TWI842228B - Fiber Optic Output Hybrid Laser System - Google Patents

Abstract

A fiber optic output hybrid laser system includes at least one blue laser module and one infrared fiber optic laser module to emit a blue laser beam and an infrared laser beam respectively; an optical fiber combiner combines the two laser beams, and an output optical component collimates the beams and generates two focal points of wavelengths; wherein the output blue laser beam and the infrared laser beam are coaxial and emit light in an overlapping manner, and the BPP is less than 10 mm xmrad; the power of the blue light is between 20 and 100 W, and the power of the infrared light is between 500 and 5000 W, and the focus of the blue light will be formed on the surface of the workpiece to be processed, while the focus of the infrared light is 1 to 3 mm away from the workpiece and penetrates into the workpiece to be processed, so as to obtain the best welding and layer cladding effect.

Description

Fiber Optic Output Hybrid Laser System

The present invention relates to laser processing, in particular to a fiber optic output mixed light laser system that uses two wavelength laser light sources to combine optical fibers so that the output light beams are coaxial and emit light in an overlapping manner, and generates two wavelength focal points through optical components to improve the stability of the laser processing process.

According to the report, laser light has good directivity and concentration, and laser processing does not cause tool wear and environmental pollution. Therefore, metal welding with laser is an important issue in today's industrial manufacturing. However, it is found that highly reflective metals such as copper, gold, silver, and aluminum have different surface absorption rates for laser light of various wavelengths at an absolute temperature of 295K. The change is shown in Figure 1. Among them, the surface absorption rate of copper material (Cu) for near-infrared laser (Near-IR) with a wavelength of about 1060nm is 5%, while the surface absorption rate of copper material (Cu) for blue laser with a wavelength of about 450nm can reach 65%. Next, as shown in Figure 2, when infrared (IR) laser is used to heat copper, the material temperature shows a dual-state phenomenon relative to the laser power. When the copper reaches the melting point, its melting temperature (absorption rate) will increase by 5 times. At this time, the power of the infrared (IR) laser must be quickly reduced to prevent the surface temperature from entering the boiling area. Although there is a molten pool (liquid metal) on the surface at this time, the change in laser power may cause the molten pool to be interrupted, thus affecting the stability of the welding process. Obviously, if infrared (IR) laser is used to weld copper materials, it is easy to cause poor quality problems such as molten pool interruption and spattering.

In recent years, the international trend of replacing infrared laser with blue laser for copper sheet welding has gradually emerged. However, blue laser is composed of many blue semiconductor laser beams. The higher the power, the more semiconductor lasers need to be combined, and the beam quality also decreases. For example, the beam parameter product (BPP) of 500W blue laser has reached 40mm x mrad, due to the small depth of field of the beam, it is not possible to weld copper plates thicker than 1mm. According to the general laser beam quality, the beam parameter product (BPP) can be used to measure the quality of the laser beam. See Figure 3, where the BPP value is obtained by multiplying the laser beam divergence angle α and the laser beam's narrowest point radius R. Therefore, the BPP value can not only quantify the quality of the laser beam, but also measure the degree to which the laser beam is focused to a small point. Since the BPP value of semiconductor lasers at high power is as high as 10 or more, the propagation characteristics and transformation characteristics of the beam will be limited.

Based on the above problems, the industry has also applied hundreds of watts of blue lasers and kilowatts of fiber lasers for spatial beam combining, but the cost is high, and spatial beam combining requires precise adjustment of optical lenses, so it has the disadvantage of poor stability, and its practicality is questioned by the industry.

Therefore, the inventors of the present invention realize that if two laser light sources with different wavelengths, blue laser and fiber laser, can be used, the combined laser beam can be focused on the welding area while reducing the laser output power and BPP value, which should further improve the process stability of copper welding; however, how to achieve the benefits of this solution has become a topic that the inventors have to actively consider.

Therefore, the main purpose of the present invention is to provide a fiber optic output mixed light laser system that can mix a high-brightness blue light module with an infrared fiber laser and output it through a single fiber.

Another purpose of the present invention is to make the output light beam effectively improve the absorption of copper metal, and have relatively high light beam quality and low processing cost, thereby improving the stability of the copper welding process.

To achieve the above-mentioned purpose, the means adopted by the present invention include: at least one blue light laser module, which emits a blue light laser beam through a blue light fiber; an infrared light fiber laser module, which emits an infrared light laser beam through an infrared light fiber; an optical fiber combiner, which is used to embed the blue light fiber and the infrared light fiber, and generate an output beam through an output optical fiber; an output optical component, which has a collimating lens and a focusing lens arranged in front and back , wherein the collimating lens is used to form the output beam into a collimated parallel beam; and the focusing lens will make the parallel beam passing through generate two focal points of wavelength, namely a first focal point and a second focal point; and the output beam generated by the output optical fiber, including the blue laser beam and the infrared laser beam, is coaxial and overlaps the light, and the beam parameter product BPP of the blue laser beam and the infrared laser beam is less than 10mm x mrad; and through the adjustment of the focusing lens, the first focal point of the blue laser beam will be formed on the surface of a material to be processed, and the second focal point of the infrared laser beam will penetrate into the material to be processed, and the distance between the first focal point and the second focal point will reach 1~3mm, so as to obtain the best welding and layer cladding effect.

According to the above-mentioned features, the blue laser module of the present invention has at least 7 blue laser diodes to excite at least 7 blue light beams with a wavelength of 400nm~670nm, an optical lens assembly, including at least 7 fast-axis collimating lenses, slow-axis collimating lenses, reflecting lenses, and a focusing lens, so that the individual blue light beams are collimated by each of the fast-axis collimating lenses and each of the slow-axis collimating lenses, and then merged into a blue laser beam in space after passing through each of the reflecting lenses, and the blue laser beam can be coupled to the core of the blue light fiber through the focusing lens.

According to the aforementioned features, the infrared fiber laser module of the present invention has a seed light source device, which uses an infrared laser diode to emit a seed laser beam with a wavelength of 1064nm, an excitation light source device, which uses a high-power semiconductor laser to emit an excitation laser beam with a wavelength of 800~980nm, a beam combiner, which couples the seed laser beam and the excitation laser beam into the fiber core of the infrared fiber to form the infrared laser beam, and an optical fiber amplifier, which amplifies the energy of the infrared laser beam.

According to the above-mentioned characteristics, the output optical fiber in the present invention has a core with a diameter of 100μm and a cladding with a diameter of 300μm.

According to the above characteristics, the wavelength of the blue laser beam in the output beam of the present invention is between 400nm~480nm, and the power is between 20~100W. The wavelength of the infrared laser beam in the output beam is between 900nm~1100nm, and the power is between 500~5000W.

With the aforementioned features, the present invention's "optical fiber output hybrid laser system" uses at least one blue laser module and one infrared fiber laser module to respectively emit a blue laser beam with a total power of less than 100 watts and an infrared laser beam with a total power of kilowatts; an optical fiber combiner combines the blue laser beam and the infrared laser beam, and an output optical component collimates the beams and generates two wavelength focal points; wherein the output blue laser beam and the infrared laser beam are coaxial and overlap, and the beam parameter product BPP is less than 10mm x mrad; the power of blue light is between 20~100W, and the power of infrared light is between 500~5000W. The focus of blue light will be formed on the surface of the material to be processed, while the focus of infrared light is 1~3mm away from it and penetrates into the material to be processed, so as to obtain the best welding and layer cladding effect; since the optical fiber beam combining used in the present invention is compared with the traditional spatial beam combining, it has a lower cost benefit; furthermore, the beam parameter product BPP of the output blue laser beam and infrared laser beam is less than 10mm x mrad, so that the combined laser beam is focused on the welding area, and its beam quality is good, which will further improve the process stability of copper welding.

10: Blue light laser module

10a: The first blue laser module

10b: Second blue laser module

11: Blue light fiber

11a: The first blue light fiber

11b: Second blue light fiber

12: Blue laser diode

13: Optical lens assembly

131: Fast axis collimator

132: Slow axis collimator

133: Reflector

134: Focusing lens

20: Infrared fiber laser module

21: Infrared optical fiber

22: Seed light source device

23: Excitation light source device,

24: beam combiner

25: Fiber optic amplifier

30: Fiber optic combiner

31: Output optical fiber

40: Output optical components

41: Collimating lens

42: Focusing lens

90: Materials to be processed

100: Implementation example of optical fiber output mixed light laser system

F: Focus

F1: First focus

F2: Second focus

L1: Blue laser beam

L11: Blue light beam

L1a: The first blue laser beam

L1b: Second blue laser beam

L2: Infrared laser beam

L21: Seed Laser Beam

L22: Excitation laser beam

L3: Output beam

L31: Parallel beam

ΔZ: Distance between positions

Figure 1 is a graph showing the absorption rate of lasers of different wavelengths on various metal surfaces.

Figure 2 is a dual-state diagram of material temperature vs. laser power when heating copper with infrared rays.

Figure 3 is a schematic diagram of the parameter product structure of the laser beam.

Figure 4 is a schematic diagram of the structure of an embodiment of the optical fiber output mixed light laser system of the present invention.

Figure 5 is a schematic diagram of the section structure of the optical fiber combiner in the present invention.

Figure 6 is a schematic diagram of the structure of the output collimator in the present invention.

Figure 7 is a schematic diagram of the state of the dual-wavelength focusing point in the present invention.

Figure 8 is a schematic diagram of the structure of the blue laser module of the present invention.

Figure 9 is a schematic diagram of the structure of the infrared fiber laser module of the present invention.

The following is a specific embodiment to illustrate the implementation of the present invention. People familiar with this art can easily understand other advantages and effects of the present invention from the content disclosed in this manual. The present invention can also be implemented or applied through other different specific embodiments. The details in this manual can also be modified and changed based on different viewpoints and applications without deviating from the spirit of the present invention.

First, the structure of the embodiment 100 of the present invention of the "optical fiber output hybrid laser system" is shown in FIG. 4, and includes: at least one blue laser module 10, which emits a blue laser beam L1 through a blue optical fiber 11; in this embodiment, the blue laser module 10 has two groups, so this embodiment includes a first blue laser module 10a connected to a first blue optical fiber 11a to emit a first blue laser beam L1a, and a second blue laser module 10b connected to a The second blue light fiber 11b emits a second blue light laser beam L1b; an infrared light fiber laser module 20 emits an infrared light laser beam L2 through an infrared light fiber 21; an optical fiber combiner 30 is used to embed the blue light fiber 11 and the infrared light fiber 21, and to generate an output light beam L3 through an output optical fiber 31 having a core with a diameter of 100 μm and a cladding with a diameter of 300 μm; in this embodiment, the optical fiber combiner 30 is embedded in the first blue light fiber 1 ... A blue light fiber 11a, a second blue light fiber 11b and the infrared light fiber 21, as shown in FIG5; an output optical component 40, as shown in FIG6, having a collimating lens 41 and a focusing lens 42 arranged in front and back, wherein the collimating lens 41 is used to form the output light beam L3 into a collimated parallel light beam L31; and the focusing lens 42 will make the parallel light beam L31 passing through generate two focal points F of wavelengths, namely a first focal point F1 and a second focal point F2. 2; and the output light beam L3 generated by the output optical fiber 31 includes the blue laser light beam L1, whose wavelength is between 400nm~480nm and whose power is between 20~100W; and the infrared laser light beam L2, whose wavelength is between 900nm~1100nm and whose power is between 500~5000W; the two light beams are coaxial and overlap, and the beam parameter product BPP of the blue laser light beam L1 and the infrared laser light beam L2 is less than 10mm x mrad; and through the adjustment of the focusing lens 42, the first focus F1 of the blue laser beam L1 will be formed on the surface of a material to be processed 90, and the second focus F2 of the infrared laser beam L2 will penetrate into the material to be processed 90, and the distance between the first focus F1 and the second focus F2 ΔZ reaches 1~3mm, as shown in Figure 7, so as to obtain the best welding and layer cladding effect.

In the present invention, the blue laser module 10, as shown in FIG. 8 , has at least 7 blue laser diodes, 9 blue laser diodes 12 in this application, to excite 9 blue light beams L11 with a wavelength of 400nm to 670nm, an optical lens assembly 13, including at least 7 fast-axis collimating lenses 131, slow-axis collimating lenses 132, and reflecting mirrors 133, In this application, there are 9 of them and a focusing lens 134, so that the individual blue light beams L11 are collimated by the fast axis collimating lenses 131 and the slow axis collimating lenses 132, and then reflected by the reflecting mirrors 133, and then merged into a blue laser beam L1 in space, and the blue laser beam L1 is focused by the focusing lens 134 and coupled into the fiber core of the blue optical fiber 11.

In the present invention, the infrared fiber laser module 20, as shown in FIG9 , has a seed light source device 22, which uses an infrared laser diode to emit a seed laser beam L21 with a wavelength of 1064nm, an excitation light source device 23, which uses a high-power semiconductor laser to emit an excitation laser beam L22 with a wavelength of 800-980nm, a beam combiner 24, which couples the seed laser beam L21 and the excitation laser beam L22 to the core of the infrared optical fiber 21 to form the infrared laser beam L2, and an optical fiber amplifier 25, which amplifies the energy of the infrared laser beam L2.

The present invention's "optical fiber output mixed light laser system" uses at least one blue laser module 10 and one infrared fiber laser module 20 to respectively emit a blue laser beam L1 with a total power less than 100 watts and an infrared laser beam L2 with a total power of 1 kilowatts; an optical fiber combiner 30 combines the blue laser beam L1 and the infrared laser beam L2, and an output optical component 40 collimates the beams and generates a focal point F of two wavelengths; wherein the output blue laser beam L1 and the infrared laser beam L2 are coaxial and overlap, and the beam parameter product BPP is less than 10 mm x mrad; the power of blue light is between 20~100W, the power of infrared light is between 500~5000W, and the first focus F1 of blue light will be formed on the surface of the material to be processed 90, while the second focus F2 of infrared light is 1~3mm away from it and penetrates into the material to be processed 90, so as to obtain the best welding and layer cladding effect; because the optical fiber beam combining used in the present invention has a lower cost than the traditional spatial beam combining; furthermore, the beam parameter product BPP of the output blue laser beam L1 and infrared laser beam L2 is less than 10mm x mrad, so that the combined laser beam is focused on the welding area, and the beam quality is good, which will further improve the process stability of copper welding.

In summary, the technical means disclosed in this invention do meet the patent requirements of inventions such as "novelty", "progressiveness" and "industrial applicability". I pray that the Bureau of Justice will grant patents to encourage inventions, without any sense of gratitude.

However, the above disclosed diagrams and descriptions are only the preferred embodiments of the present invention. Any modifications or equivalent changes made by those familiar with this technology in accordance with the spirit and scope of this case should still be included in the scope of the patent application of this case.

10: Blue light laser module

10a: The first blue laser module

10b: Second blue laser module

11: Blue light fiber

11a: The first blue light fiber

11b: Second blue light fiber

20: Infrared fiber laser module

21: Infrared optical fiber

30: Fiber optic combiner

31: Output optical fiber

40: Output optical components

100: Implementation example of optical fiber output mixed light laser system

L1: Blue laser beam

L1a: The first blue laser beam

L1b: Second blue laser beam

L2: Infrared laser beam

L3: Output beam

Claims (5)

A fiber-optic output hybrid laser system includes: at least one blue laser module, which emits a blue laser beam through a blue optical fiber; an infrared optical fiber laser module, which emits an infrared laser beam through an infrared optical fiber; an optical fiber combiner, which is used to embed the blue optical fiber and the infrared optical fiber and generate an output beam through an output optical fiber; an output optical component, which has a collimating lens and a focusing lens arranged in front and back. Lens, wherein the collimating lens is used to form the output beam into a collimated parallel beam; and the focusing lens will make the parallel beam passing through generate two focal points of wavelength, namely a first focal point and a second focal point; and the output beam generated by the output optical fiber, including the blue laser beam and the infrared laser beam, is coaxial and overlaps the light emission, and the BPP of the blue laser beam and the infrared laser beam is less than 10mm x mrad; and through the adjustment of the focusing lens, the first focal point of the blue laser beam will be formed on the surface of a material to be processed, and the second focal point of the infrared laser beam will penetrate into the material to be processed, and the first focal point and the second focal point will be 1~3mm apart, so as to obtain the best welding and layer cladding effect. As described in the first item of the patent application scope, the optical fiber output hybrid laser system, wherein the blue laser module has at least 7 blue laser diodes to excite at least 7 blue light beams with a wavelength of 400nm~670nm, an optical lens assembly, including at least 7 fast-axis collimating lenses, slow-axis collimating lenses, reflecting lenses, and a focusing lens, so that the individual blue light beams are collimated by each of the fast-axis collimating lenses and each of the slow-axis collimating lenses, and then merged into a blue laser beam in space after passing through each of the reflecting lenses, and the blue laser beam can be coupled to the fiber core of the blue light fiber through the focusing lens. As described in item 1 of the patent application, the optical fiber output mixed light laser system, wherein the infrared optical fiber laser module has a seed light source device, which uses an infrared laser diode to emit a seed laser beam with a wavelength of 1064nm, an excitation light source device, which uses a high-power semiconductor laser to emit an excitation laser beam with a wavelength of 800-980nm, a beam combiner, which couples the seed laser beam and the excitation laser beam into the fiber core of the infrared optical fiber to form the infrared laser beam, and an optical fiber amplifier, which amplifies the energy of the infrared laser beam. As described in Item 1 of the patent application, the optical fiber output hybrid laser system, wherein the output optical fiber has a core with a diameter of 100μm and a cladding with a diameter of 300μm. As described in Item 1 of the patent application, the optical fiber output hybrid laser system, wherein the wavelength of the blue laser beam in the output beam is between 400nm and 480nm, and the power is between 20 and 100W, and the wavelength of the infrared laser beam in the output beam is between 900nm and 1100nm, and the power is between 500 and 5000W.