JP2005286310A - Device for generating laser beam - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device for generating a laser beam configured to allow the highly efficient focusing of respective laser beams emitted from a plurality of beam-emission portions. <P>SOLUTION: The laser beam generating unit 2 (2A) has a semiconductor laser unit 12 having a plurality of beam emission portions 11 located in a matrix and a plurality of optical fibers 7a adapted to individually transmit laser beams L emitted respectively from the beam emission portions 11. The plurality of optical fibers 7a are arranged to be bundled on the laser-emission side to form an optical fiber bundle and also to emit the laser beams L through a tapered adaptor 31c provided on the laser-beam emission side. In effect, it becomes possible to transmit the laser beams L desirably by the optical fibers 7a, and also condense with a high efficiency by a beam transmission path 31c of the adaptor 31 having a minimized diameter to raise the power density. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

    The present invention relates to a laser light generator that condenses laser light emitted from a plurality of light emitting portions (emitters) of a semiconductor laser so that it can be used for a required application.

    Generally, a semiconductor laser (laser diode: LD) is known as a high-efficiency laser light source having high conversion efficiency from electricity to light and having an oscillation efficiency exceeding 50%, and does not require a large-scale cooling device. Therefore, it is actively utilized in fields such as the information processing industry. However, although such a semiconductor laser has high-efficiency oscillation characteristics as described above, its size is 1 mm or less and only a light output of several watts [W] can be expected. It was never used in the field.

    However, in recent years, a semiconductor laser has a high light density if it is used so as to collect light in a form in which a plurality of light sources are arranged in a one-dimensional or two-dimensional manner even when the output is small. From the viewpoint of obtaining a high-power laser beam, a semiconductor laser condensing device has been devised that uses a plurality of semiconductor lasers as a unit for laser processing (see, for example, Patent Document 1).

    The semiconductor laser concentrating device described in Patent Document 1 condenses laser light emitted (oscillated) from each light emitting portion that is a light emission source of a semiconductor laser substrate via an optical waveguide formed on the substrate, It is configured to be used for laser processing in a form with increased output. The optical waveguide has the same number of input ports as the light source on one end face, and optically transmits all the laser light received by each input port to the only output port provided on the other end face. Configured to combine.

JP-A-7-168040 (FIGS. 1 to 3)

    However, according to the semiconductor laser concentrating device disclosed in Patent Document 1, in order to condense the laser light from a plurality of light emitting portions, a relatively large substrate provided with an optical waveguide must be prepared separately. Therefore, the presence of such a substrate may impair the downsizing of the apparatus.

    Therefore, a configuration in which a plurality of optical fibers themselves are bundled into a bundle shape without using the substrate as described above and condensed individually from each optical fiber exit end of this optical fiber bundle is also conceivable. In this case, the binding portion of the optical fiber bundle has a large diameter. And when condensing low-power laser light from a large number of light emitting sections to increase the output, the higher the required laser light, the greater the number of optical fibers and the larger the bundle diameter. As a result, the power density is reduced. For this reason, when such an optical fiber is used as a laser beam condensing means, the laser emission side of the large-diameter optical fiber bundle is made as small as possible without impairing a good photoconductive state. It is eager to make it.

    In view of the circumstances described above, the present invention is a laser light generator capable of condensing each laser light from a plurality of light emitting portions with high efficiency by a combination of laser light condensing means and a tapered optical transmission path. Is intended to provide.

That is, the first invention of the present invention is a semiconductor laser unit (12, 112) provided with a plurality of light emitting portions (11, 111) arranged in a matrix and capable of emitting laser light (L) individually. ) And a laser beam generator (7, 107) having a laser beam condensing means (7, 107) capable of condensing the laser beams (L) respectively emitted from the plurality of light emitting sections (11, 111). 2, 2A, 102A)
An incident port (31a, 131a) through which the laser beam condensed by the laser beam condensing means (7, 107) is incident, an emission port (31b, 131b) corresponding to the incident port (31a, 131a), and Tapered portions (31, 131) each having a tapered optical transmission line (31c, 131c) having a gradually decreasing diameter from the entrance (31a, 131a) toward the exit (31b, 131b). It is characterized by that.

    The “matrix shape” in the present invention is not limited to a so-called matrix-like arrangement in which the pitches in the row direction and the column direction are aligned, but a plurality of rows arranged at a predetermined pitch in the row direction (or column direction). This is a broad concept including honeycomb (honeycomb), staggered, and other arrangements in which parts are arranged so as to be alternately shifted in the column direction (or row direction).

    According to a second aspect of the present invention, the cross-sectional shape of the laser light condensed by the laser light condensing means (7, 107) is equal to the opening shape of the entrance (31a, 131a), It is smaller than the opening shape.

    According to a third aspect of the present invention, the degree of aperture of the laser light in the vicinity of the exit (31b, 131b) of the optical transmission line (31c, 131c) is the same as that of the optical transmission line (31c, 131c). It is characterized by being smaller than the degree of aperture of the laser beam in the vicinity of the entrance (31a, 131a). In this specification, “the degree of aperture of laser light in a specific part” means “the beam diameter of laser light emitted from the specific part” and “the beam diameter of laser light incident on the specific part”. It means the value (ratio) divided by.

    According to a fourth aspect of the present invention, the laser beam condensing means (7) has a plurality of optical fibers capable of individually transmitting the laser beams respectively emitted from the plurality of light emitting sections (11). (7a) is an optical fiber bundle configured by bundling the laser emission side opposite to the laser receiving end (7b) facing the plurality of light emission portions (11).

    According to a fifth aspect of the present invention, the laser beam condensing means (107) is a lens.

    According to a sixth aspect of the present invention, the tapered portion (31, 131) is made of a metal material, and the optical transmission line (31c, 131c) is made of a tapered hollow portion whose inner surface is polished. The

    According to a seventh aspect of the present invention, the tapered portion (31, 131) is made of a metal material, and the optical transmission line (31c, 131c) has a tapered hollow portion formed with a reflective film on the inner surface. Consists of.

    According to an eighth aspect of the present invention, the tapered portion (31, 131) is made of a synthetic resin material, and the optical transmission line (31c, 131c) forms a metal reflective film on the inner surface by vapor deposition plating. It is comprised by the taper-shaped hollow part.

    As described above, according to the first and second aspects of the present invention, the optical transmission path, which is the optical path of the laser light, is configured to have a tapered shape with a gradually decreasing diameter from the entrance to the exit. Therefore, the power density of laser light can be increased. There are also the following effects. That is, since the light emitting portions are arranged in a matrix shape such as a matrix shape, a honeycomb shape, or a staggered shape, the laser beams from the plurality of light emitting portions are emitted in such a matrix shape. That is, the cross-sectional shape of the laser beam group composed of a plurality of laser beams (in other words, the shape of the cross-sectional area in which the plurality of laser beams are distributed) is substantially rectangular. The cross-sectional shape of the other optical transmission path is generally smaller than the cross-sectional shape of the laser beam group, and is generally circular. Therefore, when trying to make the laser light from the light emitting part incident on the optical transmission line without condensing at all, a part of the laser light does not enter the optical transmission line, and that part is “light loss”. There is a risk of becoming. In the present invention, a laser beam condensing unit is disposed between the light emitting unit and the optical transmission path, and the laser beams emitted from the plurality of light emitting units are collected by the laser beam condensing unit and then Since it is configured to be incident on the incident port, such light loss can be reduced (preferably prevented), and laser light can be used efficiently.

    According to a third aspect of the present invention, the degree of aperture of the laser light in the vicinity of the exit of the optical transmission path is set smaller than the extent of aperture of the laser light in the vicinity of the entrance of the optical transmission path. Therefore, the beam diameter of the laser beam can be reduced in stages, and the laser beam optimal for processing can be obtained in various ways.

    According to a fourth aspect of the present invention, a plurality of optical fibers are used as the laser beam condensing means, a tapered taper portion is provided on the laser emission side, and laser light is emitted through the taper portion. Based on the principle that coherent laser light can pass through a tapered optical waveguide inclined at a predetermined angle without causing any optical loss, the laser light from each light emitting part is transmitted. Power density can be increased by condensing light with high efficiency by the tapered portion having a diameter as small as possible.

    In the fifth aspect of the present invention, since a lens is used as the laser beam condensing means, the structure and the manufacturing process can be simplified as compared with the case where an optical fiber is used.

    According to a sixth aspect of the present invention, the tapered portion is made of a metal material, and the optical transmission path is made of a tapered hollow portion whose inner surface is polished. A good optical transmission line without optical loss can be easily obtained simply by forming and polishing the inner surface to a mirror surface with no unevenness.

    According to a seventh aspect of the present invention, the tapered portion is made of a metal material, and the optical transmission path is made of a tapered hollow portion having a reflection film formed on the inner surface. A good optical transmission line free from light loss can be easily obtained by simply forming it and forming a uniform reflection film on its inner surface.

    In the eighth invention of the present invention, the tapered portion is composed of a synthetic resin material, and the optical transmission path is composed of a tapered hollow portion in which a metal reflection film is formed on the inner surface by vapor deposition plating. By simply forming a tapered hole and vapor-depositing the inner surface without unevenness to finish it into a mirror surface, a good optical transmission line with no optical loss can be easily obtained. In addition, the said taper-shaped part can also be comprised with a glass material. In this case, the same effect as described above can be obtained by forming a metal reflective film on the inner surface of the optical transmission line by vapor deposition.

    Note that the numbers in parentheses are for the sake of convenience indicating the corresponding elements in the drawings, and therefore the present description is not limited to the descriptions on the drawings.

    First, a first embodiment of the present invention will be described with reference to FIGS.

    1 is an overall perspective view schematically showing an example of a machine tool having a laser beam generator to which the present invention is applied, and FIG. 2 is a side sectional view showing one laser beam generator in FIG. 3 is a perspective view showing one laser light generator in FIG. 1 in a partially disassembled form.

    As shown in FIG. 1, a machine tool 1 includes a laser light generator 2 that generates laser light, a laser transmission device 3 that transmits laser light output from the laser light generator 2 to a processing unit, and a transmission A laser irradiation device 9 for irradiating the workpiece (workpiece) W with the laser beam from the laser torch 9a.

    The laser beam generator 2 provided in the machine tool 1 includes a semiconductor laser unit 12, a cured resin 14 (see FIGS. 2 and 3), and a tip portion of an optical fiber 7 a that is blocked by the cured resin 14. A plurality of laser light generators 2A, each of which is a combined body of each of the optical fiber units 13 formed, are provided.

    In the present embodiment, the laser light generator 2 includes three laser light generators 2A. However, the number is not limited to this, and one, two, or four or more. However, it may be appropriately selected according to the level of laser light output required for each application.

    The laser light generating device 2 has a main body case 2b having a through hole 2a formed on a side surface, and the three laser light generating devices 2A are accommodated and arranged inside the main body case 2b. The laser light output from each laser light generating device 2A is transmitted to the optical fiber 8 protruding outward from the through hole 2a through the optical fiber bundle 7 including a plurality of optical fibers 7a provided for each laser light generator 2A. Is done. Laser light from an assembly of a plurality of optical fiber bundles 7 is incident on the optical fiber 8 in a converged form via an optical system (not shown).

    On the other hand, the laser transmission device 3 includes the optical fiber 8 and four optical fibers 4 having the same configuration as the optical fiber 8. Between the optical fiber 8 and the optical fiber 4, Mirrors 5 are respectively arranged. In the laser transmission device 3, when the optical fibers 4 and 8 are bent by a predetermined angle (for example, 8 degrees) or more, the laser light leaks from the optical fiber 4 to the outside. In this case, the degree of freedom in designing the laser light transmission path is improved.

    A convex lens 6a is disposed between the end of the optical fibers 8 and 4 on the laser light output side (hereinafter referred to as output side end) and the mirror 5, and the end of the optical fiber 4 on the laser light input side. A convex lens 6b is disposed between the mirror 5 (hereinafter referred to as the input side end). Laser light emitted (oscillated) from each laser light generator 2A and transmitted from the optical fiber bundle 7 via the optical fiber 8 is diffused when it is output from the output side end of the optical fiber 8. However, the diffused laser light is converted into parallel light by the convex lens 6a and then reflected by the mirror 5 to change its path by a predetermined angle.

    Further, the parallel light reflected by the mirror 5 is condensed so as to be smaller than the diameter of a core member (not shown) provided in the optical fibers 8 and 4 due to refraction by the lens 6b, and the input side end portion. To the core member. As a result, the laser light diffused and output from one core member of the optical fibers 8 and 4 is condensed and input to the core member of the other optical fiber 4.

    With the above configuration, when laser light is emitted from the laser light generator 2, the laser light is transmitted to the laser irradiation device 9 via the laser transmission device 3, and is further disposed in the laser torch 9a (FIG. The workpiece W is irradiated from the laser torch 9a so as to focus on the workpiece W through a not-shown).

    Then, by rotating the workpiece W in the direction of arrow C in FIG. 1 at a predetermined speed, it is possible to uniformly irradiate the workpiece surface with laser light. Thereby, for example, when the workpiece W is made of steel, it is possible to perform processing such as quenching to a portion of 1.0 mm to 1.5 mm from the workpiece surface. The machine tool 1 shown in FIG. 1 is for explaining a laser light transmission path, and for the sake of convenience of explanation, other parts such as a moving table and its driving device are omitted.

    Next, the configuration of the laser beam generator 2 (2A) will be described with reference to FIGS. That is, the laser light generating device 2A constituting the laser light generating device 2 has a plurality of light emission units arranged in a matrix and capable of individually emitting the laser light L as shown in FIGS. The semiconductor laser unit 12 including the unit 11 is provided, and a plurality of optical fibers 7a capable of individually transmitting the laser beams L emitted from the respective light emitting units 11 are provided.

    Note that the “matrix shape” in the present embodiment is not limited to a so-called matrix arrangement in which pitches in the row direction (X direction) and the column direction (Y direction) are respectively aligned, and the row direction (or This is a wide concept including a honeycomb (honeycomb) shape, a staggered shape, and other arrangements in which a plurality of portions arranged at a predetermined pitch in the column direction are alternately shifted in the column direction (or row direction).

    The semiconductor laser unit 12 has a substantially box-shaped heat sink in which a plurality of (for example, nine) semiconductor laser substrates 26 having a plurality of light emitting portions (emitters) 11 along the X direction are stacked on the front surface. 25. Each semiconductor laser substrate 26 includes a microlens 18 disposed so as to cover each light emitting portion 11. The microlens 18 converts laser light into parallel light, and includes a cylindrical lens or the like. Further, on both side surfaces of the heat sink 25 (for convenience, only one side is shown in FIGS. 2 and 3), a substantially rectangular heat radiation notch 25a is formed.

    The semiconductor laser substrate 26 is formed by a pn junction in which an active layer is interposed between a p-type layer and an n-type layer. On one side surface of the active layer, a p-type layer, an n-type layer, and A plurality of light emitting portions (emitters) that can oscillate laser light based on the voltage of are arranged along the X direction (FIG. 3). In such a semiconductor laser substrate 26, when a voltage is applied to the p-type layer and the n-type layer via electrodes (not shown), the laser light L (FIG. 3) is emitted from each light emitting portion 11. The

    The plurality of optical fibers 7a have a predetermined length from each tip so that each light receiving end face (laser light receiving end) 7b (FIG. 2) can be accurately opposed to the matrix-shaped light emitting portion 11. Positioning and fixing in a block shape with a glass-based cured resin 14 in such a manner that each pitch on the light receiving end surface 7b in the X direction and the Y direction corresponds to each pitch between the light emitting portions 11 in the X direction and the Y direction on a one-to-one basis. Has been. As described above, the optical fiber unit 13 is configured by the cured resin 14 and the tip portion of the optical fiber 7a blocked by the cured resin 14.

    The optical fiber unit 13 has a predetermined number (for example, 54 (6 × 9)) of light receiving end faces 7b of the optical fibers 7a positioned and cured with resin, and then the front end face 14a (FIG. 2) of the cured resin 14 with the optical fiber 7a is precisely polished so as to be exactly parallel to each light receiving end face 7b, and is formed in a rectangular parallelepiped shape in which the front-rear direction (thickness direction) is relatively thin. By using the optical fiber unit 13 having such a structure, the multiple optical fibers 7a can be accurately aligned at a time using the front end face 14a as a reference for the arrangement of the light emitting portions 11.

    In the present embodiment, the semiconductor laser substrate 26 has nine stages and the light emitting section 11 in each semiconductor laser substrate 26 has six semiconductor laser units 12 as an example. However, one semiconductor laser substrate 26 has The number of the light emitting portions 11 and the number of stacked layers of the semiconductor laser substrate 26 are not limited to this, and can be appropriately changed and set as necessary.

    The optical fiber unit 13 has a Y-direction moving frame 21 fitted around the front end surface 14a. The Y-direction moving frame 21 supports the optical fiber unit 13 and is engaged and supported by Y-direction rails 19 and 19 formed in an X-direction moving frame 20 described later so as to be movable in the Y direction. On one side surface and the other side surface, engaging projections 21a and 21b that can be slidably engaged with the Y-direction rails 19 and 19 are provided.

    On the other hand, between the semiconductor laser unit 12 and the optical fiber unit 13, positioning adjusting means 15 that can accurately adjust the positional relationship between the light emitting portion 11 and the light receiving end face 7b that should be positioned facing each other is arranged. It is installed. The positioning adjusting means 15 includes the Y-direction moving frame 21 attached to the optical fiber unit 13 and a support 30 that supports the Y-direction moving frame 21 on the semiconductor laser unit 12 side.

    That is, the support 30 includes a support base 16 that fixes and supports the semiconductor laser unit 12 in a predetermined state, and an X-direction moving frame 20 that is supported by the support base 16 so as to be movable in the X direction. The support base 16 has a base portion 16a and a base portion 16b that is formed substantially at the center of the base portion 16a and carries the semiconductor laser unit 12.

    Further, the support 16 includes column portions 16c and 16d extending in the vertical direction (Y direction) at a predetermined interval on the front side (right side in FIG. 3) of the base portion 16a, and the column portions 16c and 16d. Beam portions 17 and 17 extending so as to connect the upper portions and the lower portions of the two. As shown in FIG. 2, X-direction rails 17a and 17b extending in the length direction of the beam portions are formed in the upper beam portion 17 and the lower beam portion 17, respectively. That is, the X-direction rails 17a and 17b are arranged at a predetermined distance above and below the front surface (surface on the light emission side) of the semiconductor laser unit 12, and a predetermined distance is set on the left and right on the front surface on the light emission side. Y-direction rails 19 and 19 (for convenience, one side is not shown) are arranged in an open shape.

    Further, a screw hole (not shown) is formed at a predetermined position of the column portion 16d so as to face the X direction, and the X direction position of the X direction moving frame 20 with respect to the support base 16 is adjusted in the screw hole. An X-direction adjusting screw 22 that can be engaged is screwed together. The tip end of the X-direction adjusting screw 22 is brought into contact with one side surface of the X-direction moving frame 20.

    The X-direction moving frame 20 has a size that can form a gap that allows the Y-direction moving frame 21 to move by a predetermined distance in the X direction and the Y direction in the space S between the column portions 16c and 16d of the support base 16. It is configured as a rectangular frame. The X-direction moving frame 20 has engagement grooves 20a and 20b that can be slidably engaged with the X-direction rails 17a and 17b with the central space portion positioned on the front surface of the semiconductor laser unit 12. A screw hole 20c (see FIG. 2) formed to face the Y direction at a predetermined position of the moving frame 20, and the Y direction moving frame 21 with respect to the X direction moving frame 20 screwed into the screw hole 20c. A Y-direction adjusting screw 23 capable of adjusting the direction position. The Y-direction adjusting screw 23 has its tip 23 a abutted against the upper side surface of the Y-direction moving frame 21 accommodated in the central space portion of the X-direction moving frame 20.

    A spring member (not shown) such as a leaf spring or a coil spring is contracted between the column portion 16c and the X-direction moving frame 20, so that the X-direction adjusting screw 22 is centered on its rotation axis. By rotating in one direction or the other direction, the side surface of the X-direction moving frame 20 is pressed or released, and the X-direction position of the X-direction moving frame 20 (that is, the optical fiber unit 13) can be freely adjusted. An X-direction adjusting mechanism that can be used is configured. As shown in FIG. 2, a spring member 24 such as a leaf spring or a coil spring is contracted between the bottom surface of the X-direction moving frame 20 and the lower surface of the Y-direction moving frame 21. Therefore, by rotating the Y-direction adjusting screw 23 in one direction or the other direction, the upper surface of the Y-direction moving frame 21 is pressed or released, and the Y-direction moving frame 21 (that is, the optical fiber unit 13) Y A Y-direction adjusting mechanism that can freely adjust the direction position is configured.

    Although not shown in the drawings, the members constituting the laser light generating apparatus 2A described above are required by screws or the like so as to be convenient for assembling work or mounting the optical fiber unit 13 to the support 30. It is configured so that these parts can be easily separated and assembled.

    As described above, in the machine tool 1, the laser output from each light emitting section 11 in the semiconductor laser unit 12 is small (for example, about 1 w), but each laser light generator 2A oscillates the laser light L ( The semiconductor laser unit 12 is configured by laminating, for example, nine stages of semiconductor laser substrates 26 including a plurality of light emitting portions 11 that can be emitted. Therefore, by emitting a large number of laser beams L from the semiconductor laser unit 12 and condensing them, a high output necessary for processing the workpiece W can be obtained. As shown in FIG. 1, by providing a plurality of laser light generators 2 </ b> A, a higher-power machine tool 1 using a large number of semiconductor laser units 12 is realized.

    In the machine tool 1, the optical fiber unit 13 is assembled to the support 30 in the state shown in FIG. That is, a predetermined operation is performed in such a manner that the front end surface 14a of the optical fiber unit 13 to which the Y-direction moving frame 21 is mounted in advance is opposed to the light emitting portion 11 of the semiconductor laser unit 12 exposed from the X-direction moving frame 20. Thus, the engaging projections 21a and 21b of the Y-direction moving frame 21 are slidably engaged with the Y-direction rails 19 and 19, respectively.

    Next, in order to perform positioning adjustment in the X direction and the Y direction of the light emitting portion 11 and the light receiving end surface 7b of the laser light generating apparatus 2A assembled as described above, the light is emitted from the plurality of light emitting portions 11 and optical fibers. The laser beam L transmitted through the bundle 7 is projected on a monitor (not shown), and its state is monitored. Further, in this monitoring state, the X-direction adjusting screw 22 and the Y-direction adjusting screw 23 are rotated little by little in a required direction as appropriate, thereby supporting the optical fiber unit 13 via the Y-direction moving frame 21. The direction moving frame 20 is slightly moved in the X direction with respect to the support base 9 supporting the semiconductor laser unit 12, and the Y direction moving frame 21 supporting the optical fiber unit 13 is moved to the X direction moving frame 20. Is slightly moved in the Y direction.

    As described above, in the laser beam generator 2 (2A) provided in the machine tool 1, the optical fiber unit 13 for the multiple light emitting units 11 is appropriately rotated by rotating the X direction adjusting screw 22 and the Y direction adjusting screw 23. The positions of the light receiving end faces 7b in the X direction and the Y direction can be collectively adjusted with high accuracy.

    Next, the configuration of the optical fiber bundle 7 in FIG. 1 will be described in detail.

    4A and 4B show an example of a configuration related to an optical fiber. FIG. 4A is an enlarged side view of one optical fiber, and FIG. 4B is an optical fiber bundle in which a plurality of optical fibers are bundled. The front-end | tip part and the side view which expands and shows an adapter, The figure (c) is a front view which shows the state seen along the Vc-Vc line | wire of the figure (b).

    In the present embodiment, the adapter 31 is coupled to the tip portion as a tapered portion without particularly processing the tip portion of each optical fiber 7 a constituting the optical fiber bundle 7.

    That is, in this embodiment, as shown in FIG. 4A, the exit end 27b of the optical fiber 7a composed of the core 27 and the clad 28 has the same shape as the light receiving end face 7b. As shown in FIGS. 4B and 4C, such an optical fiber 7a has a plurality of (for example, 54) solids (a laser receiving end facing the plurality of light emitting portions 11). (The laser emission side opposite to 7b) is bundled into one) to form an optical fiber bundle 7, and furthermore, the optical fiber bundles 7 for each of the laser light generators 2A are bundled together to form a larger diameter optical fiber bundle 7 (For example, 54 × 3) are formed.

    In the present embodiment, the phrase “optical fiber bundle 7” for each laser light generator 2A is also used in a form in which three optical fiber bundles 7 are bundled. Further, the number of optical fibers 7a in FIGS. 4B and 4C does not correspond to the actual number for convenience.

    The adapter 31 constituting the tapered portion is coupled to an emission end 7 d that is a laser emission portion of the entire optical fiber bundle 7. As shown in FIG. 4 (b), the adapter 31 has a substantially cylindrical shape as a whole, and the entrance 31 a having a larger inner diameter than the exit 31 b is directed toward the exit 7 d of the optical fiber bundle 7. The coupling portion 31d that protrudes in a substantially cylindrical shape on the exit end 7d side is coupled to the optical fiber bundle 7 so as to be fitted into the outer peripheral portion of the exit end 7d. The adapter 31 is firmly fixed to the outer peripheral portion of the injection end 7d through fixing means (not shown).

    The adapter 31 forming the tapered portion includes an entrance 31a facing the exit end 7d, an exit 31b corresponding to the entrance 31a, and an optical transmission path 31c that connects the entrance 31a and the exit 31b to each other. And have. The optical transmission line 31c has a shape (tapered taper shape) that gradually decreases in diameter from the incident port 31a side toward the exit port 31b. In the present embodiment, the opening shape of the entrance 31a is circular as indicated by reference numeral 31a in FIG. 4C. A plurality of small circles indicated by broken lines inside the circle 31a indicate the cross-sectional shape of the optical fiber 7a. Therefore, the cross-sectional shape of the laser beam condensed by the optical fiber bundle 7 is small. A concentric circle smaller than the circle (precisely, an assembly of such concentric circles) is obtained, and in the present embodiment, the cross-sectional shape of the laser light collected by the optical fiber bundle 7 is, as a result, the incident aperture. It is made smaller than the opening shape of 31a. With such a configuration, all the laser light L emitted from each optical fiber 7a of the optical fiber bundle 7 can be transmitted without causing optical loss while being reflected by the inner surface of the optical transmission path 31c. Since it is configured in this manner, the optical fiber bundle 7 functions as a laser beam condensing unit for condensing the laser beams L emitted from the plurality of light emitting units 11 and entering the incident light into the incident port 31a. To do.

    The adapter 31 is made of a metal material such as aluminum, and the optical transmission path 31c is a taper that is formed so as to penetrate from the entrance 31a side to the exit 31b side of the adapter 31 so as to have a small diameter. It is comprised from a hollow shape. The inner peripheral surface of the optical transmission line 31c is strictly polished as a uniform surface without unevenness in order to suppress the optical loss during transmission as much as possible. Alternatively, in order to suppress light loss during transmission as much as possible, a reflective film capable of total reflection can be formed by plating (coating) or the like on the inner peripheral surface of the optical transmission path 31c made of a metal material.

    When the optical fiber bundle 7 in the present embodiment is used for the laser light generator 2 (2A), the laser light L emitted from a large number of light emitting portions 11 is highly efficiently generated due to the presence of the adapter 31 that is a tapered portion. There is an effect that the light can be incident on the optical fiber 8 (see FIG. 1) in a form in which the power density is increased. Moreover, since the light emission parts 11 in this Embodiment are arranged in the matrix form, the laser beam L from the several light emission part 11 is inject | emitted with such a matrix form. That is, the cross-sectional shape (in other words, the shape of the cross-sectional area in which the plurality of laser beams L are distributed) of the laser beam group composed of the plurality of laser beams L is substantially rectangular. The other optical transmission line 31c has a small cross-sectional shape (opening shape of the entrance 31a). According to the present embodiment, the optical fiber bundle 7 is arranged between the light emitting portions 11 and the optical transmission path 31 c, and the laser light emitted from the plurality of light emitting portions 11 is collected by the bundle 7. Since it is configured to be incident on the incident port 31a after being emitted, light loss (that is, light leakage when laser light is incident on the optical transmission line 31c from the optical fiber bundle 7) is avoided. The laser beam can be used efficiently. Further, in the present embodiment, a plurality of optical fibers 7a are used as the laser beam condensing means, and a tapered adapter 31 is provided on the laser emission side so that the laser beam is emitted through the adapter 31. Therefore, based on the principle that the coherent laser light can pass through the tapered optical waveguide inclined at a predetermined angle without causing any optical loss, the laser light from each light emitting portion is made as much as possible. The power density can be increased by condensing light with high efficiency by the reduced diameter adapter.

    In addition, an optical fiber bundle 7 is formed by bundling the laser emission sides of a plurality of optical fibers 7a, and the adapter 31 is coupled to the emission end 7d of the bundle 7. A configuration for obtaining a high-power laser beam for laser processing by effectively condensing a certain laser beam L without waste can be realized. Furthermore, since the adapter 31 is made of a metal material and the optical transmission line 31c is made of a tapered hollow portion whose inner surface is polished, a tapered hole is simply formed in the adapter 31 and the inner surface is not uneven. There is also an effect that a good optical transmission line 31c with no optical loss can be easily obtained only by polishing to a mirror surface.

    By the way, the adapter 31 mentioned above can also be comprised not by a metal material but by a firm synthetic resin material such as glass or transparent plastic. That is, after using glass or a synthetic resin material to form the same shape as the above metal material, a metal reflective film such as gold or silver is formed on the inner peripheral surface of the optical transmission line 31c by vacuum deposition plating. Is formed. Therefore, the adapter 31 is made of glass or a synthetic resin material, and the optical transmission path 31c is made up of a tapered hollow portion having a metal reflective film formed on the inner surface by vapor deposition plating. A good optical transmission line 31c with no optical loss can be easily obtained by simply forming the holes and simply depositing and plating the inner surface without unevenness to finish it in a mirror surface.

    Incidentally, the adapter 31 is coupled to the exit end 7d of the optical fiber bundle 7 as shown in FIG. 4B, but the adapter 31 and the optical fiber bundle 7 may not be coupled. For example, the adapter 31 and the optical fiber bundle 7 may be supported on the same case or substrate so that the entrance 31 a of the adapter 31 and the exit end 7 d of the optical fiber bundle 7 face each other.

    On the other hand, the optical transmission line 31c of the adapter 31 in the present embodiment is narrowed down with the same inclination (ratio) from the entrance port 31a to the exit port 31b as shown in FIG. The degree of aperture of the light is the same from the entrance port 31a to the exit port 31b), but the aperture of the laser beam in the vicinity of the exit port 31b of the optical transmission path 31c is the same as that of the laser beam in the vicinity of the entrance port 31a. It may be smaller than the degree. In that case, the beam diameter of the laser beam can be reduced stepwise, and in various meanings, a laser beam optimal for processing can be obtained. In this specification, “the degree of aperture of laser light in a specific part” means “the beam diameter of laser light emitted from the specific part” and “the beam diameter of laser light incident on the specific part”. It means the value (ratio) divided by.

    Hereinafter, a second embodiment of the present invention will be described with reference to FIG.

    In the first embodiment described above, the laser light condensing means (that is, means capable of condensing the laser light L emitted from the plurality of light emitting portions 11) is the light composed of the plurality of optical fibers 7a. Although constituted by the fiber bundle 7, the laser beam condensing means in the present embodiment is constituted by the lens 107 as shown in FIG. Thereby, a structure and a manufacturing process can be simplified compared with the case where an optical fiber is used. FIG. 5 is a perspective sectional view schematically showing another example of a machine tool provided with a laser beam generator to which the present invention is applied.

    In FIG. 5, reference numeral 111 denotes a light emitting part that can emit the laser light L, reference numeral 112 denotes a semiconductor laser unit configured by arranging a plurality of the light emitting parts 111 in a matrix, Reference numeral 102A denotes a laser beam generator.

Reference numeral 131c denotes a tapered optical transmission line formed so as to gradually become a small diameter, and reference numeral 131a denotes a laser beam disposed at a position facing the emission end 107d of the laser beam condensing unit 107. An incident port is indicated, and reference numeral 131b indicates an emission port corresponding to the incident port 131a. Such a component (tapered portion) 131 having the entrance 131a, the exit 131b, and the optical transmission path 131c may be configured similarly to the adapter 31 described above. That is,
Even if the tapered portion 131 is made of a metal material and the optical transmission path 131c is made of a tapered hollow portion whose inner surface is polished,
The taper portion 131 may be made of a metal material and the optical transmission path 131c may be made of a taper hollow portion having a reflection film on the inner surface, or
Even if the tapered portion 131 is made of a synthetic resin material and the optical transmission path 131c is made of a tapered hollow portion in which a metal reflection film is formed on the inner surface by vapor deposition plating,
Either is fine. Other components may be configured in the same manner as in the first embodiment.

    Since the light emitting portions 111 in the present embodiment are arranged in a matrix, the laser beams L from the plurality of light emitting portions 111 are emitted in such a matrix shape. That is, the cross-sectional shape (in other words, the shape of the cross-sectional area in which the plurality of laser beams L are distributed) of the laser beam group composed of the plurality of laser beams L is substantially rectangular. The other optical transmission line 131c has a small cross-sectional shape (opening shape of the entrance 131a). According to the present embodiment, the lens 107 is disposed between the light emitting unit 111 and the optical transmission path 131c, and the laser light emitted from the plurality of light emitting units 111 is collected by the lens 107. In addition, since it is configured to be incident on the incident port 131a, light loss (that is, light leakage when laser light is incident on the optical transmission path 131c from the lens 107) is avoided, and laser light is emitted. It can be used efficiently. Note that the lens 107 used in the present embodiment is widely distributed in a substantially quadrangular region even if the laser light group widely distributed in a substantially quadrangular region is focused on a small circular region. It is also possible to focus the laser beam group on a similar area as it is (that is, a small square area). In this case, the cross-sectional shape of the laser light condensed by the lens 107 is preferably equal to or smaller than the opening shape of the incident port 131a.

    A microlens (not shown in FIG. 5; see reference numeral 18 in FIG. 2) is arranged so as to cover each light emitting portion 111, and the laser light is converted into parallel light by the microlens. It is good to leave. In addition, the lens 107 may not only simply collect the laser light emitted from the plurality of light emitting units 111 but also collect the laser light so as to be as parallel as possible to the optical axis. In such a case, light loss (irregular reflection) in the optical transmission line 131c can be reduced.

    In the present embodiment, as is apparent from FIG. 5, the degree of laser beam narrowing in the vicinity of the exit 131b of the optical transmission path 131c is such that the laser light in the vicinity of the entrance 131a of the optical transmission path 131c. Is set smaller than the aperture degree. As a result, the beam diameter of the laser beam can be narrowed in stages, and the laser beam optimal for processing can be obtained in various ways.

    The present invention can be used in various apparatuses that use a large number of semiconductor lasers, collect laser light emitted from the semiconductor lasers, and obtain and use a laser beam with a predetermined output.

FIG. 1 is an overall perspective view schematically showing an example of a machine tool provided with a laser beam generator to which the present invention is applied. FIG. 2 is a side sectional view showing one laser beam generator in FIG. FIG. 3 is a perspective view showing one laser light generator in FIG. 1 in a partially disassembled form. 4A and 4B show an example of a configuration related to an optical fiber. FIG. 4A is an enlarged side view of one optical fiber, and FIG. 4B is an optical fiber bar in which a plurality of optical fibers are bundled. FIG. 4C is a front view showing the state seen along the line Vc-Vc in FIG. 4B. FIG. FIG. 5 is a perspective sectional view schematically showing another example of a machine tool provided with a laser beam generator to which the present invention is applied.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Machine tool 2, 2A ... Laser beam generator 7 ... Optical fiber bundle 7a ... Optical fiber 7b ... Light receiving end surface (laser light receiving end)
7d: Ejection end (end on laser emission side)
DESCRIPTION OF SYMBOLS 11 ... Light emission part 12 ... Semiconductor laser unit 27 ... Core 27b ... Outlet end (end part on the laser emission side)
28 …… Clad 31 …… Adapter 31a …… Inlet 31b …… Injector 31c …… Optical transmission path L …… Laser light

Claims (8)

A semiconductor laser unit having a plurality of light emitting portions arranged in a matrix and capable of individually emitting laser light, and capable of condensing laser light emitted from the plurality of light emitting portions A laser beam generator having a laser beam focusing means,
An incident port through which the laser beam condensed by the laser beam condensing unit is incident, an exit port corresponding to the incident port, and tapered light that gradually decreases in diameter from the incident port toward the exit port A laser light generator characterized by comprising a tapered portion comprising a transmission line.     2. The laser beam generation according to claim 1, wherein a cross-sectional shape of the laser beam focused by the laser beam focusing unit is equal to or smaller than an aperture shape of the incident port. apparatus.     3. The degree of aperture of laser light in the vicinity of the exit of the optical transmission path is smaller than the extent of aperture of laser light in the vicinity of the entrance of the optical transmission path. Laser light generator.     The laser beam condensing means has a plurality of optical fibers capable of individually transmitting laser beams respectively emitted from the plurality of light emitting units, opposite to the laser receiving ends facing the plurality of light emitting units. The laser beam generator according to any one of claims 1 to 3, wherein the laser beam generator is an optical fiber bundle configured by binding the laser emission sides of the laser beam.     The laser beam generator according to any one of claims 1 to 3, wherein the laser beam condensing unit is a lens.     6. The laser beam according to claim 1, wherein the tapered portion is made of a metal material, and the optical transmission path is made of a tapered hollow portion whose inner surface is polished. Generator.     The taper-shaped portion is made of a metal material, and the optical transmission path is formed by a tapered hollow portion having a reflection film formed on the inner surface thereof. Laser light generator. 6. The taper portion is made of a synthetic resin material, and the optical transmission path is made of a taper-shaped hollow portion having a metal reflection film formed on the inner surface by vapor deposition plating. The laser beam generator according to claim 1.

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