mirror form a second collimating and focusing mirror group, and the collimating and focusing ratio of the second collimating and focusing mirror group is less than 1.

[0023] Optionally, the focal length of the collimating mirror is 100 mm, the focal length of the first focusing mirror is 50 mm, and the focal length of the second focusing mirror is 200 mm.

[0024] Optionally, an anti-reflection window is provided at the output end cap of the collimating mirror, the first focusing mirror, the second focusing mirror, and the energy transmission optical cable.

[0025] (III) Beneficial effects

[0026] The beneficial effects of the present utility model are as follows: The laser for a high-brightness fiber laser processing device of the present utility model includes: a signal combiner, an energy transmission optical cable, and N groups of laser modules, where N is an odd number greater than or equal to 3; the central wavelengths of the laser outputs of each group of laser modules are different, and each group of laser modules includes a plurality of independent laser units; the group of laser modules with the largest number of laser units is used as the central group; the other groups of laser modules are used as the edge groups; the edge groups are located at the edge of the central group and are all connected to the input end of the signal combiner, so that the stimulated Raman scattering intensity of the output laser after beam combination by the signal combiner is lower than the stimulated Raman scattering intensity of beam combination of a laser module composed entirely of the laser units of the central group with the same power; the output end of the signal combiner is connected to one end of the energy transmission optical cable, and the other end of the energy transmission optical cable is connected to the laser head of the high-brightness fiber laser processing device. Compared with the prior art, since the central group has the largest number of laser units, and the edge groups are located at the edge of the central group and are all connected to the input end of the signal combiner, after the fiber lasers output by N groups of laser modules with different central wavelengths are power combined by the signal combiner, the wavelength is equal to the wavelength of the central group with the largest number of laser units, and the superimposed stimulated Raman scattering intensity is much smaller than the stimulated Raman scattering intensity of beam combination of laser modules with the same central wavelength and the same number. Therefore, the laser can be transmitted in an energy transmission optical cable with a finer fiber core and a smaller NA, so that the laser has higher brightness.

[0027] The high-brightness fiber laser processing equipment of the present utility model, since the laser head includes a first moving component, a second moving component, a collimating mirror, a first focusing mirror and a second focusing mirror, the first moving component can drive the first focusing mirror to move along a direction perpendicular to the optical path channel, so as to move into or out of the optical path channel, and the second moving component can drive the second focusing mirror to move along a direction perpendicular to the optical path channel, so as to move into or out of the optical path channel. Compared with the prior art, the collimating mirror and the first focusing mirror can form a first collimating and focusing mirror group, and the collimating and focusing ratio of the first collimating and focusing mirror group is greater than 1, so as to achieve a smaller beam waist diameter under the same brightness laser beam; the collimating mirror and the second focusing mirror can form a second collimating and focusing mirror group, and the collimating and focusing ratio of the second collimating and focusing mirror group is less than 1, which can achieve a smaller divergence angle under the same brightness laser beam, so as to meet the application requirements of multiple scenarios. Description of the Drawings

[0028] Figure 1 It is a schematic structural diagram of the high-brightness fiber laser processing equipment of the present utility model.

[0029] Figure 2 It is a schematic internal structure diagram of the laser head of the high-brightness fiber laser processing equipment of the present utility model;

[0030] Figure 3 It is another schematic internal structure diagram of the laser head of the high-brightness fiber laser processing equipment of the present utility model.

[0031]

Description of the Reference Numerals

[0032] 1: Laser; 11: Laser module; 12: Signal combiner; 13: Energy transmission optical cable;

[0033] 2: Laser head; 21: Collimating mirror; 22: First focusing mirror; 23: Second focusing mirror. Detailed Embodiment

[0034] In order to better explain the present utility model for easy understanding, the present utility model will be described in detail below with reference to the drawings through specific embodiments.

[0035] Referring to Figure 1 、 Figure 2 and Figure 3 , this embodiment provides a laser for a high-brightness fiber laser processing equipment. The laser 1 includes a signal combiner 12, an energy transmission optical cable 13 and N groups of laser modules 11, where N is an odd number greater than or equal to 3; the central wavelengths of the lasers output by each group of laser modules 11 are different, and each group of laser modules 11 includes a plurality of independent laser units;

[0036] The group of laser modules 11 with the largest number of laser units is used as the central group; the other groups of laser modules 11 are used as the edge groups;

[0037] The edge groups are located at the edges of the central group and are all connected to the input end of the signal combiner 12, so that the stimulated Raman scattering intensity of the output laser after beam combination by the signal combiner 12 is lower than that of the stimulated Raman scattering intensity of the beam combination of the laser module 11 with the same power and all composed of the laser units of the central group;

[0038] The output end of the signal combiner 12 is connected to one end of the energy transmission optical cable 13, and the other end of the energy transmission optical cable 13 is connected to the laser head 2 of the high-brightness fiber laser processing device. It should be noted that the central wavelengths of the laser units belonging to the same group of laser modules 11 are the same, and the central wavelengths between the laser units of different groups of laser modules 11 are different.

[0039] For the laser 1 used in the high-brightness fiber laser processing device in this embodiment, since N groups of laser modules 11, a signal combiner 12, and an energy transmission optical cable 13 are adopted, wherein the central wavelengths of the lasers output by each group of laser modules 11 are different, and each group of laser modules 11 includes a plurality of independent laser units; the group of laser modules 11 with the largest number of laser units is used as the central group; the other groups of laser modules 11 are used as edge groups; the edge groups are located at the edges of the central group and are all connected to the input end of the signal combiner 12, so that the stimulated Raman scattering intensity of the output laser after beam combination by the signal combiner 12 is lower than that of the stimulated Raman scattering intensity of the beam combination of the laser module 11 with the same power and all composed of the laser units of the central group; the N groups of laser modules 11 with different central wavelengths input multiple beams of fiber lasers with different wavelengths into the signal combiner 12, and after being combined by the signal combiner 12, they are input into the energy transmission optical cable 13, and the energy transmission optical cable 13 then outputs the combined fiber laser to the laser head 2. Compared with the prior art, since the central group has the largest number of laser units, the fiber lasers output by the N groups of laser modules 11 are power combined by the signal combiner 12, and the wavelength is equal to the wavelength of the central group with the largest number of laser modules 11, and the superimposed stimulated Raman scattering intensity is much smaller than that of the beam combination of the same number of laser modules with the same central wavelength. Therefore, this laser can be transmitted in the energy transmission optical cable 13 with a thinner core and a smaller NA, so that the laser has a higher brightness. It should be noted that NA refers to the numerical aperture of the optical fiber in the energy transmission optical cable 13. It should be noted that the "same number" in the same number of laser modules with the same central wavelength means that the number of laser units is the same as the total number of laser units of the N groups of laser modules 11 in this embodiment; "the same central wavelength" means that the central wavelength is the same as the central wavelength of the laser units of the central group, and the total power of the same number of laser modules with the same central wavelength is the same as the total power of the N groups of laser modules 11 in this embodiment. That is to say, the same number of laser modules 11 with the same central wavelength is the laser module 11 with the same power as the N groups of laser modules 11 and all composed of the laser units of the central group.

[0040] Further, the 3dB wavelength bandwidths of the fiber lasers output by the N sets of laser modules 11 are the same, all being L, and the wavelength difference between the fiber lasers output by two adjacent sets of laser modules 11 is between L and 10 nm. It should be noted that the 3dB wavelength bandwidth refers to the frequency range defined when the highest point of the power spectral density drops to 1 / 2. The 3dB wavelength bandwidth L of the fiber laser is within 10 nm.

[0041] In this embodiment, the laser unit includes a pump source, a pump combiner, a high reflector grating, an active fiber, a low reflector grating, and an output fiber that are sequentially connected along the optical path. The central wavelength and 3dB wavelength bandwidth of the fiber lasers output by the N sets of laser modules 11 are determined by the low reflector grating.

[0042] In this embodiment, the number of arms of the signal combiner 12 is greater than the total number of sets of the laser modules 11, and the power borne by a single arm of the signal combiner 12 is greater than the power of each set of laser modules 11.

[0043] This embodiment also provides a high-brightness fiber laser processing device, which includes the above-mentioned laser 1 and a laser head 2. The laser head 2 includes a lens holder (not shown in the figure), a first moving assembly (not shown in the figure), a second moving assembly (not shown in the figure), a collimating mirror 21, a first focusing mirror 22, and a second focusing mirror 23.

[0044] An optical path channel is arranged inside the lens holder. The collimating mirror 21, the second moving assembly, and the first moving assembly are sequentially arranged along the transmission direction of the laser beam in the optical path channel; the first focusing mirror 22 is arranged on the first moving assembly, and it can drive the first focusing mirror 22 to move along a direction perpendicular to the optical path channel, so as to move into or out of the optical path channel; the second focusing mirror 23 is arranged on the second moving assembly, and it can drive the second focusing mirror 23 to move along a direction perpendicular to the optical path channel, so as to move into or out of the optical path channel.

[0045] The collimation-focusing ratio of the first collimation-focusing mirror group composed of the collimating mirror 21 and the first focusing mirror 22 is greater than 1, and the collimation-focusing ratio of the second collimation-focusing mirror group composed of the collimating mirror 21 and the second focusing mirror 23 is less than 1.

[0046] Further, the focal length of the collimating mirror 21 is 100 mm, the focal length of the first focusing mirror 22 is 50 mm, and the focal length of the second focusing mirror 23 is 200 mm.

[0047] It should be noted that during use, the first moving component drives the first focusing lens 22 into the optical path channel, and at the same time, the second moving component drives the second focusing lens 23 out of the optical path channel. Thus, the first collimating and focusing lens group composed of the collimating lens 21 and the first focusing lens 22 collimates and focuses the laser beam entering the optical path channel. Since the collimation and focusing ratio of the first collimating and focusing lens group is greater than 1, it can achieve a smaller beam waist diameter under the same brightness laser beam. Or, the second moving component drives the second focusing lens 23 into the optical path channel, and at the same time, the first moving component drives the first focusing lens 22 out of the optical path channel. Thus, the second collimating and focusing lens group composed of the collimating lens 21 and the second focusing lens 23 collimates and focuses the laser beam entering the optical path channel. Since the collimation and focusing ratio of the second collimating and focusing lens group is less than 1, it can achieve a smaller divergence angle under the same brightness laser beam.

[0048] Furthermore, an anti-reflection window is provided at the output end cap of the collimating lens 21, the first focusing lens 22, the second focusing lens 23, and the energy transmission optical cable 13. The anti-reflection window can ensure that the transmittance within the 30 dB wavelength range of the output laser beam is greater than 99.8%.

[0049] In the description of the present utility model, it should be understood that the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present utility model, "a plurality of" means two or more, unless otherwise specifically defined.

[0050] In the present utility model, unless otherwise clearly specified and defined, terms such as "installation", "connection", "connection", "fixation", etc. shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium; it may be the internal communication of two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0051] In the present utility model, unless otherwise clearly specified and defined, when a first feature is "on" or "under" a second feature, it may be that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, when a first feature is "above", "over" or "on top of" a second feature, it may be that the first feature is directly above or obliquely above the second feature, or it merely means that the horizontal height of the first feature is higher than that of the second feature. When a first feature is "under", "below" or "beneath" a second feature, it may be that the first feature is directly below or obliquely below the second feature, or it merely means that the horizontal height of the first feature is lower than that of the second feature.

[0052] In the description of this specification, the descriptions of terms such as "one embodiment", "some embodiments", "embodiment", "example", "specific example" or "some examples", etc., mean that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present utility model. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, without contradiction, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0053] Although the embodiments of the present utility model have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present utility model. Those of ordinary skill in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present utility model.

Claims

1. A laser for a high-brightness fiber laser processing device, characterized in that: Comprising: A signal combiner (12), an energy transmission optical cable (13), and N sets of laser modules (11), where N is an odd number greater than or equal to 3; the central wavelengths of the lasers output by each set of laser modules (11) are different, and each set of laser modules (11) includes a plurality of independent laser units; Regarding the set of laser modules (11) with the largest number of laser units as the central group; the other sets of laser modules (11) as the edge groups; The edge groups are located at the edge of the central group and are all connected to the input end of the signal combiner (12), so that the stimulated Raman scattering intensity of the output laser after beam combination by the signal combiner (12) is lower than the stimulated Raman scattering intensity of beam combination by a laser module (11) composed entirely of the laser units of the central group with the same power; The output end of the signal combiner (12) is connected to one end of the energy transmission optical cable (13), and the other end of the energy transmission optical cable (13) is connected to the laser head (2) of a high-brightness fiber laser processing device.

2. The laser for a high-brightness fiber laser processing device according to claim 1, characterized in that: The 3dB wavelength bandwidths of the fiber lasers output by the N sets of laser modules (11) are the same, all being L, and the wavelength difference between the fiber lasers output by adjacent sets of laser modules (11) is between L - 10nm.

3. The laser for high-brightness fiber laser processing equipment according to claim 1, characterized in that: The laser unit includes a pump source, a pump combiner, a high reflector grating, an active optical fiber, a low reflector grating, and an output optical fiber connected in sequence along the optical path.

4. The laser for a high-brightness fiber laser processing device according to claim 1, characterized in that: The number of arms of the signal combiner (12) is greater than the total number of sets of laser modules (11), and the power borne by a single arm of the signal combiner (12) is greater than the power of each set of laser modules (11).

5. A high-brightness fiber laser processing device, characterized in that: Including the laser (1) and the laser head (2) described in any one of claims 1 - 4; The laser head (2) includes a mirror base, a first moving assembly, a second moving assembly, a collimating mirror (21), a first focusing mirror (22), and a second focusing mirror (23); An optical path channel is arranged inside the mirror base, and the collimating mirror (21), the second moving assembly, and the first moving assembly are arranged in sequence along the transmission direction of the laser beam in the optical path channel; The first focusing mirror (22) is arranged on the first moving assembly, and the first moving assembly can drive the first focusing mirror (22) to move along a direction perpendicular to the optical path channel, so as to move into or out of the optical path channel; The second focusing mirror (23) is arranged on the second moving assembly, and the second moving assembly can drive the second focusing mirror (23) to move along a direction perpendicular to the optical path channel, so as to move into or out of the optical path channel.

6. The high-brightness fiber laser processing equipment according to claim 5, wherein: The collimating mirror (21) and the first focusing mirror (22) form a first collimating and focusing mirror group, and the collimating and focusing ratio of the first collimating and focusing mirror group is greater than 1; The collimating mirror (21) and the second focusing mirror (23) form a second collimating and focusing mirror group, and the collimating and focusing ratio of the second collimating and focusing mirror group is less than 1.

7. The high-brightness fiber laser processing equipment according to claim 6, characterized in that: The focal length of the collimating mirror (21) is 100mm, the focal length of the first focusing mirror (22) is 50mm, and the focal length of the second focusing mirror (23) is 200mm.

8. The high-brightness fiber laser processing equipment according to claim 5, wherein: Anti-reflection windows are arranged at the collimating mirror (21), the first focusing mirror (22), the second focusing mirror (23), and the output end cap of the energy transmission optical cable (13).

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