Applications, methods, and systems for material processing using visible Raman lasers

Abstract

To provide laser additive manufacturing systems and apparatus, which use laser wavelengths below 800 nm.SOLUTION: A Raman laser module (RLM) for use in laser additive manufacturing is provided, the RLM comprising a pump laser beam source and a Raman oscillator for providing a functional laser beam having a wavelength less than about 700 nm, M2 of 2 or less, and power greater than 500 W.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001]

[0001] This application (i) claims the benefit of the filing date with respect to the filing date of U.S. Provisional Patent Application No. 62 / 042,785, August 27, 2014, under 35 United States Code, Section 119(e)(1), and (ii) claims the benefit of the filing date of U.S. Provisional Patent Application No. 62 / 193,047, July 15, 2015, under 35 United States Code, with the entire disclosures of each of those provisional patent applications incorporated herein by reference.

[0002]

[0002] The present invention relates to a laser that generates a laser beam in the range of 300 nm to 700 nm, and the laser beam includes a higher power laser beam having excellent beam quality in these wavelengths. The present invention further relates to a laser manufacturing process, a laser manufacturing system, and a laser manufacturing device, and in particular to a laser utilization manufacturing process using a novel laser beam of the novel laser of the present invention. [Background technology]

[0003]

[0003] Prior to the present invention, laser beams in the 300nm-700nm range were typically obtained from laser sources using frequency doubling of near-infrared or infrared lasers. To date, generally and especially for commercially viable systems, it is considered that the technology has not been able to scale these types of lasers to produce higher-power lasers, for example, lasers greater than 500W (0.5kW), and especially lasers greater than 1kW. Consequently, it is considered that the technology has not been able to scale these lasers to obtain high-power lasers with high beam quality in the 300nm-700nm range. This inability to obtain high-power lasers in these wavelength ranges is generally considered to be limited, technically, by the ability of nonlinear crystals to handle the thermal load and fluence levels required at high power levels, among other things. As a consequence, the highest-power, high-beam-quality lasers available by frequency doubling are currently considered to be limited to pulses of about 400W (0.4kW). Pulsing is required to manage the thermal load on the crystal. In the 300nm-700nm range, for example, it has a higher power of 1kW or more and for example M 2 It is believed that commercially viable or useful lasers with a beam quality of ~1 or higher had not been obtained prior to the present invention.

[0004]

[0004] Prior to the realization of the present invention, it is thought that there were roughly four types of blue lasers. Blue lasers are lasers having wavelengths in the range of approximately 400 nm to 505 nm, typically 405 nm to 495 nm. These blue lasers are (i) He:Cd type, (ii) Ar-ion type, (iii) diode laser direct and frequency doubling type, (iv) solid-state parametric oscillator and frequency doubling type, and (v) fiber laser doubling type and frequency shift fiber laser doubling type. (i) He:Cd type lasers are single-mode, but their power is limited to several hundred milliwatts, e.g., 0.0001 kW. Although He:Cd type lasers are typically single transverse-mode, their low efficiency (<0.025%) makes it extremely difficult to scale them to high power levels, and therefore they are not suitable for high-power material processing applications. (ii) Ar-ion lasers are highly inefficient and, as a result, are limited to relatively low power, i.e., less than approximately 0.005 kW for multi-line operation. At these low power levels, these lasers are single transverse modes with multi-wavelength operation. The lifetime of these systems is typically <5,000 hours, which is relatively short for most industrial applications. (iii) Blue diode lasers have become available in recent years. However, they are low power, typically less than 0.0025 kW, and have poor beam quality, for example, with a delayed axis. 2 >5, M on the speed axis 2 They have _~1. These devices today have a lifespan on the order of 20,000 hours and are suitable for many industrial and commercial laser applications. When attempting to scale these devices to 200 watts or more, beam quality deteriorates with increasing power. For example, at 200 watts, M 2 It is >50. (iv) Frequency-doubling blue laser sources are typically limited to an output power of around 0.50 kW. Methods for creating blue light would involve either frequency doubling a light source in the 800 nm-900 nm range or generating a third frequency using sum-frequency mixing of two different wavelengths. Both techniques require the use of nonlinear doubling crystals such as lithium niobate or KTP. These crystals are relatively short, and as a consequence, they require high peak power levels to achieve efficient conversion. When operating in CW mode, thermal and charge transfer problems may cause rapid crystal degradation and the resulting decrease in laser output power. (v) Fiber lasers that are frequency-shifted and then frequency-dualized to blue require the use of nonlinear dual-doubling crystals such as lithium niobate or KTP. These crystals are relatively short, and as a result, they require high peak power levels to achieve efficient conversion. When operating in CW mode, thermal and charge transfer problems may cause rapid degradation of the crystal and a resulting decrease in laser output power.

[0005]

[0005] Prior to the present invention, blue wavelength laser beams were typically obtained by parametric oscillators, four-wave mixing, and direct frequency doubling. These are all inefficient processes that rely on the use of nonlinear crystals to achieve blue wavelengths. These crystals cannot manage the thermal load that occurs when the laser power approaches several hundred watts (0.something kW) CW, let alone 1 kW and above.

[0006]

[0006] These prior art blue lasers and the laser beams they provide are considered unsuitable for use in laser-based manufacturing processes or systems. These prior art blue lasers are considered incapable of obtaining the high-power laser beams of embodiments of the present invention, for example, blue wavelengths with power of 0.1 kW and greater. High-power frequency doubling laser sources are typically high-speed pulse sources capable of achieving high peak power levels and consequently high conversion efficiencies. These prior art blue lasers also have temporal characteristics unsuitable for use in most laser-based manufacturing, particularly in forming articles with tight tolerances. These prior art blue lasers are incapable of providing the high power and high CW output of embodiments of the present invention.

[0007]

[0007] Prior to the present invention, laser beams of 450 nm or less were typically obtained by parametric oscillators, four-wave mixing, and frequency tripling of IR sources. These are all inefficient processes that rely on the use of nonlinear crystals to achieve short (200 nm-450 nm) wavelengths. These crystals cannot manage the thermal load that occurs when the laser power approaches several hundred watts (0.something kW) CW, let alone 1 kW and above.

[0008]

[0008] Prior to the present invention, laser beams in the 700nm-800nm ​​range were typically obtained by excitation of dye lasers, parametric oscillators, four-wave mixing, and frequency doubling of IR sources. These are all inefficient processes, as dye lasers tend to decolorize over time, have limited interaction volumes, and make it difficult to achieve high CW power levels. Other processes rely on the use of nonlinear crystals to achieve wavelengths of 700nm-800nm. These crystals cannot manage the thermal load that occurs when the laser power approaches several hundred watts (0.something kW) CW, let alone 1 kW and above.

[0009]

[0009] In use herein, unless otherwise specified, the terms “Laser Additive Manufacturing” ("LAM"), “Laser Additive Manufacturing Process,” “Additive Manufacturing Process,” and similar terms should be given their broadest possible meaning, including any other process that utilizes a laser beam at at least one stage in the manufacturing process of an article being produced (e.g., product, component, and part), as well as processes, applications, and systems such as 3D printing, three-dimensional printing, sintering, welding, and brazing. These terms are not limited or restricted by the size of the article being produced, and for example, they would cover articles from submicron, e.g., less than 1 μm, up to 1 μm, up to 10 μm, up to tens of microns, up to hundreds of microns, up to thousands of microns, up to millimeters, up to meters, and up to kilometers (e.g., a continuous LAM process that produces ribbon-like or strip-like materials).

[0010]

[0010] In use herein, unless otherwise specified, the terms “laser beam spot size” and “spot size” should be given their broadest possible meanings, including the cross-sectional shape of the laser beam, the cross-sectional area of ​​the laser beam, the shape of the laser beam irradiation area on the target, the irradiation area of ​​the laser beam on the target, and “maximum intensity spot size” i.e., the laser beam is at least 1 / e 2 This includes the cross-sectional area of ​​a laser beam having a peak value of 0.135, the "50% intensity spot size" (i.e., the cross-sectional area of ​​a laser beam having a peak value of at least 0.00675), and the cross-sectional area of ​​a laser beam having functional properties.

[0011]

[0011] In use herein, unless otherwise specified, the terms “functional utilization manufacturing laser beam,” “functional beam,” “functional laser beam,” and similar terms mean a laser beam having power, wavelength, fluence, irradiance (power per unit area), and combinations and modified forms of these properties for forming or shaping a starting material or target material into an article, by exerting a laser beam effect on these materials, for example, by sintering, brazing, annealing, welding, melting, joining, increasing adhesion, softening, cross-linking, binding, reacting, etc.

[0012]

[0012] In use herein, unless otherwise specified, the term “approximately” shall encompass a variance or range of ±10%, experimental or instrument error associated with obtaining the expressed value, and preferably a wider range thereof.

[0013]

[0013] In use herein, unless otherwise specified, the terms “optical element,” “optical component,” “optical system,” and similar terms should be given their broadest possible meanings, including any type of element or system capable of handling a laser beam (e.g., transmitting or reflecting a laser beam without being damaged or rapidly destroyed by the beam's energy); any type of element or system capable of activating a laser beam in a predetermined manner (e.g., transmitting, focusing, defocusing, shaping, collimating, steering, scanning, etc.); multiplexed beam shapes, e.g., cross, X-shape, rectangle, hexagon, array of lines, or connected or different distances of lines, squares, and cylinders. Elements or systems that provide a set of shapes such as those of a set of distanced relatives; refractive lenses; diffracting lenses; diffraction gratings; transmissive diffraction gratings; mirrors; prisms; lenses; collimators; aspherical lenses; spherical lenses; convex lenses; negative meniscus lenses; biconvex lenses; axicon, gradient refractive lenses; elements with aspherical profiles; elements with achromatic doublets; microlenses; microarrays; MEMS steering mirrors, such as those used in DLP projectors that can be used to create and steer images on the fly; lithium niobate beam steering crystals; high-speed galvanometers; combinations of linear motors and high-speed galvanometers; levitating optical heads; shape-shifting mirror devices; and combinations and variations of these and other beam handling devices.

[0014]

[0014] The background art section of the present invention is intended to introduce various aspects of the art that may be associated with embodiments of the present invention. The above discussion in this section provides a framework for a deeper understanding of the present invention and should not be considered an endorsement of the prior art. [Prior art documents] [Patent Documents]

[0015] [Patent Document 1] U.S. Provisional Patent Application No. 62 / 042,785 [Patent Document 2] U.S. Provisional Patent Application No. 62 / 193,047 [Patent Document 3] U.S. Patent No. 5,352,405 [Patent Document 4] U.S. Patent No. 5,340,656 [Patent Document 5] U.S. Patent No. 5,204,055 [Patent Document 6] U.S. Patent No. 4,863,538 [Patent Document 7] U.S. Patent No. 5,902,441 [Patent Document 8] U.S. Patent No. 5,053,090 [Patent Document 9] U.S. Patent No. 5,597,589 [Patent Document 10] U.S. Patent Application Publication No. 2012 / 0072001 [Patent Document 11] U.S. Patent No. 5,832,006 [Summary of the Invention] [Problems to be Solved by the Invention]

[0016]

[0015] Among others, there is particularly a need for a laser that provides a laser beam in the wavelength range of 300 nm - 800 nm. Specifically, among others, there is particularly a need for a blue laser and a laser beam with high power and high beam quality for use in improved laser-utilizing manufacturing processes, welding processes, cutting processes, brazing processes, polishing processes, ablation processes, and soldering processes. This need has existed for many years and has not yet been achieved. The present invention solves this problem by providing, among others, the manufactured products, devices, and processes taught and disclosed herein. [Means for Solving the Problems]

[0017]

[0016] A laser additive manufacturing (LAM) apparatus is provided, comprising: a laser for providing a functional laser beam having a wavelength of less than approximately 750 nm along a beam path; a build plate; a starting material delivery device capable of delivering a starting material and a starting material to a target area adjacent to the build plate; a laser beam delivery device having a beam shaping optical element for providing a functional laser beam and forming a laser beam spot; a motor and positioning device mechanically connected to the build plate or the laser beam delivery device or both, thereby providing relative motion between the laser beam delivery device and the build plate; and a control system having a processor, a memory device and an LAM plan, capable of carrying out the LAM plan through a predetermined arrangement of the functional laser beam and the starting material.

[0018]

[0017] Furthermore, a system, apparatus, and method having one or more of the following features, namely, the laser having a pump laser diode having a wavelength less than 500 nm and a Raman oscillator fiber; the laser having a pump laser diode and a Raman oscillator configured to provide Raman oscillation of the order of n, where n is an integer; n is selected from the group consisting of 1, 2, 3, 4, 5, 6, 7, 8, and 9; the oscillation of the order of n is Stokes; the oscillation of the order of n is anti-Stokes; the molding material is magnesium, aluminum, gallium, tin, lead, titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, zirconium, mo A system, apparatus, and method is provided having one or more of the following: selected from the group consisting of ribdenum, rhodium, palladium, silver, cadmium, tungsten, gold, mercury, metals, metal alloys, and mixtures of metals; the starting material is a powder; the starting material is a powder with a particle size of less than approximately 1 μm; the starting material is a powder with a particle size from approximately 0.05 μm to approximately 2.5 μm; the starting material is a powder with a particle size from approximately 0.05 μm to approximately 2.5 μm; the starting material is a powder with a particle size of approximately 40 μm or less; the starting material is a powder with a particle size of less than approximately 25 μm; the starting material is a powder with a particle size of less than approximately 15 μm; or the starting material is a powder with a particle size of less than approximately 0.5 μm.

[0019]

[0018] In addition, there are Raman laser modules (RLM) for use in laser-based manufacturing, with wavelengths less than approximately 700 nm and M2 2 A Raman laser module is provided that has a pump laser beam source and a Raman oscillator for providing a functional laser beam with power greater than 500W.

[0020]

[0019] Furthermore, there are also apparatuses, systems, and methods having one or more of the following features: namely, the Raman oscillator has a fiber oscillator made of a material selected from the group consisting of silica, GeO2-doped silica, and phosphorus-doped silica; the pump laser source has a diode laser; the pump laser source has a plurality of laser diodes to generate a pump laser beam having a beam parameter product of less than about 10 mm-mrad; the pump laser source has an array of at least 20 blue laser diodes; the array provides a pump laser beam having a wavelength in the range of about 405 nm to about 460 nm; the oscillator fiber has a length of about 30 m or less; the oscillator fiber has a length of about 20 m or less; the oscillator fiber has a length of about 25 m or less; the oscillator fiber has a length of about 40 m or less; and the functional laser beam has a wavelength in the range of about 405 nm to about 470 nm.

[0021]

[0020] Furthermore, apparatus, methods, and systems are provided, wherein the pump laser source has a blue laser diode system that provides a pump laser beam having a wavelength of about 405 nm to about 470 nm and a power greater than 100 W, and the Raman oscillator fiber has a core diameter of about 10 μm to 50 μm and is a graded index fiber or a step index fiber.

[0022]

[0021] In addition, means for cooling the laser, including the pump laser source, are provided, and such cooling means may be air-cooled using active or passive air cooling, liquid-cooled using a coolant or refrigerant, or water-cooled using a closed-loop water-cooling system.

[0023]

[0022] Furthermore, there are apparatuses, methods, and systems having one or more of the following features: namely, the pump laser source has a spectral beam combiner; laser beams from the RLM are coherently combined to form a single functional laser beam; the pump laser source has a drive electronic integrated laser diode which controls the current and enables rapid pulsing of the pump laser source diode to provide a pulsed pump laser beam; and there are apparatuses, methods, and systems having one or more pulse repetition rates from about 0.1 MHz to about 10 MHz.

[0024]

[0023] Furthermore, a 3D printing apparatus is provided which includes a starting material delivery device capable of delivering starting material to a target area adjacent to a predetermined molding area, a beam shaping optical element that provides a functional laser beam spot having a cross-section of less than approximately 100 microns in the molding area, and a Raman laser module (RLM).

[0025]

[0024] Furthermore, LAM systems are also provided that include a 3D printing apparatus having one or more RLMs among those described herein.

[0026]

[0025] In addition, a laser-assisted manufacturing (LAM) method is provided, comprising the steps of: providing a starting material having a predetermined maximum absorption wavelength; directing a functional laser beam having a predetermined wavelength to the starting material, wherein the functional laser beam wavelength is based on matching at least partially to the maximum absorption wavelength of the starting material; and the functional laser beam interacting with the starting material to form an article.

[0027]

[0026] Furthermore, a method, system, and apparatus having one or more of the following characteristics, namely, the functional laser beam wavelength and the maximum absorption wavelength are matched within 100 nm of each other; the functional laser beam wavelength and the maximum absorption wavelength are matched within 50 nm of each other; the functional laser beam wavelength and the maximum absorption wavelength are matched within 10% of each other; the functional laser beam wavelength and the maximum absorption wavelength are matched within 20% of each other; the functional laser beam wavelength and the maximum absorption wavelength are matched and they are the same wavelength; the article is shaped in a single step; the article has a thermal expansion of 7.5 to 32 μm / (m-K) (at 25°C), a thermal conductivity of 18 to 450 W / (m-K), an electrical resistance of 14 to 420 nΩ-m (at 20°C), a Young's modulus of 40 to 220 GPa, a shear modulus of 15 to 52 GPa, a bulk modulus of 40 to 190 GPa, a Poisson's ratio of 0.2 to 0.5, a Mohs hardness of 1 to 7, a Vickers hardness of 150 to 3500 MPa, a Brinell hardness of 35 to 2800 MPa, a density of 1.5 to 21 g / cm 3 ; the article has a thermal expansion of 7.5 to 32 μm / (m-K) (at 25°C), a thermal conductivity of 18 to 450 W / (m-K), a Young's modulus of 40 to 220 GPa, a shear modulus of 15 to 52 GPa, a bulk modulus of 40 to 190 GPa, a Poisson's ratio of 0.2 to 0.5, and a density of 1.5 to 21 g / cm 3 ; the article has an electrical resistance of 14 to 420 nΩ-m (at 20°C), a Poisson's ratio of 0.2 to 0.5, and a Mohs hardness of 1 to 7; the article has a thermal expansion of 7.5 to 32 μm / (m-K) (at 25°C), an electrical resistance of 14 to 420 nΩ-m (at 20°C), a Young's modulus of 40 to 220 GPa, a Mohs hardness of 1 to 7, and a density of 1.5 to 21 g / cm 3 ; the article has a thermal expansion of 7.5 to 32 μm / (m-K) (at 25°C), a thermal conductivity of 18 to 450 W / (m-K), an electrical resistance of 14 to 420 nΩ-m (at 20°C), a Young's modulus of 40 to 220 GPa, a shear modulus of 15 to 52 GPa, a bulk modulus of 40 to 190 GPa, a Poisson's ratio of 0.2 to 0.5, a Mohs hardness of 1 to 7, a Vickers hardness of 150 to 3500 MPa, a Brinell hardness of 35 to 2800 MPa, and a density of 1.5 to 21 g / cm 3Methods, systems, and apparatus are provided that have one or more physical properties selected from the group consisting of the following.

[0028]

[0027] Furthermore, there are also apparatuses, systems, and methods having one or more of the following features: namely, the Raman oscillator has a crystal oscillator made of a material selected from the group consisting of diamond, KGW, YVO4, and Ba(NO3)2; the Raman oscillator has a high-pressure gas; the pump laser source has a plurality of laser diodes for generating a pump laser beam having a beam parameter product of less than about 14 mm-mrad; or the pump laser source has a plurality of laser diodes for generating a pump laser beam having a beam parameter product from about 9 mm-mrad to about 14 mm-mrad. [Brief explanation of the drawing]

[0029] [Figure 1]

[0028] This is a schematic perspective view of one embodiment of the LAM system and LAM process according to the present invention. [Figure 2]

[0029] This is a cross-sectional view of a certain embodiment of the starting material at a certain stage of the LAM process according to the present invention. [Figure 2A]

[0030] This is a cross-sectional view of an embodiment of an article formed from the starting material shown in Figure 2 at a later stage of a certain embodiment of the LAM process according to the present invention. [Figure 2B]

[0031] This is a cross-sectional view of the starting material and the embodiment of the article shown in Figure 2A at a later stage of a certain embodiment of the LAM process according to the present invention. [Figure 3]

[0032] This is a cross-sectional view of a certain embodiment of the LAM article according to the present invention. [Figure 4]

[0033] This is a cross-sectional view of a certain embodiment of the LAM article according to the present invention. [Figure 5]

[0034] This is a perspective view of the LAM system according to the present invention. [Figure 6]

[0035] This is a perspective view of the LAM system according to the present invention. [Figure 7]

[0036] This is a diagram showing the output versus output coupler percentage for various Raman oscillator fiber lengths to provide a 459 nm functional laser beam according to the present invention. [Figure 8]

[0037] This is a diagram showing the output power versus output coupler percentage at various 100W pump wavelengths for providing a 455nm functional laser beam according to the present invention. [Figure 9]

[0038] This diagram shows the output power versus output coupler for a 455 nm functional laser beam from a 100 W 450 nm pump laser beam at various Raman oscillator fiber lengths according to the present invention. [Figure 10]

[0039] This diagram shows the spot size versus beam waist for a pump laser beam passing through a 500 mm focal length lens for the slow axis and fast axis of a collimated laser diode according to the present invention. [Figure 11]

[0040] This is a diagram showing the maximum absorption wavelength for embodiments of the starting materials used according to the present invention. [Figure 12]

[0041] This is a diagram showing the water absorption rate used according to the present invention. [Figure 13A]

[0042] This diagram shows the Raman-Stokes shift for Raman fibers and Raman crystals of various materials according to the present invention. [Figure 13B]

[0042] This is a diagram showing the Raman Stokes shift for Raman fibers and Raman crystals of various materials according to the present invention. [Figure 13C]

[0042] This is a diagram showing the Raman Stokes shift for Raman fibers and Raman crystals of various materials according to the present invention. [Figure 14A]

[0043] This diagram shows the Raman anti-Stokes shift for Raman fibers and Raman crystals of various materials according to the present invention. [Figure 14B]

[0043] This is a diagram showing the Raman anti-Stokes shift for Raman fibers and Raman crystals of various materials according to the present invention. [Figure 14C]

[0043] This is a diagram showing the Raman anti-Stokes shift for Raman fibers and Raman crystals of various materials according to the present invention. [Figure 15]

[0044] These are Raman spectra for three different dopant levels used in a certain embodiment of the phosphate fiber according to the present invention. [Figure 16]

[0045] This graph shows the absorption rates of various metals, illustrating the increase in absorption rate at multiple wavelengths, in an embodiment of the laser according to the present invention. [Figure 17]

[0046] This is a schematic diagram of a certain embodiment of the LAM system according to the present invention. [Figure 18]

[0047] This graph shows the laser performance of various embodiments of the laser according to the present invention. [Modes for carrying out the invention]

[0030]

[0048] Generally speaking, the present invention relates to lasers that generate laser beams having wavelengths in the range of about 200 nm to about 800 nm. Specifically, embodiments of the present invention relate to lasers that generate blue laser beams and applications of these laser beams. Embodiments of the present invention also relate to higher power or high power lasers and laser beams having wavelengths in the range of 300 nm to 700 nm, particularly in the 400 nm range and the 500 nm range, and lasers and laser beams having excellent beam quality in these wavelengths. Embodiments of the present invention further relate to laser-based manufacturing and laser material processing, in particular to laser-based manufacturing processes using the novel laser beams of the novel lasers of the present invention, as well as welding, brazing, cutting, and soldering.

[0031]

[0049] Furthermore, embodiments of the present invention relate to predetermined metal starting materials and predetermined laser wavelengths for performing laser-based manufacturing on these starting materials. In particular, embodiments of the present invention relate to predetermined laser beam wavelengths matched to metal starting materials for performing laser-based manufacturing to produce metal articles.

[0032]

[0050] Figure 1 shows a schematic diagram illustrating a certain embodiment of a LAM system and LAM process. It comprises a base 100, a laser unit 101, and a laser beam delivery assembly 102. The laser beam delivery assembly 102 has a distal end 108 located at a standoff distance 103 from the base 100 (and at a standoff distance from the starting material if the starting material is on the base). Typically, during the LAM process, the starting material (not shown in the figure) is supported by the base 100. The starting material and the laser beam are then moved relative to each other, causing the functional laser beam 109 to advance along the beam path 110 to form a laser spot 111, which contacts the starting material to bond the material together and form an article. The relative motion of the starting material and the laser spot (e.g., raster scan) is shown by arrows 104 (e.g., x-axis motion), 105 (e.g., y-axis motion), 106 (e.g., z-axis motion), and 107 (e.g., rotation), and in addition, the laser beam path and the angle at which the laser beam strikes the base and the starting material on the base can also be varied. The laser spot may also be moved in a vector manner, in which case both x and y motions occur simultaneously to move the spot to a predetermined position on the material. The angle of the laser beam on the target in Figure 1 is 90° or perpendicular to the base. This angle can be varied from 45° to 130°, from 30° to 120°, from 0° to 180°, and from 180° to 360° (for example, the article is inverted to produce a U-shaped lip as an example). Further combinations and variations of these different basic relative motions can be carried out in conjunction with the emission of the laser beam and the deposition of the starting material, and in this manner, articles of many different shapes, many different sizes, and articles of varying complexity can be manufactured. These relative motions are understood to be achieved by moving the base, moving the laser beam delivery assembly, steering the laser beam (e.g., scanning the beam with a Garbo scanner), and combinations and variations thereof.

[0033]

[0051] The laser unit and the laser beam delivery assembly may be a single integrated device, or they may be separate and optically connected, for example, via optical fibers or a levitating optical head. Furthermore, some or all of the components of the laser unit may be located within the laser beam delivery assembly, or vice versa. Similarly, these components and other components may be located separately from the laser unit and laser beam delivery assembly. These remote components may be optically associated with the laser unit and laser beam delivery assembly, functionally associated with the laser unit and laser beam delivery assembly (e.g., control communication, data communication, WiFi, etc.), or both optically and functionally. The laser unit and laser beam delivery assembly generally comprises a high-power laser (preferably a Raman laser as disclosed and taught herein, or a direct diode laser as disclosed and taught in Patent No. 62 / 193,047, the entire disclosure of which is incorporated herein by reference) and beam shaping and handling optical elements for delivering the laser beam along the laser beam path at a predetermined spot size.

[0034]

[0052] Preferably, the laser unit has a high-power laser capable of generating and propagating a laser beam at a predetermined wavelength, and can deliver the laser beam to a laser beam delivery assembly, which shapes the laser beam, and deliver the laser beam from the distal end along the laser beam path to a target, such as a base or starting material on an article under construction.

[0035]

[0053] For example, a laser beam may preferably have one, two, or more of the characteristics shown in Table I. (The columns or rows in the table are not specific to any particular embodiment, and characteristics from different rows may be combined with characteristics from different columns, for example, the power in one column may be present for all different wavelengths. A single embodiment may have characteristics from different columns and different rows of the table.)

[0036] [Table 1] *The cross-section is the longest distance across the spot, for example, along the lagging axis. For a circular spot, the cross-section is the diameter, and for an ellipse, it is the major axis.

[0037]

[0055] The laser beam delivery system houses passive and active laser beam shaping optical elements that provide a predetermined spot size at the intended standoff distance. The laser beam delivery system may further house monitoring and control devices, or may be operably associated with monitoring and control devices. For example, the device may have a down-the-pipe viewing, for instance, a high-speed video camera. In this configuration, the camera views the laser beam path downwards to the base, allowing visualization of the formation of a molten mass from the interaction between the laser beam and the starting material. Depth sensors or instruments, location sensors or instruments, laser monitoring, infrared and visible light pyrometers for measuring the molten mass temperature and the device, and other monitoring, analysis, and control devices can be used. In this configuration, the LAM process, for example, the process of forming or manufacturing an article from a starting material, can be monitored, analyzed, and controlled. Thus, the LAM process can be controlled to conform to a predetermined application, and the LAM process may be changed or modified in real time, or monitoring equipment may provide real-time feedback regarding the densification and quality of the material being processed.

[0038]

[0056] The delivery device for supplying the starting material may also be adjacent to the laser beam delivery device, or otherwise operably associated with the laser beam delivery device, or otherwise associated with the laser beam delivery device. In this configuration, the starting material is delivered onto the base or onto the article under construction, for example, by spraying, flowing, transporting, drawing, pouring, or coating. Thus, for example, the starting material can be delivered through a jet, nozzle, coaxial jet centered on the laser beam, air knife or doctor blade assembly, any device that delivers the starting material ahead of the laser beam's movement, spray nozzle, and other devices for delivering and handling the starting material. For example, starting material delivery devices and processes for delivering starting material found in 3D printing applications can be used.

[0039]

[0057] Embodiments of 3D printing apparatus, 3D printing systems, and 3D printing methods are disclosed and taught in U.S. Patents No. 5,352,405, No. 5,340,656, No. 5,204,055, No. 4,863,538, No. 5,902,441, No. 5,053,090, No. 5,597,589, and U.S. Patent Application Publication No. 2012 / 0072001, the entire disclosures of those patents and patent applications are incorporated herein by reference.

[0040]

[0058] The control system is preferably integrated, monitored, and controlled the operation of the laser, the movement of various components that provide relative motion for forming the article, and the delivery of the starting material. The control system may also integrate, monitor, and control other aspects of operation, such as monitoring, safety interlocks, laser operating conditions, and LAM processing programs or LAM processing plans. The control system may communicate (e.g., via a network) with data storage devices and data processing devices for storing and calculating various information and data related to the article, such as customer information, document information, inventory, operation history, maintenance and inspection, and LAM processing programs or LAM processing plans, or may have such data storage devices and data processing devices as part of its system.

[0041]

[0059] A LAM (Laser-Aided Manufacturing) program or LAM plan is a file, program, or set of instructions executed by a control unit to operate a LAM device, such as a 3D printer, to perform a predetermined LAM process to produce a specified article. A LAM plan may be a 3D drawing or 3D model file, based on one, or derived from one, such as a CAD file, which may, for example, be a file in a standard format including .STEP, .STL, .WRL (VRML), .PLY, .3DS, and .ZPR. The control unit has a LAM plan (e.g., available in its own memory, on a drive, on a storage device, or via a network), and uses the plan to operate the device to perform the LAM process and produce the intended article. The control unit may have the ability to directly use a 3D model file or directly convert such file into a LAM plan. The conversion may be performed by another computer and made directly available to the control unit, or it may be kept in memory or on a storage device for later use. One example of a program that converts 3D model files into LAM machining plans is ZPrint (trademark), available from Z Corp.

[0042]

[0060] The starting material may be, to name a few, a liquid, a fluid, a solid, an inverse emulsion, an emulsion, a colloid, a microemulsion, a suspension, or a combination and variation thereof. Fluid-based starting material systems, such as suspensions, colloids, and emulsions, have a carrier component and a forming element dispersed within the carrier component. The forming element interacts with a laser beam to produce an article. These starting material systems may have a carrier component that is transparent to the laser wavelength and a forming element that is absorbent to the laser wavelength. Figures 11 and 12 show the absorption characteristics of various embodiments of metal starting materials, such as shaping materials, and the absorption characteristics of water, an example of a carrier component. From these figures, it can be seen that at a wavelength of 450 nm, the forming element has high absorption, while water easily transmits this wavelength. Therefore, for fluid-based starting material systems, at predetermined laser wavelengths, particularly those in Table I, the formed components can have an absorption rate of at least twice, at least five times, at least ten times, or at least 100 times the absorption rate of the carrier component.

[0043]

[0061] Figure 16 shows the absorption characteristics of alumina, copper, gold, silver, titanium, iron, nickel, stainless steel 304, and tin, which are the main components or components of the starting material. From this graph, it can be seen that at the wavelength of this embodiment of the laser, for example line 1602, the absorption rates of these metals are higher than their absorption rates at the IR wavelength, for example line 1601.

[0044]

[0062] Preferably, for the wavelengths in Table I, the starting material is metal-based particles, such as beads, powders, or fine particles. Embodiments of the starting material can be particles of magnesium, aluminum, gallium, tin, lead, titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, zirconium, molybdenum, rhodium, palladium, silver, cadmium, tungsten, gold, and mercury, alloys of these and other metals, Inconel 625, Invar, stainless steel, stainless steel 304, and mixtures and deformed products of these and other metals and alloys. Embodiments of the starting material may also be, or may contain, silicon carbide or ceramic materials such as photo-structurable aluminosilicate glass-ceramic substrates, aluminum-filled plastics, impact-resistant nylon, nylon, glass-filled nylon, flame-retardant nylon, carbon fiber, carbon fiber-filled nylon, and rubber-like plastics. Embodiments of the system may also include a fluid gas air knife that ensures the optical system is kept clean and provides means for capturing any volatiles released during material processing. The particles may also contain metal and other materials such as ceramics or fillers, for example, when manufacturing mixed metal composite articles or composite articles. Other types of starting materials known for 3D printing technology can also be used. It is preferable that the functional laser beam wavelength be matched to the absorption characteristics of the starting material, for example, adapted to the absorption characteristics of the starting material. For example, embodiments of starting materials good for high absorption at 450 nm are shown in Figure 11, and they are also shown in Figure 16.

[0045]

[0063] Metal particles may be preferably uniformly dispersed within a fiber or rod in preparation for the feeding stage into the laser beam path to form an article. The carrier for the metal particles in the fiber or rod is preferably incorporated into the alloy being formed in such a way that the correct ratio of each metal is established, and the "tubes" of the metals provide the necessary balance of materials within the molten mass. In addition, the fiber or rod carrier may be a non-metallic material that is evaporated by the functional laser beam and removed by an air knife system with minimal, negligible, or no effect on the starting material or the formed article. The carrier material may also be selected to form part of an article, such as a composite article. For example, the functional laser beam may be given absorption properties that cause the fusion of metal particles, creating a base material for the article through fusion, into which the carrier material is then filled.

[0046]

[0064] Novel and high-power laser beams offer numerous opportunities to fabricate materials and articles that were not possible with prior art 3D printing, and were generally not obtainable at wavelengths below approximately 700 nm, by leveraging the different absorption characteristics of predetermined starting material combinations of these types. Furthermore, if the metal particles are in the submicron range, it becomes possible to fabricate unique new nanocomposite articles and nanocomposite materials.

[0047]

[0065] It should be understood that articles and molded or manufactured products may include, for example, finished products, finished components for use in a final product, products or components requiring further processing or additional manufacturing processes, materials for use in other applications, and coatings on substrates, such as coatings on wires.

[0048]

[0066] The starting material particles may consist as a whole of a single metal or a single alloy, or as a whole of a mixture of several metals, a mixture of several alloys, or a mixture of several metals and alloys, or may consist of about 5% to about 100% metal, alloy, or both. The metal-based component of the starting material particles may be placed on the outside of the particles so that it can be used for direct contact with the laser beam and for bonding the particles together. The particles may be the same shape or essentially the same shape, or the particles may be different shapes. The particles may be essentially the same size, or the particles may be different sizes. The particles may have cross-sections ranging from approximately <1 μm to approximately 1 mm, from approximately 1 μm to approximately 100 μm, from approximately 1 μm to approximately 5 μm, from approximately 0.05 μm to approximately 2.5 μm, from approximately 0.1 μm to approximately 3.5 μm, from approximately 0.5 μm to approximately 1.5 μm, from approximately 1 μm to approximately 10 μm, from approximately 0.1 μm to approximately 1 μm, and larger and smaller sizes. The particle size, for example, the cross-section, can be set to have a predetermined size with respect to a predetermined functional laser beam wavelength. Thus, for example, the particles may have sizes of approximately 1 / 10 of the laser beam spot size, the same as the laser beam wavelength, twice as large as the wavelength, three times as large as the wavelength, five times as large as the wavelength, and ten times as large as the wavelength, as well as smaller and larger sizes. Preferably, by using particles smaller in size than the laser beam spot, and by using a laser beam spot that is approximately the same size as the laser beam, for example by using the smallest spot formed by a single-mode diffraction-limited beam, it is possible to provide articles with extremely high resolution, such as high-resolution 3D prints.

[0049]

[0067] The size and shape of the particles can be predetermined with respect to a given functional laser beam spot. For example, the particles can be smaller than the laser beam spot (e.g., 1 / 2, 1 / 5, 1 / 10), approximately the same size as the laser beam spot, twice as large as the spot, three times as large as the spot, five times as large as the spot, and ten times as large as the spot. The particles may have essentially the same shape as the laser beam spot; for example, if the spot is circular, the particles may be spherical beads, or they may have different shapes, or combinations and variations thereof.

[0050]

[0068] When referring to a group of particles in a starting material that have particle sizes, if we are talking about particle size, we should use the median particle size distribution, e.g., D 50 , can be used. Typical 3D printing machines have an average particle size of 40 μm, with particles ranging in size from 15 μm to 80 μm. It is desirable to have more precise control over the particle distribution, which would improve the surface roughness of the final printed part.

[0051]

[0069] The shape of the particles in the starting material may be any volumetric shape, including, for example, spheres, pellets, rings, lenses, disks, panels, cones, frustocones, squares, rectangles, cubes, grooves, hollow sealing chambers, hollow spheres, blocks, sheets, coatings, films, skins, slabs, fibers, staple fibers, tubes, cups, amorphous or non-morphological shapes, ellipsoids, ellipsoids of spheroids, oval shapes, polyhedron-cut structures, and polyhedra (e.g., octahedrons, dodecahedrons, icosadodecahedrons, rhombic triacontahedrons, and prisms), as well as combinations of these shapes and other shapes that are more engineering and architecturally complex, and various forms. The preferred particle shape is essentially a nearly perfect sphere with a narrow size distribution, which helps the particles flow through the system and helps reduce the surface roughness of the final parts produced. When the average particle size is less than 40 μm, any shape that reduces static friction, friction, or both between particles is desirable.

[0052]

[0070] Figures 2 through 2B illustrate a schematic representation of one embodiment of the LAM process. Figure 2 shows a simplified schematic diagram in which several starting material particles, e.g., 201, 202, and 203, form two layers, 204 and 205. During operation, a functional laser beam interacts with the starting material particles, fusing them together to form the initial section of article 207, as seen in Figure 2A. In Figure 2B, an additional layer 208 of starting material particles 209 is placed on top of the initial section 206. The functional laser beam then fuses the additional layer 208 with the initial section 206, further forming article 207. This process is then repeated until the article is completed.

[0053]

[0071] In the process and article embodiments shown in Figures 2 to 2B, the article is fabricated as essentially a solid monolithic material, for example, as shown in initial section 206. The LAM device and LAM process, and in particular the LAM device using the laser beam shown in Table I, are capable of producing articles of exceptional strength without the need for a separate infiltration or resin infiltration process to reinforce the article's strength. Thus, the embodiments of the LAM device and process can produce articles that are 2, 3, 4, 10, or even stronger than articles produced by a single process using current 3D printers, or even articles produced by a two-step re-infiltration process, in just one step (i.e., without subsequent infiltration, filling, or refilling processes). Thus, embodiments of the LAM-fabricated articles of the present invention, such as 3D printed articles, can have the characteristics shown in Table II.

[0054] [Table 2]

[0055]

[0073] Embodiments of LAM-formed articles and LAM-formed materials, particularly embodiments of articles formed by a single-step 3D printing process, may have one or more of the following properties: thermal expansion 0 to 32 μm / (mK) (at 25°C), thermal conductivity 18 to 450 W / (mK), electrical resistance 14 to 420 nΩ-m (at 20°C), Young's modulus 40 to 220 GPa, shear modulus 15 to 52 GPa, bulk modulus 40 to 190 GPa, Poisson's ratio 0.2 to 0.5, Mohs hardness 1 to 7, Vickers hardness 150 to 3500 MPa, Brinell hardness 35 to 2800 MPa, and density 1.5 to 21 g / cm³. 3 It may have one or more of the following: , and combinations of these and other features and characteristics.

[0056]

[0074] Figure 3 shows an embodiment of an article made of metal starting material having the form of a fabricated skeleton 301, which can be formed by selectively fusing metal starting material together using a functional laser beam in accordance with a LAM (Laser Application Molding) plan. The skeleton 301 has interconnected filaments, e.g., 302, 303 and voids, e.g., 304. Further LAM or other processes may be performed on this article 301, which may be a finished product, e.g., a filter.

[0057]

[0075] Figure 4 shows one embodiment of a molded article 400 made from several different sizes of starting material particles, for example 401, 403, and 404. The particles are fused together at joints 405, 406, and 407 to form voids, for example 408. Further LAM processes or other processes may be performed on this article 400, or it may be a finished product.

[0058]

[0076] Figure 5 shows a perspective view of one embodiment of the LAM system 500. The system 500 has a cabinet 501 that houses a laser unit, a laser beam delivery assembly and a base. The cabinet 501 further houses a motor, sensors, actuators, nozzles, a starting material delivery device, and other devices used to perform relative motion or deliver the starting material in a predetermined manner, such as equipment and devices for performing LAM processing planning. The cabinet 501 and more specifically the components within the cabinet 501 communicate data and control with an operating station 502 having a control unit via a cable 503. The control unit may be a PLC (Programmable Logic Controller), an automation and device controller, a PC, or another type of computer capable of performing LAM processing planning. In this embodiment, the operating station has two GUIs (Graphical User Interfaces) 503, 504, such as monitors. The cabinet 501 has an access panel 505, which may have a window with laser-safe glass.

[0059]

[0077] In embodiments of the LAM system, the system and preferably the cabinet may house the following additional components: an automatic air filter, a bulk storage unit for the starting material, a compressor for delivering clean air for the finished product, and an internal filtering system capable of keeping the build area (e.g., where a functional laser beam interacts with and fuses the starting material) clean and free from dust and other substances that could interfere with the progression of the laser beam along its path. Furthermore, the control unit may be located inside or adjacent to the cabinet, or it may be located in a remote location but in control and data communication with the system. Additionally, oxygen monitors may be used in both the build chamber and the filter, and it is desirable to use them to continuously monitor for oxygen deficiency.

[0060]

[0078] Figure 6 shows a perspective view of the LAM build area 600. The build area 600 has a build platform 601 with a drive motor 602, which is connected to the platform 601 by an articulated robot 603. This system allows control of the platform's movement, direction, angle, and standoff distance. The starting material delivery assembly 604 has a starting material feeding line 605 and a nozzle 606 positioned adjacent to the location where the laser beam 608 is aimed. The laser beam 608 is delivered from a laser head 614. The laser head 614 has a camera 611 for visualizing the LAM process, a connector 612 and optical fiber 613 for delivering a functional laser beam from the laser unit, and a beam shaping optical element assembly 607, such as a focusing optical element, for delivering the laser beam 608 along the laser beam path 616 to the target area 617. The laser head 614 has two laser positioning devices 609, 610 that use the laser beam to measure and monitor the position, size, and shape of the article as it is being formed during the LAM process. The laser head 614 has a stand 615 connected to a frame not shown. The frame and drive motor 602 may further be integrated and movable to provide additional types of relative motion.

[0061]

[0079] Lower wavelength ranges, such as around 700 nm and below, offer significant advantages in LAM, particularly in 3D printing. These lower wavelength ranges provide higher absorption capacity in starting materials, especially metals and metal-based starting materials, which, among other benefits, contribute to more efficient LAM processes. For example, thanks to higher absorption capacity, less power is required to perform the bonding stage of the starting materials for forming the object. This, in turn, can result in faster build times, lower-cost LAM devices, and LAM devices with less maintenance and longer duty cycles, among other advantages.

[0062]

[0080] For example, embodiments of 3D printers for creating metal objects can have linear printing speeds greater than 1 m / s, greater than 5 m / s, and greater than 10 m / s. Furthermore, generally depending on the material, a blue laser can cut metal sheets 2 mm or thinner at least about four times faster than a CO2 laser and at least about twice as fast as a fiber laser. From a different perspective, this means that a 2 kW blue laser can achieve the same cutting speed as a 5 kW-8 kW CO2 laser for these materials. The increased absorption of blue laser light is an advantage and desirable when the adiabatic process dominates the laser process, as is the case with cutting, welding, and sintering of thin materials. This advantage is less useful or provides less benefit for materials 5 mm or thicker, because the effect on the process is less than the total power used, as the process is limited by the thermal diffusivity and the resulting absorption characteristics of the material being processed.

[0063]

[0081] In addition, lower wavelengths allow for substantially smaller spot sizes and greater control over the fabrication process. This method enables the production of articles with sharper edges and smoother surfaces, possessing highly refined surface features and properties comparable to those of micro-machined parts, using this LAM system. Basically, the spot size formed by the laser is limited by the wavelength of the source laser; the shorter the wavelength, the smaller the spot size formed for a given focal length system. However, if the same spot size is desired, using a blue laser with a longer focal length lens compared to an IR laser allows the blue laser to provide eight times the addressable volume of an IR laser source.

[0064]

[0082] The minimum feature size and surface roughness are determined by combining the system's spot size with the size of the particles being fused. Using smaller diameter particles (<40 μm, <10 μm, or <1 μm) with beam sizes of <40 μm, <10 μm, or <1 μm) allows for the creation of parts with minimum feature sizes on the order of ~40 μm, ~10 μm, or ~1 μm, resulting in a dramatic improvement in surface roughness for parts <1 μm. The use of smaller spots and smaller particles to form the part means that the shrinkage and stress of the part can be controlled much better than with larger particles, inevitably resulting in greater part stability. The smaller the volume of material being processed, the less energy is required to melt the "voxels," and consequently, the substrate or part being fabricated experiences a lower thermal gradient during manufacturing, inevitably resulting in less shrinkage as the part "cools" from its processing temperature. Therefore, by using less laser power, for example, lower thermal input, to fuse particles into a solid, it becomes possible to create objects with greater strength and lower deformation.

[0065]

[0083] Embodiments of this laser provide a laser beam in the range of 300 nm to 800 nm. Embodiments of the Raman laser of the present invention provide a laser beam having wavelengths in the range of 300 nm to 700 nm, particularly in the range of 400 nm and 500 nm. Embodiments of this Raman laser have powers of at least about 10 W (0.01 kW), at least about 100 W (0.1 kW), at least about 1,000 W (1 kW), at least about 5 kW, and greater. In addition, the Raman lasers and laser beams of the present invention have excellent beam quality. Thus, embodiments of these Raman-generated laser beams can have the beam parameter scalability shown in Figure 18. This figure highlights the beam parameters that can be generated using a direct blue laser diode source (450 nm), line 1801, a wavelength-combined blue laser diode source, line 1802, an optically combined Raman laser source, line 1803, and a wavelength-combined blue Raman laser source, line 1804. Raman laser sources offer superior source brightness compared to IR lasers of comparable power output. Wavelength-combined Raman laser sources provide unparalleled power and beam brightness across a wide range of output power levels. Raman laser sources can achieve scalability comparable to wavelength-combined Raman laser sources, along with the development of large-core optical fibers capable of maintaining single-mode performance across a wide spectral range (~10 μm for fused silica).

[0066]

[0084] Notably, while the main focus of this specification is on the use of the Raman high-power blue laser of the present invention in LAM processes, LAM systems, and LAM devices, there are many current and future applications for the Raman laser of the present invention. For example, embodiments of the Raman laser of the present invention include: applications in welding, cutting, heat treatment, brazing, and surface modification; exciting an n-Raman order fiber laser to achieve any visible wavelength; providing a blue Raman laser beam with at least about 10W of power for combination with a digital mirror device for projecting color images, including 3D capabilities; providing a blue Raman laser beam with at least about 10W of power for recreational purposes; providing a blue Raman laser beam with at least about 10W of power for exciting phosphorus to produce a white light source that can be used in projection systems, headlights, or lighting systems; providing a blue Raman laser beam with at least about 10W of power for underwater laser ranging; providing a blue Raman laser beam with at least about 10W of power for underwater communications, including encrypted communications; and laser ranging, especially in high-moisture environments such as fog and clouds. To provide a blue Raman laser beam with at least approximately 10W of power for laser ranging in high-moisture environments; to provide a blue Raman laser beam with at least approximately 10W of power for communications, particularly encrypted communications in high-moisture environments such as fog and clouds; to provide a blue Raman laser beam with at least approximately 1000W of power for use as a laser weapon underwater and in high-moisture environments such as fog and clouds; to provide a blue Raman laser beam with at least approximately 10,000W of power for ship salvage and offshore salvage operations, particularly salvage operations in surface, tidal, and subsurface environments; to provide a blue Raman laser beam with at least approximately 1000W of power for use as a laser weapon on the ocean, a few feet above the ocean, through ocean waves, and below the ocean surface; to provide a blue Raman laser beam with at least approximately 1000W of power for use as a non-lethal laser weapon;Applications can be found in providing a blue Raman laser beam with at least approximately 100W of power for glass cutting; a blue Raman laser beam with at least approximately 1000W of power for paint removal; a blue Raman laser beam with at least approximately 100W of power for seabed diamond discovery by Raman scattering; and a blue Raman laser beam with at least approximately 100W of power for melting AuSn solder and for soldering in general.

[0067]

[0085] Embodiments of the blue Raman laser of the present invention can find applications in most current laser cutting, processing, and manufacturing systems. Blue Raman lasers are readily interchangeable into these systems, replacing existing IR (infrared, >700nm) lasers currently used in such systems. In these systems, blue Raman lasers can provide 2 to 10 times greater efficiency and processing speed increases, as well as other advantages, compared to the IR lasers they replace. Furthermore, blue Raman lasers can provide an improved system overall with lower power requirements and a smaller footprint. Thus, for example, embodiments of blue Raman lasers could be used to swap out IR lasers used in laser systems within manufacturing facilities, such as large automobile manufacturing plants. Preferably, this laser swap-out can be carried out with minimal changes to other components of the laser system, such as the need to coat the beam-delivering optical elements for blue wavelengths.

[0068]

[0086] Generally, embodiments of the blue Raman laser of the present invention use a solid-state laser to excite an n-order Raman laser and cause it to oscillate between 410 nm and 800 nm. In one embodiment, an array of blue diode lasers emitting in the 405 nm–475 nm region (having at least 10, at least 50, and at least 1000 diodes) can excite an n-order Raman laser and cause it to oscillate in any order, e.g., n-Raman order, between 410 nm and the near-infrared 800 nm. While larger orders or other orders are understood to be achievable and conceived in the present invention, the n-order within the 405 nm–475 nm range is preferred at present because there are several commercially available laser diodes available in wavelength excitation ranges that provide an n-order Raman range.

[0069]

[0087] In one embodiment, a blue diode laser array can excite an anti-Stokes Raman laser that generates wavelengths as short as 300 nm through the nth-order Raman laser. The gain of the anti-Stokes laser is substantially lower than that of the Stokes laser, but it is preferable to use a low-loss medium when transitioning from a 450 nm pump wavelength to 300 nm.

[0070]

[0088] In one embodiment, the blue laser diode pump is based on individual laser diodes, either in the T056 example or individually mounted. Generally, the pumped laser beam from the laser diodes is collimated in two axes. The laser diodes can be mounted in a module package and then inserted into a backplane so that all the laser diodes are aligned and focused into a single fiber simultaneously. The laser diodes may further be mounted on a single carrier, their beams collimated, and emitted into the fiber by a single focusing optical element. Thus, the laser diode beam is emitted into a double-clad fiber, where the outer cladding is 20 μm or larger, and the inner core has a diameter sufficient to support single-mode operation in the nth Raman order, which should be the output laser wavelength. The ratio of the outer cladding to the inner core is limited by a threshold of the order of n+1, where it is desired to excite the nth order and not the n+1. n+1 can be suppressed by limiting the outer-to-inner core ratio, fiber length, or by filters within the resonator that suppress the order of n+1.

[0071]

[0089] In a preferred embodiment, the Raman blue laser of the present invention can be scaled up to 2.9 kW when excited by a high-brightness blue laser source. At these power levels, the conversion efficiency from the blue laser diode pump to 455 nm or 459 nm wavelengths is as high as 80%, resulting in a system electro-optical conversion efficiency of ≥20%.

[0072]

[0090] The Raman conversion process depends, and can be highly, on the mode loss of the optical fiber at blue wavelengths. This loss is primarily due to Rayleigh scattering within the fiber and scales according to the inverse fourth power of the wavelength, resulting in a loss of the order of 30 dB / km at 450 nm. This loss can be a concern and, in some embodiments, can be the primary concern during laser system design. To address this loss, embodiments of this Raman laser can use short optical fibers (e.g., <15m, <10m, <5m, <3m). These shorter-length embodiments improve the operating efficiency of the laser. However, it is understood that longer fibers are envisioned. Thus, Raman oscillation fibers can be 30m or longer, 50m or longer, 80m or longer, and 100m or longer.

[0073]

[0091] Modeling this embodiment of the Raman laser demonstrates that a relatively high output coupler reflectivity can be used to achieve a high oscillation power level in the first Raman transform order, resulting in efficient energy transfer to this order. Energy conversion losses due to the Raman shift are minimal, as the pump wavelength is 447 nm, allowing oscillation in the first Raman order to occur at 455 nm. This corresponds to only a 2% quantum defect, leaving 98% of the energy available at the conversion wavelength. However, Rayleigh scattering in the fiber limits the conversion efficiency to less than 80% for the shortest fiber modeled (6 m). Shorter fiber lasers than this modeled laser are also conceived, and it is understood that larger and smaller conversion efficiencies can be achieved. Conversely, if Rayleigh scattering, which accounted for 85% of the loss in fused silica fibers, can be reduced in optical fibers, for example in P2O5-doped fibers, while maintaining a gain greater than 5, even greater efficiencies can be achieved.

[0074]

[0092] The Raman conversion laser of the present invention can handle n-Raman order. This capability can be utilized in the design to design a fiber laser output that can oscillate at a predetermined wavelength and, for example, 455 nm or 459 nm. This embodiment can be designed to oscillate simultaneously at two different wavelengths, for example, 455 nm and 459 nm. It is desirable to suppress the next Raman order. This suppression can be achieved, for example, by sufficient AR coating on the fiber, limiting the fiber length and limiting the cladding-to-core ratio, adding an in-line lossy filter at the next Raman order, and combinations and variations thereof.

[0075]

[0093] In addition to fibers, Raman oscillators can also be made of crystals and gases. Raman crystal oscillators may be made of, for example, diamond, KGW, YVO4, and Ba(NO3)2. Raman gas oscillators may be made of, for example, high-pressure gases at a pressure of 50 atmospheres, high-pressure hydrogen, and high-pressure methane.

[0076]

[0094] By combining a clad-pumped Raman laser with a laser diode beam, various combination methods enable the design and construction of several-kW fiber lasers at wavelengths in the 400nm–800nm ​​range, for example, at 455nm or 459nm. Figure 7 shows the predicted output as a function of fiber length for this laser source, when laser diode power up to 4,000 watts is emitted into a 200μm diameter cladding with a 30μm single-mode core. Figure 7 shows the power output in W vs. % output coupler for Raman fiber lasers generating a 459nm laser beam from Raman fibers of lengths 20m, 15m, 10m, 8m, and 6m. These shorter fiber embodiments have the additional advantage of reducing, mitigating, and preferably eliminating the harmful effects of other nonlinear phenomena such as stimulated Brillouin scattering, and suppressing Raman-order oscillations of the next order.

[0077]

[0095] In the embodiments, methods using a diamond Raman transducer or similar material use a conventional resonator, such as a semi-confocal or fully confocal resonator, in combination with a mode-matched pump beam. Diamond is unparalleled due to its extremely large Stokes shift and high Raman gain coefficient.

[0078]

[0096] Table III shows embodiments of the Stokes shift for various oscillators, with the first Stokes shift corresponding to a 29 nm shift in the wavelength of light from 450 nm to 479 nm, which is one of the largest single Stokes shifts achievable using currently available materials that are transparent to this wavelength. High-power visible operation can also be achieved using other Raman conversion methods, such as emitting into pure fused silica fiber, GeO2-doped optical fiber, P2O5 (phosphorus)-doped optical fiber, KGW crystals excited by an array or single laser source of laser diodes, YVO4 (yttrium vanadate) crystals excited by an array or single laser source of laser diodes, or Ba(NO3)2 (barium nitrate) crystals excited by an array or single laser source of laser diodes.

[0079] [Table 3]

[0080]

[0098] One embodiment of the packaging concept for these laser diodes enables an extremely compact, high-density configuration using a highly modular design that can provide sufficient redundancy for exceptionally high reliability. An embodiment of the blue diode laser apparatus oscillates at 450 nm at 20°C. This wavelength can be shifted to lower wavelengths by cooling the diode; for example, the wavelength shift of a GaN laser diode is on the order of 0.04 to 0.06 nm / °C. The wavelength can also be lowered by locking the diode with an external diffraction grating, such as a volume Bragg grating (VBG) or a Littrow or Littmann-Metcuff external cavity type engraved diffraction grating. Only one VBG is needed to lock the entire pump array to the required wavelength; however, two, three, or more VBGs can be used. The pump wavelength can be set to 450 nm so that the Raman laser oscillates at either 455 nm or 459 nm. Note that the 455 nm line has lower gain than the 459 nm line, resulting in lower conversion efficiency.

[0081]

[0099] The blue laser diode pump is fiber-coupled and fusion-spliced ​​to a Raman laser, such as a Raman oscillator fiber. This is preferable and provides the most robust design capable of operating under extreme conditions such as high vibration and wide temperature fluctuations. Although preferable for extreme conditions, it is recognized that other methods, such as free space with external optical elements, can also be employed for coupling pump lasers and multiple pump lasers to a Raman oscillator fiber.

[0082]

[0100] Figure 8 shows the modeled output of a Raman oscillator fiber laser with a 62.5 μm diameter cladding and a 10 μm diameter core. The laser has an HR diffraction grating at the pump wavelength at the distal end of the fiber and an HR diffraction grating at the first Raman order at the pump input end of the fiber. The reflectivity of the output coupler at the distal end of the fiber at the first Raman order is varied to study its dependence on fiber length and pump center wavelength. A design requiring high reflectivity at the first Raman order is favorable for suppressing second-order Raman oscillation, but not a requirement. The results for varying the pump wavelengths coupled to this Raman oscillator fiber from 450 nm, 449 nm, 448 nm, and 447 nm are shown in Figure 8 for the 455 nm oscillator output, thus demonstrating the pump bandwidth at a given wavelength for the oscillator. In this graph and model, the output power is shown as a function of the wavelengths of the output coupler and the pump source. The fiber is 15 meters long and has a cladding diameter of 62.5 μm with a Na of 0.21. The higher Na of the outer cladding allows for the injection of equally high power levels into the cladding.

[0083]

[0101] The results of a 459 nm Raman laser simulation are shown in Figure 9. In this embodiment, the Raman laser provides a 459 nm laser beam, and the output power is shown as a function of the output coupler for two different fiber lengths, 20 m and 15 m. The cladding and core configuration is identical to that of the embodiment in Figure 8, and 459 nm is the first Raman order for these fibers when the laser diode is excited at a 450 nm center wavelength. This wavelength can be stabilized using a volume Bragg diffraction grating, which has only a slight impact on the output power, if operation over a wide temperature range is desired.

[0084]

[0102] An embodiment of a blue laser diode pump generating a 450 nm beam was measured using a 500 nm focal length lens to determine the beam plane and, consequently, the fiber diameter capable of emitting the laser array. Figure 10 shows the beam waist as a function of output power, which does not change substantially with the output power of the instrument. This figure shows a 1 / e lagging axis of 200 μm. 2 This shows that it has a waist, which translates to a 30 μm waist beam when using an 80 mm focal length lens. Figure 10 also graphs the velocity axis. This suggests that for this embodiment, a coupling efficiency of over 90% can be achieved in a 62.5 μm diameter fiber. Prior to firing into a 62.5 μm diameter fiber, the pump power and brightness can be doubled using both polarization states. Thus, in this embodiment, a 200 watt input to the Raman oscillator laser fiber results in an output of approximately 60 watts or more.

[0085]

[0103] The high-brightness blue laser diodes used in the embodiments shown in Figures 7-10 provide sufficient fluence to enable Raman oscillation in a single-mode core and generate enough gain to provide a Raman-generated laser beam. Thus, these embodiments overcome one of the key challenges hindering the development of visible Raman lasers: high losses in visible wavelengths in optical fibers. This is considered to be one, if not the primary, reason why visible Raman oscillator lasers were overlooked by this technology and not exemplary or proposed by other technologies prior to the present invention.

[0086]

[0104] Embodiments of the Raman oscillator of the present invention can be fabricated from many different types of materials. Preferably, for the fibers, they are silica-based, including silica-based fibers doped with GeO2 or P2O5, the properties of which are shown in Table III. Other heavy metals can also be used as dopants for various types of oscillators, where the operating wavelength is close to the absorption band edge, producing exceptionally high Raman gains that can be substantially higher than those of conventional sources. One example of this for 500 nm light is tellurite-doped glass, in which case the Raman gain is nearly 40 times greater than that of fused silica. Other dopants may be used that yield similar results at a target wavelength of 450 nm.

[0087]

[0105] In a preferred embodiment, for a double-clad fiber where the cladding is relatively low-loss at the pump wavelength and the core is >3 μm, >10 μm, and in some embodiments >20 μm, a high NA outer cladding is used. The cladding / core ratio is preferably kept below the threshold for second-order Stokes self-oscillation. The first-order Stokes gain is determined by the intensity of the light in the cladding coupled to the core, while the second-order Stokes gain is determined by the first-order Stokes oscillation in the core. As mentioned above, this is a limiting factor and depends on the loss in the fiber, the oscillation power at the first-order Stokes, the length of the fiber and thus the total gain, and any feedback in the second-order Stokes signal. This process ultimately limits the amount of brightness enhancement that can be achieved in this way, which can be addressed by scalability, for example, as shown in Figure 18, in which case the Raman source requires a wavelength-beam combination method to achieve high brightness and high power.

[0088]

[0106] Raman amplification has an extremely wide bandwidth that enables modulation speeds well into the GHz regime. This rapid modulation is achievable in the case of blue Raman laser sources due to the short lifetime associated with the inversion process. Rapid modulation performance can be of great benefit in laser-based manufacturing applications, for example, when parts have high spatial frequencies or sharp details that need to be reproduced. Ideally, faster on / off switching of the laser would allow for faster printing of parts. For example, in some embodiments, given a scanning speed, the spatial frequency of the part becomes the limiting factor to the printing speed, because a laser that can only be modulated at a few kHz requires the scanner to move at a low speed to reproduce minute details, while a laser that can be modulated at tens of GHz regimes allows for faster scanning of the part, and consequently, faster printing of the part.

[0089]

[0107] Table IV shows a comparison of fiber laser build speeds with those of equivalent power levels blue lasers. This table shows that, for a given spot size, blue lasers can achieve larger build volumes, and depending on the material being compared, the speed increases between 1.2 times (titanium) and >80 times (gold) based on the absorption enhancement of the laser wavelength.

[0090] [Table 4]

[0091]

[0109] Figure 13A shows the transitions that occur through three Raman-order Stokes to provide a 478 nm functional laser beam from a 450 nm pump source.

[0092]

[0110] Examples of Raman fiber lasers having different materials and different wavelength outputs for n-order Stokes shifts when excited by a 450 nm laser are shown in Figures 13B and 13C. All of these fibers have a 20 μm diameter core and a 50 μm cladding thickness.

[0093]

[0111] Figure 14A shows the transitions that occur through three Raman-order anti-Stokes to provide a 425 nm functional laser beam from a 450 nm pump source.

[0094]

[0112] Examples of Raman fiber lasers having different materials and different wavelength outputs for n-order Stokes shifts when excited by a 450 nm laser are shown in Figures 14B and 14C. All of these fibers have a 20 μm diameter core and a 50 μm cladding thickness.

[0095]

[0113] Figure 15 shows the Raman spectra of phosphate-doped fibers. The P2O5 concentrations in the fibers are 18 mol% for line 1, 7 mol% for line 2, and for fused silica fibers without P2O5 (e.g., 0 nik%) for line 3. The laser emission is several cm -1 From 1330cm -1 This can be achieved over a wide range of frequencies up to [specific frequency range].

[0096]

[0114] The following embodiments are provided to illustrate various embodiments of the LAM system, LAM method, and Raman oscillator laser of the present invention. These embodiments are illustrative and should not be considered to limit the scope of the present invention, nor should they otherwise limit the scope of the present invention. [Examples]

[0097]

[0115] Example 1

[0116] A 200W, approximately 1 MHz Raman laser module (RLM) capable of modulation up to 2 MHz, suitable for various manufacturing applications and specific manufacturing applications. 2The system includes a forward-pumped Raman standard laser module (SLM) as a pump laser for the Raman laser oscillator fiber to provide a 460nm laser beam. The pump standard laser module (SLM) provides a 200W, 10mm-mrad, ~450nm laser beam, which will be used as a forward-pumped pump for the laser oscillator fiber. The oscillator fiber has a 60μm-100μm cladding and a 10μm-50μm core, providing a 200W output, <0.3mm-mrad, ~460nm laser beam. [Examples]

[0098]

[0117] Example 2

[0118] The RLM 5 units of Example 1 are included in the laser-based manufacturing system shown in Figure 5. Their beams are combined to form a single 1 kW functional laser beam. This embodiment can be used to print, for example, shape or fabricate metal-based articles. [Examples]

[0099]

[0119] Example 3

[0120] The five RLMs of Example 1 are included in the laser-based manufacturing system shown in Figure 6. Their beams are combined to form a single 1kW functional laser beam. This embodiment can be used to print, for example, shape or fabricate metal-based articles. [Examples]

[0100]

[0121] Example 4

[0122] The seven RLMs of Example 1 are included in the 3D printer shown in Figure 5. Their beams are combined to form a single 1.4 kW functional laser beam. Embodiments of this example can be used to print, for example, shape or fabricate metal-based articles. [Examples]

[0101]

[0123] Example 5

[0124] The RLM10 units of Example 1 are included in the laser-based manufacturing system shown in Figure 6. Their beams are combined to form a single 2kW functional laser beam. This embodiment can be used to print, for example, shape or fabricate metal-based articles. [Examples]

[0102]

[0125] Example 6

[0126] The Raman laser module (RLM) is a 200W, approximately 460nm Raman laser capable of modulation up to 2MHz, suitable for a variety of manufacturing applications and specific manufacturing applications. 2 To provide a laser beam, a back-pump Raman standard laser module is provided as a pump laser for the Raman laser oscillator fiber. The pump standard laser module (SLM) provides a 200W, 10mm-mrad, ~450nm laser beam, which will be used as a back-pump for the laser oscillator fiber. The oscillator fiber has a 60μm-100μm cladding and a 10μm-50μm core, providing a 200W output, <0.3mm-mrad, ~460nm laser beam. [Examples]

[0103]

[0127] Example 7

[0128] The RLM5 units of Example 6 are included in the laser-based manufacturing system shown in Figure 5. Their beams are combined to form a single 1kW functional laser beam. This embodiment can be used to print, for example, shape or fabricate metal-based articles. [Examples]

[0104]

[0129] Example 8

[0130] The RLM8 of Example 6 is included in the laser-based manufacturing system shown in Figure 6. Their beams are combined to form a single 1.6 kW functional laser beam. This embodiment can be used to print, for example, shape or fabricate metal-based articles. [Examples]

[0105]

[0131] Example 9

[0132] The RLM unit of Example 6 is included in the laser-based manufacturing system shown in Figure 5. The LRM provides a single 0.2 kW functional laser beam. This embodiment can be used to print, for example, shape or fabricate metal-based articles. [Examples]

[0106]

[0133] Example 10

[0134] A high-power Raman laser excited by a high-brightness blue laser diode having an output power of >1 watt in any n-Raman order from the initial pump wavelength. [Examples]

[0107]

[0135] Example 11

[0136] Example 10 of laser use for material processing applications such as welding, cutting, heat treatment, brazing, and surface modification. [Examples]

[0108]

[0137] Example 12

[0138] A high-power blue laser diode system (405nm-475nm) capable of emitting 100 watts into a 50μm fiber. [Examples]

[0109]

[0139] Example 13

[0140] A high-power blue laser diode system with a >5 mm-mrad beam parameter product for exciting a Raman fiber laser. [Examples]

[0110]

[0141] Example 14

[0142] A high-power blue laser diode system with a >10 mm-mrad beam parameter product for exciting a Raman fiber laser. [Examples]

[0111]

[0143] Example 15

[0144] A high-power blue laser diode system that excites an n-Raman order fiber laser to achieve any visible wavelength. [Examples]

[0112]

[0145] Example 16

[0146] A high-power blue laser diode system that excites a Raman fiber laser having output power for all n orders, where n > 0. [Examples]

[0113]

[0147] Example 17

[0148] 2>M 2 >1 beam quality high-power Raman laser system. [Examples]

[0114]

[0149] Example 18

[0150] A high-power Raman laser system with >1 watt operating in the 410nm-500nm range, suitable for processing materials. [Examples]

[0115]

[0151] Example 19

[0152] A high-power blue Raman laser system with >1000 watts for cutting, welding, brazing, polishing, and marking materials. [Examples]

[0116]

[0153] Example 20

[0154] A high-power blue Raman laser system with a modular design and a high-power diode pump system, exceeding 10 watts. [Examples]

[0117]

[0155] Example 21

[0156] A high-power blue Raman laser system with an air-cooled blue diode laser pump, exceeding 10 watts. [Examples]

[0118]

[0157] Example 22

[0158] A high-power blue diode laser system whose beams are spectrally combined to generate a <10 nm composite beam, which can be used to excite a high-power Raman laser system. [Examples]

[0119]

[0159] Example 23

[0160] Low M 2 For example, M is a value less than 2.5, less than 2.0, less than 1.8, less than 1.5, and less than 1.2. 2 A high-power blue Raman laser system with >10 watts, where beams are spectrally combined to generate a composite beam with a specific value. [Examples]

[0120]

[0161] Example 24

[0162] A system of >10 watts high-power blue Raman lasers and amplifiers coherently combined to generate an extremely high-power, diffraction-limited beam. [Examples]

[0121]

[0163] Example 25

[0164] Example 23 is a high-power blue diode laser system that uses a prism to spectrally combine the beams. [Examples]

[0122]

[0165] Example 26

[0166] In the high-power blue diode laser Raman laser pump of Example 23, a diffraction element is used to spectrally combine the beams. [Examples]

[0123]

[0167] Example 27

[0168] In the high-power blue diode laser Raman laser pump of Example 23, a volume Bragg diffraction grating is used to spectrally combine the beams. [Examples]

[0124]

[0169] Example 28

[0170] A >10 watt high-power blue Raman laser for use with digital mirror devices for projecting color images, including 3D capabilities. [Examples]

[0125]

[0171] Example 29

[0172] A high-power blue Raman laser with >10 watts for recreational purposes. [Examples]

[0126]

[0173] Example 30

[0174] A >10 watt high-power blue Raman laser for exciting phosphorus to generate a white light source that can be used in projection systems, headlights, or lighting systems. [Examples]

[0127]

[0175] Example 31

[0176] An array of high-power blue laser diode modules locked to a narrow frequency band by a volume Bragg diffraction grating to excite a Raman fiber laser system. [Examples]

[0128]

[0177] Example 32

[0178] An array of high-power blue laser diode modules locked to a narrow frequency band by a fiber Bragg diffraction grating to excite a Raman fiber laser system. [Examples]

[0129]

[0179] Example 33

[0180] An array of high-power blue laser diode modules locked to a narrow frequency band by a transmission diffraction grating for exciting a Raman fiber laser. [Examples]

[0130]

[0181] Example 34

[0182] An array of high-power blue laser diode modules locked to a specific wavelength range by a transmission diffraction grating for exciting an n-order Raman laser. [Examples]

[0131]

[0183] Example 35

[0184] An air-cooled or water-cooled heat exchanger mounted on a backplane to dissipate heat from a laser diode module and a Raman fiber laser. [Examples]

[0132]

[0185] Example 36

[0186] A laser diode module with integrated drive electronics that control current and enable rapid pulsing of the laser diode to excite a Raman laser. [Examples]

[0133]

[0187] Example 37

[0188] A high-power Raman laser based on a diamond-like transducer material, wherein the Raman laser is excited by a visible laser diode array that is mode-matched to Raman laser modes. [Examples]

[0134]

[0189] Example 38

[0190] Examples 37 of laser use for material processing such as welding, cutting, brazing, heat treatment, and surface modification. [Examples]

[0135]

[0191] Example 39

[0192] The fabrication speed of a certain embodiment of the UV laser (350 nm) of the present invention is compared with the fabrication speed of a prior art IR fiber laser (1070 nm). From Table IV above, it can be seen that a significantly higher fabrication speed can be obtained by using the embodiment of the present invention. [Examples]

[0136]

[0193] Example 40

[0194] Embodiments 1-8 can be combined with or otherwise incorporated into milling machines such as CNC machines, or laser, sonic, waterjet, or other types of milling, machining, or cutting devices. This includes Raman laser additive-subtractive manufacturing devices and processes. In some embodiments, a functional Raman laser beam can be used to shape an article, which is then further machined, i.e., material is removed. The Raman laser beam can also be used to add lost material to a worn article, which is then further machined. Other variations and combinations of adding, removing, and adding material to reach a final product, final part, or final article are also conceivable. Thus, in one embodiment, the removal of material added by a Raman laser beam is provided. In laser machining additive-subtractive apparatus and processes, the laser used for removal (e.g., subtractive manufacturing, cutting laser beam, machining laser beam) can be a Raman generation beam, a LAM functional beam, or separate beams with different wavelengths (e.g., IR such as wavelength > 1,000 nm), and the cutting laser beam and the functional laser beam (LAM beam) may follow essentially the same beam delivery path, or they may follow essentially distinct beam delivery paths, and they may share some or all of the combinations or variations of beam shaping optical elements and beam delivery optical elements, or none at all. [Examples]

[0137]

[0195] Example 41

[0196] Embodiments 1-8 provide a platform that is a longitudinally moving surface or support, such as a belt, conveyor, or connected and overlapping leaves, which enables the fabrication of a continuous ribbon, rod, fiber, rope, wire, pipe, strip, or other elongated structure. [Examples]

[0138]

[0197] Example 42

[0198] Embodiments of Examples 1 and 6 are used in the laser-based manufacturing system shown in Figure 17. System 1700 includes a hopper 1701 for holding the starting material, an adjustable weighing plate 1702 for delivering the starting material, a work station 1703, a transfer chamber 1704, a weighing plate actuator pin 1705, a shuttle 1711, a rack and pinion shuttle drive 1706, a shuttle stepping motor 1707, a waste container 1708, an elevator stepping motor 1709, and an elevator 1710. [Examples]

[0139]

[0199] Example 43

[0200] The LAM system is comprised of a Garbo scanning powder bed process and a Garbo scanning powder bed system. The laser delivery device includes a collimator / beam expander for the laser beam, an XY Garbo scanning system, and an F theta lens. The collimator / beam expander can be fixed or variable depending on the fabrication process, decreasing the beam expander ratio if a larger spot size is required. Similarly, if a smaller spot size is required on the part, increasing the beam expander ratio produces a larger diameter emission beam. The powder is placed on the workbench by a starting material delivery device and its height is adjusted by a height adjustment mechanism. In this embodiment, only movement in the z-axis direction is required for the workbench. A variable focus lens may be used in the laser beam path to achieve movement in the z-axis direction. [Examples]

[0140]

[0201] Example 44

[0202] A high-power blue laser diode system with a >10 mm-mrad beam parameter product that can be used for welding, cutting, brazing, polishing, and marking materials such as metals, plastics, and non-metallic materials. [Examples]

[0141]

[0203] Example 45

[0204] Multiple RLMs are coherently combined using either a master oscillator power amplifier configuration or a Fourier transform external resonator. An embodiment of a system for coherent beam combining is disclosed and taught in U.S. Patent No. 5,832,006, the entire disclosure of which is incorporated herein by reference.

[0142]

[0205] It should be noted that there are no prerequisites for providing or addressing the theories underlying any novel and groundbreaking processes, materials, performance, or other beneficial features and properties that are the subject matter of or associated with embodiments of the present invention. Nevertheless, various theories are provided herein to further advance the art of this field. Unless otherwise expressly stated, the theories proposed herein do not in any way limit, restrict, or narrow the scope of the invention described in the claims for which protection is to be granted. These theories may not be necessary or may not be put into practice in utilizing the present invention. Furthermore, it should be understood that the present invention may lead to new and previously unknown theories for explaining the function-characteristics of embodiments of the methods, articles, materials, devices, and systems of the present invention, and such subsequent theories do not limit the scope of the present invention for which protection is to be granted.

[0143]

[0206] Various embodiments of the systems, apparatus, techniques, methods, activities, and operations shown herein may also be used for various other activities or in other fields in addition to those shown herein. Furthermore, these embodiments may be used, for example, with other apparatus or activities that may be developed in the future, or with existing apparatus or activities that have been partially modified based on the teachings herein. Moreover, the various embodiments shown herein may be used in various different combinations in conjunction with one another. Thus, for example, the configurations provided in the various embodiments herein may be used in conjunction with one another, and the scope of the invention to be protected shall not be limited to specific embodiments, specific examples, or specific manifestations, configurations, or arrangements shown in specific figures.

[0144]

[0207] The present invention can also be embodied in forms other than those specifically disclosed herein without departing from its spirit or essential features. The embodiments described should be considered in all respects to be illustrative and not limiting. [Explanation of symbols]

[0145] 100 base 101 Laser Unit 102 Laser beam delivery assembly 103 Standoff distance from base 104 x-axis motion of the relative motion of the starting material and the laser spot 105 y-axis motion 106 z-axis motion 107 rotations 108 Distal end of laser beam delivery assembly 109 Functional laser beams 110 Laser beam path 111 Laser Spot 201, 202, 203 Starting material particles 204, 205 layers 206 Initial classification 207 Goods 208 Additional Layers 209 Starting material particles 301 Sculptural Skeleton 302, 303 Interconnected filaments 304 void 400 Modeled products 401, 403, 404 Starting material particles 405, 406, 407 joints 408 void 500 LAM system 501 Cabinet 502 Operating Station 503 Cable 503, 504 GUI (Graphical User Interface) 505 Access Panel 600 LAM build area 601 Build Table 602 Drive motor 603 Articulated robot 604 Starting material delivery assembly 605 Departure material supply line 606 Nozzle 607 Beam-shaping optical element assembly 608 Laser Beams 609, 610 Laser positioning devices 611 Camera 612 connector 613 Optical Fiber 614 Laser Head 615 Stand 616 Laser beam paths 617 Target Area 1601 Wavelength of IR laser 1602 Laser wavelengths 1700 Laser-based manufacturing systems 1701 Hopper 1702 Adjustable Measuring Plate 1703 Workshop Station 1704 Transfer room 1705 Measuring plate actuator pin 1706 Rack and Pinion Shuttle Drive 1707 Shuttle Stepping Motor 1708 Waste bin 1709 Elevator Stepping Motor 1710 Elevator 1711 Shuttle 1801 Direct Blue Laser Diode Source (450nm) 1802 Wavelength Combination Blue Laser Diode Source 1803 Optically combined Raman laser source 1804 Wavelength Combination Blue Raman Laser Source

Claims

1. A laser processing apparatus for fabricating parts, a. A laser having a pump laser diode for providing a functional laser beam along a beam path, wherein the functional laser beam has a wavelength in the range of 405 to 450 nm and a wavelength of less than 2 M ２ , and a laser having a power in the range of 1 to 2.25 kW, b. A platform having a target area for placing the target material, c. A laser beam delivery apparatus having a beam shaping optical element for providing a functional laser beam and forming a functional laser beam spot, d. A motor and positioning device mechanically connected to the base, the laser beam delivery device, or both, and configured to provide relative movement between the laser beam delivery device and the base, e. A control system having a processor and a memory device, capable of performing a laser process plan by a predetermined arrangement of the functional laser beam spots on the target area, A laser processing apparatus equipped with the following features.

2. The laser processing apparatus according to claim 1, wherein the functional laser beam has a beam parameter product of 0.3 to 0.6 mm-mrad.

3. The laser processing apparatus according to claim 1 or 2, wherein the functional laser beam spot has a cross-section of 1 to 10 μm.

4. The laser processing apparatus according to claim 1 or 2, wherein the functional laser beam spot has a cross-section of 1 to 2 μm.

5. The laser processing apparatus according to any one of claims 1 to 4, wherein the functional laser beam has a beam waist of 10 μm.

6. The laser processing apparatus according to any one of claims 1 to 5, wherein the functional laser beam is a continuous beam.

Images