Double-channel composite light spot laser

Abstract

The utility model discloses a double-channel composite light spot laser, which comprises a laser source for outputting fundamental frequency light, a rotatable reflecting mirror, a first frequency doubling light path and a second frequency doubling light path, wherein when the reflector is located at a first rotation angle alpha, the fundamental frequency light enters the reflector, and after being reflected, the fundamental frequency light enters the first frequency doubling light path; when the reflector is located at a second rotation angle beta, the fundamental frequency light directly enters the second frequency doubling light path without passing through the reflector; each frequency doubling light path is sequentially provided with a frequency doubling crystal, a coupling mirror and an output optical fiber, after the fundamental frequency light passes through the frequency doubling crystal, part of the fundamental frequency light is converted into frequency doubling light, and the rest of the fundamental frequency light and the frequency doubling light are coupled into the output optical fiber through the focusing mirror. The composite light spot laser provided by the utility model can realize dual-channel output, and the light spot is formed by combining two wavelengths.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of laser, especially a kind of double-channel composite spot laser. BACKGROUND

[0002] In recent years, the rapid development of high-power green laser has attracted widespread attention of scholars at home and abroad, and has been gradually applied to industrial processing, 3C electronics, medical treatment, military defense and other fields. The development of high-power green laser has attracted much attention. Compared with more common near-infrared light source, green light source has two obvious advantages in laser manufacturing: first, at short wavelengths, metals (especially copper, gold, silver and other high-reflectivity materials) have higher absorption. At room temperature, the absorption of copper to green light near 532 nm is nearly 40%, while the absorption of near-infrared laser near 1 μm is less than 5%, and the processing efficiency of green light is about 8 times that of near-infrared laser. In addition, green laser has small back reflection in the welding process, which can effectively prolong the service life of the laser compared with fiber laser. Compared with blue semiconductor laser, green laser can maintain single-mode beam quality at kilowatt-level high-power output, so it can provide lower divergence and smaller focus during processing, effectively improving the processing precision. Fiber laser technology has technical potential in generating high-power and high-brightness green laser, such as efficient heat management, good beam quality, high photoelectric conversion efficiency and low cost.

[0003] However, when using fiber laser as base frequency laser for frequency doubling, the optical conversion efficiency is low due to the cavity-out frequency doubling mode, resulting in a lot of base frequency light not being converted, so that mixed light of 1064 nm and 532 nm is output. In order to not waste the unused base frequency laser, the base frequency light is mixed and then coupled out, which can solve the problem of base frequency light not being absorbed and the problem of 1064 nm welding high-reflectivity materials. SUMMARY

[0004] In view of the above-mentioned shortcomings of the prior art, the purpose of the utility model is to provide a composite spot laser capable of realizing double-channel output and having spot formed by combination of two wavelengths.

[0005] To achieve the above-mentioned purpose and other related purposes, the utility model provides a double-channel composite spot laser, which comprises a laser source for outputting base frequency light, and further comprises a rotatable mirror, a first frequency-doubled light path and a second frequency-doubled light path.

[0006] When the mirror is at a first rotation angle α, the base frequency light is incident to the mirror and is reflected to the first frequency-doubled light path.

[0007] When the mirror is at the second rotation angle β, the fundamental light is not reflected by the mirror and directly enters the second frequency-doubled light path.

[0008] Each frequency-doubled light path is sequentially provided with a frequency-doubling crystal, a coupling mirror and an output optical fiber. After the fundamental light passes through the frequency-doubling crystal, part of the fundamental light is converted into frequency-doubled light, and the remaining fundamental light and the frequency-doubled light are coupled into the output optical fiber through the focusing mirror.

[0009] Optionally, when the mirror is at the second rotation angle, the fundamental light enters the mirror and is reflected to the second frequency-doubled light path.

[0010] Optionally, in each frequency-doubled light path, a rotatable half-wave plate is arranged in front of the frequency-doubling crystal.

[0011] Optionally, a focusing mirror is arranged behind the laser source to convert the fundamental light entering each frequency-doubled light path into a focused light beam.

[0012] Optionally, the input end of the output optical fiber is fused with an end cap.

[0013] Optionally, the composite spot laser further comprises a third frequency-doubled light path. When the mirror is at a third rotation angle γ, the fundamental light enters the mirror and is reflected to the third frequency-doubled light path.

[0014] Optionally, the rotation speed of the mirror is adjustable.

[0015] Optionally, the rotation frequency of the mirror is controlled to control the light pulses of the fundamental light entering the first frequency-doubled light path and the second frequency-doubled light path.

[0016] Optionally, the wavelength of the fundamental light is 1064 nm, and the wavelength of the frequency-doubled light is 532 nm.

[0017] Optionally, the laser source is a narrow-line-width polarization-maintaining fiber laser.

[0018] As described above, the double-channel composite spot laser provided by the application is provided with two frequency-doubled light path channels. In each frequency-doubled light path channel, the frequency-doubling crystal couples the fundamental light and the frequency-doubled light into the output optical fiber, which improves the energy utilization efficiency. The composite spot formed by the two wavelengths is beneficial to improving the welding speed, adjusting the depth of the molten pool and suppressing the welding spatter. Each of the two frequency-doubled light path channels has an independent output optical fiber. The laser output by the laser source adjusts the time proportion of the fundamental light entering the two frequency-doubled light path channels according to the pulse ratio, which can realize double-channel fast switching and double-channel output based on one laser source, thereby reducing the equipment cost. BRIEF DESCRIPTION OF DRAWINGS

[0019] One or more embodiments are illustrated by way of example in the drawings and are described herein in connection with the embodiments described. These embodiments are described in connection with the drawings so that it can be understood, and are not intended to limit the scope of the embodiments to the embodiments described. The drawings are not to scale and are intended for use in conjunction with the explanations in this specification and embodiments. Identical reference numerals denote the same elements throughout the description of the drawings.

[0020] Figure 1 is a structural schematic diagram of a dual-channel composite light spot laser provided by the embodiment.

[0021] Figure 2 is a structural schematic diagram of a dual-channel composite light spot laser provided by the embodiment.

[0022] Figure 3 is an output light pulse schematic diagram of a dual-channel composite light spot laser provided by the embodiment. DETAILED DESCRIPTION

[0023] In order to facilitate the understanding of the present application, the present application will be described in more detail below in conjunction with the drawings and specific embodiments. It should be noted that when an element is described as "fixed to" another element, it can be directly on the other element or one or more intervening elements can be present therebetween. When an element is described as "electrically connected" to another element, it can be directly connected to the other element or one or more intervening elements can be present therebetween. The terms "upper", "lower", "inner", "outer", "bottom", etc. used in the specification indicate the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second", "third", etc. are only for the purpose of description and cannot be understood as indicating or implying relative importance.

[0024] Unless otherwise defined, all technical and scientific terms used in the specification are the same as those commonly understood by those skilled in the art to which the present application belongs. The terms used in the specification of the present application are only for the purpose of describing the specific embodiments and are not intended to limit the present application. The term "and / or" used in the specification includes any and all combinations of one or more related listed items.

[0025] In addition, the technical features involved in the different embodiments of the present application described below can be combined with each other as long as there is no conflict between them.

[0026] The present embodiment provides a dual-channel composite light spot laser 10, as shown in Figure 1As shown, the dual-channel composite spot laser 10 comprises a laser 11, a focusing mirror 12, a reflecting mirror 13, a first frequency-doubling light path 14 and a second frequency-doubling light path 15. Among them,

[0027] The laser 11 is used to generate a fundamental frequency light Iω, for example, a narrow-line-width polarization-maintaining fiber laser, and the output high-power-density laser is diverged through a fusion end cap to reduce the power density and prevent the fiber end face from being burned.

[0028] The focusing mirror 12 is used to converge the fundamental frequency light. Since the light beam emitted by the laser 11 is a divergent light beam, the optical power density is small, and the frequency-doubling crystal can only have a frequency-doubling effect when the power density of the laser beam is higher than the threshold value. Therefore, the focusing mirror 12 is arranged to form a convergent light beam from the divergent laser beam.

[0029] The reflecting mirror 13 is rotatably arranged, for example, assembled to a metal clamp block, and the metal clamp block is controlled to rotate by a motor. The rotation speed and rotation angle of the motor are controlled by the device software. The rotation of the reflecting mirror 13 can be controlled by the motor, and the angle of the reflecting mirror 13 can be further controlled to realize the channel selection function of the frequency-doubling light path.

[0030] The first frequency-doubling light path 14 and the second frequency-doubling light path 15 are completely the same, and each comprises a frequency-doubling crystal (142 and 152), a coupling mirror (143 and 153) and an output fiber (144 and 154). Taking the first frequency-doubling light path 14 as an example, the frequency-doubling crystal 142 is used to convert the input fundamental frequency light into frequency-doubled light. However, due to the limitation of frequency-doubling efficiency, only part of the fundamental frequency light is converted into frequency-doubled light, and the remaining part of the fundamental frequency light is emitted from the frequency-doubling crystal together with the frequency-doubled light, and the emitted light beam is a divergent light beam. In order to improve the energy utilization rate, in the embodiment, each frequency-doubling light path guides the remaining part of the fundamental frequency light together with the frequency-doubled light into the output fiber. Therefore, a beam splitter is no longer arranged, and a coupling mirror 143 is arranged instead. The coupling mirror 143 is used to establish a spatial coupling relationship between the frequency-doubling crystal 142 and the output fiber 144, and to couple the divergent composite light beam composed of two frequency light beams into the output fiber 144 with low loss. The output fiber 144 mixes and homogenizes the fundamental frequency light and the frequency-doubled light, and finally forms a composite light beam output.

[0031] Based on the above light path structure of the composite spot laser 10, as shown in FIG. 2, Figure 1As shown, when the mirror 13 is at the first rotation angle a, the mirror 13 reflects the fundamental frequency light to the first frequency-doubled light path 14, at this time, the first frequency-doubled light path 14 works, and the second frequency-doubled light path 15 does not work. The narrow line width linearly polarized fundamental frequency light enters the first frequency-doubled light path, and the focusing mirror 12 focuses the fundamental frequency light into the frequency-doubled crystal for frequency doubling. The frequency-doubled light (for example, green light of 532 nm) generated by frequency doubling and the unused fundamental frequency light (for example, near-infrared light of 1064 nm) will be coupled into the output optical fiber with an end cap through the coupling mirror group (for example, the coupling lens group is coated with antireflection film of 1064 nm and 532 nm) for transmission. Similarly, when the mirror 13 is at the second rotation angle β, the mirror 13 does not reflect, at this time, the first frequency-doubled light path 14 does not work, and the second frequency-doubled light path 15 works. Similarly, the narrow line width linearly polarized fundamental frequency light enters the first frequency-doubled light path, and the focusing mirror 12 focuses the fundamental frequency light into the frequency-doubled crystal for frequency doubling. The frequency-doubled light (for example, green light of 532 nm) generated by frequency doubling and the unused fundamental frequency light (for example, near-infrared light of 1064 nm) will be coupled into the output optical fiber with an end cap through the coupling mirror group (for example, the coupling lens group is coated with antireflection film of 1064 nm and 532 nm) for transmission.

[0032] In some embodiments, as shown, a half-wave plate (141 and 151) can also be arranged in each frequency-doubled light path, and the half-wave plate (141 and 151) can be arranged to rotate. The frequency-doubling efficiency of the frequency-doubled crystal (142 and 152) is related to the polarization direction of the incident fundamental frequency light Iω. In fact, only linearly polarized light with a specific polarization direction can be incident on the frequency-doubled crystal (142 and 152) at a certain specific angle to obtain optimal frequency-doubling efficiency. The polarization direction and the incident angle when the frequency-doubling efficiency is optimal are defined as the phase matching direction of the frequency-doubled crystal (142 and 152). The frequency-doubling efficiency of the frequency-doubled crystal (142 and 152) can be adjusted by adjusting the linearly polarized light direction of the incident fundamental frequency light Iω. The half-wave plate (141 and 151) can adjust the linearly polarized light direction of the fundamental frequency light. When the half-wave plate (141 and 151) is at different rotation angles, the light vector direction of the fundamental frequency light can correspondingly deflect, that is, by rotating the half-wave plate (141 and 151), the linearly polarized light direction of the fundamental frequency light Iω can be changed, and the frequency-doubling efficiency can be further changed. And thereby control the power ratio of the fundamental frequency light and the frequency-doubled light in the composite light beam output by the output optical fiber, thereby increasing the diversity of parameter matching in various processing scenarios. For example, in the laser welding application scenario, a composite light beam with a high power ratio of 532 nm wavelength is used for preheating. When the welding material is in a molten state, the half-wave plate is rotated to adjust the power ratio, and the power ratio of 1064 nm wavelength is increased to form a deep spoon hole and improve the welding effect on high-reflectivity materials.

[0033] In some embodiments, as shown, Figure 2As shown, a third frequency-doubled light path 16 can also be provided, and the light path structure of the third frequency-doubled light path is the same as that of the first frequency-doubled light path 14 and the second frequency-doubled light path 15, and includes a frequency-doubled crystal 162, a coupling mirror 163, and an output optical fiber 164. When the mirror 13 is at a third rotation angle γ, the mirror 13 reflects the fundamental light to the third frequency-doubled light path 16 for transmission, and the composite light beam is output by the third frequency-doubled light path 16, thereby achieving three-channel output of one laser source, so that one laser can process the products of three workstations, and the utilization rate of the laser is improved. Similarly, more frequency-doubled light paths can be provided, and the mirror can rotate the fundamental light to each frequency-doubled light path at a specific rotation angle.

[0034] In some embodiments, as shown, the output pulse of the laser 11 is controlled, and the high-frequency rotating mirror is synchronized to quickly switch the frequency-doubled light path channel, so that one laser corresponds to two output channels, the utilization rate of the laser is improved, and the time proportion of the mirror at each rotation angle is also controlled, so that the pulse waveform and power ratio of the laser output by each frequency-doubled light path are flexibly controlled. Figure 3

[0035] It should be noted that in the above-mentioned dual-channel composite spot laser 10, the focusing mirror 12 is located between the laser and the mirror, and in actual application, the focusing mirror 12 can also be arranged after the mirror. Moreover, the focusing mirror 12 is used for converging the light beam, and in actual application, the lens group that bears the converging function is a lens group composed of a collimating lens and a focusing lens, and at this time, the mirror can also be arranged between the collimating lens and the focusing lens.

[0036] In summary, the composite spot laser provided by the present application focuses the frequency-doubled light and the fundamental light that is not frequency-doubled to form a composite light beam, which combines the unused frequency-doubled light source and improves the energy utilization rate. Moreover, the efficiency of converting the fundamental light into frequency-doubled light by the frequency-doubled crystal is adjusted by the half-wave plate, so that the energy proportion of each wavelength part of the formed composite light beam is adjusted, thereby adapting to different processing scenes, which is beneficial to the improvement of the welding speed, the adjustment of the molten pool depth, and the suppression of the welding spatter. Therefore, the present application effectively overcomes the various shortcomings in the prior art and has high industrial utilization value.

[0037] The above-mentioned embodiments only exemplarily illustrate the principles and effects of the present application, and are not used to limit the present application. Any person skilled in the art can modify or change the above-mentioned embodiments without departing from the spirit and scope of the present application. Therefore, all equivalent modifications or changes completed by those skilled in the art without departing from the spirit and technical thought disclosed by the present application should be covered by the claims of the present application.​

Claims

1. A dual-channel composite spot laser comprising a laser source for outputting fundamental light, characterized in that, Also comprising: a rotatable mirror, a first frequency-doubled light path and a second frequency-doubled light path; wherein, when the mirror is at a first rotation angle, the fundamental light is incident to the mirror and then to the first frequency-doubled light path after being reflected; when the mirror is at a second rotation angle, the fundamental light is directly incident to the second frequency-doubled light path without the mirror; each frequency-doubled light path is sequentially provided with a frequency-doubled crystal, a coupling mirror and an output fiber, and after the fundamental light passes through the frequency-doubled crystal, part of the fundamental light is converted into frequency-doubled light, and the remaining part of the fundamental light and the frequency-doubled light are coupled into the output fiber through a focusing mirror.

2. The dual-channel composite spot laser of claim 1, wherein, In each frequency-doubled light path, a rotatable half-wave plate is arranged in front of the frequency-doubled crystal.

3. The dual-channel composite spot laser according to claim 1 or 2, characterized in that, when the mirror is at a second rotation angle, the fundamental light is incident to the mirror and then to the second frequency-doubled light path after being reflected; 4. The dual-channel composite spot laser of claim 1 or 2, wherein, a focusing mirror is arranged behind the laser source to convert the fundamental light incident to each frequency-doubled light path into a focused light beam.

5. The dual-channel composite spot laser of claim 1 or 2, wherein, The input end of the output fiber is fused with an end cap.

6. The dual-channel composite spot laser of claim 1 or 2, wherein, The composite spot laser is further provided with a third frequency-doubled light path, and when the mirror is at a third rotation angle γ, the fundamental light is incident to the mirror and then to the third frequency-doubled light path after being reflected.

7. The dual-channel composite spot laser of claim 1 or 2, wherein, The rotation speed of the mirror is adjustable.

8. The dual-channel composite spot laser of claim 7, wherein, The rotation frequency of the mirror is controlled to control the light pulses of the fundamental light incident to the first frequency-doubled light path and the second frequency-doubled light path.

9. The dual-channel composite spot laser of claim 1 or 2, wherein, The wavelength of the fundamental light is 1064nm, and the wavelength of the frequency-doubled light is 532nm.

10. The dual-channel composite spot laser of claim 1 or 2, wherein, The laser source adopts a narrow-line-width polarization-maintaining fiber laser.

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