Laser module, laser device, and laser processing device comprising them

Abstract

To provide a laser assembly that injects a laser beam on a long-wavelength side, and a laser module capable of suppressing deterioration of an output efficiency.SOLUTION: A laser module 100 at least comprises: a housing 110; a base 10 housed in an internal part of them; and a plurality of layer assembling bodies 40. Each assembling body 40 includes a laser diode bar 43. A wavelength of a laser beam LB injected from each of a plurality of laser diode bars 43 is different each other. In an inner side of the base 10, a cooling channel 11 having an inflow entrance 11A and an outflow entrance 11B of a cooling water is provided. Each assembling body 40 is arranged onto an upper surface of the base 10 that is arranged with an interval so as to be along a long direction of the cooling channel 11. A wavelength of a plurality of laser beam LB becomes shorter as far from the inflow entrance 11A.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to a laser module, a laser device, and a laser processing device including the same. [Background technology]

[0002] In recent years, laser processing technology has been widely used in metal processing and the like. In laser processing, the use of semiconductor laser elements (also called direct diode lasers (DDLs)) allows for the miniaturization and high efficiency of laser light sources. A widely used technology uses multiple laser diode bars, each of which has multiple emitters that emit laser light, as semiconductor laser elements, and combines the laser beams to increase the output of the laser light output from the laser light source.

[0003] In this case, in order to increase the output of the laser light and extend the life of the laser light source, a configuration is often adopted in which the laser light source is efficiently cooled during operation to suppress temperature rise.

[0004] For example, Patent Document 1 discloses a configuration in which a plurality of input beam modules each having a laser light source such as a laser diode are prepared, each of the plurality of input beam modules is connected to a heat exchange manifold, and a heat exchange fluid such as cooling water is caused to flow through a conduit provided in the heat exchange manifold to cool the input beam module. In this configuration, a plurality of laser beams respectively emitted from a plurality of laser light sources are combined inside the input beam module to form a single laser beam, thereby increasing the output of the laser beam emitted from the input beam module. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] US Patent Application Publication No. 2018 / 241179 Summary of the Invention [Problem to be solved by the invention]

[0006] In the conventional configuration disclosed in Patent Document 1, a wavelength combining technique is used to combine multiple laser beams, in which multiple laser diodes or laser diode bars emit laser beams of different wavelengths.

[0007] However, according to the investigations of the present inventors, it has been found that in this case, as the oscillation wavelength becomes longer, the output efficiency of the laser light tends to decrease.

[0008] A decrease in output efficiency means that the component of the power input to the laser diode that does not contribute to light emission increases. In other words, a decrease in output efficiency increases the amount of heat generated by the laser diode.

[0009] On the other hand, it is known that if the amount of heat generated increases and the temperature of the laser diode rises, the life of the laser diode during use is shortened.

[0010] However, Patent Document 1 does not disclose any technology for suppressing the above-mentioned decrease in output efficiency of the laser diode, and therefore the decrease in the life span of the laser diode.

[0011] The present disclosure has been made in consideration of these points, and its object is to provide a laser module, a laser device, and a laser processing device equipped with the same, which are capable of efficiently cooling the laser assembly emitting laser light on the longer wavelength side in a laser module including a plurality of laser assemblies, each having a laser light source that emits laser light of different wavelengths, and suppressing a decrease in output efficiency. [Means for solving the problem]

[0012] In order to achieve the above-mentioned object, the laser module of the present disclosure is a laser module comprising at least a housing, a base, and a plurality of laser assemblies each having a laser light source, wherein the base and the plurality of laser assemblies are housed inside the housing, a refrigerant flow path having a refrigerant inlet and outlet is provided inside the base, the plurality of laser light sources each emit laser light having a different wavelength, the plurality of laser assemblies are arranged on an upper surface of the base, above the refrigerant flow path and at intervals from each other along the longitudinal direction of the refrigerant flow path, and the wavelength of the laser light emitted from each of the plurality of laser light sources becomes shorter as it moves away from the inlet.

[0013] The laser device according to the present disclosure is a laser device having a plurality of the laser modules and at least a beam combiner attached to the plurality of the laser modules, wherein each of the plurality of the laser modules emits a module laser light, and in each of the plurality of the laser modules, a first side on which an output port of the module laser light is provided faces the same direction, and the beam combiner is attached to the first side of the plurality of the laser modules and combines the plurality of the module laser lights into a single combined laser light.

[0014] The laser processing apparatus according to the present disclosure is characterized by comprising at least the laser device, a power source that supplies power for laser oscillation to the laser device, an optical fiber that guides the combined laser light, and a laser head attached to the output end of the optical fiber. Effect of the Invention

[0015] According to the present disclosure, it is possible to reliably and efficiently cool a laser assembly that is included in a laser module and that emits laser light on the long wavelength side, thereby suppressing a decrease in the output power and lifespan of the laser light in the laser assembly. [Brief description of the drawings]

[0016] [Figure 1] 1 is a schematic configuration diagram of a laser processing device according to a first embodiment. [Diagram 2] FIG. 2 is a schematic configuration diagram of a main part of a laser module. [Figure 3A] FIG. 2 is a perspective view of a laser assembly. [Figure 3B] FIG. 2 is an exploded perspective view of the laser assembly. [Figure 3C] FIG. 3C is a cross-sectional view taken along line IIIC-IIIC in FIG. 3A. [Figure 4] FIG. 2 is a schematic diagram illustrating the configuration of an optical system of a laser module. [Diagram 5] 1 is a schematic configuration diagram of a main part of a laser device. [Figure 6] FIG. 13 is a schematic configuration diagram of a main part of a laser module according to a comparative example. [Figure 7] FIG. 13 is a schematic configuration diagram of a main part of a laser device according to a comparative example. [Figure 8] FIG. 2 is a diagram showing the relationship between the wavelength of laser light and the laser light output. [Figure 9] FIG. 13 is a diagram showing the relationship between the flow rate of cooling water and the temperature of a laser assembly. [Figure 10] FIG. 11 is a schematic configuration diagram of a main part of a laser device according to a second embodiment. [Figure 11] FIG. 11 is a schematic configuration diagram of a main part of a laser module according to a second embodiment. [Figure 12] FIG. 13 is a perspective view of a laser assembly according to a modified example. [Figure 13] FIG. 11 is an exploded perspective view of a laser assembly according to Modification 2. [Figure 14] FIG. 13 is a schematic configuration diagram of a main part of a laser device according to another embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. Note that the following description of the preferred embodiments is merely illustrative in nature and is not intended to limit the present disclosure, its application, or its uses.

[0018] (Embodiment 1) [Laser processing equipment configuration] FIG. 1 is a schematic diagram showing the configuration of a laser processing device according to this embodiment.

[0019] In this specification, "orthogonal" or "parallel" means that the two objects are orthogonal or parallel, including the assembly tolerances and processing tolerances of the laser processing apparatus 1000 and its components, and does not mean that the objects being compared are orthogonal or parallel in the strict sense.

[0020] The laser processing apparatus 1000 includes a control unit 400, a chiller 500, a power source 600, a laser device 700, an optical fiber 800, and a laser head 900. The laser device 700 includes four laser modules 100, a beam combiner 200, and a focusing optical unit 300. The chiller 500 may be disposed outside the laser device 700.

[0021] The laser module 100 has a plurality of laser diode bars 43 (see FIG. 2) therein, and emits a module laser beam by combining laser beams emitted from emitters (not shown) included in each of the plurality of laser diode bars 43. The configuration of the laser module 100 will be described in detail later.

[0022] The beam combiner 200 has a plurality of optical components (not shown) inside, and combines the module laser light LB emitted from each of the four laser modules 100. M (See Fig. 4) C (called) coupled laser light LB C The four module laser beams LB are combined into one beam and output to the light collecting optical unit 300. M Combined laser light LB C In combining the two, spatial combining techniques are used.

[0023] The focusing optical unit 300 has at least a focusing lens (not shown) therein. The focusing lens focuses the combined laser beam LB C The light is focused and made incident on the incident end face of the optical fiber 800.

[0024] The control unit 400 controls the laser oscillation of the laser modules 100. Specifically, the control unit 400 controls the laser oscillation of each of the four laser modules 100 by supplying control signals such as output voltage and on-time to the power supply 600. It is also possible to control the laser oscillation of each of the four laser modules 100 individually. For example, the laser oscillation output and on-time may be different for each laser module 100. The control unit 400 is composed of, for example, one or more CPUs (Central Processing Units) or MCUs (Micro Control Units).

[0025] The control unit 400 also has a storage unit (not shown), which stores laser processing conditions, processing operation programs, etc. The storage unit is configured with semiconductor memories such as RAM (Random Access Memory) and ROM (Read Only Memory). The storage unit may also be configured with HDD (Hard Disk Drive), SSD (Solid State Drive), etc.

[0026] Furthermore, the control unit 400 may control the operation of the chiller 500, specifically, the temperature and flow rate of the cooling water supplied from the chiller 500. One chiller 500 may be provided for one laser module 100, and the control unit 400 may control the temperature and flow rate of the cooling water for each chiller 500 individually.

[0027] The control unit 400 may also control the operation of a robot (not shown) to which the laser head 900 is attached.

[0028] The display unit 410 displays processing parameters during laser processing and the output of module laser light. The display unit 410 typically includes a display device such as a liquid crystal display or an organic EL display.

[0029] The chiller 500 supplies cooling water adjusted to a predetermined temperature and flow rate to each of the four laser modules 100. The cooling water is used to cool each of the multiple laser assemblies 40 arranged inside the laser module 100, specifically, the laser diode bars 43.

[0030] As described above, the power supply 600 supplies power for performing laser oscillation to each of the four laser modules 100. The power supplied to each of the four laser modules 100 may be different in response to a command from the control unit 400. The power supply 600 may also supply power to a moving part of the laser processing apparatus 1000, for example, the robot described above. Note that power may be supplied to the moving part of the laser processing apparatus 1000 from a separate power supply (not shown).

[0031] Module laser light LB emitted from each of the four laser modules 100 M Combined laser light LB C By combining with the laser beam LB C It is possible to obtain a high-output laser processing apparatus 1000 having an output exceeding several kW. The number of laser modules 100 arranged in the laser processing apparatus 1000 is not particularly limited to the example shown in FIG.

[0032] The optical fiber 800 is optically coupled to a focusing lens (not shown) of the focusing optical unit 300, and receives the combined laser light LB from the focusing lens of the focusing optical unit 300. C is transmitted to the laser head 900.

[0033] The laser head 900 receives the combined laser light LB transmitted through the optical fiber 800. CFor example, in the laser processing apparatus 1000 shown in FIG. 1, the combined laser beam LB is directed toward a workpiece W, which is an object to be processed and is disposed at a predetermined position. C The workpiece W is laser-processed.

[0034] [General configuration of laser module and configuration of laser assembly] Fig. 2 shows a schematic configuration diagram of a main part of a laser module. Fig. 3A shows a perspective view of a laser assembly, Fig. 3B shows an exploded perspective view of the laser assembly, and Fig. 3C shows a cross-sectional view taken along line IIIC-IIIC in Fig. 3A.

[0035] For ease of explanation, the size and shape of each component in Fig. 2 are different from the actual ones. For example, the shapes of the cooling water channels 11 and 31 in the base 10 and the cooler 30 are different from the actual ones. Furthermore, the connection position of the bus bar 50 to the laser assembly 40 is also different from the actual ones.

[0036] In the following description, the arrangement direction of the multiple laser assemblies 40 may be referred to as the X direction. The X direction is also the arrangement direction of the emitters (not shown) in the laser diode bar 43 included in the laser assembly 40. The direction in which the base 10, the support block 20, the cooler 30, and the laser assembly 40 are stacked may be referred to as the Z direction. The direction perpendicular to the X direction and the Z direction may be referred to as the Y direction. The Y direction is parallel to the emission direction of the laser light (not shown) emitted from each emitter of the laser diode bar 43. In the Z direction, the side where the base 10 is arranged may be referred to as the top or upper side, and the side where the laser assembly 40 is arranged may be referred to as the bottom or lower side. However, this is not particularly limited.

[0037] As shown in Fig. 2, the laser module 100 has at least a base 10, a support block 20, a cooler 30, a plurality of laser assemblies 40, and a bus bar 50 inside a housing 110 (see Fig. 4). As shown in Fig. 4, the laser module 100 further has a plurality of types of optical components inside the housing 110. The configuration of the laser module 100 including the optical system will be described later.

[0038] The base 10 is a rectangular parallelepiped member made of metal, and has a cooling water channel (coolant flow path) 11 therein. The base 10 may be made of an insulating material as long as the material has high thermal conductivity. A cooling water pipe 80 is connected to the cooling water channel 11 via a manifold 70. The cooling water pipe 80 is connected to a chiller 500. The manifold 70 is commonly attached to a first side surface 111 of a housing 110 of the four laser modules 100 (see FIG. 8).

[0039] The support block 20 is a metal member made of copper or the like, and has a cooling water passage 21 (see FIG. 3B). The cooling water passage 21 is connected to the cooling water passage 11 of the base 10. The support block 20 is assembled integrally with the cooler 30 and the laser assembly 40, and is placed on the base 10. Specifically, fixing screws 60 are inserted and fastened into screw holes 22, 34, and 41a provided in the support block 20, the cooler 30, and the first electrode block 41 of the laser assembly 40, respectively. In this way, the support block 20, the cooler 30, and the laser assembly 40 are assembled integrally.

[0040] Furthermore, fastening members (not shown) such as bolts or screws are inserted through screw holes 23 (see FIG. 3B) provided in the support block 20 and screw holes (not shown) provided in the base 10, and fastened. In this manner, the support block 20 to which the cooler 30 and the laser assembly 40 are attached is attached and fixed to the base 10.

[0041] The cooler 30 is a plate-like member having a cooling water passage 31. When the support block 20, the cooler 30 and the laser assembly 40 are integrally assembled and placed on the upper surface of the base 10, the cooling water passage 31 is located below the submount 42 on which the laser diode bar 43 is mounted (see FIGS. 3B and 3C).

[0042] In order to electrically insulate the laser assembly 40 from the support block 20 and the base 10, the upper and lower surfaces of the cooler 30 are covered with an insulating material having high thermal conductivity, for example, an insulating sheet 32 ​​(see FIG. 3C) made of aluminum nitride (AlN) ceramic. In order to improve the thermal contact between the cooler 30 and the support block 20, and between the cooler 30 and the first electrode block 41, a sheet having high thermal conductivity, for example, a metal sheet 33 made of a copper plate (see FIG. 3C) is interposed between the insulating sheet and each member.

[0043] The laser assembly 40 includes at least a first electrode block 41, a submount 42, a laser diode bar 43, an insulating sheet 45, and a second electrode block 46.

[0044] 3B and 3C, the first electrode block 41 is made of copper or a copper alloy and is a conductive member having a step. The first electrode block 41 is electrically connected to the submount 42 and the laser diode bar 43 via an upper sheet of the metal sheets 33 provided on the cooler 30 and metal solder 44 (see FIG. 3B).

[0045] The submount 42 is a plate-shaped conductive member that mechanically supports the laser diode bar 43 and dissipates heat generated during operation of the laser diode bar 43 to the cooler 30. The submount 42 is joined to a metal sheet 33 provided on the upper surface of the cooler 30 via metal solder 44.

[0046] The laser diode bar 43 has a plurality of emitters (not shown) spaced apart from each other in the X direction. During operation of the laser diode bar 43, laser light is emitted in the Y direction from each of the plurality of emitters. In this embodiment, a p-side electrode (not shown) of the laser diode bar 43 is bonded to the upper surface of the submount 42 via metal solder (not shown). This is because the active layer (light emitting layer; not shown) of each emitter is located closer to the p-side electrode than the n-side electrode (not shown). In other words, the active layer that generates heat during operation of the laser diode bar 43 is disposed close to the submount 42, which is located closer to the cooler 30.

[0047] However, without being particularly limited to this, the n-side electrode of the laser diode bar 43 may be bonded to the upper surface of the submount 42 via metal solder.

[0048] The second electrode block 46 is made of copper or a copper alloy and is a conductive member having a step. With the positions of the components in the laser assembly 40 fixed, the upper surface of the step of the second electrode block 46 abuts against the laser diode bar 43 via a gold bump (not shown) or the like formed on the upper surface of the n-side electrode of the laser diode bar 43. In the laser assembly 40, the second electrode block 46 is disposed such that the bottom surface of the step is located higher in the Z direction than the upper surface of the step.

[0049] The first electrode block 41 and the second electrode block 46 are formed with a plurality of screw holes 41a, 46a, respectively. After the first electrode block 41 and the second electrode block 46 are arranged at a predetermined position, the screw 61 is inserted through the screw hole 41a of the first electrode block 41 and the screw hole 46a of the second electrode block 46 facing the first electrode block 41, with the washer 62 sandwiched therebetween, and fastened. In this way, the first electrode block 41 and the second electrode block 46 are fixed to each other while maintaining a predetermined positional relationship. As described above, the first electrode block 41 is attached and fixed to the support block 20 and the cooler 30 by the fixing screw 60. The submount 42 on which the laser diode bar 43 is mounted is fixed to a predetermined position on the upper surface of the cooler 30 by the metal solder 44. That is, when the laser assembly 40 is assembled to the support block 20 and the cooler 30, each part is fixed to each other while maintaining a predetermined positional relationship.

[0050] As shown in FIG. 3C, the second electrode block 46 is disposed at a distance from the first electrode block 41 in the Y direction. As shown in FIGS. 3B and 3C, an insulating sheet 45 made of resin or the like is interposed between the bottom surface of the step of the first electrode block 41 and the bottom surface of the step of the second electrode block 46 facing the first electrode block 41. The insulating sheet 45 is provided with a plurality of through holes 45a, into which screws 61 are inserted. When the first electrode block 41 and the second electrode block 46 are fastened by the screws 61, the insulating sheet 45 is sandwiched between the first electrode block 41 and the second electrode block 46 in a positioned state. Therefore, the second electrode block 46 is assembled to the first electrode block 41 and both are fixed, while the second electrode block 46 is electrically insulated from the first electrode block 41.

[0051] As described above, the metal sheet 33 provided on the upper side of the cooler 30 is electrically insulated from other parts of the cooler 30, including the cooling water passage 31, by the insulating sheet 32 ​​arranged below it. Therefore, the laser assembly 40 is assembled to the support block 20 and the cooler 30 and fixed to each other, while the laser assembly 40 is electrically insulated from the support block 20 and the cooler 30.

[0052] The first electrode block 41 is provided with a screw hole 41b spaced apart from the screw hole 41a in the Y direction. Similarly, the second electrode block 46 is provided with a screw hole 46b spaced apart from the screw hole 46a in the Y direction.

[0053] The busbar 50 is a plate-shaped conductive member made of copper or a copper alloy, and has through holes 50a at both ends. A fastening member such as a screw (not shown) is inserted through one of the through holes 50a of the busbar 50 and a screw hole 41b provided in the first electrode block 41, and the two are fastened together, whereby the busbar 50 is attached and fixed to the first electrode block 41 and the two are electrically connected to each other. Similarly, a fastening member such as a screw (not shown) is inserted through the other through hole 50a of the busbar 50 and a screw hole 46b provided in the second electrode block 46, and the two are fastened together, whereby the busbar 50 is attached and fixed to the second electrode block 46 and the two are electrically connected to each other.

[0054] 3A and 3C, the bus bar 50 attached to the first electrode block 41 and the bus bar 50 attached to the second electrode block 46 are positioned at the same height in the Z direction with respect to the upper surface of the cooler 30. This simplifies the process of attaching the bus bar 50 to the laser assembly 40. Furthermore, the shape of the bus bar 50 can be simplified.

[0055] [Optical configuration of laser module] Fig. 4 shows a schematic diagram of the optical system of the laser module. For ease of explanation, the size and shape of each component in Fig. 4 are different from the actual ones.

[0056] As shown in FIG. 4, in the laser module 100, in addition to a plurality of laser assemblies 40 mounted on a base 10, a plurality of reflecting mirrors 120, a diffraction grating 130 which is an optical coupling element, and an external resonator mirror 140 are provided inside a housing 110, with a predetermined positional relationship being maintained between them.

[0057] It should be noted that the arrangement of the optical system shown in Fig. 4, i.e., the arrangement of the laser assembly 40, the reflecting mirror 120, and the diffraction grating 130, is merely an example and is not particularly limited to this. In addition to the arrangement shown in Fig. 4, a further set of reflecting mirrors 120 may be provided. Although Fig. 4 shows a transmissive diffraction grating 130, the diffraction grating 130 may be a reflective type.

[0058] In addition, inside the housing 110, other optical components are attached, for example, optical components such as collimator lenses that shape the beam shape of the laser light LB emitted from the laser diode bar 43, to each of the laser assemblies 40, but these are not shown and will not be described.

[0059] The plurality of reflecting mirrors 120 reflect the laser light LB emitted from each emitter (not shown) of the plurality of laser diode bars 43 toward the diffraction grating 130.

[0060] The diffraction grating 130 diffracts the laser light LB reflected by each of the multiple reflecting mirrors 120 and directs the laser light LB toward the external cavity mirror 140 .

[0061] The external cavity mirror 140 transmits a portion of the incident laser light LB and reflects the remaining portion toward the diffraction grating 130. In this manner, an external cavity is formed between the external cavity mirror 140 and each of the multiple laser modules 100. This will be further described.

[0062] As shown in Fig. 4, the laser light LB emitted from the laser diode bars 43 is reflected by the reflecting mirror 120, diffracted by the diffraction grating 130, and then incident on the external cavity mirror 140. A part of the incident laser light LB is transmitted, while the remaining part is reflected toward the diffraction grating 130 and returns to the laser diode bar 43. Most of this reflected return light is transmitted through the light-emitting end face of the laser diode bar 43 and reaches a reflecting layer (not shown) formed on the rear end face, which is the opposite face. The laser light LB is further reflected by the reflecting layer and is again emitted to the outside of the laser diode bar 43 from the light-emitting end face.

[0063] Of the laser light LB emitted from each emitter of the laser diode bar 43, only light having a wavelength (hereinafter referred to as a lock wavelength) that satisfies the diffraction condition of the diffraction grating 130 and is reflected by the external resonator mirror 140 returns to the original emitter. As a result, an external resonator is formed between the above-mentioned reflective layer formed on the rear end face of the laser diode bar 43 and the external resonator mirror 140. As a result, laser light LB is output from the laser diode bar 43, specifically, from each of the multiple emitters.

[0064] The lock wavelength of each emitter is λ L , the diffraction period of the diffraction grating 130 is d, the incident angle of the laser light LB to the diffraction grating 130 is α, the exit angle of the laser light LB from the diffraction grating 130 is β, and the order of the diffraction grating 130 is m, then the lock wavelength λ L is expressed by equation (1). d(sinα+sinβ)=mλ L ...(1) Generally, the order of the diffraction grating 130 is m=1.

[0065] For example, as shown in Fig. 4, the inclination angles of the respective reflecting mirrors 120 are adjusted so that the aforementioned incident angle α changes according to the arrangement position of the laser diode bar 43, more specifically, according to the arrangement of the multiple emitters. That is, in the example shown in Fig. 4, the actual inclination angle of the reflecting mirror 120 differs for each laser diode bar 43. In this way, the lock wavelength of the emitters formed in the laser diode bar 43 changes stepwise from one end to the other end of the laser diode bar 43.

[0066] Each emitter can oscillate by external resonance only when the inherent gain wavelength intensity of the laser diode bar 43 is equal to or greater than a predetermined value. In other words, the gain peak wavelength λ g Therefore, the laser module 100 of this embodiment oscillates at a lock wavelength within a predetermined range and does not oscillate at a lock wavelength outside the predetermined range. g The upper and lower limit ranges are the lock wavelengths λ of the emitters at both ends of the laser diode bar 43. L Difference Δλ L_bar The optical design of the laser diode bar 43 and each emitter is performed so that the lock wavelength λ of the emitters at both ends falls within the range. L Difference Δλ L_bar varies depending on the distance between the laser diode bar 43 and the diffraction grating 130. Although it also depends on the number of emitters and the number and positions of the laser diode bars 43, Δλ is usually L_bar is in the range of about 1 nm to several nm.

[0067] The relative positions of the laser assembly 40, the reflecting mirror 120, and the diffraction grating 130, as well as the diffraction period d and the thickness of the diffraction grating 130, are specified so that the optical axes of the laser beams LB emitted from the emitters of the laser diode bar 43 overlap each other when they pass through the diffraction grating 130. In this way, the multiple laser beams LB are integrated into a single high-output module laser beam LB. M The module laser light LB MThe laser beam passes through the external resonator mirror 140 and is emitted from the light exit port 150 provided in the housing 110 to the outside of the housing 110. The optical path length of the laser beam constituting the external resonator is determined by the arrangement of the optical system inside the laser module 100. When the optical path length is determined, the arrangement of the laser diode bars 43 and each emitter is also uniquely determined. That is, as shown in FIG. 2 and FIG. 4, the laser diode bars 43 are arranged in the order of the wavelength of the laser beam LB. In the configuration shown in the present embodiment, since the optical path length of the laser beam LB on the long wavelength side is short, the laser diode bar 43 and the emitter having the longest wavelength of the laser beam LB are arranged at the position closest to the light exit port 150. The laser diode bars 43 and the emitters are arranged so that the wavelength of the laser beam LB becomes longer as it moves away from the light exit port 150.

[0068] [Overall configuration of the laser module] Here, the configuration of the laser module 100 will be further explained.

[0069] As shown in FIG. 2, a plurality of laser assemblies 40, each of which has a support block 20 and a cooler 30 assembled thereto, are arranged on the upper surface of the base 10 along the X direction and spaced apart from each other in the X direction. In the example shown in FIG. 2, the bus bar 50 attached to the second electrode block 46 of one laser assembly 40 is bent downward along the Z direction and connected to the first electrode block 41 of the adjacent laser assembly 40. However, as described above, in reality, the bus bar 50 connecting the second electrode block 46 of one laser assembly 40 and the first electrode block 41 of the adjacent laser assembly 40 are at the same height with respect to the upper surface of the base 10. However, the shape of the bus bar 50 may be the shape shown in FIG. 2. In that case, the screw hole 41b is formed in the first electrode block 41 so as to be located below the screw hole 46b of the second electrode block 46.

[0070] Next, the connection relationship between the multiple laser assemblies 40 in the laser module 100 will be further described.

[0071] The multiple laser assemblies 40 are connected in series by multiple bus bars 50. In other words, the polarity of the electrodes of the laser diode bar 43 connected to one end of the bus bar 50 is different from the polarity of the electrodes of the laser diode bar 43 connected to the other end of the bus bar 50. Although FIG. 2 shows an example in which 12 laser assemblies 40 are connected in series, this is not particularly limited. The module laser light LB emitted from the laser module 100 is M The number can be changed appropriately depending on the output specifications, etc.

[0072] In addition, among the multiple laser assemblies 40, in the laser assembly 40 that is closest to the power source 600, the other end of the bus bar 50 connected to the first electrode block 41 is electrically connected to the positive terminal of the power source 600.

[0073] On the other hand, in the laser assembly 40 among the multiple laser assemblies 40, which is located farthest from the power source 600, the other end of the bus bar 50 connected to the first electrode block 41 is routed inside the housing and electrically connected to the negative terminal of the power source 600.

[0074] Next, the flow of the cooling water when the laser diode bar 43 is in operation will be described.

[0075] 2, the cooling water passages 11, 21, and 31 provided in the base 10, the support block 20, and the cooler 30, respectively, are in communication with each other. The cooling water passages 11, 21, and 31 may be collectively referred to as a cooling mechanism 90.

[0076] The cooling water passage 11 provided in the base 10 has an inlet 11A and an outlet 11B. In this embodiment, the inlet 11A and the outlet 11B are provided on the upper surface of the base 10, that is, on a surface of the base 10 that intersects with the mounting surface of the laser assembly 40, in this case, on the side surface of the base 10.

[0077] As shown in Fig. 2, the laser assemblies 40a to 40l are connected in parallel to the cooling water passage 11. The cooling water supplied to the inlet 11A from the chiller 500 through the cooling water pipe 80 and the manifold 70 passes through the cooling water passages 11, 21, and 31 in sequence in each of the laser assemblies 40a to 40l, and is discharged from the outlet 11B to the outside of the base 10. The discharged cooling water is further collected in the chiller 500 through the manifold 70 and the cooling water pipe 80, and is supplied to the cooling water pipe 80 again. In other words, the chiller 500 is a cooling water circulation mechanism that circulates the cooling water through a path formed by the cooling water passages 11, 21, and 31.

[0078] In addition, pressure loss occurs in the cooling water while it flows through the cooling water passage 11. For this reason, the flow rate of the cooling water flowing through the cooling water passage 21 provided in the support block 20 and the cooling water passage 21 provided in the cooler 30 is highest in the laser assembly 40l, and the flow rate of the cooling water decreases in the laser assemblies 40k to 40a in this order. In other words, the cooling efficiency of the laser assembly 40 by the cooling water is highest in the laser assembly 40l, and decreases in the laser assemblies 40k to 40a in this order.

[0079] Moreover, heat generated during operation of the laser diode bar 43 is dissipated through the submount 42 and the metal sheet 33 into the cooling water flowing through the cooling water passage 31. The heated cooling water passes through the cooling water passages 21 and 11, is discharged from the outlet 11B to the outside of the base 10, and is then collected in the chiller 500 through the manifold 70 and the cooling water piping 80. The collected cooling water is cooled to a predetermined temperature in the chiller 500, and is then supplied to the cooling water piping 80 again.

[0080] Next, the positional relationship between the plurality of laser assemblies 40 in the laser module 100 and the inlet 11A of the cooling water passage 11 will be further described.

[0081] 2 and 4, the laser diode bars 43 in the twelve laser assemblies 40, more specifically, the laser light LB emitted from each emitter included in each laser diode bar 43, have different wavelengths. The laser assembly 40 having the laser diode bar 43 with the longest wavelength of the laser light LB is referred to as laser assembly 40a, and the laser assemblies 40b to 40l are listed in order of decreasing wavelength of the laser light LB.

[0082] 2 and 4, the laser assemblies 40a to 40l are arranged on the upper surface of the base 10 at intervals from one another in the X direction. Among the laser assemblies 40a to 40l, the laser assembly 40a is arranged at a position closest to the inlet 11A of the cooling water passage 11. The laser assemblies 40b to 40l are arranged on the upper surface of the base 10 in the order of increasing distance from the inlet 11A. In the laser diode bars 43 included in each of the laser assemblies 40a to 40l, the emitters are arranged so that the wavelength of the emitted laser light LB becomes shorter as it gets farther from the inlet 11A.

[0083] By arranging the laser assemblies 40a-40l and the laser diode bars 43 included in each of them on the upper surface of the base 10 as described above, the laser diode bar 43 that emits the longest wavelength laser light LB, or more specifically, the emitter, is located at the position closest to the inlet 11A. The wavelength of the laser light LB emitted from the laser diode bar 43, or more specifically, the emitter, becomes shorter as it moves away from the inlet 11A.

[0084] [Layout of each part in the laser device] Fig. 5 is a schematic configuration diagram of a main part of the laser device according to embodiment 1. For convenience of explanation, the light collecting optical unit 300 is omitted in Fig. 5.

[0085] 5, the laser module 100 has a light exit port 150 on a first side surface 111. The beam combiner 200 is disposed in contact with the first side surface 111 so as to cover the light exit port 150. Although not shown, the module laser light LB emitted from the light exit port 150 is incident on the contact surface of the beam combiner 200 with the laser module 100. M A light entrance is provided through which light passes.

[0086] 2, the beam combiner 200 is attached in contact with the first side surface 111 of each of the four laser modules 100. In other words, in each of the four laser modules 100, the module laser light LB M The first side surface 111 on which the light exit port 150 is provided faces the same direction. The beam combiner 200 combines the module laser light LB emitted from each of the four laser modules 100. M A single combined laser beam LB C Bind to.

[0087] Also, as shown in FIG. 5, if the second side 112 that intersects with the first side 111 in the housing 110 is taken as the reference plane, the inlet 11A and the outlet 11B are located at a position farther from the second side 112 along the longitudinal direction of the first side 111 than the beam combiner 200.

[0088] More specifically, when viewed along the longitudinal direction of the first side surface 111, the height of the contact surface of the beam combiner 200 with the first side surface 111 is lower than the height of the first side surface 111. More specifically, the height of the contact surface of the beam combiner 200 with the first side surface 111 is lower than at least a value obtained by subtracting the height of the manifold 70 from the height of the first side surface 111.

[0089] 1 shows an example in which the laser module 100 and the focusing optical unit 300 are arranged on the same side of the beam combiner 200. However, in this embodiment, the focusing optical unit 300 is actually arranged on the opposite side of the beam combiner 200 to the laser module 100.

[0090] [Effects, etc.] As described above, the laser module 100 according to this embodiment includes at least the housing 110, the base 10 housed inside the housing 110, and a plurality of laser assemblies 40 (laser assemblies 40a to 40l).

[0091] The laser assembly 40 has a laser diode bar 43 as a laser light source. The laser diode bar 43 has a plurality of emitters. The wavelengths of the laser light LB emitted from each of the plurality of laser diode bars 43 provided in the laser module 100 are different from each other. More specifically, the wavelengths of the laser light LB emitted from each of the plurality of emitters included in each of the plurality of laser diode bars 43 are different from each other.

[0092] Inside the base 10, a cooling water passage 11 having an inlet 11A and an outlet 11B for cooling water is provided.

[0093] The laser assemblies 40a to 40l are arranged on the upper surface of the base 10 above the cooling water passage 11 and along the longitudinal direction of the cooling water passage 11 at intervals from one another.

[0094] The wavelength of the laser light LB emitted from each of the laser diode bars 43 included in each of the laser assemblies 40a to 40l becomes shorter as it moves away from the inlet 11A. Moreover, the wavelength of the laser light LB emitted from each of the emitters included in each of the laser diode bars 43 becomes shorter as it moves away from the inlet 11A.

[0095] According to this embodiment, the longer the wavelength of the laser light LB, the closer the laser diode bar 43 or emitter is to be disposed in a location closer to the inlet 11A. This can improve the cooling efficiency of the laser assembly 40 having the laser diode bar 43 on the long wavelength side with low output efficiency. This will be further described.

[0096] Fig. 6 is a schematic diagram of a main part of a laser module according to a comparative example, and Fig. 7 is a schematic diagram of a main part of a laser device according to a comparative example.

[0097] Fig. 8 is a diagram showing the relationship between the wavelength of the laser light and the laser light output, and Fig. 9 is a diagram showing the relationship between the flow rate of the cooling water and the temperature of the laser assembly.

[0098] The laser module 100 shown in FIG. 6 differs from the laser module 100 shown in FIG. 2 in that the laser assembly 40l is positioned closest to the inlet 11A, and the laser assemblies 40k to 40a are positioned in this order farther from the inlet 11A.

[0099] 6, the wavelength of the laser light LB emitted from each of the laser diode bars 43 included in each of the laser assemblies 40a to 40l becomes longer as it moves away from the inlet 11A. Moreover, the wavelength of the laser light LB emitted from each of the emitters included in each of the laser diode bars 43 becomes longer as it moves away from the inlet 11A.

[0100] On the other hand, according to the study of the present inventors, it was found that as the wavelength of the laser light LB emitted from the laser diode bar 43, more specifically, from each emitter, becomes longer, the output of the laser light LB decreases, as shown in Fig. 8. In the example shown in Fig. 8, the wavelength λ1 is 430 nm and the wavelength λ2 is 450 nm. When the output characteristic of the laser light LB with respect to the wavelength is linearly approximated, the output of the laser light LB with the wavelength λ2 is reduced to about 53% of the output of the laser light LB with the wavelength λ1.

[0101] 9, as the cooling water flow rate increases, the temperature of the laser assembly 40 decreases. Since the water passage systems of the cooling water passages 11, 21, and 31 are fixed, as the cooling water flow rate increases, the flow rate of the cooling water flowing through the cooling water passages 11, 21, and 31 also increases. In other words, the closer to the inlet 11A, the higher the cooling efficiency of the laser assembly 40 by the cooling water.

[0102] On the other hand, in the laser module 100 shown in Fig. 6, the laser diode bar 43 having the longest wavelength of the laser light LB, i.e., the lowest output efficiency, and the laser assembly 40l having an emitter are disposed at a position farthest from the inlet 11A. Also, the laser diode bar 43 having the shortest wavelength of the laser light LB, i.e., the highest output efficiency, and the laser assembly 40a having an emitter are disposed at a position closest to the inlet 11A. In other words, the cooling efficiency of the laser assembly 40 emitting the laser light LB on the long wavelength side is lower than that of the laser assembly 40 emitting the laser light LB on the short wavelength side.

[0103] 6, in the laser assemblies 40 emitting the long-wavelength laser light LB, such as the laser assemblies 40l and 40k, heat generated during operation is not sufficiently discharged, resulting in a large temperature rise in the laser diode bars 43. This reduces the lifespan of the long-wavelength laser diode bars 43, which have low output efficiency and generate a large amount of heat, and ultimately reduces the lifespan of the laser module 100 itself.

[0104] The shortened life of the laser module 100 increases the frequency of replacement of the laser module 100, which increases the maintenance costs of the laser device 700 and, in turn, the laser processing device 1000. For example, M When the output of the laser assembly 40l drops by about 10% from the initial value, the use of the laser module 100 is prohibited. In this case, when the laser assembly 40l reaches the end of its life and becomes malfunctioning, the laser module 100 including the laser assembly 40l becomes almost unusable.

[0105] On the other hand, according to the present embodiment, as described above, the laser diode bar 43 having the longest wavelength of the laser light LB, i.e., the lowest output efficiency, and the laser assembly 40l having an emitter are disposed at the position closest to the inlet 11A. Also, the laser diode bar 43 having the shortest wavelength of the laser light LB, i.e., the highest output efficiency, and the laser assembly 40a having an emitter are disposed at the position farthest from the inlet 11A.

[0106] That is, the cooling efficiency of the laser assembly 40 having the long-wavelength laser diode bars 43 with low output efficiency and large heat generation is improved. This makes it possible to suppress the shortening of the lifespan of the laser diode bars 43, and thus the shortening of the lifespan of the laser module 100. Furthermore, the frequency of replacing the laser module 100 can be reduced, and an increase in the maintenance cost of the laser device 700, and therefore the laser processing device 1000, can be suppressed.

[0107] The laser assembly 40 has at least a first electrode block 41, a submount 42, a laser diode bar 43, and a second electrode block 46. The laser diode bar 43 is a laser light source having a plurality of emitters that each emit a laser beam LB. The laser assembly of this embodiment has an insulating sheet 45 between the first electrode block 41 and the second electrode block 46.

[0108] The first electrode block 41 is connected to an electrode of one polarity of the laser diode bar 43, in this case the positive electrode, and the second electrode block 46 is connected to an electrode of the other polarity of the laser diode bar 43, in this case the negative electrode.

[0109] The second electrode block 46 of one laser assembly 40 and the first electrode block 41 of another laser assembly 40 adjacent to the one laser assembly 40 are connected by a bus bar 50, and multiple laser assemblies 40 are connected in series.

[0110] In the multiple laser assemblies 40, the laser assemblies 40 are connected with a bus bar 50, and the laser diode bars 43 included in each are connected in series. In this manner, a large current can be supplied to each laser diode bar 43 without significantly increasing the current supplied from the power source 600. This also increases the output of the laser light LB emitted from each laser diode bar 43, and therefore the module laser light LB emitted from the laser module 100. M The output can be increased.

[0111] The laser module 100 of this embodiment further includes a diffraction grating 130 and an external cavity mirror 140, which are optical coupling elements, inside the housing 110.

[0112] The diffraction grating 130 converts the laser beams LB emitted from the multiple emitters included in the laser diode bar 43 into a single module laser beam LB M Bind to.

[0113] The external cavity mirror 140 reflects the laser light LB transmitted through the diffraction grating 130 toward the diffraction grating 130 .

[0114] The laser diode bar 43 is provided with a reflective layer having a predetermined reflectance on the surface of the emitter opposite to the emission end surface from which the laser light LB is emitted.

[0115] An external cavity is formed between the external cavity mirror 140 and the reflective layer, and a module laser beam LB coupled with the diffraction grating 130 is emitted. M is emitted to the outside of the housing 110.

[0116] By configuring the laser module 100 in this manner, the laser light LB emitted from the multiple emitters included in each of the multiple laser diode bars 43 is wavelength-combined to generate a single module laser light LB M can be generated and made highly powerful.

[0117] When the diffraction grating is a reflective type, the external cavity mirror 140 reflects the laser light LB reflected by the diffraction grating toward the diffraction grating .

[0118] The laser device 700 according to this embodiment includes a plurality of laser modules 100 and at least a beam combiner 200 attached to the plurality of laser modules 100.

[0119] Each of the laser modules 100 emits a module laser light LB M is emitted.

[0120] In each of the laser modules 100, a module laser light LB M The first side surface 111 of the housing 110, in which the light exit port 150 through which the light is emitted is provided, faces the same direction.

[0121] The beam combiner 200 is attached to the first side 111 of the laser modules 100 and transmits the laser light LB M A single combined laser beam LB C Bind to.

[0122] By configuring the laser device 700 in this manner, the module laser light LB emitted from each of the multiple laser modules 100 M A single combined laser beam LB C In addition, it is easy to combine multiple modules with laser light LB M A single combined laser beam LB C By combining with the laser beam LB C For example, the module laser light LB M In the case where the output of the laser beam LB1 is about 300 W to 1 kW, according to this embodiment, the laser beam LB1 having an output of about 1.2 kW to 4 kW is C can be generated and emitted to the outside of the laser device 700.

[0123] In the laser device 700 of this embodiment, the coupled laser light LBC In order to improve the efficiency of optical coupling, a focusing optical unit 300 is provided after the beam combiner 200 .

[0124] If the second side 112 of the housing 110, which intersects with the first side 111, is taken as the reference plane, the inlet 11A and the outlet 11B are located at a position farther from the second side 112 along the longitudinal direction of the first side 111 than the beam combiner 200.

[0125] In particular, in this embodiment, when the second side 112 is used as the reference plane and viewed along the longitudinal direction of the first side 111, the height of the abutment surface of the beam combiner 200 with the first side 111 is lower than the height of the first side 111.

[0126] By defining the positional relationship between the inlet 11A and the outlet 11B and the beam combiner 200 as described above, the height of the beam combiner 200 along the longitudinal direction of the first side surface 111 can be made lower than the height of the housing 110. This allows the beam combiner 200, and therefore the laser device 700, to be made smaller in size.

[0127] In the laser device 700, cooling water is supplied to each of the cooling water inlets 11A of the laser modules 100 from a chiller 500 provided outside the laser modules 100 via a manifold 70. Furthermore, cooling water is collected from each of the cooling water outlets 11B of the laser modules 100 to the chiller 500.

[0128] By configuring the laser device 700 in this way, it is possible to reduce the amount of cooling water used to cool each laser diode bar 43, thereby reducing the operating costs of the laser device 700 and, in turn, the laser processing device 1000. In addition, it is possible to reduce the amount of cooling water discharged to the outside, thereby reducing the impact on the environment.

[0129] In addition, the cooling water collected from the laser module 100 absorbs heat generated during operation of the laser diode bar 43 and its temperature rises. As shown in this embodiment, after cooling to a certain temperature by the chiller 500, it is again supplied to the laser module 100, thereby suppressing a decrease in the cooling efficiency of the multiple laser assemblies 40 and, in turn, the laser diode bars 43 contained therein. This makes it possible to suppress a decrease in the lifespan of each laser diode bar 43, and, in turn, to suppress a decrease in the lifespan of the laser module 100. Furthermore, the frequency of replacement of the laser module 100 can be reduced, and an increase in the maintenance cost of the laser device 700 and, in turn, the laser processing device 1000 can be suppressed.

[0130] The laser processing apparatus 1000 according to this embodiment includes a laser device 700, a power source 600 for supplying power for laser oscillation to the laser device 700, and a combined laser beam LB C The laser head 900 is attached to the output end of the optical fiber 800. In this embodiment, the light collecting optical unit 300 is attached to the input end of the optical fiber 800, and the laser head 900 is attached to the output end of the optical fiber 800. C is guided to the laser head 900 through the optical fiber 800 .

[0131] According to this embodiment, a plurality of module laser beams LB M By combining these, a high-power combined laser beam LB C In the laser module 100, the cooling efficiency of the laser assembly 40 that emits the long-wavelength laser light LB can be increased, so that the temperature rise of the long-wavelength laser assembly 40, which has a lower output efficiency and a larger amount of heat generation than the short-wavelength laser, can be suppressed. This makes it possible to suppress the shortening of the lifespan of the laser module 100 and the laser device 700, and to suppress the shortening of the operational reliability and further the shortening of the lifespan of the laser processing device 1000.

[0132] (Embodiment 2) FIG. 10 is a schematic configuration diagram of a main part of a laser device according to the second embodiment, and FIG. 11 is a schematic configuration diagram of a main part of a laser module according to the second embodiment.

[0133] For ease of explanation, in FIG. 10 and the following drawings, the same parts as those in the first embodiment are denoted by the same reference numerals, and detailed explanations thereof will be omitted.

[0134] The laser device 700 of this embodiment shown in Fig. 10 differs from the laser device 700 of the first embodiment shown in Fig. 5 in that cooling water is introduced into the housing 110 from a third side surface 113 that faces the second side surface 112 and the first side surface 111 in the longitudinal direction. Therefore, as shown in Fig. 10, the manifold 70 is also attached to the third side surface 113 of the housing 110.

[0135] In addition, the laser module 100 of this embodiment shown in FIG. 11 differs from the laser module 100 of embodiment 1 shown in FIG. 2 in that a cooling water inlet 11A and outlet 11B are provided on the upper surface of the base 10, i.e., the mounting surface for the laser assembly 40.

[0136] In the laser device 700 shown in the first embodiment, the manifold 70 is attached to a first side surface 111 which is the mounting surface of the beam combiner 200, and cooling water is introduced into the housing 110 from the first side surface 111.

[0137] According to the first embodiment, as described above, it is possible to reduce the height and size of the beam combiner 200. On the other hand, the arrangement of the focusing optical unit 300 is limited to the opposite side of the beam combiner 200 from the laser module 100. In this case, when the laser device 700 is viewed as a whole, it may not be possible to achieve a sufficient size reduction.

[0138] On the other hand, according to this embodiment, the manifold 70 is attached to a third side surface 113 different from the first side surface 111, and the cooling water is introduced into the inside of the housing 110 from the third side surface 113.

[0139] In this way, the degree of freedom in the layout relationship between the laser module 100, the beam combiner 200, and the focusing optical unit 300 in the laser device 700 can be increased.

[0140] Moreover, according to this embodiment, it is possible to achieve the same effects as those achieved by the configuration shown in the first embodiment. That is, the cooling efficiency of the laser assembly 40 having the long-wavelength laser diode bars 43, which have low output efficiency and large heat generation, is improved. This makes it possible to suppress the shortening of the life of the laser diode bars 43, and thus the shortening of the life of the laser module 100. Furthermore, it is possible to reduce the frequency of replacement of the laser module 100, and thus to suppress an increase in the maintenance cost of the laser device 700, and thus the laser processing device 1000.

[0141] In addition, in FIG. 11, an example in which the inlet 11A and the outlet 11B are provided on the upper surface of the base 10 is shown, but the present invention is not limited thereto. As shown in FIG. 2, the inlet 11A and the outlet 11B may be provided on the side surface of the base 10. In this case, the cooling water pipe 80 is routed inside the housing 110. In addition, in this embodiment, the cooling water pipe 80 is bent, so that the pressure loss of the cooling water in the cooling water pipe 80 may be increased compared to the case shown in the first embodiment. In addition, the pressure loss of the cooling water may also be increased at the connection portion between the cooling water pipe 80 and the cooling water passage 11 compared to the case shown in the first embodiment. In consideration of these, the pipe diameter may be increased at least in the cooling water pipe 80 at the bent portion and the connection portion with the cooling water passage 11.

[0142] <Variation 1> FIG. 12 is a perspective view of a laser assembly according to the first modification.

[0143] Laser assembly 40 of this modified example shown in FIG. 12 differs from laser assembly 40 of the first embodiment shown in FIGS. 3A to 3C in the following points.

[0144] First, the bus bar 50 and the first electrode block 41 are integrated. Also, the bus bar 50 and the second electrode block 46 are integrated. In this specification, "integrated" refers to a state in which a plurality of members are in advance positioned and then inseparably joined. For example, in this modification, the bus bar 50 and the first electrode block 41, and the bus bar 50 and the second electrode block 46 are integrated by being joined by welding. However, various integration methods can be selected. For example, the bus bar 50 and the first electrode block 41 or the second electrode block 46 may be integrated by crimping or the like.

[0145] Moreover, by integrating the busbar 50 with the first electrode block 41, and the busbar 50 with the second electrode block 46, respectively, the screw hole 41b is omitted in the first electrode block 41, and the screw hole 46b is omitted in the second electrode block 46. Moreover, one of the through holes 50a formed at both ends of the busbar 50 is omitted.

[0146] As shown in this modification, by integrating bus bar 50 and first electrode block 41, and bus bar 50 and second electrode block 46, respectively, the number of assembly steps for laser assembly 40 can be reduced.

[0147] <Variation 2> FIG. 13 is an exploded perspective view of a laser assembly according to the second modification.

[0148] The laser assembly 40 of this modified example shown in Fig. 13 differs from the structure shown in Figs. 3A to 3C in that a submount 42 and a laser diode bar 43 joined to the submount 42 are sandwiched and fixed between a first electrode block 48 and a second electrode block 49 from above and below. The shape of the first electrode block 48 is also different from the shape of the first electrode block 41 shown in Figs. 3A to 3C. The shape of the second electrode block 49 is also different from the shape of the second electrode block 46 shown in Figs. 3A to 3C. However, the materials of the first electrode block 48 and the second electrode block 49 are the same as the materials of the first electrode block 41 and the second electrode block 46, respectively.

[0149] Unlike the first electrode block 41, the first electrode block 48 does not have a step. However, the first electrode block 48 has a recess 48c that is open at the front. A submount 42 and a laser diode bar 43 bonded to the submount 42 are disposed in the recess 48c. The p-side electrode of the laser diode bar 43 is bonded to the submount 42, which is the same as the configuration shown in the first embodiment.

[0150] Unlike the second electrode block 46, the second electrode block 49 has no steps. The lower surface of the second electrode block 49, in other words, the surface electrically connected to the n-side electrode of the laser diode bar 43, is a substantially flat surface.

[0151] The insulating sheet 45 has a cutout provided therein so as to surround the recess 48c when viewed from above.

[0152] When assembling the laser assembly 40, the submount 42 and the laser diode bar 43 are mounted after being positioned in the recess 48c of the first electrode block 48. Furthermore, an insulating adhesive (not shown) is placed on the upper surface of the first electrode block 48 in a position surrounding the recess 48c. With the through hole 45a and the screw hole 48a of the first electrode block 48 overlapping, the insulating sheet 45 is bonded to the first electrode block 48 using the insulating adhesive.

[0153] Next, the second electrode block 49 is placed on the surface of the first electrode block 48 so that the screw hole 48a of the first electrode block 48 and the screw hole 49a of the second electrode block 49 overlap. Furthermore, with a washer 62 interposed, a screw 61 is inserted through the screw hole 48a of the first electrode block 48, the through hole 45a of the insulating sheet 45, and the screw hole 49a of the second electrode block 49, and fastened.

[0154] In this manner, the submount 42 and the laser diode bar 43 are sandwiched and fixed between the first electrode block 48 and the second electrode block 49. When connecting the first electrode block 48 and the bus bar 50, the through hole 50a of the bus bar 50 and the screw hole 48b of the first electrode block 48 are overlapped with each other, and screws 63 are inserted through the through hole 50a and the screw hole 48b to fasten them together. When connecting the second electrode block 49 and the bus bar 50, the through hole 50a of the bus bar 50 and the screw hole 49b of the second electrode block 49 are overlapped with each other, and screws 63 are inserted through the through hole 50a and the screw hole 49b to fasten them together.

[0155] In this modification, each of the multiple laser assemblies 40, specifically, each of the multiple first electrode blocks 48, is disposed on the upper surface of the base 10. As a result, in each of the multiple laser assemblies 40, the first electrode block 48 is cooled by the cooling water flowing through the cooling water passage 11 of the base 10.

[0156] When the laser assembly 40 having the configuration shown in this modification is used, the support block 20 and the cooler 30 can be omitted from the laser module 100. This allows the laser module 100 to be made more compact.

[0157] (Other embodiments) The components shown in the first and second embodiments and the first and second modifications can be appropriately combined to form new embodiments.

[0158] For example, the laser assembly 40 shown in the first and second modified examples may be applied to the laser module 100 shown in the second embodiment.

[0159] In the present specification, the laser device 700 and the laser processing device 1000 equipped with four laser modules 100 have been described as examples. However, depending on the output range of the laser light required for laser processing, only one laser module 100 may be mounted on the laser device 700 and the laser processing device 1000. In addition, when there is one laser module 100, the beam combiner 200 is omitted.

[0160] Further, in the present specification, the laser diode bar 43 having a plurality of emitters has been described as an example of the laser light source, but a laser diode having a single emitter may also be used.

[0161] In addition, the position of the manifold 70 attached to the laser module 100 is not limited to those shown in the first and second embodiments. For example, as shown in FIG. 14, the manifold 70 may be arranged on a side surface intersecting the first side surface 111 and the second side surface 112 of the housing 110. In this case, the inlets 11A and 11B of the cooling water passage 11 are arranged on the base 10 so as to open toward the Y direction shown in FIGS. 2 and 11. In this case, similarly to the configuration shown in the second embodiment, the size constraint of the beam combiner 200 attached to the housing 110 of the laser module 100 is relaxed. In addition, the degree of freedom of the arrangement relationship between the laser module 100, the beam combiner 200, and the focusing optical unit 300 in the laser device 700 is increased.

[0162] In addition, in the present specification, an example has been shown in which the cooling water supplied from the chiller 500 passes through the cooling water piping 80 and the cooling water passages 11, 21, and 31 and is recovered in the chiller 500, but this is not particularly limited. For example, a non-aqueous refrigerant such as Galden (registered trademark) may be used instead of the cooling water. That is, the cooling water piping 80 in the present specification may be read as the refrigerant piping 80. Also, the cooling water passages 11, 21, and 31 may be read as the refrigerant flow paths 11, 21, and 31, respectively. The chiller 500 is a refrigerant circulation mechanism 500. [Industrial Applicability]

[0163] The laser module of the present disclosure is a laser module including multiple laser assemblies, each having a laser light source that emits laser light of different wavelengths, and is useful because it can efficiently cool the laser assembly that emits laser light on the longer wavelength side, thereby suppressing a decrease in output efficiency and a decrease in the lifespan of the laser module. [Explanation of symbols]

[0164] 10 Base 11 Cooling water channel (coolant flow path) 11A Inlet 11B Outlet 20 Support Block 21 Cooling water channel (coolant flow path) 30 Cooler 31 Cooling water channel (refrigerant flow path) 40(40a~40l) Laser assembly 41 First electrode block 41a Screw hole 42 Submount 43 Laser Diode Bar 44 Metal Solder 45 Insulation sheet 46 Second electrode block 48 First Electrode Block 49 Second electrode block 50 Busbar 60 Fixing screw 70 Manifold 80 Cooling water piping (refrigerant piping) 90 Cooling mechanism 100 Laser Module 110 Cabinet 111 First aspect 112 Second aspect 113 Third aspect 120 Reflective Mirror 130 Diffraction Grating 140 External Cavity Mirror 150 Light exit port 200 Beam Combiner 300 Condenser Optical Unit 400 Control section 410 Display section 500 Chiller (refrigerant circulation mechanism) 600 power supply 700 Laser Equipment 800 Optical Fiber 900 Laser Head 1000 Laser processing equipment W work

Claims

1. A laser module including at least a housing, a base, and a plurality of laser assemblies each having a laser light source, the base and the plurality of laser assemblies are housed within a housing; A coolant flow path having a coolant inlet and an outlet is provided inside the base, The plurality of laser light sources emit laser beams having different wavelengths, the laser assemblies are disposed on an upper surface of the base, above the coolant flow passage, and spaced apart from one another along a longitudinal direction of the coolant flow passage; A laser module, characterized in that the wavelength of the laser light emitted from each of the plurality of laser light sources becomes shorter as it moves away from the inlet.

2. 2. The laser module according to claim 1, the laser light source is a laser diode bar having a plurality of emitters each emitting the laser light, the laser assembly includes at least the laser diode bar, a submount, a first electrode block, and a second electrode block; the first electrode block is connected to an electrode of one polarity of the laser diode bar, and the second electrode block is connected to an electrode of the other polarity of the laser diode bar, A laser module characterized in that the second electrode block of one of the laser assemblies and the first electrode block of another of the laser assemblies adjacent to the one of the laser assemblies are connected by a bus bar, thereby connecting a plurality of the laser assemblies in series.

3. 3. The laser module according to claim 2, a first electrode block and a bus bar, the first electrode block and the bus bar being integrated together, and a second electrode block and the bus bar being integrated together.

4. 3. The laser module according to claim 2, Further comprising an optical coupling element and an external resonator mirror inside the housing; the optical coupling element couples the laser light emitted from each of the plurality of emitters included in the laser diode bar; the external cavity mirror reflects the laser light, which has been transmitted through or reflected by the optical coupling element, toward the optical coupling element; the laser diode bar is provided with a reflective layer having a predetermined reflectance on a surface of the emitter opposite to an emission end surface of the laser light, an external resonator is configured between the external resonator mirror and the reflective layer of the emitter from which the laser light is emitted; A laser module, characterized in that a module laser light coupled by the optical coupling element is emitted to the outside of the housing.

5. A laser device comprising a plurality of laser modules according to claim 1 and at least a beam combiner attached to the plurality of laser modules, Each of the plurality of laser modules emits a module laser beam; In each of the plurality of laser modules, a first side surface on which an output port of the module laser light is provided faces the same direction, The beam combiner is attached to the first side surface of the plurality of laser modules, and combines the plurality of module laser beams into a single combined laser beam.

6. 6. The laser device according to claim 5, A laser device characterized in that the coolant is supplied to each of the inlets of the multiple laser modules from a coolant circulation mechanism provided outside the multiple laser modules via a manifold, and the coolant is recovered to the coolant circulation mechanism from each of the outlets of the multiple laser modules.

7. 7. The laser device according to claim 6, When a second side surface of the housing that intersects with the first side surface is set as a reference surface, A laser device, characterized in that the inlet and the outlet are provided at a position farther from the second side surface along the longitudinal direction of the first side surface than the beam combiner.

8. 7. The laser device according to claim 6, When a second side surface of the housing that intersects with the first side surface is taken as a reference surface and the housing is viewed along a longitudinal direction of the first side surface, A laser device, characterized in that a height of a contact surface of the beam combiner with the first side surface is lower than a height of the first side surface.

9. 7. The laser device according to claim 6, When a second side surface of the housing that intersects with the first side surface is taken as a reference surface and the housing is viewed along a longitudinal direction of the first side surface, the manifold is attached to a third side surface of the housing that faces the second side surface in the longitudinal direction, The laser device, wherein the coolant is introduced into the housing from the third side surface.

10. A laser device according to any one of claims 5 to 9, a power source for supplying power for laser oscillation to the laser device; an optical fiber for guiding the combined laser beam; and a laser head attached to the output end of the optical fiber.

Images