JP7382498B2 - Packages for high power laser devices - Google Patents

Description

(Related application)
This application claims the benefit and priority of U.S. Patent Application No. 16/654,339, filed October 16, 2019, the entire disclosure of which is incorporated herein by reference.
(Technical field)

In various embodiments, the present invention relates to laser devices, such as laser diodes and laser diode bars, and specifically to apparatus for packaging such laser devices.

High power laser systems are utilized for many different applications such as welding, cutting, drilling, and material processing. Such laser systems typically include a laser emitter from which the laser light is coupled into an optical fiber (or simply "fiber") and a laser light beam from the fiber onto the workpiece to be processed. and a focusing optical system. Wavelength beam combining (WBC) is a technique for scaling the output power and brightness from a laser diode, laser diode bar, stack of diode bars, or other laser arranged in a one- or two-dimensional array. WBC methods have been developed to combine beams along one or both dimensions of an array of emitters. A typical WBC system includes multiple emitters, such as one or more diode bars, that are combined using dispersive elements to form a multi-wavelength beam. Each emitter in the WBC system is individually resonant and stabilized through wavelength-specific feedback from a common partially reflective output coupler, which is filtered by a dispersive element along the beam combining dimension. Exemplary WBC systems are disclosed in U.S. Pat. No. 6,192,062, filed February 4, 2000, and U.S. Pat. , U.S. Pat. No. 8,670,180, filed Aug. 25, 2011, and U.S. Pat. (herein incorporated by reference).

While techniques such as WBC have been successful in producing laser-based systems for a wide variety of applications, wider adoption of such systems will require ever-higher levels of laser output power. is bringing about. Higher laser power typically involves driving the laser diode at increasingly higher currents, which results in higher operating temperatures and simultaneous thermal management challenges that are intended to prevent temperature-based reliability challenges. . Lasers for high power laser systems are disclosed, for example, in US Pat. No. 9,178,333, filed March 24, 2015, the entire disclosure of which is incorporated herein by reference (Incorporated) is packaged utilizing a highly thermally conductive mount that may define an enclosed passageway for the flow of a cooling fluid therethrough. However, even such solutions may not completely address all of the thermal management issues that arise in high power laser systems. Additionally, packaging-related issues such as mechanical stability, stress, and corrosion (eg, caused by cooling fluids) can occur in high-power laser systems. Therefore, a need exists for improved packaging systems for high power lasers that address the thermal, mechanical, and electrical needs for such devices.

US Patent No. 6,192,062 US Patent No. 9,178,333

According to embodiments of the invention, a laser emitter, such as a laser diode bar, is utilized with a multi-component package designed to improve the mechanical, thermal, and electrical performance of the device. Embodiments of the invention feature a two-part anode cooler for the laser emitter, where the two parts of the anode cooler provide liquid cooling for the laser emitter while also resisting adverse effects such as corrosion and mechanical deformation. Designed to optimize effectiveness. Embodiments of the present invention are located above (and/or in thermal contact with) the laser emitter so as to remove additional heat from the laser emitter and further improve the thermal properties of the device. An optional cathode cooler (mechanical contact) may also be included.

In various embodiments, the anode cooler includes, consists essentially of, or consists of a bottom anode cooler and a top anode cooler disposed thereon; is in direct contact with the laser emitter. The bottom anode cooler has an active cooling section that features an array of through holes or nozzles that direct cooling fluid (e.g., water) upward toward the receiving portion of the top anode cooler directly below the laser emitter. may be included. Impingement of cooling fluid on this portion of the upper anode cooler provides temperature control during operation of the laser emitter. Cooling allows for lower junction temperatures of the laser emitter during operation, thereby providing improved reliability of the device and/or operation of the laser emitter at higher current levels for higher power output. enable.

The back side of the receiving portion of the top anode cooler can be modified to improve the effectiveness of the cooling jets emerging from the bottom anode cooler and impinging on the top anode cooler. For example, this impingement surface of the upper anode cooler facilitates the mixing and circulation of the cooling fluid, so as to increase the area of contact through which convection occurs, so as to accelerate the transition of the cooling fluid into cooling turbulence. It may be non-planar and/or textured or shaped so as to interfere with any boundary layer in the cooling fluid jet. For example, the impact surface may incorporate a pattern of studs, grooves, and/or indentations to improve the thermal performance of the device. The upper anode cooler has reinforcements that improve the mechanical strength of the upper anode cooler (e.g., its resistance to mechanical deformation) while substantially maintaining the reduction in thermal resistance produced by the patterned impingement surface. Supports may also be incorporated. Such struts may allow at least a portion of the impingement surface to be extremely thin, thereby improving cooling of the overlying laser emitter. In various embodiments, reinforcing struts are formed in the bottom anode cooler. For example, struts may be formed and protrude above through-holes or nozzles formed in the bottom anode cooler to form cooling fluid jets.

In various embodiments, the top and bottom anode coolers, or at least the portions thereof with which the cooling fluid is in direct contact, resist both erosion caused by the moving cooling fluid and corrosion caused by reaction with the cooling fluid. comprising, consisting essentially of, or consisting of one or more materials. For example, embodiments of the present invention may utilize jets of cooling fluid traveling at a velocity of about 10 m/sec or even higher, such high velocity fluid (e.g., water) dissolving traditional heat sink materials such as aluminum or copper. may erode and/or corrode. These materials are preferably mechanically robust and rigid to resist deformation during operation, packaging, and storage, and are also at least somewhat electrically conductive. The material may have a coefficient of thermal expansion (CTE) that substantially matches that of the material of the laser emitter itself, such as GaAs (6-8 ppm CTE) or InP (4-5 ppm CTE). In various embodiments, the top and/or bottom anode cooler material has a CTE ranging from about 0.5 ppm to about 12 ppm, thereby providing low cycle fatigue during operation of the laser device and during the packaging process itself. allows for low stress. In various embodiments, the top and/or bottom anode cooler material has a CTE ranging from about 0.5 ppm to about 4 ppm, or from about 6 ppm to about 10 ppm. In various embodiments, one of the top or bottom anode coolers has a CTE ranging from about 0.5 ppm to about 4 ppm (or ranging from about 2 ppm to about 4 ppm), while the other has a CTE ranging from about 6 ppm to about 4 ppm. It has a CTE ranging from about 10 ppm (or ranging from about 6 ppm to about 8 ppm).

In an exemplary embodiment, all or a portion of the top and/or bottom anode cooler is made of copper and tungsten alloy (CuW), tungsten, tungsten carbide (WC), alumina, mullite, diamond, or silicon carbide (SiC). comprising, consisting essentially of, or consisting of one or more materials such as (eg, single crystal SiC). In various embodiments, all or a portion of the top and/or bottom anode coolers include, consist essentially of, or consist of another material such as aluminum, copper, or stainless steel; and/or at least a portion of the bottom anode cooler is coated with a coating of one or more materials such as CuW, tungsten, WC, alumina, mullite, diamond, or SiC. In various embodiments, the top anode cooler and the bottom anode cooler include, consist essentially of, or consist of different materials. For example, in various embodiments, the top anode cooler comprises, consists essentially of, or consists of SiC, while the bottom anode cooler comprises, consists essentially of, or consists of alumina. consists of it. In various embodiments, the top and/or bottom anode coolers are electrically insulating and/or free of, essentially free of, or free of one or more metals. One benefit of such an embodiment is the elimination of spurious charge conduction through the anode cooler that could thereby damage the beam emitter being cooled.

As utilized herein, a material with a high thermal conductivity or "thermally conductive material" is a material with a high thermal conductivity of at least 100 Watts per meter per Kelvin (W m ^-1 K ^-1 ), at least 170 W m ^{- 1} ·K ⁻¹ , at least 200 W·m ⁻¹ ·K ⁻¹ , at least 250 W·m ⁻¹ ·K ⁻¹ , or even at least 300 W·m ⁻¹ ·K ⁻¹ . As utilized herein, a material with high electrical conductivity or "conductive material" is, for example, at least 1 x 10 ⁵ Siemens per meter (S/m), at least 1 x 10 ⁶ Siemens per meter (S/m) at 20°C. S/m, or even at least 1×10 ⁷ S/m. As utilized herein, a material with a high electrical resistivity or “electrically insulating material” has a resistivity of at least 1×10 ⁸ ohm-meters (Ω·m), at least 1×10 ¹⁰ Ω·m, or even It has an electrical resistivity of at least 1×10 ¹² Ω·m.

Laser devices according to embodiments of the invention may be utilized in WBC systems to form high brightness, low beam parameter product (BPP) laser systems. BPP is the product of the divergence angle (half angle) of the laser beam and the radius of the beam at its narrowest point (ie, beam waist, minimum spot size). BPP quantifies the quality of a laser beam and the extent to which it can be focused into a small spot and is typically expressed in units of millimeters-milliradians (mm-mrad). A Gaussian beam has the lowest possible BPP as determined by the wavelength of the laser light divided by pi. The ratio of the BPP of a real beam to the BPP of an ideal Gaussian beam at the same wavelength is expressed as ^M2 or the "beam quality factor", which is a wavelength-independent measure of beam quality, and the "best" quality is Corresponds to a "lowest" beam quality factor of 1.

As known to those skilled in the art, a laser is generally defined as a device that generates visible or invisible light through stimulated emission of light. Lasers generally have properties that make them useful in a variety of applications such as those mentioned above. Common laser types include semiconductor lasers (eg, laser diodes and diode bars), solid state lasers, fiber lasers, and gas lasers. Laser diodes are generally based on a simple diode structure that supports the emission of photons (light). However, to improve efficiency, power, beam quality, brightness, tunability, etc., this simple structure is generally modified to provide a variety of many practical types of laser diodes. Laser diode types include small edge-emitting types that produce output power from a few milliwatts to approximately half a watt in a beam with high beam quality. The structure type of diode lasers is a double heterostructure laser that includes a layer of low bandgap material sandwiched between two high bandgap layers; a very thin intermediate layer (quantum well) that provides high efficiency and quantization of the laser's energy. a quantum well laser comprising more than one quantum well layer to improve the gain characteristics; a quantum well laser comprising more than one quantum well layer to improve the gain characteristics; a quantum wire or to replacing the intermediate layer with a wire or dot to produce a higher efficiency quantum well laser quantum sea (dot) laser; quantum cascade laser that allows lasing at relatively long wavelengths that can be tuned by modifying the thickness of the quantum layer; the most common commercial laser diode and produced A separate confinement heterostructure laser that includes two layers above and below a quantum well layer to efficiently confine light; commonly used in demanding optical communications applications, with a simple A distributed feedback laser containing an integrated grating that facilitates generating a stable set of wavelengths during manufacturing by reflecting one wavelength; another laser in that light is emitted from its surface rather than its edges; Vertical cavity surface emitting lasers (VCSELs), which have a structure different from diodes; and vertical external cavity surface emitting lasers (VECSELs), which are tunable lasers that primarily use double heterostructure diodes and include a grating or multi-prism grating configuration. ) and external cavity diode lasers. External cavity diode lasers are often wavelength tunable and exhibit small emission linewidths. Laser diode types are characterized by multimode diodes with elongated output facets and generally have poor beam quality, but broad-area lasers that generate several watts of power; compared with broad-area lasers, improved beam quality and Tapered lasers characterized by astigmatic mode diodes with tapered output facets exhibiting brightness; ridge waveguide lasers characterized by elliptical mode diodes with oblong output facets; and circular with output facets It also includes a variety of high power diode-based lasers, including slab-coupled optical waveguide lasers (SCOWLs), which are characterized by mode diodes and can generate Watt-level output in a diffraction-limited beam with a generally circular profile.

A diode laser bar is a type of semiconductor laser that includes a one-dimensional array of broad-area emitters or, alternatively, a subarray that includes, for example, 10 to 20 narrow stripe emitters. Broad area diode bars typically include, for example, 19 to 49 emitters, each having dimensions of approximately 1 μm by 100 μm. Beam quality along the 1 μm dimension or fast axis is typically diffraction limited. Beam quality along the 100 μm dimension or slow axis or array dimension is typically many times diffraction limited. Typically, a diode bar for commercial applications has a laser cavity length of about 1-4 mm, is about 10 mm wide, and produces an output power of several tens of watts. Most diode bars operate within the wavelength range of 780-1,070 nm, with wavelengths of 808 nm (for pumping neodymium lasers) and 940 nm (for pumping Yb:YAG) being the most prominent. The wavelength range of 915-976 nm is used to pump erbium-doped or ytterbium-doped high-power fiber lasers and amplifiers.

Embodiments of the invention couple one or more input laser beams (eg, emitted by a laser device packaged as detailed herein) into an optical fiber. In various embodiments, the optical fiber includes multiple cladding layers surrounding a single core, multiple separate core regions (or "cores") within a single cladding layer, or multiple cladding layers. It has multiple cores surrounded by.

As used herein, "optical element" refers to a lens, mirror, prism, grating, etc. that redirects, reflects, bends, or optically manipulates electromagnetic radiation in any other manner. It can refer to any one of them. As used herein, beam emitter, emitter, or laser emitter or laser refers to any electromagnetic beam generating device, such as a semiconductor element, which generates an electromagnetic beam and which may or may not be self-resonant. include. These also include fiber lasers, disk lasers, non-solid state lasers, etc. Generally, each emitter includes a back reflective surface, at least one optical gain medium, and a front reflective surface. Optical gain media increase the gain of electromagnetic radiation, which can be visible, infrared, and/or ultraviolet light, but is not limited to any particular portion of the electromagnetic spectrum. The emitter may include or consist essentially of multiple beam emitters, such as diode bars configured to emit multiple beams. The input beams received in embodiments herein may be single wavelength or multiwavelength beams that are combined using various techniques known to those skilled in the art. In addition, references herein to "laser," "laser emitter," or "beam emitter" refer not only to single diode lasers, but also to diode bars, laser arrays, diode bar arrays, and single vertical cavity planes. Also includes light emitting lasers (VCSELs) or arrays thereof.

In one aspect, embodiments of the invention feature a laser package that includes, consists essentially of, or consists of a bottom anode cooler and a top anode cooler. The bottom anode cooler defines a plurality of ports at least partially therethrough for forming jets of cooling fluid through the ports. A top anode cooler is placed above the bottom anode cooler. The upper anode cooler includes or defines a laser platform for receiving the laser emitter thereon. The upper anode cooler defines a recess therein. A recess is placed below the laser platform. The recess has an impingement surface facing the port of the bottom anode cooler so that cooling fluid introduced into the bottom anode cooler and jetted through the port is directed to the impingement surface of the top anode cooler. Impact and cool the laser emitter placed on the laser platform.

Embodiments of the invention may include one or more of the following in any of various combinations. At least a portion of the bottom anode cooler and/or the top anode cooler comprises or consists essentially of copper, aluminum, stainless steel, CuW, tungsten, WC (tungsten carbide), alumina, mullite, diamond, and/or SiC. consists of or can consist of them. At least a portion of the impingement surface has a pattern (e.g., a raised and/or recessed texture, roughness, and/or a set of raised and/or recessed features) to enhance cooling of the ejected cooling fluid. ) can be defined. The pattern may include, consist essentially of, or consist of indentations, grooves, and/or studs. At least a portion of the impact surface may define a plurality of struts to improve mechanical stability of the laser platform. The package may include a cathode cooler positioned above a top anode cooler. A portion of the cathode cooler may overhang and not be in contact with the laser platform of the upper anode cooler. The ports may be spaced from the impingement surface to form a mixing channel. The package includes an inlet line for conducting cooling fluid through the bottom anode cooler and into the proximal end of the mixing channel through (i) a port and (ii) conducting cooling fluid out from the distal end of the mixing channel. and an exit line for. The mixing channel may have a height selected from a range of about 0.01 mm to about 30 mm. The center-to-center spacing of the ports may be selected from a range of about 0.1 mm to about 8 mm. The diameter (or other lateral dimension, such as width or length) of at least one of the ports may be selected from a range of about 0.025 mm to about 5 mm. The ratio of the height of the mixing channel to the diameter of at least one of the ports may be selected from a range of about 0.1 to about 30. The coefficient of thermal expansion of the top anode cooler and/or the bottom anode cooler may be selected from a range of about 0.5 ppm to about 12 ppm, or even about 3 ppm to about 10 ppm. The package may include a laser emitter located on the laser platform. Laser emitters may each include, or consist essentially of, one or more diode bars that emit and are configured to emit a plurality of separate beams (eg, laser beams).

In another aspect, embodiments of the invention include or essentially include a beam emitter, focusing optics, a dispersive element, a plurality of reflective output couplers, a bottom anode cooler, and a top anode cooler. a wavelength beam combining laser system consisting of or consisting of the following: The beam emitter emits a plurality of separate beams (eg, laser beams) and may have first and second opposing surfaces. Concentrating optics focus the beams onto the dispersive element. The distance between the dispersive element and the concentrating optic may approximately correspond to the focal length of the concentrating optic (in other embodiments, this distance is less than or greater than the focal length of the concentrating optic). ). A dispersive element receives and disperses the received concentrated beam. A plurality of reflective output couplers receive the dispersed beam and direct it therethrough as a multi-wavelength output beam (i.e., through the output couplers, e.g., toward a workpiece to be processed with or to receive the multi-wavelength beam). (a) positioned to transmit a portion of the dispersed beam and reflect a second portion of the dispersed beam back toward the dispersive element; A second portion of the dispersed beam may propagate back to the beam emitter as feedback for the beams, fixing each beam at its individual wavelength. The wavelengths of the different beams may be different from each other. The bottom anode cooler defines a plurality of ports at least partially therethrough for forming jets of cooling fluid through the ports. A top anode cooler is placed above the bottom anode cooler. The upper anode cooler includes or defines a laser platform for receiving the laser emitter thereon. The upper anode cooler defines a recess therein. A recess is placed below the laser platform. The recess has an impingement surface facing the port of the bottom anode cooler so that cooling fluid introduced into the bottom anode cooler and jetted through the port is directed to the impingement surface of the top anode cooler. Impact and cool the beam emitter placed on the laser platform.

Embodiments of the invention may include one or more of the following in any of various combinations. The dispersive element may include, consist essentially of, or consist of a diffraction grating (eg, a reflection or transmission grating). At least a portion of the impingement surface has a pattern (e.g., a raised and/or recessed texture, roughness, and/or a set of raised and/or recessed features) to enhance cooling of the ejected cooling fluid. ) can be defined. The pattern may include, consist essentially of, or consist of indentations, grooves, and/or studs. At least a portion of the impact surface may define a plurality of struts to improve mechanical stability of the laser platform. The package may include a cathode cooler positioned above a top anode cooler. A portion of the cathode cooler may overhang and not be in contact with the laser platform of the upper anode cooler. A portion of the cathode cooler may be placed above and in thermal contact with the beam emitter.

In yet another aspect, embodiments of the invention include an anode cooler, a laser platform on the anode cooler for receiving a laser emitter, and a mixing channel between the anode cooler and the laser platform; characterized by a laser package consisting essentially of or consisting of the same. The mixing channel includes an impingement surface in thermal contact with the laser platform and a jet array opposite the impingement surface across the mixing channel. The jet array includes a plurality of ports for forming jets of cooling fluid therethrough, whereby the cooling fluid introduced into the anode cooler and jetted through the ports impinges on the impingement surface; Cool the laser emitter placed on the laser platform.

Embodiments of the invention may include one or more of the following in any of various combinations. The mixing channel may be partially or substantially completely enclosed within the anode cooler. At least a portion of the anode cooler comprises, consists essentially of, or consists of copper, aluminum, stainless steel, CuW, tungsten, WC (tungsten carbide), alumina, mullite, diamond, and/or SiC. It can consist of At least a portion of the impingement surface has a pattern (e.g., a raised and/or recessed texture, roughness, and/or a set of raised and/or recessed features) to enhance cooling of the ejected cooling fluid. ) can be defined. The pattern may include, consist essentially of, or consist of indentations, grooves, and/or studs. At least a portion of the impact surface may define a plurality of struts to improve mechanical stability of the laser platform. The package may include a cathode cooler disposed above the anode cooler. A portion of the cathode cooler may overhang and not be in contact with the laser platform of the anode cooler. The mixing channel may have a height selected from a range of about 0.01 mm to about 30 mm. The center-to-center spacing of the ports may be selected from a range of about 0.1 mm to about 8 mm. The diameter (or other lateral dimension, such as width or length) of at least one of the ports may be selected from a range of about 0.025 mm to about 5 mm. The ratio of the height of the mixing channel to the diameter of at least one of the ports may be selected from a range of about 0.1 to about 30. The coefficient of thermal expansion of the anode cooler may be selected from a range of about 0.5 ppm to about 12 ppm, or even about 3 ppm to about 10 ppm. The package may include a laser emitter located on the laser platform. Laser emitters may include, or consist essentially of, one or more diode bars, each of which emits and is configured to emit a plurality of separate beams (eg, laser beams).

In another aspect, embodiments of the invention include a beam emitter, concentrating optics, a dispersive element, a plurality of reflective output couplers, an anode cooler, and an anode cooler for receiving the beam emitter. A wavelength beam combining laser system comprising, consisting essentially of, or consisting of a laser platform and a mixing channel between an anode cooler and the laser platform. The beam emitter emits a plurality of separate beams (eg, laser beams) and may have first and second opposing surfaces. Concentrating optics focus the beams onto the dispersive element. The distance between the dispersive element and the concentrating optic may approximately correspond to the focal length of the concentrating optic (in other embodiments, this distance is less than or greater than the focal length of the concentrating optic). ). A dispersive element receives and disperses the received concentrated beam. A plurality of reflective output couplers receive the dispersed beam and direct it therethrough as a multi-wavelength output beam (i.e., through the output couplers, e.g., toward a workpiece to be processed with or to receive the multi-wavelength beam). (a) positioned to transmit a portion of the dispersed beam and reflect a second portion of the dispersed beam back toward the dispersive element; A second portion of the dispersed beam may propagate back to the beam emitter as feedback for the beams, fixing each beam at its respective wavelength. The wavelengths of the different beams may be different from each other. The mixing channel includes an impingement surface in thermal contact with the laser platform and a jet array opposite the impingement surface across the mixing channel. The jet array includes a plurality of ports for forming jets of cooling fluid therethrough, whereby the cooling fluid introduced into the anode cooler and jetted through the ports impinges on the impingement surface; Cool the beam emitter placed on the laser platform.

Embodiments of the invention may include one or more of the following in any of various combinations. The dispersive element may include, consist essentially of, or consist of a diffraction grating (eg, a reflection or transmission grating). At least a portion of the impingement surface has a pattern (e.g., a raised and/or recessed texture, roughness, and/or a set of raised and/or recessed features) to enhance cooling of the ejected cooling fluid. ) can be defined. The pattern may include, consist essentially of, or consist of indentations, grooves, and/or studs. At least a portion of the impact surface may define a plurality of struts to improve mechanical stability of the laser platform. The package may include a cathode cooler disposed above the anode cooler. A portion of the cathode cooler may be overhanging and not in contact with the laser platform. A portion of the cathode cooler may be placed above and in thermal contact with the beam emitter.

In one aspect, embodiments of the invention feature a laser package that includes, consists essentially of, or consists of a bottom anode cooler and a top anode cooler. The bottom anode cooler includes: (i) a top surface; (ii) a bottom surface opposite the top surface; (iii) an entry recess defined in the bottom surface; (iv) a top recess defined in the top surface; v) a plurality of hollow ports for forming jets of cooling fluid therethrough fluidly connecting the entry recess and the upper recess; A top anode cooler is placed above the bottom anode cooler. The top anode cooler may be placed over only a portion of the bottom anode cooler. The top anode cooler may be in direct mechanical contact with the bottom anode cooler. The top anode cooler can be attached directly to the bottom anode cooler via attachment material. The upper anode cooler has (i) a top surface and (ii) a bottom surface opposite the top surface. The bottom surface includes, consists essentially of, or consists of an impingement surface defining a non-planar pattern projecting into the top recess of the bottom anode cooler, thereby introducing into the bottom anode cooler. The cooling fluid ejected through the port impinges on the impingement surface of the upper anode cooler and cools the laser emitter disposed on the top surface of the upper anode cooler.

Embodiments of the invention may include one or more of the following in any of various combinations. At least a portion of the bottom anode cooler and/or the top anode cooler comprises or consists essentially of copper, aluminum, stainless steel, CuW, tungsten, WC (tungsten carbide), alumina, mullite, diamond, and/or SiC. consists of or can consist of them. The thermal conductivity of the top anode cooler may exceed that of the bottom anode cooler. The non-planar pattern may include, consist essentially of, or consist of a plurality of raised features. The bottom anode cooler may define a plurality of raised struts disposed between the openings of the ports. The package may include a cathode cooler positioned above a top anode cooler. A portion of the cathode cooler may overhang and not touch the top surface of the upper anode cooler. The cathode cooler may not be configured for flow of cooling fluid therethrough. The upper anode cooler may not be configured for flow of cooling fluid therethrough.

The non-planar pattern may be spaced from the port openings to form mixing channels for the cooling fluid. The mixing channel may have a height selected from a range of about 0.025 mm to about 50 mm. The ratio of the height of the mixing channel to the diameter of at least one of the ports may be selected from a range of about 0.1 to about 30. The ratio of the height of the mixing channel to the diameter of at least one of the ports may be selected from a range of about 8 to about 30. The ratio of the height of the mixing channel to the diameter of at least one of the ports may be selected from a range of about 0.1 to about 2. The center-to-center spacing of the ports may be selected from a range of about 0.1 mm to about 8 mm. The diameter (or other lateral dimension, such as width or length) of at least one of the ports may be selected from a range of about 0.025 mm to about 5 mm. The area, length, and/or width of the top surface of the top anode cooler may be less than the area, length, and/or width of the top surface of the bottom anode cooler. The bottom anode cooler may define an outlet channel therein fluidly connecting the upper recess with an outlet aperture defined in the bottom surface of the bottom anode cooler and spaced from the entry recess. The attachment material may attach a portion of the bottom surface (eg, at least a portion of the peripheral portion) of the top anode cooler to a portion of the top surface of the bottom anode cooler. The attachment material may include, consist essentially of, or consist of adhesives, solders, and/or brazing materials. The coefficient of thermal expansion of the top anode cooler and/or the bottom anode cooler may be selected from a range of about 0.5 ppm to about 12 ppm. The bottom anode cooler may include, consist essentially of, or consist of alumina, and/or the top anode cooler may include, consist essentially of, or consist of SiC. The top anode cooler and/or the bottom anode cooler may be electrically insulated. The package may include a laser emitter located on the laser platform. Laser emitters each include, consist essentially of, or consist of one or more diode bars that emit and are configured to emit a plurality of separate beams (e.g., laser beams). It can happen.

In another aspect, embodiments of the invention include or essentially include a beam emitter, focusing optics, a dispersive element, a plurality of reflective output couplers, a bottom anode cooler, and a top anode cooler. a wavelength beam combining laser system consisting of or consisting of the following: The beam emitter emits a plurality of separate beams (eg, laser beams) and may have first and second opposing surfaces. Concentrating optics concentrate and/or converge the plurality of beams toward the dispersive element. The distance between the dispersive element and the focusing optic may approximately correspond to the focal length of the focusing optic (in other embodiments, this distance is less than or greater than the focal length of the focusing optic). . A dispersive element receives and disperses the received concentrated beam. A plurality of reflective output couplers receive the dispersed beam and direct it therethrough as a multi-wavelength output beam (i.e., through the output couplers, e.g., toward a workpiece to be processed with or to receive the multi-wavelength beam). (a) positioned to transmit a portion of the dispersed beam and reflect a second portion of the dispersed beam back toward the dispersive element; A second portion of the dispersed beam may propagate back to the beam emitter as feedback for the beams, fixing each beam at its individual wavelength. The wavelengths of the different beams may be different from each other. The bottom anode cooler includes: (i) a top surface; (ii) a bottom surface opposite the top surface; (iii) an entry recess defined in the bottom surface; (iv) a top recess defined in the top surface; v) a plurality of hollow ports for forming jets of cooling fluid therethrough fluidly connecting the entry recess and the upper recess; A top anode cooler is placed above the bottom anode cooler. The top anode cooler may be placed over only a portion of the bottom anode cooler. The top anode cooler may be in direct mechanical contact with the bottom anode cooler. The top anode cooler can be attached directly to the bottom anode cooler via attachment material. The upper anode cooler has (i) a top surface and (ii) a bottom surface opposite the top surface. A beam emitter is disposed across or on top of the upper anode cooler. The bottom surface includes, consists essentially of, or consists of an impingement surface defining a non-planar pattern projecting into the top recess of the bottom anode cooler, thereby introducing into the bottom anode cooler. The cooling fluid ejected through the port impinges on the impingement surface of the upper anode cooler and cools the beam emitter.

Embodiments of the invention may include one or more of the following in any of various combinations. The dispersive element may include, consist essentially of, or consist of a diffraction grating (eg, a reflection or transmission grating). At least a portion of the bottom anode cooler and/or the top anode cooler comprises or consists essentially of copper, aluminum, stainless steel, CuW, tungsten, WC (tungsten carbide), alumina, mullite, diamond, and/or SiC. consists of or can consist of them. The thermal conductivity of the top anode cooler may exceed that of the bottom anode cooler. The non-planar pattern may include, consist essentially of, or consist of a plurality of raised features. The bottom anode cooler may define a plurality of raised struts disposed between the openings of the ports. The laser system may include a cathode cooler positioned above an upper anode cooler. A portion of the cathode cooler may overhang and not touch the top surface of the upper anode cooler. The cathode cooler may not be configured for the flow of cooling fluid therethrough. The upper anode cooler may not be configured for the flow of cooling fluid therethrough.

The non-planar pattern may be spaced from the port openings to form mixing channels for the cooling fluid. The mixing channel may have a height selected from a range of about 0.025 mm to about 50 mm. The ratio of the height of the mixing channel to the diameter of at least one of the ports may be selected from a range of about 0.1 to about 30. The ratio of the height of the mixing channel to the diameter of at least one of the ports may be selected from a range of about 8 to about 30. The ratio of the height of the mixing channel to the diameter of at least one of the ports may be selected from a range of about 0.1 to about 2. The center-to-center spacing of the ports may be selected from a range of about 0.1 mm to about 8 mm. The diameter (or other lateral dimension, such as width or length) of at least one of the ports may be selected from a range of about 0.025 mm to about 5 mm. The area, length, and/or width of the top surface of the top anode cooler may be less than the area, length, and/or width of the top surface of the bottom anode cooler. The bottom anode cooler may define an outlet channel therein fluidly connecting the upper recess with an outlet aperture defined in the bottom surface of the bottom anode cooler and spaced from the entry recess. The attachment material may attach a portion of the bottom surface (eg, at least a portion of the peripheral portion) of the top anode cooler to a portion of the top surface of the bottom anode cooler. The attachment material may include, consist essentially of, or consist of adhesives, solders, and/or brazing materials. The coefficient of thermal expansion of the top anode cooler and/or the bottom anode cooler may be selected from a range of about 0.5 ppm to about 12 ppm. The bottom anode cooler may include, consist essentially of, or consist of alumina, and/or the top anode cooler may include, consist essentially of, or consist of SiC. The beam emitter may include or consist essentially of one or more diode bars. The top anode cooler and/or the bottom anode cooler may be electrically insulated.

These and other objects, together with the advantages and features of the invention disclosed herein, will become more apparent through reference to the following description, accompanying drawings, and claims. Furthermore, it is to be understood that the features of the various embodiments described herein are not mutually exclusive and may exist in various combinations and permutations. As used herein, the term "substantially" means ±10%, and in some embodiments, ±5%. The term "consisting essentially of" means to exclude other materials that contribute to the function, unless otherwise defined herein. Nevertheless, such other materials may be present in minor amounts, collectively or individually. As used herein, the terms "radiation" and "light" are used interchangeably, unless indicated otherwise. As used herein, the term "downstream" or "optically downstream" is utilized to indicate the relative placement of a second element that the light beam strikes after encountering the first element; The element is "downstream" or "optically downstream" of the second element. As used herein, the "optical distance" between two components is the distance between the two components that is actually traveled by a beam of light; the optical distance is, for example, reflected from a mirror, or It can, but is not necessarily, equal to the physical distance between two components due to the change in propagation direction experienced by light traveling from one of the elements to the other.
The present invention provides, for example, the following.
(Item 1)
A laser package, the laser package comprising:
A bottom anode cooler, the bottom anode cooler comprising: (i) a top surface; (ii) a bottom surface opposite the top surface; (iii) an entry recess defined in the bottom surface; (iv) an upper recess defined in the upper surface; and (v) a plurality of hollow ports, the plurality of hollow ports fluidly connecting the entry recess and the upper recess and allowing air to flow through them. a bottom anode cooler forming a jet of cooling fluid;
an upper anode cooler disposed above only a portion of the bottom anode cooler;
Equipped with
The upper anode cooler has (i) a top surface; and (ii) a bottom surface opposite the top surface;
The bottom surface includes an impingement surface defining a non-planar pattern that protrudes into the top recess of the bottom anode cooler, thereby causing a droplet to be introduced into the bottom anode cooler and ejected through the port. The cooled cooling fluid impinges on the impingement surface of the upper anode cooler to cool a laser emitter disposed on the upper surface of the upper anode cooler.
(Item 2)
The laser package of item 1, wherein the thermal conductivity of the top anode cooler is greater than the thermal conductivity of the bottom anode cooler.
(Item 3)
The laser package of item 1, wherein the non-planar pattern comprises a plurality of raised features.
(Item 4)
The laser package of item 1, wherein the bottom anode cooler defines a plurality of raised struts disposed between openings of the ports.
(Item 5)
Item 1, further comprising: (i) a cathode cooler disposed above the upper anode cooler, a portion of the cathode cooler overhanging and not in contact with a top surface of the upper anode cooler. laser package.
(Item 6)
6. The laser package of item 5, wherein the cathode cooler is not configured for flow of cooling fluid therethrough.
(Item 7)
The laser package of item 1, wherein the upper anode cooler is not configured for flow of cooling fluid therethrough.
(Item 8)
The laser package of item 1, wherein the non-planar pattern is spaced from the port opening to form a mixing channel for the cooling fluid.
(Item 9)
9. The laser package of item 8, wherein the mixing channel has a height selected from a range of about 0.025 mm to about 50 mm.
(Item 10)
9. The laser package of item 8, wherein the ratio of the height of the mixing channel to the diameter of at least one of the ports is selected from a range of about 0.1 to about 30.
(Item 11)
9. The laser package of item 8, wherein the ratio of the height of the mixing channel to the diameter of at least one of the ports is selected from a range of about 8 to about 30.
(Item 12)
9. The laser package of item 8, wherein the ratio of the height of the mixing channel to the diameter of at least one of the ports is selected from a range of about 0.1 to about 2.
(Item 13)
The laser package of item 1, wherein the center-to-center spacing of the ports is selected from a range of about 0.1 mm to about 8 mm.
(Item 14)
The laser package of item 1, wherein the diameter of at least one of the ports is selected from a range of about 0.025 mm to about 5 mm.
(Item 15)
The laser package of item 1, wherein the area of the top surface of the top anode cooler is smaller than the area of the top surface of the bottom anode cooler.
(Item 16)
The bottom anode cooler defines an outlet channel therein, the outlet channel fluidly connecting the top recess with an outlet opening defined in the bottom surface of the bottom anode cooler, and the outlet channel fluidly connecting the top recess with an outlet opening defined in the bottom surface of the bottom anode cooler. is spaced apart from the entry recess.
(Item 17)
2. The laser package of item 1, further comprising a mounting material that attaches a portion of the bottom surface of the top anode cooler to a portion of the top surface of the bottom anode cooler.
(Item 18)
18. The laser package of item 17, wherein the attachment material comprises at least one of an adhesive, a solder, or a brazing material.
(Item 19)
The laser package of item 1, wherein the bottom anode cooler comprises alumina and the top anode cooler comprises SiC.
(Item 20)
The laser package of item 1, wherein the top anode cooler and the bottom anode cooler are electrically insulated.
(Item 21)
The laser package of item 1, further comprising a laser emitter disposed on the top surface of the upper anode cooler, the laser emitter comprising a laser diode bar configured to emit a plurality of beams. .
(Item 22)
A wavelength beam combining laser system, the laser system comprising:
a beam emitter that emits a plurality of separate beams;
a focusing optical system for focusing the plurality of beams toward a dispersive element;
the beam receiving; a dispersing element for dispersing the received beam;
a plurality of reflective output couplers, the plurality of reflective output couplers configured to receive the dispersed beam, transmit a portion of the dispersed beam therethrough as a multi-wavelength output beam; a plurality of reflective output couplers positioned to reflect a second portion of the dispersed beam back toward the element;
A bottom anode cooler, the bottom anode cooler comprising: (i) a top surface; (ii) a bottom surface opposite the top surface; (iii) an entry recess defined in the bottom surface; (iv) an upper recess defined in the upper surface; and (v) a plurality of hollow ports, the plurality of hollow ports fluidly connecting the entry recess and the upper recess and allowing air to flow through them. a bottom anode cooler forming a jet of cooling fluid;
an upper anode cooler disposed above only a portion of the bottom anode cooler;
Equipped with
The upper anode cooler has (i) a top surface, the beam emitter being disposed on the top surface of the upper anode cooler, and (ii) a bottom surface opposite the top surface. and the bottom surface includes an impingement surface defining a non-planar pattern protruding into the upper recess of the bottom anode cooler so that the A laser system in which cooling fluid ejected through a port impinges on the impingement surface of the upper anode cooler to cool the beam emitter.
(Item 23)
23. The laser system of item 22, wherein the dispersive element comprises a diffraction grating.
(Item 24)
23. The laser system of item 22, wherein the thermal conductivity of the top anode cooler is greater than the thermal conductivity of the bottom anode cooler.
(Item 25)
23. The laser system of item 22, wherein the non-planar pattern comprises a plurality of raised features.
(Item 26)
23. The laser system of item 22, wherein the bottom anode cooler defines a plurality of raised struts disposed between openings of the ports.
(Item 27)
Item 22, further comprising: (i) a cathode cooler disposed above the upper anode cooler, a portion of the cathode cooler overhanging and not in contact with the upper surface of the upper anode cooler. laser system.
(Item 28)
28. The laser system of item 27, wherein the cathode cooler is not configured for flow of cooling fluid therethrough.
(Item 29)
23. The laser system of item 22, wherein the upper anode cooler is not configured for flow of cooling fluid therethrough.
(Item 30)
23. The laser system of item 22, wherein the non-planar pattern is spaced from an opening of the port to form a mixing channel for the cooling fluid.
(Item 31)
31. The laser system of item 30, wherein the mixing channel has a height selected from a range of about 0.025 mm to about 50 mm.
(Item 32)
31. The laser system of item 30, wherein the ratio of the height of the mixing channel to the diameter of at least one of the ports is selected from a range of about 0.1 to about 30.
(Item 33)
31. The laser system of item 30, wherein the ratio of the height of the mixing channel to the diameter of at least one of the ports is selected from a range of about 8 to about 30.
(Item 34)
31. The laser system of item 30, wherein the ratio of the height of the mixing channel to the diameter of at least one of the ports is selected from a range of about 0.1 to about 2.
(Item 35)
23. The laser system of item 22, wherein the port center-to-center spacing is selected from a range of about 0.1 mm to about 8 mm.
(Item 36)
23. The laser system of item 22, wherein the diameter of at least one of the ports is selected from a range of about 0.025 mm to about 5 mm.
(Item 37)
23. The laser system of item 22, wherein the area of the top surface of the top anode cooler is less than the area of the top surface of the bottom anode cooler.
(Item 38)
The bottom anode cooler defines an outlet channel therein, the outlet channel fluidly connecting the top recess with an outlet opening defined in the bottom surface of the bottom anode cooler, and the outlet channel fluidly connecting the top recess with an outlet opening defined in the bottom surface of the bottom anode cooler. is spaced apart from the entry recess.
(Item 39)
23. The laser system of item 22, further comprising a mounting material that attaches a portion of the bottom surface of the top anode cooler to a portion of the top surface of the bottom anode cooler.
(Item 40)
40. The laser system of item 39, wherein the attachment material comprises at least one of an adhesive, a solder, or a brazing material.
(Item 41)
23. The laser system of item 22, wherein the bottom anode cooler comprises alumina and the top anode cooler comprises SiC.
(Item 42)
23. The laser system of item 22, wherein the top anode cooler and the bottom anode cooler are electrically insulated.

In the drawings, like reference symbols generally refer to the same parts throughout the different figures. Additionally, the drawings are not necessarily to scale, emphasis instead generally being placed upon illustrating the principles of the invention. In the following description, various embodiments of the invention are described with reference to the following drawings.

FIG. 1 is a perspective view of a two-piece anode cooler for a laser emitter, according to an embodiment of the invention.

FIG. 2 is a perspective view of a laser package incorporating the two-piece anode and cathode coolers of FIG. 1, according to an embodiment of the invention.

3A-3C are perspective, top, and bottom views, respectively, of a bottom anode cooler, according to an embodiment of the invention.

FIG. 4 is a schematic illustration of a fluid jet formed by an opening in a bottom anode cooler, according to an embodiment of the invention.

FIG. 5A is a side view of a top anode cooler, according to an embodiment of the invention.

FIG. 5B is a cross-sectional view of the upper anode cooler of FIG. 5A.

FIG. 5C is an enlarged portion of the cross-sectional view of FIG. 5B.

FIG. 5D is a bottom view of the upper anode cooler of FIG. 5A.

FIG. 6A is a bottom view of a top anode cooler, according to an embodiment of the invention.

FIG. 6B is a cross-sectional view of the upper anode cooler of FIG. 6A.

FIG. 6C is a bottom view of a top anode cooler, according to an embodiment of the invention.

FIG. 6D is a cross-sectional view of the upper anode cooler of FIG. 6C.

FIG. 7 is a side/cross-sectional view of a laser package, according to an embodiment of the invention.

FIG. 8A is an exploded cross-sectional view of a two-piece anode cooler for a laser emitter, according to an embodiment of the invention.

FIG. 8B is an exploded cross-sectional view of a two-piece anode cooler for a laser emitter, according to an embodiment of the invention.

FIG. 8C is a cross-sectional view of a two-piece anode cooler for a laser emitter, according to an embodiment of the invention.

FIG. 8D is a perspective view of an upper anode cooler, according to an embodiment of the invention.

FIG. 8E is a perspective view of a bottom anode cooler, according to an embodiment of the invention.

FIG. 9 is a schematic diagram of a wavelength beam combining laser system incorporating a packaged laser according to an embodiment of the invention.

FIG. 1 depicts a two-piece anode cooler 100 according to an embodiment of the invention. As shown, cooler 100 includes, consists essentially of, or consists of a top anode cooler 110 located above a bottom anode cooler 120 . The upper anode cooler 110 typically features a platform 130 on which a laser emitter (not shown for clarity) is located. Platform 130 may be sized and shaped to accommodate a desired laser emitter (eg, a diode bar). As shown, the platform 130 may be slightly elevated above the rest of the upper anode cooler in the intended emission direction of the laser emitter. In other embodiments, the top surface of upper anode cooler 110 is substantially planar and platform 130 is part of that planar surface. Top anode cooler 110 may be secured to bottom anode cooler 120 via one or more screws or other fasteners, at least during operation. In other embodiments, the top and bottom anode coolers 110, 120 are attached together, for example, utilizing techniques such as welding, soldering, or brazing, thereby providing integrated one-piece anode cooling. Form a vessel. In such embodiments, the upper anode cooler 110 may not define holes or openings therethrough for receiving screws or other fasteners. In yet other embodiments, the top and bottom anode coolers 110, 120 may be replaced by single-piece anode coolers having the characteristics of the top and bottom anode coolers 110, 120 detailed herein; Such single-piece coolers may be machined from solid metal or other pieces of material. Accordingly, references herein to "top anode cooler" and "bottom anode cooler" refer to machined, in various embodiments, from a single piece of material or (e.g., welded, soldered) may be taken to refer to the corresponding parts of an integrated "anode cooler" that are either fabricated as multiple parts that are substantially permanently fastened together (by brazing, etc.).

As described in more detail below, the bottom anode cooler 120 incorporates an array of cooling jets through which a cooling fluid (e.g., water) flows to the top anode directly below the laser emitter. impingement surface on cooler 110; The jet of cooling fluid cools the laser emitter, thereby improving performance and reliability and/or enabling high current (and therefore high power) operation. All or a portion of the top anode cooler 110 and/or the bottom anode cooler 120 may include or consist of one or more materials such as copper, CuW, tungsten, alumina, mullite, diamond, SiC, and/or WC. consists of or may consist of. In various embodiments, all or a portion of the top and/or bottom anode coolers 110, 120 include, consist essentially of, or consist of another material such as aluminum, copper, or stainless steel. , at least a portion of the top and/or bottom anode coolers 110, 120 are made of CuW, tungsten, WC, alumina, mullite, diamond, SiC, or one or more other materials that are resistant to fluid-induced corrosion and/or erosion. Coated with a coating of one or more materials, such as a coating material. All or a portion of top anode cooler 110 and/or bottom anode cooler 120 may be electrically insulated.

All or a portion of the top anode cooler 110 and/or the bottom anode cooler 120 may include, consist essentially of, or consist of different materials. For example, in various embodiments, top anode cooler 110 comprises, consists essentially of, or consists of SiC (e.g., single crystal SiC), while bottom anode cooler 120 comprises or consists of alumina. , consisting essentially of or consisting of. The use of different materials for the top and bottom anode coolers may provide one or more advantages in various embodiments of the invention. For example, in various embodiments, it is desirable for top anode cooler 110 to have a high thermal conductivity while bottom anode cooler 120 to have a lower thermal conductivity. (For example, in various embodiments, the thermal conductivity of the single crystal SiC cooler (which may depend on temperature) is between 300 and 400 W·m ⁻¹ ·K ⁻¹ , or even higher (e.g., up to about 500 W·m ^-1 ·K ^-1 ), while the thermal conductivity of the alumina cooler can range from 5 to 30 W·m ^-1 ·K ^-1 ). In various embodiments, the thermal conductivity of the upper anode cooler 110 The thermal conductivity exceeds the thermal conductivity of the bottom anode cooler 120 by a factor of 2 or more, 5 times or more, or even 10 times or more. In embodiments where the thermal conductivity of the top anode cooler 110 exceeds that of the bottom anode cooler 120, heat can be easily removed from the beam emitter by the top anode cooler 110, allowing for better thermal control of the beam emitter. While the bottom anode cooler 120 itself may be absorbing heat from the beam emitter, the top anode cooler 110, or a cooling fluid flowing through it (as detailed herein) more resistant to temperature fluctuations (and simultaneous mechanical stress and/or deformation) induced by heat from

In various embodiments, the top anode cooler 110 may include, for example, an attachment between the top anode cooler and a bottom anode cooler (in various embodiments, including or essentially a brazed or soldered joint attachment). containing, consisting essentially of, or consisting of semiconducting materials and/or materials with high electrical resistance (e.g., SiC) to prevent electrochemical corrosion in Consists of. The upper anode cooler 110 desirably also has high mechanical strength, allowing its thickness to be reduced or minimized, and from the pressure of the cooling fluid below the upper anode cooler 110. The cooling effect of the cooling fluid can be maximized while maintaining resistance to bending. Such bending can result in "smile" defects in the laser device and a concomitant loss of performance and/or efficiency of the laser system in which the laser device operates.

As mentioned above, in various embodiments, the bottom anode cooler 120 includes, consists essentially of, or consists of a material that has a low thermal conductivity (eg, alumina). The low thermal conductivity of the bottom anode cooler 120 may prevent bending or deformation of the laser device (and resulting output instability) resulting from the low temperature of the cooling fluid. In various embodiments of the present invention, the bottom anode cooler 120 comprises, consists essentially of, or consists of a ceramic material such that it can be fabricated by, for example, injection molding or three-dimensional printing. Complex shapes can be formed through additive manufacturing techniques.

FIG. 2 depicts a laser package 150 that incorporates the two-part anode cooler 100 of FIG. A cathode cooler 200 is added, which is located above the section). Cathode cooler 200 may improve the thermal performance of the packaged device by removing additional heat from the laser emitter. Cathode cooler 200 also improves the mechanical stability of the packaged device, thereby minimizing or substantially reducing packaging, burn-in, and/or deformation of the laser emitter during operation. can be eliminated. Cathode cooler 200 may be passively cooled or may incorporate one or more internal channels through which a cooling fluid is conducted. That is, in some embodiments, cathode cooler 200 may be configured to conduct cooling fluid therethrough, while in other embodiments, cathode cooler 200 is solid and conducts cooling fluid therethrough. may be configured not to accept or conduct. In various embodiments, the cathode cooler 200 is configured not to receive a laser emitter thereon, i.e., the cathode cooler 200 may not incorporate a laser emitter platform or another laser emitter thereon. may not be sized, shaped, and/or configured for attachment. As shown, cathode cooler 200 may have a top and/or bottom surface that is smaller in area, length, and/or width than that of bottom anode cooler 120. That is, in various embodiments, cathode cooler 200 does not entirely overlap (and/or has a different size than) bottom anode cooler 120 and/or top anode cooler 110.

The cathode cooler 200 may include, consist essentially of, or consist of one or more of the materials defined above for the top and bottom anode coolers 110, 120, or , one or more of the materials specified above for the top and bottom anode coolers 110, 120, or coated with one or more other materials (e.g., aluminum , copper, stainless steel), consisting essentially of them, or consisting of them. In other embodiments, cathode cooler 200 may include, consist essentially of, or consist of copper (eg, uncoated copper). In various embodiments, cathode cooler 200 may include, consist essentially of, or consist of electrically insulating materials such as those described above with respect to top and bottom anode coolers 110, 120.

3A, 3B, and 3C are perspective, top, and bottom views, respectively, of a bottom anode cooler 120 according to various embodiments of the invention. As shown, the bottom anode cooler 120 can be generally straight, with the connection of the bottom anode cooler 120 to the top anode cooler 110 and/or to the underlying substrate or mount or other hardware within the laser system. may feature one or more through holes 300 for. At least a portion 310 of the top surface of the bottom anode cooler 120 defines an array of openings (or "ports") 320 through which cooling fluid is directed toward the top anode cooler 110 and toward the bottom anode cooler 110. This portion of cooler 110 is also referred to herein as the “active cooling portion” 310. The openings 320 may be substantially cylindrical in shape and the cross-sectional area of the openings 320 may be substantially constant through their thickness. In other embodiments, the sidewalls of one or more of the openings 320 are tapered to form a nozzle. In various embodiments, the center-to-center spacing of openings 320 ranges from about 0.1 mm to about 8 mm. In various embodiments, the diameter (or other lateral dimension, eg, width, in embodiments featuring non-circular openings) of opening 320 ranges from about 0.025 mm to about 5 mm. The active cooling portion 310 of the bottom anode cooler 120 may be substantially rectangular in shape and may be substantially coplanar with the remainder of the top surface of the bottom anode cooler 120. In other embodiments, as shown in FIG. 3A, the active cooling portion 310 extends upwardly from the remainder of the top surface of the bottom anode cooler 120, for example, from about 0.1 mm to about 5 mm. In yet other embodiments, the active cooling portion (at least opening 320) is recessed below the remainder of the top surface of bottom anode cooler 120, for example, about 0.025 mm to about 50 mm.

The bottom anode cooler 120 also features passageways 330 for the inlet and outlet of cooling fluid, which is routed through the bottom anode cooler 120 and through the active cooling section 310 (as discussed in more detail below). It flows toward the top anode cooler 110 and back out from the bottom anode cooler 120 (eg, through one or more openings proximate the perimeter of the active cooling section). In operation, the flow of cooling fluid into, through, and out of bottom anode cooler 120 may be pulsed or substantially continuous.

FIG. 4 depicts a schematic diagram of a single cooling fluid jet 400 formed by one of the openings 320 in the bottom anode cooler 120, and in the figure shows the end of the nozzle (in an embodiment of the present invention). facing upward in Figure 4 but facing downward in Figure 4) is spaced a distance z ₀ from the impingement surface (towards which the cooling fluid flows, e.g. at least a portion of the impingement surface of the upper anode cooler). is placed.
This distance z ₀ between the opening 320 and the impingement surface defines the height of the "mixing channel" formed between the bottom anode cooler 120 and the top anode cooler 110, in which the Cooling fluid is ejected from the opening 320 to cool the impingement surface (and thus the laser emitter disposed thereon). In various embodiments, the mixing channel may also be considered to include an impingement surface. The nozzle has a diameter d. According to various embodiments of the invention, the ratio of z ₀ to d is about 0.1 to about 30, about 0.1 to about 2, about 0.1 to about 1, about 1 to about 2, about 8 to about 30, about 8 to about 10, about 10 to about 30, about 15 to about 30, or about 20 to about 30. Such a ratio of nozzle distance to nozzle diameter, in various embodiments, has been found to improve the thermal performance of the cooling fluid through the turbulence generated from the jets flowing through the nozzle; Ratios outside this range may result in insufficient turbulence, mixing, and cooling action of the cooling fluid. In various embodiments, the active cooling portion features a plurality of different openings 320. In such embodiments, the spacing between openings 320 is such that each opening is sufficient to minimize or substantially eliminate stagnation zones of ejection (as depicted in FIG. 4). may result in mixing of the cooling fluid ejected from the cooling fluid. That is, turbulence and/or mixing cooling fluid from adjacent jets can improve the cooling effect from the jets and vice versa.

5A and 5D are side and bottom views, respectively, of top anode cooler 110 according to various embodiments of the invention. As shown, FIG. 5B is a cross-sectional view taken through line 5B-5B on the diagram of FIG. 5A, and FIG. 5C is an enlarged view of a portion of FIG. 5B. As shown, the upper anode cooler 110 has a generally planar upper platform 130 for supporting the laser emitter. Below the laser emitter platform 130, the top anode cooler 110 may define a recess 500 for receiving the active cooling portion 310 of the bottom anode cooler 120 when the top and bottom anode coolers are mounted together. . Recess 510 may have a lower portion 502 sized and shaped to accommodate all or a portion of active cooling portion 310 of bottom anode cooler 120. In various embodiments, the thickness 503 of the lower portion 520 is approximately equal to the height that the active cooling portion 310 projects above the remaining portion of the top surface of the bottom anode cooler 120. Recess 510 may also have an upper portion 505 for receiving the cooling liquid jet generated by active cooling portion 310.

At least a portion of the upper surface of recess 500 forms an impingement surface 510 for receiving a jet of cooling fluid directed upwardly by active cooling portion 310 of bottom anode cooler 120 . The spacing 520 between the impingement surface 510 and the top surface of the upper anode cooler 110 (where the laser emitter is located) is typically quite small, thereby improving the cooling effectiveness of the jet. In various embodiments, this spacing 520 ranges from about 0.1 mm to about 5 mm.

As shown in FIGS. 5B and 5C, at least a portion of the impingement surface 510 of the upper anode cooler 110 may be modified (i.e., shaped) to improve the cooling effectiveness of jets directed thereon. For example, the impingement surface 510 may define one or more indentations 530 oriented upwardly toward the laser emitter, effectively creating a thin shaped region of the impingement surface 510. In other embodiments, recess 530 may be oriented downwardly and away from the laser emitter. The depression 530 (or other shape) may have a height 540 of, for example, 0.001 mm to 1.8 mm. Although the depressions 530 are depicted as circular in FIG. may have different shapes and may be distributed and/or spaced in any of a variety of different spacings or geometries.

Impingement surface 510 may define one or more struts 550 extending across the width of a recess within upper anode cooler 110. The struts 550 have a thickness 560 that exceeds the thickness of one or more peripheral portions of the upper anode cooler 110 (e.g., which may be shaped or otherwise thinned to improve the thermal performance of the cooling fluid jets). is defined by a portion of the upper anode cooler 110 having a . In various embodiments, the presence of one or more struts 550 within the recess 500 within the upper anode cooler 110 improves the mechanical strength of the upper anode cooler 110 during assembly and/or operation of the laser emitter. (e.g. resist deformation). According to various embodiments, the struts 550 can have a strut height 560 (ie, the distance of extension above the peripheral portion of the impact surface) ranging from about 0.01 mm to about 6.2 mm. The struts 550 can have a strut width 570 ranging from about 0.045 mm to about 6 mm. In various embodiments, the spacing 580 between adjacent struts can range from about 0.25 mm to about 3.6 mm. Although struts 550 are depicted in FIG. 5D as being rectangular and having a constant width, in various embodiments struts 550 may have other shapes. In various embodiments, upper anode cooler 110 does not incorporate struts 550. As shown in FIG. 5D, the top anode cooler 110 may also feature one or more through holes 590 to facilitate coupling of the top anode cooler 110 and the bottom anode cooler 120. In various embodiments, one or more struts 550 may be formed in the bottom anode cooler 120 in addition to or instead of being formed in the top anode cooler 110.

6A and 6C are bottom views of additional exemplary embodiments of upper anode cooler 110, according to additional embodiments of the present invention. As shown, FIG. 6B is a cross-sectional view of FIG. 6A along line 6B-6B, and FIG. 6D is a cross-sectional view of FIG. 6C along line 6D-6D. As shown in FIG. 6A, the impingement surface 510 of the upper anode cooler 100 may be modified to form a pattern of recessed grooves 600 spaced at intervals 610. In various embodiments, spacing 610 can range from about 0.01 mm to about 2.8 mm. As shown in FIG. 6C, the impingement surface 510 of the upper anode cooler 100 may be modified to form a pattern of studs 620 that are raised (i.e., away from the top surface of the upper anode cooler 110). As shown, the studs 620 can be substantially square or rectangular in cross-section and can be arranged in a regular pattern or grid. In other embodiments, all or some of the studs 620 may have other cross-sectional shapes (eg, circular, polygonal, etc.). In various embodiments, the size of one or more of the studs 620 may vary along its thickness (ie, height). For example, the size of one or more of the studs 620 may increase or decrease in a direction away from the laser platform 130. The width (or other lateral dimension) of each stud 620 may range, for example, from 0.1 mm to 5 mm. The spacing between adjacent studs 620 may range, for example, from 0.1 mm to 5 mm. The embodiment of FIGS. 6A and 6C may also feature one or more struts 550 as described above and shown in FIGS. 5B-5D.

FIG. 7 is a cross-sectional/side view of an assembled laser package 150 corresponding to the perspective view of FIG. 2, according to an embodiment of the invention. As shown, laser package 150 features top and bottom anode coolers 110, 120 and an overlying cathode cooler 200. The cathode cooler 200 and the top anode cooler define an opening 700 therebetween for receiving the laser emitter, and when received within the opening, the laser emitter emerges from the bottom anode cooler 120 and Cooling occurs via jets of cooling fluid that impinge on the impingement surface 510 of the upper anode cooler 110. As shown on FIG. 7, the distance 710 between the impingement surface 510 of the top anode cooler 110 and the upper surface of the active cooling portion 310 of the bottom anode cooler 120 is the distance 710 discussed above and depicted in FIG. corresponds to the distance z ₀ .

8A-8C depict another two-piece anode cooler 100 according to various embodiments of the invention. As shown, in various embodiments, upper anode cooler 110 may not define a recess therein. Alternatively, as shown in FIGS. 8A-8C, the top and bottom surfaces of the upper anode cooler 110, except for all or a portion of the impingement surface 510, may feature a plurality of protruding features, such as an array of studs 620. It can be substantially planar. That is, all or a portion of the top surface 110 of the top anode cooler can be a laser platform 130 that is substantially coplanar with any other portion of the top surface of the top anode cooler 110. obtain. In such embodiments, the top anode cooler 110 is configured to cover and/or seal a recess 800 defined in the bottom anode cooler 120 above the top opening of the cooling fluid port 320. (e.g., determine size and shape). Thus, in various embodiments, no portion of bottom anode cooler 120 is surrounded by or fits within any portion of upper anode cooler 110. In various embodiments, the length and/or width of recess 800 (e.g., in the top surface of bottom anode cooler 120) is, for example, about 0.5 mm to about 50 mm, or about 3 mm to about 50 mm, or about 3 mm. It may range from about 30 mm, or about 10 mm to about 30 mm, or about 5 mm to about 30 mm, or about 5 mm to about 20 mm, or about 1 mm to about 20 mm. In various embodiments, the length of the top of recess 800 is different than its width, while in other embodiments the length and width are approximately equal to each other. In various embodiments, the top surface of upper anode cooler 110 has a length and/or width that is about 20%, about 30%, about 50%, or about 100% greater than that of recess 800.

In various embodiments, the top anode cooler 110 connects to the bottom anode via an attachment material 810 that may include, consist essentially of, or consist of, for example, adhesives, solders, and/or brazing materials. It can be attached to cooler 120. In other embodiments, the top anode cooler 110 may be attached to the bottom anode cooler 120 via one or more screws or other fasteners, as shown in the previous figures. (As shown in FIG. 8B, the top surface of the upper anode cooler 110 incorporates a mounting material (such as any of those described with respect to mounting material 810) thereon for attachment of a laser emitter thereto. obtain.)

As also shown in FIGS. 8A-8C, bottom anode cooler 120 may define a lower recess 820 for receiving cooling fluid (eg, from an external reservoir or heat exchanger). The cooling fluid flows from the lower recess 820 into the port 320 and forms a cooling fluid jet that impinges on the impingement surface 510 of the upper anode cooler 110. Thus, in various embodiments of the invention, the cooling fluid port fluidly connects the lower recess 820 to the upper recess 800. That is, in various embodiments, the cooling fluid ports do not extend to the top and/or bottom surface of bottom anode cooler 120. Such embodiments may provide beneficial mixing of cooling fluids and superior thermal control both below and above the cooling fluid ports.

After the cooling fluid cools the laser emitter on the laser platform 130, it may exit the bottom anode cooler 120 via one or more outlet channels 830. As shown, the outlet channel 830 may only partially intersect the recess 800; that is, the diameter (or width or other lateral direction) of the outlet channel 830 away from the recess 800 may overlap the outlet channel 830. It may be larger than the size of the end of the outlet channel 830 that actually fluidly connects with the recess 800. Such embodiments may beneficially slow the rate of evacuation through outlet channel 830 and ensure sufficient mixing and cooling within recess 800. In various embodiments, the cross-sectional area of the outlet channels 830 is greater than or approximately equal to the sum of the cross-sectional areas of the ports 320 to accommodate the flow of cooling fluid therefrom. In various embodiments, the bottom anode cooler 120 is mounted on and/or attached to a base platform (e.g., a base for multiple different anode coolers 120, each with a laser emitter thereon). and the lower recess 820 may be fluidly connected to a fluid source (e.g., a delivery line or port in the base platform), while the outlet channel 830 may be fluidly connected to a fluid sink (e.g., a fluid line or port in the base platform). or a port). Lower recess 820 and/or outlet channel 830 may be sealed to the base platform, for example, via an O-ring or other sealing agent to prevent leakage of cooling fluid. As shown in FIGS. 8A-8C, during cooling, cooling fluid may enter the recess 800 at its bottom (i.e., from port 320) and exit from the recess 800 at its outer surface, thereby causing the port The area available for cooling jets formed by the cooling jets can be maximized.

In various embodiments, the center-to-center spacing of ports 320 can range from about 0.1 mm to about 8 mm, for example. In various embodiments, the diameter (or width) of port 320 can range from about 0.025 mm to about 5 mm, for example. In various embodiments, the studs 620 (and/or other features protruding from the bottom surface of the upper anode cooler 110) can have a height ranging from about 0.01 mm to about 15 mm, for example. Although not shown in FIGS. 8A-8C, in various embodiments the anode cooler 100 shown in FIGS. 8A-8C may also be utilized with a cathode cooler 200 thereon.

As shown, the top anode cooler 110 can be quite thin, such that the bottom anode cooler 120 accommodates the beam (e.g., its divergence) emitted by the laser emitter above the top of the top anode cooler 120. A front recess 840 may be defined therein for providing access. That is, in various embodiments, the top surface of the bottom anode cooler 120 (with a recess 800 and may be substantially planar (except for any through-holes 300 formed). The edge of the bottom anode cooler 120 at the top of the front recess 840 may also beneficially provide an alignment surface for the beam emitter and/or optics associated with or fastened thereto. In the front recess 840, the top surface of the bottom anode cooler 120 may be recessed below the top surface, for example, about 0.025 mm to about 20 mm. In various embodiments, the thickness of the bottom anode cooler 120 in the region of the front recess 840 is, for example, less than about 85%, less than about 75%, or less than the thickness of the remainder of the bottom anode cooler 120. It can be less than about 50%. In various embodiments, the thickness of the bottom anode cooler 120 in the region of the front recess 840 is, for example, at least 40%, at least 50%, at least 60% of the thickness of the remainder of the bottom anode cooler 120. , or at least 70%.

As shown, the top anode cooler 110 can have an outer portion that overlaps and can be attached to the top surface of the bottom anode cooler 120. The outer portion may surround an inner portion in which impact surfaces (eg, features such as studs and/or indentations) are located. The thickness of the outer portion of the upper anode cooler 110 may range, for example, from about 0.05 mm to about 5 mm, from about 0.05 mm to about 2 mm, from about 0.5 mm to about 2 mm, or from about 1 mm to about 5 mm. In various embodiments, the thickness of the inner portion of the upper anode cooler 110 is such that the impingement feature is, for example, about 0.05 mm to about 5 mm, about 0.05 mm to about 2 mm, about 0.5 mm to about 2 mm, or It is substantially identical to that of the outer portion, except that it may protrude from the inner portion by a distance ranging from about 1 mm to about 5 mm. In various embodiments, the thickness or height of the bottom anode cooler 120 (at least the portions defining the recess 800 and/or excluding the front recess 840) is significantly thicker than that of the top anode cooler 110. Such an embodiment advantageously allows for the formation of a strong cooling jet within the bottom anode cooler 120 while minimizing the material thickness through which the heat generated by the beam emitter is removed. For example, the thickness of the bottom anode cooler 120 can range, for example, from about 0.8 mm to about 35 mm, from about 5 mm to about 35 mm, from about 10 mm to about 35 mm, or from about 20 mm to about 35 mm. In various embodiments, the thickness of the bottom anode cooler 120 is about 50%, about 100%, about 200% the thickness of the top anode cooler 110 (eg, either its inner or outer portion), It may exceed about 300%, about 400%, about 500%, or even about 700%.

One or more dimensions (eg, length and/or width) and/or surface area of top anode cooler 110 may be less than a corresponding dimension and/or surface area of bottom anode cooler 120. For example, in various embodiments, the length of top anode cooler 110 (e.g., in a direction parallel to that of the beam emitted by the laser emitter toward front recess 840) is longer than the length of bottom anode cooler 120 (and and/or its upper surface) may be less than 75%, less than 50%, less than 40%, less than 30%, or even less than 20% of the corresponding length. In various embodiments, the length and/or width of the upper anode cooler 110 may range, for example, from about 2 mm to about 50 mm, from about 2 mm to about 20 mm, from about 2 mm to about 10 mm, or from about 10 mm to about 20 mm.

In various embodiments, the length of the bottom anode cooler 120 (e.g., of its top and/or bottom surface) (i.e., the dimensions shown in FIG. 8C) is at least 50% greater than that of the top anode cooler 110, at least It can be greater than 100%, at least 150%, at least 200%, at least 300%, at least 400%, or at least 500%. In various embodiments, the length of the bottom anode cooler 120 can range, for example, from about 10 mm to about 75 mm, or from about 20 mm to about 75 mm, from about 30 mm to about 75 mm, or from about 40 mm to about 75 mm.

In various embodiments, the width of the bottom anode cooler 120 (i.e., the dimension into the page of FIG. 8C) is at least 10%, at least 25%, at least 50%, at least 100% larger than that of the top anode cooler 110. %, at least 150%, at least 200%, at least 300%, at least 400%, or at least 500%. In various embodiments, the width of the bottom anode cooler 120 can range, for example, from about 2 mm to about 55 mm, from about 3 mm to about 55 mm, from about 5 mm to about 55 mm, from about 10 mm to about 55 mm, or from about 20 mm to about 55 mm. .

In various embodiments, top anode cooler 110 and bottom anode cooler 120 are oriented for cooling fluid flow generally parallel to the top and/or bottom surfaces of top anode cooler 110 and bottom anode cooler 120. It lacks any channels (eg, fluid channels) defined therein. And, as shown, in various embodiments, the upper anode cooler 110 may be completely devoid of any fluid channels therein. Accordingly, various embodiments of the present invention may provide superior mechanical strength compared to coolers incorporating such channels.

FIG. 8D is a backside view of the upper anode cooler 110 depicted in FIGS. 8A-8D. As shown, in various embodiments, the impingement surface 510 (or "inner portion") can have approximately the same size and shape of the opening of the recess 800 in the bottom anode cooler 120, and the impingement surface One or more (typically a plurality of) protruding features such as studs 620 may be included to enhance cooling of the cooling fluid jets directed at 510 . As mentioned above, the impingement surface 510 may otherwise be substantially coplanar with the bottom outer boundary (or "outer portion") 840 of the upper anode cooler 110; In embodiments, impingement surface 510 is not coplanar with outer boundary 840, ie, impingement surface 510 may protrude below or above outer boundary 840. As shown in FIGS. 8A and 8B, outer border 840 may receive attachment material 810 and thus attach top anode cooler 110 to bottom anode cooler 120. In various embodiments, impingement surface 510 (and/or any protruding features thereon) includes a different material than that of outer boundary 840 and/or another portion of upper anode cooler 110 (e.g., its top surface). or consists essentially of or may consist of.

In various embodiments, impact surface 510 may not include protruding features, ie, impact surface 510 may be substantially planar. Although such embodiments may be more easily manufactured, the lack of raised features or other non-planar patterns may compromise the cooling effectiveness of the cooling jets impinging on the impingement surface 510.

FIG. 8E is a top perspective view of bottom anode cooler 120, according to various embodiments of the invention. As shown, one or more struts 550 may be defined within recess 800, for example between rows of ports 320. As mentioned above, struts 550 may provide improved mechanical strength to anode cooler 100. In various embodiments, the struts 550 extend across the entire dimension (e.g., length and/or width) of the recess 800, while in other embodiments the struts extend across the entire dimension (e.g., length and/or width) of the recess 800. Extends only partially across the dimension. While struts 550 extend above the openings of ports 320, in typical embodiments, struts 550 do not extend to the top surface of bottom anode cooler 120 (i.e., out of recess 800), and instead In embodiments, struts 550 extend only a portion of the distance between ports 320 and features protruding from impingement surface 510 so as not to block or otherwise obstruct the flow of cooling fluid within recess 800. There is.

In various embodiments, the struts 550 in the bottom anode cooler 120 form or help form an exit channel for flow of coolant fluid from the recess 800 through the exit channel 830. The dimensions of these struts 550 allow the coolant fluid to flow over a larger area, thereby providing a lower coolant fluid velocity over a larger area, so that the ports 320 are closer to the front of the bottom anode cooler 120. (or the "front port") and the port 320 (or "back port") proximate the outlet channel 830. This low pressure variation, in turn, promotes the creation of a more even flow between the front and rear ports since the flow is a function of the pressure drop across the port.

Packaged laser emitters (eg, diode bars) according to embodiments of the invention may be utilized within WBC laser systems. FIG. 9 depicts an exemplary WBC laser system 900 that utilizes a packaged laser 905. Packaged laser 905 may correspond, for example, to one or more laser emitters disposed within laser package 150 or on top of two-piece anode cooler 100 as detailed herein; It may be utilized for thermal management (eg, cooling) of one or more fluid jets as detailed herein. In the example of FIG. 9, laser 905 features a diode bar with four beam emitters that emit beam 910 (see enlarged input diagram 915), but embodiments of the invention feature any number of individual beam emitters. A beam-emitting diode bar or a two-dimensional array or stack of diodes or diode bars may be utilized. In FIG. 915, each beam 910 is represented by a line, the length or longer dimension of the line representing the slow divergence dimension of the beam, and the height or shorter dimension representing the fast divergence dimension. Collimation optics 920 may be used to collimate each beam 910 along the fast dimension. Transforming optics 925, which may include or consist essentially of one or more cylindrical or spherical lenses and/or mirrors, are used to combine each beam 910 along WBC direction 930. Conversion optics 925 then superimposes the composite beam onto a dispersive element 935 (which may include, consist essentially of, or consist of a diffraction grating, e.g., a reflection or transmission grating) to form a composite beam. is then transmitted onto output combiner 940 as a single output profile. Output combiner 940 then transmits composite beam 945, as shown on output front view 950. Output coupler 940 is typically partially reflective and serves as a common front facet for all laser elements within this external cavity system 900. The external cavity is a lasing system with a secondary mirror displaced a distance away from the emission aperture or facet of each laser emitter. In some embodiments, additional optics are installed between the emission aperture or facet and the output coupler or partially reflective surface. Output beam 945 may be coupled into an optical fiber and/or utilized for welding, cutting, annealing, etc. applications.

The terms and expressions employed herein are used as terms of description rather than limitation, and the use of such terms and expressions includes any equivalents of the features shown or described, or any portion thereof. It is recognized that there is no intention to exclude, and that various modifications are possible within the scope of the claimed invention.

Claims (42)

A laser package, the laser package comprising:
A bottom anode cooler, the bottom anode cooler comprising: (i) a top surface; (ii) a bottom surface opposite the top surface; (iii) an entry recess defined in the bottom surface; ) an upper recess defined in the upper surface; and (v) a plurality of hollow ports, the plurality of hollow ports fluidly connecting the entry recess and the upper recess; a bottom anode cooler forming a jet of cooling fluid through a plurality of hollow ports ;
an upper anode cooler disposed above only a portion of the bottom anode cooler , the upper anode cooler having (i) a top surface; and (ii) a bottom surface opposite the top surface; and the bottom surface of the top anode cooler includes an impingement surface defining a non-planar pattern protruding into the top recess of the bottom anode cooler, thereby causing a Cooling fluid introduced and ejected through the plurality of hollow ports impinges on the impingement surface of the upper anode cooler and cools a laser emitter disposed on the upper surface of the upper anode cooler. , a top anode cooler , and a laser package. The laser package of claim 1, wherein the thermal conductivity of the top anode cooler is greater than the thermal conductivity of the bottom anode cooler. The laser package of claim 1, wherein the non-planar pattern comprises a plurality of raised features. The laser package of claim 1, wherein the bottom anode cooler defines a plurality of raised struts disposed between openings of the plurality of hollow ports. The laser package further includes: (i) a cathode cooler disposed above the upper anode cooler, a portion of the cathode cooler overhanging and contacting a top surface of the upper anode cooler; 2. The laser package according to claim 1, wherein the laser package does not include a laser package. 6. The laser package of claim 5, wherein the cathode cooler is not configured for flow of cooling fluid through the cathode cooler . The laser package of claim 1, wherein the upper anode cooler is not configured for flow of cooling fluid through the upper anode cooler . The laser package of claim 1, wherein the non-planar pattern is spaced from openings of the plurality of hollow ports to form a mixing channel for the cooling fluid. 9. The laser package of claim 8, wherein the mixing channel has a height selected from a range of about 0.025 mm to about 50 mm. 9. The laser package of claim 8, wherein a ratio of the height of the mixing channel to the diameter of at least one of the plurality of hollow ports is selected from a range of about 0.1 to about 30. 9. The laser package of claim 8, wherein a ratio of the height of the mixing channel to the diameter of at least one of the plurality of hollow ports is selected from a range of about 8 to about 30. 9. The laser package of claim 8, wherein a ratio of the height of the mixing channel to the diameter of at least one of the plurality of hollow ports is selected from a range of about 0.1 to about 2. The laser package of claim 1, wherein the center-to-center spacing of the plurality of hollow ports is selected from a range of about 0.1 mm to about 8 mm. The laser package of claim 1, wherein a diameter of at least one of the plurality of hollow ports is selected from a range of about 0.025 mm to about 5 mm. The laser package of claim 1, wherein the area of the top surface of the top anode cooler is smaller than the area of the top surface of the bottom anode cooler. The bottom anode cooler defines an outlet channel therein, the outlet channel fluidly connecting the top recess with an outlet opening defined in the bottom surface of the bottom anode cooler; The laser package of claim 1, wherein an aperture is spaced from the entry recess. 2. The laser package of claim 1 , wherein the laser package further comprises a mounting material that attaches a portion of the bottom surface of the top anode cooler to a portion of the top surface of the bottom anode cooler. 18. The laser package of claim 17 , wherein the attachment material comprises at least one of an adhesive, a solder, or a brazing material. The laser package of claim 1, wherein the bottom anode cooler comprises alumina and the top anode cooler comprises SiC. The laser package of claim 1, wherein the top anode cooler and the bottom anode cooler are electrically insulating. The laser package further comprises a laser emitter disposed on the top surface of the upper anode cooler, the laser emitter comprising a laser diode bar configured to emit a plurality of beams . The laser package according to item 1. A wavelength beam combining laser system, the laser system comprising:
a beam emitter that emits a plurality of separate beams;
concentrating optics for concentrating the plurality of separate beams toward a dispersive element;
a dispersive element for receiving the plurality of separate beams and dispersing the plurality of separate beams;
a partially reflective output coupler, the partially reflective output coupler configured to receive the plurality of separate beams dispersed by the dispersive element ; and to receive the plurality of separate beams dispersed by the dispersive element. transmitting a portion of the plurality of separate beams through the partially reflective output coupler as a multi-wavelength output beam ; and a second of the plurality of separate beams dispersed by the dispersive element back toward the dispersive element. a partially reflective output coupler positioned to reflect a portion of the
A bottom anode cooler, the bottom anode cooler comprising: (i) a top surface; (ii) a bottom surface opposite the top surface; (iii) an entry recess defined in the bottom surface; ) an upper recess defined in the upper surface; and (v) a plurality of hollow ports, the plurality of hollow ports fluidly connecting the entry recess and the upper recess; a bottom anode cooler forming a jet of cooling fluid through a plurality of hollow ports ;
a top anode cooler disposed above only a portion of the bottom anode cooler , the top anode cooler comprising: (i) a top surface of the top anode cooler; and (ii) a bottom surface opposite the top surface, the bottom surface of the top anode cooler being in the top recess of the bottom anode cooler. an impingement surface defining a non-planar pattern protruding from the upper anode cooler, such that cooling fluid introduced into the bottom anode cooler and ejected through the plurality of hollow ports is directed to the upper anode cooler. an upper anode cooler that impinges on an impact surface and cools the beam emitter. 23. The laser system of claim 22, wherein the dispersive element comprises a diffraction grating. 23. The laser system of claim 22, wherein the thermal conductivity of the top anode cooler is greater than the thermal conductivity of the bottom anode cooler. 23. The laser system of claim 22, wherein the non-planar pattern comprises a plurality of raised features. 23. The laser system of claim 22, wherein the bottom anode cooler defines a plurality of raised struts disposed between openings of the plurality of hollow ports. The laser system further includes: (i) a cathode cooler disposed above the upper anode cooler, a portion of the cathode cooler overhanging and contacting the upper surface of the upper anode cooler; 23. The laser system of claim 22, which does not. 28. The laser system of claim 27, wherein the cathode cooler is not configured for flow of cooling fluid through the cathode cooler . 23. The laser system of claim 22, wherein the upper anode cooler is not configured for flow of cooling fluid through the upper anode cooler . 23. The laser system of claim 22, wherein the non-planar pattern is spaced from openings of the plurality of hollow ports to form a mixing channel for the cooling fluid. 31. The laser system of claim 30, wherein the mixing channel has a height selected from a range of about 0.025 mm to about 50 mm. 31. The laser system of claim 30, wherein a ratio of the height of the mixing channel to the diameter of at least one of the plurality of hollow ports is selected from a range of about 0.1 to about 30. 31. The laser system of claim 30, wherein a ratio of the height of the mixing channel to the diameter of at least one of the plurality of hollow ports is selected from a range of about 8 to about 30. 31. The laser system of claim 30, wherein a ratio of the height of the mixing channel to the diameter of at least one of the plurality of hollow ports is selected from a range of about 0.1 to about 2. 23. The laser system of claim 22, wherein the center-to-center spacing of the plurality of hollow ports is selected from a range of about 0.1 mm to about 8 mm. 23. The laser system of claim 22, wherein a diameter of at least one of the plurality of hollow ports is selected from a range of about 0.025 mm to about 5 mm. 23. The laser system of claim 22, wherein the area of the top surface of the top anode cooler is less than the area of the top surface of the bottom anode cooler. The bottom anode cooler defines an outlet channel therein, the outlet channel fluidly connecting the top recess with an outlet opening defined in the bottom surface of the bottom anode cooler; 23. The laser system of claim 22, wherein an aperture is spaced from the entry recess. 23. The laser system of claim 22 , further comprising a mounting material that attaches a portion of the bottom surface of the top anode cooler to a portion of the top surface of the bottom anode cooler. 40. The laser system of claim 39, wherein the attachment material comprises at least one of an adhesive, a solder, or a brazing material. 23. The laser system of claim 22, wherein the bottom anode cooler comprises alumina and the top anode cooler comprises SiC. 23. The laser system of claim 22, wherein the top anode cooler and the bottom anode cooler are electrically insulated.

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