High-power laser lighting device

Abstract

The invention relates to a high-power laser lighting device comprising: a plurality of high-power laser sources, each having a laser transmission fiber, with each laser transmission fiber having a transmitting end face; the optical fiber bundle assembly is formed by combining a plurality of laser transmission optical fibers, and each laser transmission optical fiber is surrounded by a sheath; the fly's-eye lens array is installed in the frame and composed of a plurality of sub-lenses, the sub-lenses are closely arranged, each laser transmission optical fiber in the optical fiber bundle assembly corresponds to one sub-lens in the fly's-eye lens array, and a laser beam output by each laser transmission optical fiber is coaxial with the optical axis of the corresponding sub-lens in the fly's-eye lens array. The frame on which the fly-eye lens array is mounted is adjustable relative to the transmitting end face to output an illumination beam having a predetermined divergence angle. The divergence angle of an output light beam can be freely adjusted in different illumination applications; the mixed divergence angle of the output light beam, the mixed output light beam and the light spot morphology are realized; and the output efficiency is higher.

Description

Technical Field

[0001] The present invention relates to a high-power laser lighting device, in particular to a high-power laser lighting device with a variable divergence angle. Background Art

[0002] Laser beam power scalability is crucial for high-power laser industrial applications. Scaling output to >10kW and even beyond 100kW has always been a challenge. When such power levels are required and fiber transmission is required, the typical approach is to combine many low-power laser beams and feed them into a single multimode fiber (MMF), while managing thermal, optical, and system-level limitations.

[0003] Among the different power upgrading technologies, the traditional method is based on the spatial multiplexing of the beam stack of semiconductor laser sources or fiber laser sources. More typically, a fiber combiner is used. The combiner is usually formed by fusing multiple input optical fibers 102 (e.g., multimode optical fibers with a core diameter of 100 to 400 μm) to an output optical fiber 104 at a fusion node 103. The brightness of the output optical fiber is close to the combined brightness of the input optical fibers. In power upgrading, the laser power of multiple sub-unit laser sources 101 is coupled into the input optical fiber of the fiber combiner, and the combined power is output from the output optical fiber 104, such as Figure 1 In some industrial systems, fiber combiners can typically combine 7 to 61 input fibers into one output fiber. Multiple combiners can also be used for multi-stage combining. However, this power upgrade method has several disadvantages: 1) The manufacturing cost of the fiber combiner is high, and the structure becomes complex as the number of input fibers increases; because the power loss at the fusion combination may cause severe heat in high-power applications, good thermal management is required to avoid combiner failure during high-power operation, affecting operation or even causing combustion; 2) When the fiber output beam is collimated, high-power beam output through the fiber combiner lacks flexibility, and the mixing of light in the output fiber makes it impossible to change the intensity and wavelength distribution of the collimated beam; One of the main problems with using a combiner for power upgrade is the limited size of the output fiber; Although in many applications such as welding and heating, there is no high brightness requirement due to the large spot size, it is difficult to manufacture a fiber combiner with an output fiber size exceeding 1 to 2 mm due to manufacturing reasons and the rigidity of the optical cable. Therefore, in the optical solution of very high power systems, there is a bottleneck in the high brightness area, which limits the level of power upgrade. The high-brightness area, namely the fusion zone between the input and output fibers, as well as the output end of the fiber, requires extremely careful thermal management and other special treatments. However, for many applications, especially low-brightness laser applications, this is unnecessary and should be avoided. Therefore, although fiber-optic transmission systems are very convenient to use, the brightness bottleneck area of ​​lasers makes it difficult to achieve megawatt-level systems. Summary of the Invention

[0004] The purpose of the present invention is to overcome the deficiencies in the prior art and provide a high-power laser lighting device.

[0005] The purpose of the present invention is achieved through the following technical solutions:

[0006] High power laser lighting device, features: including

[0007] A plurality of high-power laser sources, each high-power laser source having a laser transmission optical fiber;

[0008] A fiber bundle assembly, comprising a plurality of laser transmission optical fibers forming a fiber bundle, each laser transmission optical fiber being surrounded by a sheath;

[0009] A fly-eye lens array consisting of multiple sub-lenses is installed in the frame. The sub-lenses are closely arranged, and each laser transmission optical fiber corresponds to a sub-lens. The laser beam output by each laser transmission optical fiber is coaxial with the optical axis of the corresponding sub-lens in the fly-eye lens array. The frame accommodating the fly-eye lens array can be adjusted relative to the emission plane to output an illumination beam with a predetermined divergence angle.

[0010] Furthermore, in the above-mentioned high-power laser lighting device, the multiple high-power laser sources are high-power laser sources of multiple different power levels.

[0011] Furthermore, in the above-mentioned high-power laser lighting device, the multiple high-power laser sources include at least two high-power laser sources with different wavelengths.

[0012] Furthermore, in the above-mentioned high-power laser lighting device, the high-power laser source is a fiber-coupled semiconductor laser, a fiber laser or a solid-state laser.

[0013] Furthermore, in the above-mentioned high-power laser lighting device, the high-power laser source is a continuous laser source or a pulsed laser source.

[0014] Furthermore, in the above-mentioned high-power laser lighting device, each laser transmission optical fiber is installed in the sheath and is separated from other laser transmission optical fibers by a distance of 1 mm to 100 mm.

[0015] Furthermore, in the above-mentioned high-power laser lighting device, the sheath is a heat-conducting sheath made of glass, ceramic or metal.

[0016] Furthermore, in the above-mentioned high-power laser lighting device, the laser transmission optical fiber is a multimode optical fiber, a single-mode optical fiber or a fiber laser transmission optical fiber.

[0017] Furthermore, in the above-mentioned high-power laser illumination device, the laser transmission optical fibers in the optical fiber bundle assembly are arranged in a predetermined manner to output an illumination light beam with a predetermined power distribution.

[0018] Furthermore, in the above-mentioned high-power laser lighting device, the sub-lenses of the fly-eye lens array are arranged in a close-packed square form or in a close-packed hexagonal form.

[0019] Furthermore, in the above-mentioned high-power laser lighting device, the sub-lenses are separated by metal walls.

[0020] Furthermore, in the above-mentioned high-power laser lighting device, the sub-lens is a circular sub-lens, and the light aperture of the sub-lens is circular.

[0021] Furthermore, in the above-mentioned high-power laser lighting device, the fly-eye lens array is installed at a predetermined position, and the divergence angle of the output laser beam of the fly-eye lens array is equal to or greater than A / f, where A refers to the core diameter of the laser transmission optical fiber, and f refers to the focal length of the sub-lens.

[0022] Furthermore, in the above-mentioned high-power laser lighting device, the output end faces of all laser transmission optical fibers are located on the same emission plane.

[0023] Furthermore, in the above-mentioned high-power laser lighting device, the divergence angle is controlled by changing the numerical aperture of the laser beam emitted by the laser transmission optical fiber.

[0024] Furthermore, in the above-mentioned high-power laser lighting device, the emission end face of at least one laser transmission optical fiber is placed at a predetermined distance from the emission faces of the other laser transmission optical fibers.

[0025] Compared with the prior art, the present invention has significant advantages and beneficial effects, which are specifically reflected in the following aspects:

[0026] ① The present invention provides a power upgrade solution for a fiber-optic output laser source without a high-brightness bottleneck area and without the power level limitation of a fiber combiner. This solution allows for free adjustment of the output beam divergence angle for different lighting applications; achieves mixed output beam divergence angles, mixed output beams, and spot shapes; facilitates the combination of output wavelengths; and achieves higher output efficiency by eliminating transmission losses caused by the fiber fusion zone.

[0027] ② The frame housing the fly-eye lens array can be adjusted relative to the emission plane to output an illumination beam with a predetermined divergence angle, allowing the output power of the fiber-conducted laser source to be upgraded without the high-brightness bottleneck or the power level limitation of the fiber combiner;

[0028] ③ The laser transmission optical fibers are arranged in a predetermined manner to transmit an illumination beam having a predetermined wavelength distribution and output an illumination beam having a predetermined power distribution;

[0029] ④ The divergence angle of the output beam emitted from each sub-lens is controlled by changing the numerical aperture NA of the laser beam emitted from the laser transmission fiber; the fiber output light angle generated by different NA can be achieved by selecting the type of high-power laser source or the parameters of the transmission fiber;

[0030] ⑤ Each sub-lens of the fly-eye lens array is separated by a metal wall so that the heat can be directed into the frame of the fly-eye lens array for better cooling. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 : Schematic diagram of the structure of the background technology device;

[0032] Figure 2a : A schematic structural diagram of the device of Example 1;

[0033] Figure 2b : Schematic diagram of the structure of the sheath surrounding the laser transmission optical fiber;

[0034] Figure 2c : Schematic diagram of sub-lenses closely arranged in a hexagonal shape;

[0035] Figure 2d : Schematic diagram of sub-lenses closely arranged in a square shape;

[0036] Figure 2e : Schematic diagram of the metal wall structure;

[0037] Figure 3 : A schematic structural diagram of the device of Example 2;

[0038] Figure 4a : A schematic structural diagram of the device of Example 3;

[0039] Figure 4b : Schematic diagram of the intensity distribution of semiconductor laser and fiber laser;

[0040] Figure 5a : A schematic structural diagram of the device of Example 4;

[0041] Figure 5b : Schematic diagram of the wavelength distribution of the output beam near field of the dual-wavelength (λ1, λ2) system;

[0042] Figure 6a : A schematic structural diagram of the device of Example 5;

[0043] Figure 6b : Schematic diagram of the near-field beam power distribution output by two power modules (W1, W2);

[0044] Figure 7 : Schematic diagram of the structure of the device of Example 6. DETAILED DESCRIPTION

[0045] A high-power laser illumination device comprises: multiple high-power laser sources 1, each having a laser transmission fiber 2; a fiber bundle assembly 3, comprising a fiber bundle formed by combining multiple laser transmission fibers, each surrounded by a sheath 4; and a frame 6, mounted with a fly-eye lens array 5 comprising multiple sub-lenses 7 with a predetermined focal length f. The sub-lenses are closely arranged, with each laser transmission fiber corresponding to a sub-lens. The laser beam 21 output by each laser transmission fiber is coaxial with the optical axis 22 of the corresponding sub-lens within the fly-eye lens array. The frame 6 housing the fly-eye lens array can be adjusted relative to the emission plane to output an illumination beam with a predetermined divergence angle θ. The adjustment method can specifically employ mechanical adjustment methods such as a lead screw.

[0046] Example 1

[0047] High power laser lighting devices, such as Figure 2a Each high-power laser source includes a laser transmission optical fiber 2 (with a core diameter of a), a fiber bundle assembly 3 consisting of multiple laser transmission optical fibers, each of which is surrounded by a sheath 4 of glass or heat-conducting material, such as Figure 2b The output end faces of the optical fibers are located on a common emission plane 8. A fly-eye lens array 5, consisting of multiple sub-lenses 7 with a predetermined focal length f, is mounted in a frame 6. The sub-lenses are closely arranged, and each laser transmission fiber corresponds to a sub-lens. The output laser beam 21 is coaxial with the optical axis 22 of the corresponding sub-lens within the fly-eye lens array. The frame housing the fly-eye lens array can be adjusted relative to the emission plane to output an illumination beam with a predetermined divergence angle θ. This allows for the output power of fiber-transmitted laser sources to be upgraded, without the bottleneck of high brightness or the power level limitations of fiber combiners.

[0048] The fly-eye lens array can be arranged in various forms, such as Figure 2c The sub-lenses of the compound eye lens array are closely arranged in a hexagonal configuration, such as Figure 2d The sub-lenses of the compound eye lens array are closely arranged in a square shape. Figure 2e For better thermal management, each sub-lens is separated by a metal wall 10, directing heat into the frame 6 for improved cooling. The frame 6 can be water-cooled if necessary. For circular fiber output, the clear aperture of the sub-lens is also circular. The fly-eye lens array is composed of circular sub-lenses. Due to the larger volume of metal surrounding the sub-lenses, heat conduction is improved.

[0049] Example 2

[0050] like Figure 3, a high-power laser lighting device, each high-power laser source includes a laser transmission optical fiber 2 with a core diameter a, and the emission end face 8a of at least one laser transmission optical fiber is placed at a predetermined distance d from the emission surface 8b of other laser transmission optical fibers. A compound eye lens array 5 composed of a plurality of sub-lenses 7 with a predetermined focal length f is mounted in a frame 6, the sub-lenses are closely arranged, each laser transmission optical fiber corresponds to a sub-lens, and the output laser beam is coaxial with the optical axis 22 of the corresponding sub-lens in the compound eye lens array. The frame accommodating the compound eye lens array can be adjusted relative to the emission plane to output an illumination beam with a predetermined divergence angle. The output power of the fiber-transmitted laser source can be upgraded, without the high brightness bottleneck or the power level limitation of the fiber combiner. The high-power laser source 1 can be a fiber-optic transmission semiconductor laser source or a fiber laser source.

[0051] Example 3

[0052] like Figure 4a A high-power laser illumination device is provided. Each high-power laser source has a laser transmission fiber 2 with the same or different core diameters. The output end faces of all laser transmission fibers are located on the same emission plane 8. A fly-eye lens array 5 is mounted in a frame 6 and consists of multiple sub-lenses 7 with a predetermined focal length f. The sub-lenses are closely arranged, and each laser transmission fiber corresponds to a sub-lens. The frame accommodating the fly-eye lens array can be adjusted relative to the emission plane to output an illumination beam with a predetermined divergence angle.

[0053] At least one high power laser source is a fiber laser source. The far field spot morphology obtained is a combination of fiber laser and fiber-delivered semiconductor laser, such as Figure 4b , intensity distribution of semiconductor laser and fiber laser, where fiber laser can be single mode or multimode.

[0054] Example 4

[0055] like Figure 5a A high-power laser lighting device includes multiple high-power laser sources 1λ1, 1λ2, 1λ3, 1λ4, 1λ5, 1λ6, 1λ7, and 1λ8. The high-power laser sources output lasers of at least two different wavelengths. The output end faces of all laser transmission optical fibers are located on the same emission plane 8. A fly-eye lens array 5 composed of multiple sub-lenses 7 with a predetermined focal length f is mounted in a frame 6. The sub-lenses are closely arranged, each laser transmission optical fiber corresponds to a sub-lens, and the output laser beam 21 is coaxial with the optical axis 22 of the corresponding sub-lens in the fly-eye lens array. The frame accommodating the fly-eye lens array can be adjusted relative to the emission plane to output an illumination beam with a predetermined divergence angle.

[0056] The laser transmission optical fibers in the fiber bundle assembly are arranged in a predetermined manner to transmit an illumination beam with a predetermined wavelength distribution. Figure 5b The wavelength distribution of the near-field output beam of a dual-wavelength (λ1, λ2) system. The output wavelength can be selected from the visible to near-infrared spectrum. For example, the wavelength can be selected from 300 and 1550 nm, such as 375, 450, 532, 650, 780, 790, 808, 9xx, and 10xx nm. The wavelength width of the laser source can be narrowband or broadband.

[0057] Example 5

[0058] like Figure 6a A high-power laser illumination device with a variable output divergence angle includes multiple high-power laser sources 1W1, 1W2, 1W3, 1W4, 1W5, 1W6, 1W7, and 1W8 of different power levels. Each high-power laser source includes a laser transmission fiber, a fiber bundle assembly 3 composed of multiple laser transmission fibers, the output end faces of the fibers being located on a common emission plane 8, and a fly-eye lens array 5 mounted in a frame 6 and composed of multiple sub-lenses 7 with predetermined focal lengths f. The sub-lenses are closely arranged, with each laser transmission fiber corresponding to a sub-lens, and the output laser beam 21 is coaxial with the optical axis 22 of the corresponding sub-lens in the fly-eye lens array.

[0059] When the frame containing the fly-eye lens array is adjusted in a predetermined manner relative to the emission plane 8, a light beam with a variable divergence angle can be output. When adjusted in a pre-planned manner, an illumination light beam with a predetermined divergence angle can be output. The laser transmission optical fibers in the fiber bundle assembly are arranged in a predetermined manner to transmit an illumination light beam with a predetermined power distribution pattern. Figure 6b , the near-field beam power distribution output by the two power modules (W1, W2) after being combined and arranged according to a pre-planned method.

[0060] Example 6

[0061] like Figure 7 A high-power laser illumination device with a variable output divergence angle includes multiple high-power laser sources of different power levels, each of which has a laser transmission fiber with a core diameter a; a fiber bundle assembly 3 composed of multiple laser transmission fibers, each fiber surrounded by a glass or metal thermally conductive sheath and separated from the other fibers by a distance, with the spacing between each fiber and the other fibers being 1 to 100 mm. The output end faces of all fibers are located on the same emission plane 8. A fly-eye lens array 5 is mounted in a frame 6 and is composed of multiple sub-lenses 7 with a predetermined focal length f. The sub-lenses are closely arranged, each laser transmission fiber corresponds to a sub-lens, and the output laser beam 21 is coaxial with the optical axis 22 of the corresponding sub-lens in the fly-eye lens array.

[0062] The divergence angle of the output light beam emitted from each sub-lens is controlled by changing the numerical aperture NA of the laser beam emitted from the laser transmission fiber. The fiber output light angles θ1 and θ2 generated by two different numerical apertures NA are achieved by selecting the type of high-power laser source or the parameters of the transmission fiber. The types of laser sources include fiber-transmitted semiconductor lasers, fiber lasers and other solid-state lasers. Obviously, multiple high-power laser sources are single-type lasers or combinations of different types of lasers. The fly-eye lens array is adjusted to a predetermined position so that the divergence angle θ of the laser beam from the fly-eye lens array is approximately equal to A / f, where A refers to the core diameter of the laser transmission fiber and f refers to the focal length f of the sub-lens. The fly-eye lens array is positioned at a position so that the divergence angle of the laser beam output by the fly-eye lens array is substantially greater than A / f. It is also preferred that the clear aperture of the sub-lens is minimized without blocking light to maximize the brightness of the combined output beam.

[0063] Laser delivery fibers are single-mode, multimode, or clad large-mode-area fibers for fiber lasers. Non-circular fibers, such as rectangular or square fibers, are also possible. The thermally conductive material surrounding the fiber is glass, ceramic, or thermally conductive metal. Standard fiber connectors, such as SMA, D-80, QBH, or QD, can be used. Depending on the laser source, each laser delivery fiber output beam can have the same or different power, wavelength, beam quality, and operating mode. Any predetermined fiber output beam can be inserted to work with compound-eye optics and output a beam with predetermined characteristics. Pulsed laser output can be combined with continuous laser light in a single device.

[0064] In summary, the present invention provides a power upgrade solution for fiber-optic laser sources without high-brightness bottlenecks or fiber combiner power level limitations. This solution allows for flexible adjustment of the output beam divergence angle for different lighting applications, achieves mixed output beam divergence angles, and achieves mixed output beam and spot shapes. This facilitates the combination of output wavelengths and achieves higher output efficiency by eliminating transmission losses caused by the fiber fusion zone.

[0065] The frame housing the fly-eye lens array can be adjusted relative to the emission plane to output an illumination beam with a predetermined divergence angle, allowing the output power of fiber-guided laser sources to be upgraded without the high-brightness bottleneck or the power level limitations of fiber combiners.

[0066] The laser transmission optical fibers are arranged in a predetermined manner to transmit an illumination beam having a predetermined wavelength distribution and output an illumination beam having a predetermined power distribution.

[0067] The divergence angle of the output beam emitted from each sub-lens is controlled by changing the numerical aperture (NA) of the laser beam emitted from the laser delivery fiber. The fiber output light angles generated by different NAs can be achieved by selecting the type of high-power laser source or the parameters of the delivery fiber.

[0068] Each sub-lens of the fly-eye lens array is separated by metal walls so that heat can be directed into the frame of the fly-eye lens array for better cooling.

Claims

1. High-power laser lighting device, characterized by: Include A plurality of high-power laser sources (1), each high-power laser source having a laser transmission optical fiber (2), each laser transmission optical fiber having an emission end face; an optical fiber bundle assembly (3) consisting of laser transmission optical fibers, each of which is surrounded by a sheath (4); A compound eye lens array (5) composed of a plurality of sub-lenses (7) mounted in a frame (6), wherein the sub-lenses are closely arranged, each laser transmission optical fiber in the optical fiber bundle assembly corresponds to a sub-lens, and the laser beam (21) output by each laser transmission optical fiber is coaxial with the optical axis (22) of the corresponding sub-lens in the compound eye lens array; The frame (6) on which the fly-eye lens array is mounted can be adjusted relative to the emission end face to output an illumination light beam with a predetermined divergence angle.

2. The high-power laser lighting device according to claim 1, characterized in that: The multiple high-power laser sources (1) are high-power laser sources of multiple different power levels.

3. The high-power laser lighting device according to claim 1 or 2, characterized in that: The high power laser source (1) is a fiber-coupled semiconductor laser, a fiber laser or a solid-state laser.

4. The high-power laser lighting device according to claim 1 or 2, characterized in that: The high power laser source (1) is a continuous laser source or a pulsed laser source.

5. The high-power laser lighting device according to claim 1, characterized in that: Each laser transmission optical fiber is installed in the sheath and is separated from other laser transmission optical fibers by a distance, the distance between which is 1 mm to 100 mm.

6. The high-power laser lighting device according to claim 1 or 5, characterized in that: The sheath is a thermally conductive sheath made of glass, ceramic or metal.

7. The high-power laser lighting device according to claim 1, characterized in that: The laser transmission optical fibers in the optical fiber bundle assembly (3) are arranged in a predetermined manner to output an illumination light beam with a predetermined power distribution.

8. The high-power laser lighting device according to claim 1, characterized in that: The sub-lenses of the compound eye lens array (5) are arranged in a square or hexagonal manner.

9. The high-power laser lighting device according to claim 1 or 8, characterized in that: The sub-lenses are separated by metal walls (10).

10. The high-power laser lighting device according to claim 1 or 8, characterized in that: The sub-lens is a circular sub-lens, and the light aperture of the sub-lens is circular.

11. The high-power laser lighting device according to claim 1, characterized in that: The compound eye lens array (5) is installed at a predetermined position. The divergence angle of the output laser beam of the compound eye lens array is equal to or greater than A / f, where A refers to the core diameter of the laser transmission optical fiber and f refers to the focal length f of the sub-lens.

12. The high-power laser lighting device according to claim 1, characterized in that: The output end faces of all laser transmission optical fibers are located on the same emission plane (8).

13. The high-power laser lighting device according to claim 1, characterized in that: The divergence angle is controlled by changing the numerical aperture of the laser beam emitted from the laser delivery fiber.

14. The high-power laser lighting device according to claim 1, characterized in that: In the optical fiber bundle assembly, the emission end face (8a) of at least one laser transmission optical fiber is placed at a predetermined distance from the emission end faces (8b) of other laser transmission optical fibers.

15. The high-power laser lighting device according to claim 1, characterized in that: The high-power laser source includes at least one fiber laser source, and the fiber laser source has a higher output beam quality than other high-power laser sources; The frame (6) on which the fly-eye lens array is mounted can be adjusted relative to the emission end face to output illumination light beams with at least two different divergence angles, and the divergence angle of the light beam generated by the fiber laser source is smaller than the divergence angle of the light beam generated by other high-power laser sources.

16. The high-power laser lighting device according to claim 15, characterized in that: Other high-power laser sources besides fiber laser sources are fiber-coupled semiconductor laser sources.

17. The high-power laser lighting device according to claim 15, characterized in that: The frame (6) on which the compound eye lens array is mounted is adjusted so that each emitting end face is at the focal position of the corresponding sub-lens.

18. The high-power laser lighting device according to claim 1, characterized in that: The high-power laser source (1) comprises at least two high-power laser sources with different wavelengths.

19. The high-power laser lighting device according to claim 18, characterized in that: The optical fiber emission end faces of high-power laser sources of different wavelengths are placed at different positions, so that the illumination beams generated by the high-power laser sources of different wavelengths have the same divergence angle after the frame (6) on which the compound eye lens array is mounted is adjusted relative to the emission end face.

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