JP2019206031A - Laser machining device - Google Patents

Abstract

To provide a machining device using a laser.SOLUTION: A laser machining device includes: a semiconductor laser device which radiates a plurality of laser beams; an optical conversion section which condenses the plurality of laser beams into L condensed beams; and L optical fibers which receive the L condensed beams. The semiconductor laser device has N semiconductor laser bars. Each of the N semiconductor laser bars has a plurality of emitters radiating the plurality of laser beams. L is an integer of 2 or more and N is an integer of 1 or more.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a laser processing apparatus.

Conventionally, a heating laser beam for a laser processing machine using a CO ₂ gas laser is known (for example, Patent Document 1). By using a CO ₂ gas laser, high intensity laser light of several W to several KW class necessary for material processing can be stably obtained. The laser intensity of several W class is used for cutting resin and cloth and welding different materials. On the other hand, a laser source with high output intensity of several KW class is used for metal plate, block processing, and cutting.
[Prior art documents]
[Patent Literature]
[Patent Document 1] Japanese Patent Application Laid-Open No. 2011-29438 [Patent Document 2] Japanese Patent Application Laid-Open No. 2006-175813

However, the oscillation wavelength of the CO ₂ gas laser beam is as long as 10 μm. The lens for CO ₂ gas laser light is limited to ZnSe material, and it is necessary to manufacture with a high-pressure press and is expensive. For this purpose, it is common to use a reflection mirror made of silicon single crystal. As a result, the material cost increases and the operability of the heating beam is inferior. There is no material with high transmittance in the long wavelength region of 10 μm. For this reason, in the conventional laser processing apparatus, since an optical fiber cannot be used, the operativity of a heating beam is bad. In the case of a CO ₂ laser of several KW class, the path length of the light at the mirror interval constituting the resonator is several meters. It is difficult to reduce the size due to the length of the gas pipe installed between the resonator mirrors. Furthermore, additional equipment such as a circulator for cooling CO ₂ gas is required, resulting in a large size. When it is desired to process a large number of holes, these laser beams are processed by reflecting a single heating beam in a reflecting direction at a high speed by a mirror. Therefore, the accuracy of the processed hole shape is greatly impaired.

  In the system using a fiber laser, since the oscillation wavelength of the fiber laser is about 1 μm, a quartz lens or a quartz fiber can be used. However, fiber lasers are expensive.

  On the other hand, although it is limited to a single crystal growth apparatus, a method of branching a laser beam from one semiconductor laser apparatus by a mirror has been proposed. However, a laser beam with high intensity is used as the branched laser beam used in the laser processing apparatus. A mirror cannot be used for branching of the laser processing apparatus. In the case of mirror branching, it is necessary to ensure 100% reflectivity under the condition that the mirror is tilted by about 45 degrees. Therefore, it is necessary to control the film thickness of the multilayer laminated thin film composed of several layers constituting the mirror with high accuracy. It is difficult to ensure a reflectivity of 100% due to film thickness variations in manufacturing. In this case, the temperature of the mirror rises due to energy absorption of the laser light. As a result, the multilayer film on the reflecting surface of the mirror may be damaged. Further, even when the damage does not occur, the mirror reflecting surface is distorted. The thermal distortion of the mirror reflecting surface moves the focused beam spot on the incident surface of the optical fiber. Such a distortion not only changes the fiber output intensity but also causes the end of the fiber entrance surface to melt. It is also sensitive to vibrations of the support base and ambient temperature changes to maintain a 45 degree tilt angle. Therefore, the method of branching the laser beam by the mirror is not suitable for the laser processing apparatus.

  In the first aspect of the present invention, a semiconductor laser device that irradiates a plurality of laser beams, an optical conversion unit that focuses the plurality of laser beams into L focused beams, and L focused beams A semiconductor laser device having N semiconductor laser bars, and each of the N semiconductor laser bars has a plurality of emitters for emitting a plurality of laser beams. And a laser processing apparatus in which L is an integer of 2 or more and N is an integer of 1 or more.

An example of the outline | summary of the laser processing apparatus 100 which concerns on Example 1 is shown. An example of the outline | summary of the laser processing apparatus 100 which concerns on Example 2 is shown. It is a figure for demonstrating the optical system of the laser processing apparatus 100 which concerns on Example 1 and Example 2. FIG. An example of the optical fiber 60 which has the circular optical fiber core 62 is shown. An example of the optical fiber 60 which has the polygonal optical fiber core 62 is shown. An example of the optical fiber 60 which has the three optical fiber cores 62 is shown. An example of measurement of the irradiation intensity distribution of the heating beam 104 is shown. An example of measurement of the irradiation intensity distribution of the heating beam 104 is shown. An example of measurement of the irradiation intensity distribution of the heating beam 104 is shown. An example of measurement of the irradiation intensity distribution of the heating beam 104 is shown. An example of the structure of the laser processing apparatus 100 which concerns on Example 3 is shown. An example of the structure of the laser processing apparatus 100 which concerns on Example 4 is shown. An example of the structure of the laser processing apparatus 100 which concerns on Example 5 is shown.

  Hereinafter, the present invention will be described through embodiments of the invention, but the following embodiments do not limit the invention according to the claims. In addition, not all the combinations of features described in the embodiments are essential for the solving means of the invention.

[Example 1]
FIG. 1 shows an example of an outline of a laser processing apparatus 100 according to the first embodiment. The laser processing apparatus 100 includes a power supply 10, a semiconductor laser apparatus 20, an adjustment unit 50, a control unit 55, an optical fiber 60, an optical conversion unit 70, and an irradiation head 80.

  The power supply 10 supplies power to the semiconductor laser device 20. The laser processing apparatus 100 has only a single power supply 10 that supplies power to the semiconductor laser apparatus 20. Since the laser processing apparatus 100 has only a single power supply 10, a plurality of power supplies for supplying power to the semiconductor laser apparatus 20 are not required.

  The cooling unit 15 supplies cooling water to the semiconductor laser device 20. The laser processing apparatus 100 may have only a single cooling unit 15 that cools the semiconductor laser apparatus 20. That is, the semiconductor laser device 20 is provided with one water inlet and one water outlet. For example, the cooling unit 15 includes a chiller for cooling the semiconductor laser device 20.

  The semiconductor laser device 20 emits a plurality of laser beams 21. In one example, the semiconductor laser device 20 includes a plurality of emitters and includes one or more N semiconductor laser bars. The semiconductor laser device 20 of this example has one input / output terminal 22 and one input / output terminal 24.

  The input / output terminal 22 is a terminal for connecting the power supply 10 and the semiconductor laser device 20. In one example, the input / output terminal 22 may include one input terminal and one output terminal. The input / output terminal 22 is an example of a first input / output terminal.

  The input / output terminal 24 is a terminal for connecting the cooling unit 15 and the semiconductor laser device 20. In one example, the input / output terminal 24 may include one cooling water inlet and one water outlet. The input / output terminal 24 is an example of a second input / output terminal.

  The optical conversion unit 70 converts the plurality of laser beams 21 into predetermined L focused beams 102. L is an integer of 2 or more. L may be an odd number or an even number. In this example, the case of L = 3 will be described, but the present invention is not limited to this. The optical conversion unit 70 includes a first optical system 30 and a second optical system 40.

  The first optical system 30 converts the laser light 21 into light parallel to a predetermined direction. In one example, the first optical system 30 converts the laser light 21 into light parallel to the traveling direction. For example, the first optical system 30 includes an arbitrary lens such as a cylindrical lens or a microlens.

  The second optical system 40 converts the laser light 21 parallel to the traveling direction into L condensed beams 102. The second optical system 40 causes the L condensed beams 102 to enter the optical fiber 60.

  The adjustment unit 50 adjusts the intensity of the L condensed beams 102. The adjustment unit 50 may individually adjust the intensities of the L focused beams 102. For example, the adjustment unit 50 includes L dampers that absorb the condensed beam 102.

  The control unit 55 adjusts the amount of the condensed beam 102 that is absorbed by controlling the adjustment unit 50. Thereby, the control unit 55 adjusts the intensity of the focused beam 102. For example, the control unit 55 adjusts the position of the damper included in the adjustment unit 50. The control unit 55 may observe the intensity of the L heating beams 104 and control the intensity of the L condensed beams 102 independently of each other. The control unit 55 is an example of a first control unit.

  The control unit 55 controls the adjustment unit 50 to modulate the condensed beam 102 into pulsed light. For example, the control unit 55 applies a voltage to the Pockel cell element included in the adjustment unit 50 to adjust the deflection direction of the focused beam 102. The control unit 55 may control the pulse frequencies of the L focused beams 102 independently of each other. In one example, the control unit 55 controls the pulse frequency and transmission intensity of the focused beam 102 by controlling the adjustment unit 50. The pulse frequency and transmission intensity of the focused beam 102 are controlled by adjusting the pulse width and time interval of the focused beam 102.

  The optical fiber 60 receives the condensed beam 102 and propagates it. The optical fiber 60 has an optical fiber core 62 on the incident side. The L optical fibers 60 may be provided with L optical fiber cores 62 correspondingly. The irradiation head 80 has L radiation-side fibers 66 on the radiation side of the heating beam 104.

  The optical fiber core 62 receives the focused beam 102. Since the L optical fiber cores 62 are provided, the L focused beams 102 are received. The optical fiber core 62 of this example includes three optical fiber cores 62a to 62c.

  The radiation side fiber 66 conducts and radiates the focused beam 102 received by the optical fiber core 62 to a predetermined position. The radiation side fiber 66 of this example includes three radiation side fibers 66a to 66c. For example, the radiation side fiber 66 a to the radiation side fiber 66 c are wired to connect the condensed beam 102 to the irradiation head 80.

  The irradiation head 80 is provided on the radiation side of the optical fiber 60. The irradiation head 80 emits the condensed beam 102 received from the optical fiber 60 as a heating beam 104. The irradiation head 80 processes the irradiation intensity distribution of the heating beam 104. The irradiation head 80 of this example includes three irradiation heads 80a to 80c corresponding to the emission side fibers 66a to 66c. The control unit 55 may control the position and angle of the irradiation head 80 by computer control or the like. The irradiation head 80 may move in a three-dimensional space with high accuracy and high speed by a drive system.

  The processing material 110 is a material processed by the heating beam 104. The material of the processing material 110 is not particularly limited. In the semiconductor laser processing apparatus 100, the structure and optical system of the semiconductor laser apparatus 20 may be designed so as to generate the heating beam 104 having a wattage corresponding to the material of the processing material 110. For example, the work material 110 is provided with a plurality of holes 112 by the heating beam 104. The laser processing apparatus 100 of this example can form a hole 112 having an arbitrary shape by controlling the irradiation intensity distribution and shape of the heating beam 104. Moreover, the accuracy of the hole 112 can be improved by optimally adjusting the irradiation intensity distribution of the heating beam 104.

  Note that the positions of the L irradiation heads 80 may be changed as appropriate according to the processing method of the processing material 110. The L irradiation heads 80 may be provided regularly or irregularly.

  The L irradiation heads 80 may irradiate the same region of the processing material 110 or different regions. The L irradiation heads 80 may include two or more irradiation heads 80 arranged at non-equal intervals on the same circumference centered on the irradiation region by the heating beam 104. The distances of the L irradiation heads 80 from the processing material 110 may be the same or different. The L irradiation heads 80 are a first irradiation head that irradiates the heating beam 104 and a second irradiation head that is disposed in a region other than the same circumference centered on the irradiation region of the first irradiation head by the heating beam 104. And may include.

  The L irradiation heads 80 may irradiate the processing material 110 with the heating beam 104 at different angles. For example, the angle formed between the heating beam 104a irradiated by the irradiation head 80a and the processing material 110 may be vertical, or may be an acute angle or an obtuse angle. Further, the angles formed by the irradiation head 80a and the other irradiation heads 80b and 80c may be parallel or different angles.

  The laser processing apparatus 100 of this example can be applied to various uses by freely changing the number, intensity, irradiation position, and the like of the L heating beams 104. For example, the laser processing apparatus 100 is used for applications such as forming holes in the processing material 110, forming patterns, and melting the processing material 110. Moreover, since the laser processing apparatus 100 can form many patterns simultaneously, it is excellent in processing efficiency. The laser processing apparatus 100 can process a desired three-dimensional structure. The heating beam 104 can be emitted from a three-dimensional direction.

[Example 2]
FIG. 2 shows an example of an outline of the laser processing apparatus 100 according to the second embodiment. In this example, differences from the laser processing apparatus 100 according to the first embodiment will be particularly described. The laser processing apparatus 100 of this example shows an outline when a semiconductor laser apparatus 120 is further added to the laser processing apparatus 100 of the first embodiment. The laser laser processing apparatus 100 includes the semiconductor laser apparatus 120, the power source 12, the optical conversion unit 170 including the first optical system 130 and the second optical system 140, the sensor unit 150, and the control in the configuration of the first embodiment. 155, an optical fiber core 62d, and an irradiation head 80d.

  The cooling unit 15 supplies cooling water to the semiconductor laser device 20 and the semiconductor laser device 120. The laser processing apparatus 100 may include only the single cooling unit 15 that cools the semiconductor laser apparatus 20 and the semiconductor laser apparatus 120. For example, the cooling unit 15 includes a chiller for cooling the semiconductor laser device 20 and the semiconductor laser device 120.

  The semiconductor laser device 120 emits a plurality of laser beams 121. In one example, the semiconductor laser device 120 has a plurality of emitters and includes N semiconductor laser bars. The semiconductor laser device 120 of this example has one input / output terminal 122 and one input / output terminal 124.

  The input / output terminal 122 is a terminal for connecting the power supply 12 and the semiconductor laser device 120. One input / output terminal 122 of this example is provided in the semiconductor laser device 120.

  The input / output terminal 124 is a terminal for connecting the cooling unit 15 and the semiconductor laser device 120. In one example, the input / output terminal 124 may include one cooling water inlet and one water outlet. The cooling unit 15 may be connected in parallel with the input / output terminal 24 and the input / output terminal 124. One input / output terminal 124 of this example is provided in the semiconductor laser device 120.

  The optical conversion unit 170 converts the plurality of laser beams 121 into a focused beam 102d. The focused beam 102d of this example is incident on one optical fiber core 62d, but may be incident on a plurality of optical fiber cores 62.

  The first optical system 130 converts the laser light 121 into light parallel to a predetermined direction. The first optical system 130 may have the same configuration as the first optical system 30.

  The second optical system 140 converts the laser beam 121 parallel to the traveling direction into a focused beam 102d. The second optical system 140 may have the same configuration as the second optical system 40.

  The sensor unit 150 detects the intensity of a specific focused beam 102 among the L focused beams 102. The sensor unit 150 of this example detects the intensity of the focused beam 102d. The sensor unit 150 measures scattered light from the fiber incident end face. The probe may be a light intensity detection device using a pn junction.

  The control unit 155 adjusts the intensity of the focused beam 102d by controlling the power supplied to the semiconductor laser device 120 that emits the focused beam 102d. The control unit 155 outputs a control voltage for controlling the output of the power supply 12 based on the voltage signal from the sensor unit 150. Thereby, the irradiation intensity of the condensed beam 102d can be adjusted without a damper. The control unit 155 is an example of a second control unit.

  The optical fiber 60 receives the condensed beam 102 and propagates it. The optical fiber 60 has an optical fiber core 62 on the incident side. The L optical fibers 60 may be provided with L optical fiber cores 62 correspondingly. The irradiation head 80 has L radiation-side fibers 66 on the radiation side of the heating beam 104.

  The optical fiber core 62 receives the focused beam 102. Since the L optical fiber cores 62 are provided, the L focused beams 102 are received. The optical fiber core 62 of this example includes four optical fiber cores 62a to 62d.

  The radiation side fiber 66 conducts and radiates the focused beam 102 received by the optical fiber core 62 to a predetermined position. The radiation side fiber 66 of this example includes four radiation side fibers 66a to 66d. For example, the radiation side fiber 66 a to the radiation side fiber 66 d are wired to connect the condensed beam 102 to the irradiation head 80.

  The irradiation head 80 is provided on the radiation side of the optical fiber 60. The irradiation head 80 emits the condensed beam 102 received from the optical fiber 60 as a heating beam 104. The irradiation head 80 processes the irradiation intensity distribution of the heating beam 104. The irradiation head 80 of this example includes four irradiation heads 80a to 80d corresponding to the emission side fibers 66a to 66d. The control unit 55 may control the position and angle of the irradiation head 80 by computer control or the like. The irradiation head 80 may move in a three-dimensional space with high accuracy and high speed by a drive system.

  The processing material 110 is a material processed by the heating beam 104. The material of the processing material 110 is not particularly limited. In the semiconductor laser processing apparatus 100, the structures and optical systems of the semiconductor laser apparatuses 20 and 120 may be designed so as to generate the heating beam 104 having a wattage corresponding to the material of the processing material 110. For example, the work material 110 is provided with a plurality of holes 112 by the heating beam 104. The laser processing apparatus 100 of this example can form a hole 112 having an arbitrary shape by controlling the irradiation intensity distribution and shape of the heating beam 104. Moreover, the accuracy of the hole 112 can be improved by optimally adjusting the irradiation intensity distribution of the heating beam 104.

  Note that the positions of the L irradiation heads 80 may be changed as appropriate according to the processing method of the processing material 110. The L irradiation heads 80 may be provided regularly or irregularly.

  The L irradiation heads 80 may irradiate the same region of the processing material 110 or different regions. The L irradiation heads 80 may include two or more irradiation heads 80 arranged at non-equal intervals on the same circumference centered on the irradiation region by the heating beam 104. The distances of the L irradiation heads 80 from the processing material 110 may be the same or different. The L irradiation heads 80 are a first irradiation head that irradiates the heating beam 104 and a second irradiation head that is disposed in a region other than the same circumference centered on the irradiation region of the first irradiation head by the heating beam 104. And may include.

  The L irradiation heads 80 may irradiate the processing material 110 with the heating beam 104 at different angles. For example, the angle formed between the heating beam 104a irradiated by the irradiation head 80a and the processing material 110 may be vertical, or may be an acute angle or an obtuse angle. Further, the angles formed by the irradiation head 80a and the other irradiation heads 80b and 80c may be parallel or different angles.

  The laser processing apparatus 100 of this example can be applied to various uses by freely changing the number, intensity, irradiation position, and the like of the L heating beams 104. For example, the laser processing apparatus 100 is used for applications such as forming holes in the processing material 110, forming patterns, and melting the processing material 110. Moreover, since the laser processing apparatus 100 can form many patterns simultaneously, it is excellent in processing efficiency. The laser processing apparatus 100 can process a desired three-dimensional structure. The heating beam 104 can be emitted from a three-dimensional direction.

  The laser processing apparatus 100 according to the second embodiment is characterized in that a plurality of semiconductor laser apparatuses can be used. The laser processing apparatus 100 of this example is effective in the case where a part of a branched laser intensity becomes small when dividing from a single semiconductor laser apparatus and dividing a large number of lasers. Reduction in laser intensity due to branching can be prevented. Even in such a case, the semiconductor laser device needs only one cooling water supply system, and the temperature in the immediate vicinity of the semiconductor laser can be controlled, so that the semiconductor output can be stabilized.

  FIG. 3 is a diagram for explaining an optical system of the laser processing apparatus 100 according to the first and second embodiments. The laser processing apparatus 100 includes a semiconductor laser bar 26, a cylindrical lens 32, a microlens 34, a microlens 42, a damper 52, and an optical fiber 60.

The semiconductor laser bar 26 has a total of K emitters 28 and emits K laser beams 21. The K emitters 28 in this example have a width W _x in the X-axis direction and are arranged in the X-axis direction at a predetermined pitch P. The intensity of one laser beam 21 emitted from one emitter 28 is several W. For example, when the intensity of one laser beam 21 emitted from one emitter 28 is 10 W, the intensity of the laser beam 21 emitted from the semiconductor laser bar 26 having 12 emitters 28 is 120 W. The number of emitters 28 may be determined according to the required intensity. The X-axis direction is an example of a first direction. The Y-axis direction is an example of the second direction.

Here, the laser beam 21 emitted from the semiconductor laser bar 26 has components in the X-axis direction and the Y-axis direction. For example, the semiconductor laser bar 26 emits laser light 21 with divergence angle of the Y-axis direction theta _y, X-axis direction theta _x.

  The first optical system 30 converts the k laser beams 21 into light parallel to the traveling direction (for example, the Z axis). The first optical system 30 has a cylindrical lens 32 and a microlens 34. The first optical system 30 of this example converts the K laser beams 21 emitted from the semiconductor laser bar 26 so as to be parallel to the traveling direction Z-axis. The first optical system 30 can prevent loss of transmission intensity of the laser light 21 and damage to the optical fiber 60 by converting the laser light 21 into parallel light parallel to the traveling direction (for example, the Z axis). it can.

  The cylindrical lens 32 converts the component in the Y-axis direction into a direction parallel to the traveling direction. The cylindrical lens 32 includes a cylindrical lens. The cylindrical lens 32 has a flat surface on which the laser beam 21 is incident and a cylindrical curved surface from which the laser beam 21 radiates. However, the shape of the cylindrical lens 32 is not limited to this example. For example, the cylindrical lens 32 is a first axial cylindrical lens FAC.

Microlens 34 converts the laser beam 21 which emits a diverging angle theta _x in the traveling direction parallel to the direction. The microlens 34 has K convex lenses arranged in the X-axis direction. For example, the micro lens 34 is a slow axis lens SAC.

  The first optical system 30 converts the laser light 21 into light parallel to the traveling direction (for example, the Z axis) by combining the cylindrical lens 32 and the microlens 34.

The semiconductor laser device 20 emits laser light 21 from each emitter 28 in a two-dimensional elliptical shape with respect to the traveling direction (for example, the Z axis). The divergence angle of the laser beam 21 is Θ _{x in} the X-axis direction and Θ _y in the Y-axis direction. In the embodiment, a semiconductor laser bar 26 having 12 emitters with Θ _x = 8 ° and Θ _y = 30 ° is used. The divergence angle of the laser light 21 also varies.

  The laser processing apparatus 100 causes a plurality of focused beams 102 having radiation angles and variations thereof to enter the optical fiber 60. The laser beam 21 must be incident within the diameter of the incident surface of the optical fiber core 62. Then, the laser beam 21 is incident within the allowable incident angle Θ of the optical fiber core 62.

  Here, a relationship of NA = sin (Θ) is established between the allowable incident angle Θ to the optical fiber 60 and the numerical aperture NA. That is, when the numerical aperture NA = 0.22, the allowable incident angle Θ is 12.8 degrees and the maximum allowable incident angle is ± 12.8 degrees.

  When the condensed beam 102 enters the optical fiber 60 beyond the allowable incident angle Θ, it is not totally reflected at the interface between the optical fiber core 62 and the optical fiber cladding 64 described later, which is a material around the optical fiber core 62. The light transmission intensity is attenuated. Furthermore, the light energy of the transmitted focused beam 102 may cause heat generation, which may cause the quartz of the optical fiber 60 to melt and break.

  The diameter of the optical fiber core 62 is about 0.6 mm. The second optical system 40 strictly condenses the condensed beam 102 within the diameter of the optical fiber core 62. Therefore, when the diameter of the focused beam 102 is large, the optical fiber 60 may be melted. The incident angle and the focused diameter of the focused beam 102 satisfy the conditions corresponding to the characteristics of the optical fiber 60. In particular, when the intensity of the heating beam 104 is increased, the requirements for the first optical system and the second optical system become severe.

The microlenses 34 constituting the first optical system 30 are designed so that the laser beams 21 converted in parallel do not overlap each other in order to branch the laser beam 21 into L condensed beams 102. From the divergence angle Θ _{x of} the emitter 28, the width W _{x of} the emitter 28, and the pitch P of the emitter 28 in the X-axis direction, the focal length of the microlens 34 is provided so as to satisfy the following condition.

X-axis direction of the beam width B _x of the laser light 21 is converted into parallel light, in order not to overlap with the laser light 21 is converted into adjacent parallel light is designed to satisfy the following equation.
[Equation 1]
B _x ≦ P
Further, the beam width B _x is expressed by the following equation.
[Equation 2]
B _x = (E _x1 · sin (Θ _x / 2)) · 2 + W _x
E _x1 is the focal length of the convex lens constituting the microlens 34. The focal length _Ex1 of the microlens 34 satisfies the following equation.
[Equation 3]
(E _x1 · sin (Θ _x / 2)) · 2 + W _x ≦ P
When the focal length E _{x1 of the} microlens 34 is larger than ((P−W _x ) / 2) / (sin (Θ _x / 2)), the laser beam from the adjacent emitter 28 has a beam width B _{x in the} X-axis direction. It overlaps with 21.

The cylindrical lens 32 constituting the first optical system 30 is preferably provided closer to the emitter 28 emission surface than the microlens 34. Since the divergence angle Θ _{y in} the Y-axis direction of the laser light 21 is larger than the divergence angle Θ _{x in} the X-axis direction, the component parallel to the traveling direction (for example, the Z axis) of the Y-axis direction component of the laser light 21 first. It is preferable to convert to Thus, an increase in the width B _y in the Y-axis direction of the laser beam 21 can be suppressed.

It is preferable that the focal length E _y1 of the cylindrical lens 32 is designed to be the smallest possible size based on the processed shape of the cylindrical lens. For example, the focal length E _y1 of the cylindrical lens 32 in the Y-axis direction is 0.6 mm. The focal length _Ex1 of the microlens 34 may be 1.4 mm. Since the thickness of the cylindrical lens 32 becomes 0.8 mm, in order to install the microlens 34 in the Z-axis direction of the cylindrical lens 32, it requires a large focal length _{E x1} than 0.8 mm.

In the semiconductor laser bar 26 of this example, 12 is the number of X-axis direction of the emitter 28, the pitch P of the X-axis direction width _{W x} is 0.2 mm, the X-axis direction of the emitter 28 is 0.4 mm, the emitter 28 The length W _y in the Y-axis direction is 0.01 mm. Laser light 21 emitted from each emitter diverges into a two-dimensional ellipsoidal shape. The divergence angles of the laser light 21 emitted from the twelve emitters in this example are Θ _y = 30 ° and Θ _x = 8 °.

The beam width _Bx is calculated by the following equation.
[Equation 4]
B _x = (E _x1 · sin (Θ _x / 2)) · 2 + W _x = 0.195 + 0.2 = 0.395 mm
The beam width B _x is equal to or less than the pitch P of the emitter 28 = 0.4 mm and satisfies the formula (3).

  As described above, the first optical system 30 appropriately sets the optical parameters of the cylindrical lens 32 and the microlens 34 so that the laser beams 21 irradiated by the semiconductor laser device 20 do not overlap each other. Can be converted to As a result, the first optical system 30 can branch the laser beam 21 into L condensed beams 102.

Next, a design guideline for the second optical system 40 for branching the collimated laser beam 21 into L focused beams 102 will be described. The necessary conditions for the first optical system 30 for branching the laser beam 21 into the condensed beam 102 are as described above. As described above, the relationship NA = sin (Θ) is established between the allowable incident angle Θ to the optical fiber 60 and the numerical aperture NA. That is, when the numerical aperture NA = 0.22, the allowable incident angle Θ is 12.8 degrees and the maximum allowable incident angle is ± 12.8 degrees. From this request, when the K emitters 28 are condensed on L fibers by the microlens 42 constituting the second optical system 40, the focal length F _x2 of the second optical system 40 in the X direction is given by It becomes.
[Equation 5]
F _x2 ≧ ΣB _x / (2 · sin (Θ))

The focal length F _{x2 in} the X direction of the microlens 42 constituting the second optical system 40 is such that the laser light 21 from the k emitters 28 out of the total number K of emitters 28 is condensed on one optical fiber core 62. To do. For that purpose, the focal length F _x2 is designed so that the incident angle from the width ΣB _{x in} the X-axis direction of the total number K of the partial k laser beams 21 falls within 2 · sin (Θ). The focal length F _x2 may be larger than ΣB _x / (2 · sin (Θ)).

When the k laser beams 21 from the k emitters 28 are incident on the optical fiber core 62, the width ΣB _x of the laser beam 21 in the X-axis direction is expressed by the following equation.
[Equation 6]
ΣB _x = P · (k−1) + B _x
That is, the following equation is satisfied.
ΣB _x = P · (k−1) + (E _x1 · sin (Θ _x / 2)) · 2 + W _x
P is the pitch of the emitter 28 in the X-axis direction.

Here, for example, in the semiconductor laser bar 26, the number of emitters 28 is 12, the width W of the emitters 28 is 0.2 mm, and the pitch P is 0.4 mm. When the twelve laser beams 21 are divided into three, the number of emitters 28 per one condensed beam 102 is k = 4. Since B _x is an expression (Expression 4), ΣB _x is expressed by the following expression.
ΣB _x = 0.4 · (4-1) + 0.395 = 1.595mm

Therefore, ΣB _x /(2·sin(Θ))=3.65. When the numerical aperture NA = 0.22, F _x2 may be selected as a focal length greater than 3.65 mm. Therefore, F _x2 = 3.65 mm is the minimum value. In the case of F _{x2 having} a focal length larger than 3.65 mm, the incident angle to the optical fiber core 62 becomes small. The distance from the emitter 28 is preferably set to a minimum value.

The microlens 42 constituting the second optical system 40 is a microlens composed of three convex lenses. The microlens 42 may have three convex lenses configured as a single body. When the number k of the laser beams 21 incident on the micro lens 42 is different, the value of ΣB _{x in} the equation (2) is different. F _x2 is determined so as to satisfy Equation (5) with the maximum value of ΣB _x .

Position of the microlens 42 constituting the second optical system 40, when the distance from the incident surface of the optical fiber core 62 is C _x, must satisfy the following equation. That is, the focal length F _x2 satisfying the equation (5) must be set, and the position C _{x of the} microlens 42 having the focal length F _x2 must satisfy the following equation.
[Equation 7]
2 · F _x2 ≧ C _x ≧ (1-2 · CR / ΣB _x ) · F _x2
Here, CR is the radius of the optical fiber core 62. When the cross section of the optical fiber core 62 is rectangular, the radius CR of the optical fiber core 62 may be the shortest distance from the center of the rectangle to the outer periphery of the rectangle.

If C _x is smaller than (1-2 · CR / ΣB _x ) · F _{x 2} , the edge of the optical fiber core 62 is irradiated with the laser beam 21, causing core damage. Since the laser beam 21 has high intensity, it causes serious damage. Laser light 21 when C _x becomes larger than the focal length is increased. If C _x is larger than 2 · F _x 2, the edge of the optical fiber core 62 is irradiated with the laser light 21 to cause damage to the core.

Here, when CR = 0.3 mm, the optical fiber core 62 is (1-2 · CR / ΣB _x ) · F _x2 = (1-2 × 0.3 / 1.595) × 3.65 = 2.23 mm. Therefore, _{C x} is placed microlenses 42 in a position that satisfies 7.3mm ≧ _{C x} ≧ 2.23mm.

In Example 1 and Example 2, the position of the microlens 42 was C _x = 3.5 mm. The distance was about the same as the focal length _Fx2 . The space for installing the damper 52 in the condensing microlens 42 and the optical fiber core 62 was considered in order to make the laser beam 21 to the core surface as small as possible.

  As described above, by appropriately designing the first optical system 30 and the second optical system 40, the k laser beams 21 emitted from the k emitters 28 per one condensed beam 102 are converted into one light. The light can be condensed on the fiber core 62.

The design guideline for the second optical system 40 described above is the same in the Y-axis direction. When using the focal length E _y1 of the cylindrical lens 32, the width B _y of the traveling direction and parallel to the laser beam 21 is represented by the following formula.
[Equation 8]
B _y = E _y1 (2 · sin (Θ _y / 2))
The divergence angle Θ _y is a divergence angle in the Y-axis direction from the semiconductor laser device 20.

From the request of the numerical aperture NA, the focal length _Fy2 of the condensing lens in the Y-axis direction is expressed by the following equation.
[Equation 9]
F _y2 ≧ B _y / (2 · sin (Θ))

Therefore, the following equation is established from the divergence angle Θ _y of the emitter 28, the focal length E _y1 of the cylindrical lens 32 of the first optical system 30, and the numerical aperture NA.
[Equation 10]
F _y2 ≧ (E _y1 · sin (Θ _y / 2)) · 2 / (2 · sin (Θ))

Distance C _y from the condenser lens having a focal length F _y2 to the light receiving surface of the optical fiber core 62 satisfies the following equation to enter the optical fiber core 62.
[Equation 11]
2 · F _y2 ≧ C _y ≧ (1-2 · CR / B _y ) · F _y2

Distance C _y from the condenser lens having a focal length F _y2 to the light receiving surface of the optical fiber core 62, the case of the arrangement close to the entrance core surface, focused beam 102 which is incident is incident on the outside of the optical fiber core 62 The optical fiber 60 is seriously damaged. When the distance _Cy is larger than this, the incident focused beam 102 may enter the outside of the optical fiber core 62 and the optical fiber 60 may be damaged. Accordingly, the distance _{C y} is desirably about the focal length _{F y2.}

In the first and second embodiments, the laser light 21 in the Y-axis direction from each emitter 28 has a divergence angle of Θ _y = 30 °. By setting the cylindrical lens used in the first optical system 30 to the focal length E _y1 = 0.6 mm, the laser beam 21 becomes parallel with a width B _y = 0.5 mm in the Y-axis direction. Diameter 0.6mm because _{B y} of the optical fiber core 62 is smaller than this. In the present embodiment, the width of the laser beam 21 in the Y-axis direction can be incident on the optical fiber core 62 without being particularly condensed by the second optical system 40. Since the incident angle to the optical fiber core 62 is parallel light, it is zero degrees. It is obvious that the numerical aperture is less than or equal to NA. Therefore, in the first and second embodiments, the second optical system 40 does not have to have a condenser lens in the Y-axis direction.

  The damper 52 in the first and second embodiments is a carbon damper that adjusts the intensity of the focused beam 102. The dampers 52 are installed at the edges of the respective condensed beams 102. The damper 52a is installed below the condensed beam 102a. The lower beam of the condensed beam 102a is absorbed by the upper edge of the damper 52a, and the intensity of the condensed beam 102a is adjusted. The damper 52c is installed below the condensed beam 102c. The lower beam of the condensed beam 102c is absorbed by the upper edge of the damper 52c, and the intensity of the condensed beam 102c is adjusted. The damper 52b is installed on the upper part of the condensed beam 102b. The upper beam of the condensed beam 102b is absorbed by the lower edge of the damper 52b, and the intensity of the condensed beam 102b is adjusted. The carbon of the damper 52 has a reflectance that is small enough to adjust the intensity of the focused beam 102. The damper 52 preferably has a material with high absorption efficiency.

  Moreover, it is preferable that the damper 52 has a high thermal conductivity so that heat can be dissipated when the condensed beam 102 is absorbed. For example, the thermal conductivity of carbon in the damper 52 is as high as that of copper. By introducing the cooling water into the copper plate installed on the back surface of the damper 52, the absorbed heat from the condensed beam 102 is efficiently absorbed.

  The damper 52 of this example absorbs the condensed beam 102 at the upper and lower ends. The damper 52 includes three dampers 52a to 52c corresponding to the condensed beams 102a to 102c. The vertical position of the damper 52 can be adjusted by voltage driving with a piezo element. The dampers 52a to 52c may be driven independently. The height of the damper 52 can be adjusted with an accuracy of several μm using a piezo element. By adjusting the height of the damper 52 with the voltage, it is possible to strictly control with the external voltage source while measuring the intensity of the heating beam 104. Thereby, the laser processing apparatus 100 can externally control the intensity of the L heating beams 104.

  FIG. 4A shows an example of an optical fiber 60 having a circular optical fiber core 62. The optical fiber 60 has an optical fiber core 62 and an optical fiber cladding 64.

  The optical fiber core 62 propagates the incident focused beam 102. The optical fiber core 62 has a circular cross section. The radius CR of the optical fiber core 62 is CR = 0.3 mm. The numerical aperture of the optical fiber 60 is NA = sin (Θ) = 0.22.

  The optical fiber cladding 64 covers the periphery of the optical fiber core 62. That is, the structure of the optical fiber 60 is a two-layer structure of an optical fiber core 62 and an optical fiber clad 64 covering the periphery thereof. The refractive index of the optical fiber cladding 64 is smaller than the refractive index of the optical fiber core 62. Due to the difference in refractive index between the optical fiber core 62 and the optical fiber cladding 64, the condensed beam 102 is confined in the optical fiber core 62. For example, the optical fiber cladding 64 comprises a fluorinated silicon oxide material.

  The optical fiber 60 is confined within the optical fiber core 62 by totally reflecting the focused beam 102 at the interface between the optical fiber core 62 and the optical fiber cladding 64. The optical fiber 60 can reduce the internal loss by totally reflecting the focused beam 102. For example, the allowable incident angle of the optical fiber 60 is Θ = 12.72. In this case, the optical fiber 60 confines the focused beam 102 incident within the complete acceptance angle 2 · Θ = 2 · 12.72 ° = 25.44 ° within the optical fiber core 62.

  FIG. 4B shows an example of an optical fiber 60 having a polygonal optical fiber core 62. The polygon may include a substantially triangular shape or a substantially rectangular shape. The optical fiber core 62 of this example is different from the optical fiber core 62 of FIG. 4A in that it has a rectangular cross section.

  The optical fiber 60 of this example may have the same numerical aperture NA as in FIG. 4A. For example, when the numerical aperture NA = 0.22, the allowable incident angle of the optical fiber 60 is Θ = 12.72. In this case, the optical fiber 60 confines the focused beam 102 incident within the complete acceptance angle 2 · Θ = 25.44 ° within the optical fiber core 62.

  The first optical system 30 and the second optical system 40 enter the laser beam 21 so as to be within the diameter 2 · CR of the optical fiber core 62 within the complete light receiving angle 2 · Θ of the optical fiber 60. The diameter of the optical fiber core 62 is the size between the upper end and the lower end of the optical fiber core 62 in the Y-axis direction when the cross section of the optical fiber core 62 is rectangular.

  FIG. 4C shows an example of an optical fiber 60 having three optical fiber cores 62. The optical fiber 60 has three optical fiber cores 62 and an optical fiber cladding 64. The optical fiber 60 may have four or more optical fiber cores 62.

  The optical fiber core 62 of the first embodiment includes three optical fiber cores 62a to 62c. The three optical fiber cores 62a to 62c are arranged one-dimensionally in the X-axis direction. The three optical fiber cores 62 a to 62 c are covered with a common optical fiber cladding 64. Thereby, the one optical fiber 60 is comprised. The cross-sectional shape of the optical fiber core 62 may be appropriately set according to the specifications of the diameter of the optical fiber core 62 and the numerical aperture NA.

  The optical fiber core 62a has a circular cross section. The cross-sectional shape of the optical fiber core 62a may be the same as the cross-sectional shape of the optical fiber core 62 shown in FIG. 4A.

  The optical fiber core 62b and the optical fiber core 62c have a rectangular cross-sectional shape. The cross-sectional shapes of the optical fiber core 62b and the optical fiber core 62c may be the same as the cross-sectional shape of the optical fiber core 62 shown in FIG. 4B. The cross-sectional shapes of the plurality of optical fiber cores 62 may be the same or different.

  By appropriately setting the shape of the optical fiber core 62, even when the intensity of the focused beam 102 is increased, failures such as melting of the optical fiber core 62 can be suppressed. Further, the power loss of the condensed beam 102 can be minimized and the condensed beam 102 can be transmitted to the radiation surface of the optical fiber 60.

  On the incident side of the optical fiber 60, L optical fiber cores 62 may be combined into one. The optical fiber clad 64 of this example covers the three optical fiber cores 62a to 62c. By using a single incident side of the optical fiber 60, the focused beam 102 can be incident without using individual independent optical systems.

  On the other hand, L optical fiber cores 62 are independently provided on the radiation side of the optical fiber 60. That is, as shown in FIG. 1, the optical fiber 60 has three independent optical fibers 60a to 60c. Thereby, the laser processing apparatus 100 can irradiate the processing material 110 with the heating beam 104 from any direction.

  The L irradiation heads 80 may emit the heating beams 104 having the same irradiation intensity distribution or may emit the heating beams 104 having different irradiation intensity distributions.

  The optical fiber 60 can improve the processing accuracy of the processing material 110 by appropriately selecting the shape of the optical fiber core 62. When the optical fiber core 62 is rectangular, the irradiation intensity distribution of the heating beam 104 is a top hat type irradiation intensity distribution that is substantially uniform in the X′-axis and Y′-axis directions constituting the plane orthogonal to the traveling direction. The shape of the irradiation intensity distribution can be changed according to the optical system of the irradiation head 80. The irradiation intensity distribution of the top hat type is suitable when the processing material 110 is processed without a gap.

  Further, when the optical fiber core 62 is circular, a bell-shaped irradiation intensity distribution is obtained in which the irradiation intensity at the center is maximum and decreases gradually as the distance from the central axis increases. The shape of the irradiation intensity distribution can be changed according to the optical system of the irradiation head 80. For example, by changing the optical system of the irradiation head 80, the spread size of the irradiation intensity distribution in the X′-axis direction and the Y′-axis direction can be adjusted. The bell-shaped irradiation intensity distribution is suitable for processing the processed material 110 into a smooth cross-sectional shape and for smooth processing of a three-dimensional surface.

  FIG. 5A shows an example of measurement of the irradiation intensity distribution of the heating beam 104. In this example, a two-dimensional irradiation intensity distribution surrounded by a width of 8 mm in the X′-axis direction and a width of ± 10 mm in the Y′-axis direction is shown.

  The heating beam 104 of this example has a top hat type irradiation intensity distribution. The laser processing apparatus 100 generates a heating beam 104 having a top hat type irradiation intensity distribution by a rectangular optical fiber core 62.

  The irradiation intensity distribution in this example is a result of actually measuring the irradiation intensity distribution of the heating beam 104 on the irradiation surface of the processing material 110 with a beam profiler. This measurement result is a measurement result obtained by plotting the irradiation intensity of the heating beam on a two-dimensional (X ′, Y ′) plane orthogonal to the Z ′ axis on the vertical axis, with the traveling direction of the heating beam 104 as the Z ′ axis. . The irradiation surface of the processing material 110 is located 200 mm from the irradiation head 80.

  The irradiation intensity distribution of the heating beam 104 is a top hat type irradiation intensity distribution in which the irradiation intensity is within ± 5% in a two-dimensional rectangular shape surrounded by a width of 8 mm in the X ′ axis direction and 4 mm in the Y ′ axis direction. ing. The distance from the position where the irradiation intensity is zero to the position where the irradiation intensity is maximum is within 0.05 mm.

  The laser processing apparatus 100 can cut the cross section of the processing material 110 with an accuracy of 50 μm or less by cutting the material using the heating beam 104 of this example. The laser processing apparatus 100 can also cut the cross section of the heating beam 104 with an accuracy of 0.05 mm or less. The heating beam 104 of this example shows an irradiation intensity distribution when used for processing a material having a size of several mm. The laser processing apparatus 100 can adjust the width of the rectangular shape of the cross section of the heating beam 104 from several tens mm to about 0.1 μm.

  FIG. 5B shows a measurement example of the irradiation intensity distribution of the heating beam 104. In this example, a two-dimensional irradiation intensity distribution surrounded by a width of 8 mm in the X′-axis direction and a width of ± 10 mm in the Y′-axis direction is shown.

  The heating beam 104 of this example has a bell-shaped irradiation intensity distribution. The laser processing apparatus 100 uses a rectangular optical fiber core 62 to generate a heating beam 104 with a bell-shaped irradiation intensity distribution.

  The irradiation intensity distribution in this example is a result of actually measuring the irradiation intensity distribution of the heating beam 104 on the irradiation surface of the processing material 110 with a beam profiler. This measurement result is a measurement result obtained by plotting the irradiation intensity of the heating beam on the two-dimensional (X ′, Y ′) plane orthogonal to the Z ′ axis on the vertical axis, with the traveling direction of the heating beam 104 as the Z axis ′. . The irradiation surface of the processing material 110 is located 200 mm from the irradiation head 80.

  The irradiation intensity distribution of the heating beam 104 is a top hat type in the region surrounded by the width of 8 mm in the X ′ axis direction and ± 5 mm (position of 10% intensity) in the Y ′ axis direction, and the Y ′ axis direction. Indicates a bell-shaped irradiation intensity distribution. The intensity distribution in the X ′ axis direction has a uniform irradiation intensity. On the other hand, the Y′-axis direction has a bell-shaped irradiation intensity that decreases in the ± direction with the central axis as the maximum intensity. That is, the heating beam 104 of this example is used when the cut surface in the Y′-axis direction is sharp and the cut surface in the X′-axis direction is to be processed into a curved shape. The heating beam 104 of this example shows an irradiation intensity distribution when used for processing a material having a size of several mm. The laser processing apparatus 100 can adjust the X′-axis direction of the cross section of the heating beam 104 from several tens mm to about 0.1 μm.

  FIG. 5C shows a measurement example of the irradiation intensity distribution of the heating beam 104. In this example, a two-dimensional irradiation intensity distribution surrounded by a width of 8 mm in the X′-axis direction and a width of ± 10 mm in the Y′-axis direction is shown.

  The heating beam 104 of this example has a top-hat type irradiation intensity distribution in the X′-axis direction and a bell-shaped irradiation intensity distribution in the Y′-axis direction. For example, the laser processing apparatus 100 generates a heating beam 104 having a top hat type irradiation intensity distribution by a rectangular optical fiber core 62.

  The irradiation intensity distribution in this example is a result of actually measuring the irradiation intensity distribution of the heating beam 104 on the irradiation surface of the processing material 110 with a beam profiler. This measurement result is a measurement result in which the irradiation intensity of the heating beam on a two-dimensional (X ′, Y ′) plane orthogonal to the Z ′ axis is plotted on the vertical axis, with the traveling direction of the heating beam 104 as the Z axis. The irradiation surface of the processing material 110 is located 200 mm from the irradiation head 80.

  The irradiation intensity distribution of the heating beam 104 has a top hat type irradiation intensity in the X′-axis direction of 8 mm, and a bell-shaped irradiation intensity in the ± 10 mm (10% intensity position) in the Y′-axis direction. The intensity distribution in the X ′ axis direction has a uniform irradiation intensity. On the other hand, the Y′-axis direction has a bell-shaped irradiation intensity that decreases in the ± direction with the central axis as the maximum intensity. The irradiation intensity distribution in this example is obtained by adjusting the position of the cylindrical lens used in the optical system of the irradiation head 80.

  FIG. 5D shows a measurement example of the irradiation intensity distribution of the heating beam 104. The heating beam 104 of this example has a bell-shaped irradiation intensity distribution. The laser processing apparatus 100 generates a heating beam 104 having a bell-shaped irradiation intensity distribution by a circular optical fiber core 62.

  The irradiation intensity distribution in this example is a result of actually measuring the irradiation intensity distribution of the heating beam 104 on the irradiation surface of the processing material 110 with a beam profiler. This measurement result is a measurement result obtained by plotting the irradiation intensity of the heating beam on a two-dimensional (X ′, Y ′) plane orthogonal to the Z ′ axis on the vertical axis, with the traveling direction of the heating beam 104 as the Z ′ axis. . The irradiation surface of the processing material 110 is located 200 mm from the irradiation head 80.

  The irradiation intensity distribution of the heating beam 104 has a bell-shaped irradiation intensity of ± 1 mm (10% intensity position) in the X′-axis direction and a bell-shaped irradiation intensity of ± 1 mm (10% intensity position) in the Y′-axis direction. Thus, a two-dimensional irradiation intensity distribution surrounded by a width of ± 1 mm in the X′-axis direction and a width of ± 1 mm in the Y′-axis direction is shown. The X′-axis and Y′-axis directions have a bell-shaped irradiation intensity that decreases in the ± direction with the center point as the maximum intensity. The intensity position at the irradiation intensity of 10% can be changed by adjusting the position of the lens used in the optical system of the irradiation head 80. The heating beam 104 of this example shows an irradiation intensity distribution when used for processing a material having a size of several mm. The laser processing apparatus 100 can adjust the width of the bell shape of the cross section of the heating beam 104 from several tens mm to about 0.1 μm.

[Example 3]
FIG. 6A shows an example of the configuration of the laser processing apparatus 100 according to the first and second embodiments. The semiconductor laser device 20 of this example includes N semiconductor laser bars 26 stacked on an N layer. The laser processing apparatus 100 can output a high-power heating beam 104 of several hundred W to several KW by laminating the semiconductor laser bars 26. Unlike the embodiment of FIG. 3, the laser processing apparatus 100 of this example does not divide the laser beam 21 in the X-axis direction.

N semiconductor laser bars 26 are stacked in the Y-axis direction. The semiconductor laser bar 26 of this example, are stacked in a stacked spacing S _y predetermined. The semiconductor laser bars 26 may be stacked at equal intervals or may be stacked at different intervals.

  Here, the laser processing apparatus 100 of the present example does not need to provide an independent power source for each semiconductor laser bar 26 even when a plurality of semiconductor laser bars 26 are used. Further, even when the laser processing apparatus 100 uses a plurality of semiconductor laser bars 26, it is not necessary to provide an independent cooling water chiller apparatus for each semiconductor laser bar 26.

  Although the laser processing apparatus 100 of this example includes the stacked semiconductor laser bars 26, it only needs to have one power supply 10 and one cooling unit 15, and a cooling water route branched before the semiconductor laser apparatus 20 is prepared. You don't have to. In other words, the semiconductor laser device 20 may have one cooling water supply port and one cooling water drain port. Thereby, the laser processing apparatus 100 can make the temperature measuring point of the semiconductor laser apparatus 20 having the stacked semiconductor laser bars 26 at one place. The laser processing apparatus 100 can control the temperature of the semiconductor laser apparatus 20 with higher accuracy than when temperature management is performed at a plurality of temperature measurement points. Thereby, the variation of the heating beam 104 depending on the temperature of the semiconductor laser device 20 can be reduced.

  On the other hand, when a plurality of cooling units 15 are provided, temperature management is performed at a plurality of temperature measurement points. In this case, each cooling water flowing from each semiconductor laser device was measured at the cooling water temperature after the merge. For this reason, it is necessary to set the temperature accuracy high. Even if the temperature accuracy after a plurality of cooling waters merge is controlled, the emitter temperature of each semiconductor laser device cannot be controlled. Further, in order to control the temperature of each semiconductor laser device, the same number of chiller devices as the number of semiconductor laser devices are required for each of the plurality of cooling waters. Using a chiller with a temperature accuracy of 0.1 ° C. to 0.05 ° C. or less is disadvantageous in terms of cost.

  The semiconductor laser bar 26 of this example is laminated in six layers in the Y-axis direction. The laser processing apparatus 100 branches from the semiconductor laser bar 26 stacked in six stages into three optical fibers 60. That is, the laser light 21 output from the two-stage semiconductor laser bar 26 is incident on each of the optical fibers 60. When the laser beam 21 is converted into parallel light to obtain the focused beam 102, the parallel laser beams 21 are converted so as not to overlap each other.

  Further, the laser processing apparatus 100 of the present example includes a cylindrical lens 32 and a microlens 34 as the first optical system 30. The laser processing apparatus 100 includes a cylindrical lens 44 and a cylindrical lens 46 as the second optical system 40.

The cylindrical lens 32 and the micro lens 34 are designed so that the laser light 21 is parallel to the traveling direction. As in Example 2, even when stacking the semiconductor laser bar 26, as in Example 1, appropriately designing the focal length E _x1 focal length E _y1 and a microlens 34 of the cylindrical lenses 32 . For example, the focal length _Ex1 of the microlens 34 is set so that the adjacent laser beams 21 do not overlap as in the case of the first embodiment.

The cylindrical lens 32 configuring the first optical system 30 is preferably provided before the microlens 34. Since the divergence angle Θ _{y in} the Y-axis direction of the laser light 21 is larger than the divergence angle Θ _{x in} the X-axis direction, the component parallel to the traveling direction (for example, the Z axis) of the Y-axis direction component of the laser light 21 first. It is preferable to convert to Thus, an increase in the width B _y in the Y-axis direction of the laser beam 21 can be suppressed.

It is preferable that the focal length E _y1 of the cylindrical lens 32 is designed to be the smallest possible size based on the processed shape of the cylindrical lens. For example, the focal length E _y1 of the cylindrical lens 32 in the Y-axis direction is 0.6 mm. The focal length _Ex1 of the micro lens 34 is 1.4 mm. Since the thickness of the cylindrical lens 32 is required 0.8 mm, in order to install the microlens 34 in the Z-axis direction of the cylindrical lens 32, it requires a large focal length _{E x1} than 0.8 mm.

In the semiconductor laser bar 26 of Example 3, 12 the number of X-axis direction of the emitter 28, the pitch P of the X-axis direction width _{W x} is 0.2 mm, the X-axis direction of the emitter 28 is the 0.4 mm, the emitter 28, the length W _y in the Y-axis direction is 0.01 mm. The number of stacked semiconductor laser bars 26 is six. Stacking spacing _{S y} of the semiconductor laser bar 26 was 2.5 mm. The laser light 21 emitted from each emitter 28 diverges into a two-dimensional ellipsoidal shape. The divergence angles of the laser light 21 emitted from the twelve emitters 28 in this example are Θ _y = 30 ° and Θ _x = 8 °.

The focal length E _y1 of the cylindrical lens 32 is set so that the parallel laser beams 21 from the semiconductor laser bars 26 stacked in the Y-axis direction do not overlap. The focal length E _y1 of the cylindrical lens 32 is designed based on the emitter divergence angle Θ _y , the emitter width W _y , and the stacking interval S _y of the semiconductor laser bars 26. Stacking spacing S _y is the spacing in the Y-axis direction of the emitter 28 in the stacked semiconductor laser bar 26.

  The second optical system 40 focuses the laser light 21 converted into parallel light by the first optical system 30 onto L optical fibers 60. The second optical system 40 of this example includes a cylindrical lens 44 and a cylindrical lens 46.

  The cylindrical lens 44 condenses the laser light 21 in the Y-axis direction. The cylindrical lens 44 includes three cylindrical lenses 44a to 44c arranged in the Y-axis direction. The cylindrical lens 44 is an example of a second cylindrical lens.

  The cylindrical lens 46 condenses the laser light 21 in the X-axis direction. Thereby, the laser beam 21 is condensed on the optical fiber core 62. The cylindrical lens 46 is an example of a first cylindrical lens.

Next, a design method in the X-axis direction of the second optical system 40 when the semiconductor laser device 20 has a plurality of stacked semiconductor laser bars 26 will be described. In order to prevent the laser light 21 from overlapping in the Y-axis direction, the width B _{y of} the laser light 21 converted into parallel light in the Y-axis direction is designed to satisfy the following expression.
[Equation 12]
B _y ≦ S _y

When the distance from the emitter 28 of the cylindrical lens 32 and the focal length E _y1, beam width B _y in the Y-axis direction is represented by the following formula.
[Equation 13]
B _y = (E _y1 · sin (Θ _y / 2)) · 2 + W _y
That is, the following equation is satisfied.
[Formula 14]
(E _y1 · sin (Θ _y / 2)) · 2 + W _y ≦ S _y
The emitter width W _y is the width of the emitter 28 in the Y-axis direction. Here, the focal length _{E y1} of the microlens 34 is 0.6 _mm, since it is W _y = 0.01, _B y is calculated by the following equation.
B _y = (0.6 · sin (30 ° / 2)) · 2 + 0.01 = 0.31 + 0.01 = 0.32 mm
Since S _y = 2.5 mm, Expression (12) is satisfied. Therefore, the laser beams 21 of the semiconductor laser bar 26a and the semiconductor laser bar 26b do not overlap.

The beam width ΣB _{y in} the Y-axis direction of the laser beam 21 converted into parallel emitted from the N-layer stacked structure with the stacking interval S _y is expressed by the following equation.
[Equation 15]
ΣB _y = S _y · (N−1) + B _y
ΣB _y = (E _y1 · sin (Θ _y / 2)) · 2 + W _y + S _y · (N−1)
In Example 3, ΣB _y = 2.4 · (2-1) + 0.32 = 2.7 mm.

The focal length F _y2 of the cylindrical lens 44a for making the laser light 21 converted into the parallel light having the beam width ΣB _y incident at the allowable condensing angle of the numerical aperture NA = sin (Θ) = 0.22 is the beam width B _{When y} is replaced with the beam width ΣB _y of the laser beam 21 incident on the cylindrical lens 44a, the following equation is satisfied.
[Equation 16]
F _y2 ≧ ΣB _y / (2 · sin (Θ))

Since ΣB _y is expressed by Equation (15), the focal length F _y2 of the cylindrical lens 44a is expressed by the following equation.
[Equation 17]
F _y2 ≧ (E _y1 · sin (Θ _y / 2)) · 2 + W _y + S _y · (N−1) / (2 · sin (Θ))

The position C _y from the cylindrical lens 44a having a focal length F _y2 to the light receiving surface of the optical fiber core 62, it is necessary to enter the optical fiber core 62 satisfies the following equation.
[Equation 18]
2 · F _y2 ≧ C _y ≧ (1-2 · CR / ΣB _y ) · F _y2

For example, when the numerical aperture NA of the fiber NA = sin (Θ) = 0.22 and CR = 0.3 mm, B _y = 0.32 mm and ΣB _y = 2.7 mm, so F _y2 is expressed by the following equation. .
F _y2 = ΣB _y /(2·sin(Θ))=2.7/(2×0.22)=6.13
Position of the cylindrical lens 21, the distance C _y from the incident core surface is set so as to satisfy the following equation.
2 · 6.13 ≧ C _y ≧ (1-2 · 0.3 / 2.7) · 6.13
12.26 ≧ C _y ≧ 0.126
In Example 3, the focal length _{F y2} of the cylindrical lens 44a was 6 mm.

The optical fiber 60 has an optical fiber core 62 and an optical fiber clad 64. The optical fiber 60 may further include an exterior. When using the individual optical fiber 60 having the optical fiber core 62, the optical fiber clad 64, and the coating for the exterior, assuming that the entire diameter of the optical fiber 60 is Fmax, the distance CD between the optical fiber core 60a and the optical fiber 60b is Are set to satisfy the following equation.
CD ≧ Fmax

The interval between the focused beams 102 matches the interval CD of the optical fiber 60. Therefore, the interval CD is expressed by the following equation.
CD = F _y2 · (2 · sin (Θ) + S _y · (n−1))
Here, the width of the focused beam and B _y, a focal length of the Y-axis direction of the second optical system is F _y2. S _y is an interval in the Y-axis direction of the semiconductor laser bar 26.

The focal length F _y2 is expressed by the following equation.
F _y2 = ΣB _y / (2 · sin (Θ))

  In this case, the laser processing apparatus 100 makes a focused beam 102 obtained by condensing the laser light 21 from the n-layer semiconductor laser bars 26 out of N stacked semiconductor laser bars 26 incident on one optical fiber 60. be able to.

In the case of Example 2, since F _y2 = 6.13 mm, the interval CD is expressed by the following equation.
CD = F _y2 · (2 · sin (Θ) + S _y · (n−1)) = 6.13 · 2 · 0.22 + 2.5 = 2.69 + 2.5 = 5.19 mm

  If the diameter Fmax of one optical fiber 60 having a sheath is 5 mm or less, an independent optical fiber can be used. When such an optical fiber cannot be prepared, the optical fiber 60 of the common optical fiber cladding 64 illustrated in FIG. 4C may be used. The laser beam 21 may be branched using a reflection mirror.

The cylindrical lens 46 makes the laser light 21 condensed in the X-axis direction incident on the L optical fibers 60. The focal length F _x2 of the cylindrical lens 46 may be determined using the same mathematical formula as in the first embodiment. However, the cylindrical lens 46 of this example is adjusted so that each of the laser beams 21 incident from the stacked semiconductor laser bars 26 is incident on the optical fiber 60.

Width .SIGMA.B _x in the X-axis direction of the laser beam 21 is represented by the following formula.
[Equation 19]
B _x = (E _x1 · sin (Θ _x / 2)) · 2 + W _x
[Equation 20]
ΣB _x = P · (K−1) + B _x

In this case, the focal length F _x2 of the second optical system 40 in the X-axis direction is expressed by the following equation.
[Equation 21]
F _x2 ≧ ΣB _x / (2 · sin (Θ))
It is. The focal length F _x2 satisfies the following equation.
[Equation 22]
F _x2 ≧ (P · (K−1) + B _x ) / (2 · sin (Θ))

The distance _{C x} of the optical fiber core 62a and the cylindrical lens 46a is represented by the following formula.
[Equation 23]
2 · F _x2 ≧ C _x ≧ (1-2 · CR / ΣB _x ) · F _x2

The semiconductor laser bar 26 of this example, 12 pieces total number K in the X-axis direction of the emitter 28, the pitch P of the X-axis direction width _{W x} is 0.2 mm, the X-axis direction of the emitter 28 is 0.4 mm, the emitter 28, the length W _y in the Y-axis direction is 0.01 mm. The number of stacked semiconductor laser bars 26 is six. Stacking spacing _{S y} of the semiconductor laser bar 26 was 2.5 mm. The laser light 21 emitted from each emitter 28 diverges into a two-dimensional ellipsoidal shape. The divergence angles of the laser light 21 emitted from the twelve emitters 28 in this example are Θ _y = 30 ° and Θ _x = 8 °.

The cylindrical lens 32 configuring the first optical system 30 is preferably provided before the microlens 34. Since the divergence angle Θ _{y in} the Y-axis direction of the laser light 21 is larger than the divergence angle Θ _{x in} the X-axis direction, the component parallel to the traveling direction (for example, the Z axis) of the Y-axis direction component of the laser light 21 first. It is preferable to convert to Thus, an increase in the width B _y in the Y-axis direction of the laser beam 21 can be suppressed.

It is preferable that the focal length E _y1 of the cylindrical lens 32 is designed to be the smallest possible size based on the processed shape of the cylindrical lens. For example, the focal length E _y1 of the cylindrical lens 32 in the Y-axis direction is 0.6 mm. The focal length _Ex1 of the micro lens 34 is 1.4 mm. Since the width of the cylindrical lens 32 is required 0.8 mm, in order to install the microlens 34 in the Z-axis direction of the cylindrical lens 32, it requires a large focal length _{E x1} than 0.8 mm.

In the semiconductor laser bar 26 of this example, 12 is the number of X-axis direction of the emitter 28, the pitch P of the X-axis direction width _{W x} is 0.2 mm, the X-axis direction of the emitter 28 is 0.4 mm, the emitter 28 The length W _y in the Y-axis direction is 0.01 mm. The laser light 21 emitted from each emitter 28 diverges into a two-dimensional ellipsoidal shape. The divergence angles of the laser light 21 emitted from the twelve emitters 28 in this example are Θ _y = 30 ° and Θ _x = 8 °.

In one example, B _x , ΣB _x and F _x2 are as follows:
B _x = 0.395mm
ΣB _x = P · (K−1) + B _x = 0.4 · (12−1) + 0.395 = 4.79
F _x2 ≧ ΣB _x /(2·sin(Θ))=4.795/(2×0.22)=10.9

The distance _{C x} of the optical fiber core 62a and the cylindrical lens 46a is represented by the following formula.
2 · F _x2 ≧ C _x ≧ (1-2 · CR / ΣB _x ) · F _x2
Therefore, _{C x} satisfies the following equation.
21.8 ≧ C _x ≧ 9.5
In Example 2, C _x = 11 mm, and C _x was approximately the same as the focal length F _x2 = 10.9 mm.

  Here, in the three optical fibers 60, when the numerical aperture NA and the core diameter are different, the cylindrical lenses 46a to 46c may have different characteristics. Further, the arrangement of the cylindrical lenses 46a to 46c may be different depending on the optical fibers 60a to 60c.

The laser processing apparatus 100 of this example includes one semiconductor laser apparatus 20 in which N semiconductor laser bars 26 in which K emitters 28 are arranged in the X-axis direction are stacked in the Y-axis direction. When the number of emitters 28 used for the light beam 102 is k, the following equation is satisfied.
K × N ≧ k × L
However, K, k, and N are integers of 1 or more.

  As described above, the laser processing apparatus 100 of this example appropriately sets the optical system of the first optical system 30 and the second optical system 40 to generate a high-power heating beam 104 from one semiconductor laser apparatus 20. Can branch and take out.

  Note that the laser processing apparatus 100 of this example equally divides the six-stage semiconductor laser bars 26. However, the laser processing apparatus 100 may form the heating beam 104 with three levels of output intensity from the top in the first, second, and third stages.

  The optical fiber 60 of the present example includes the rectangular, circular, and rectangular optical fiber cores 62a to 62c, but is not limited thereto.

  The light receiving surfaces of the optical fibers 60a to 60c in this example are provided at equal intervals from the cylindrical lenses 46a to 46c, respectively. The distance between the light receiving surface of the optical fiber 60a and the cylindrical lens 46 is preferably set to be short within a range that satisfies the optical conditions.

  The second optical system 40 of this example includes only a lens system of a cylindrical lens 44 and a cylindrical lens 46. Thereby, the second optical system 40 can reduce heat generated during optical conversion of the laser light 21. Further, the configuration of the second optical system 40 is simplified, and the size of the optical system is reduced.

[Example 4]
FIG. 6B illustrates an example of the configuration of the laser processing apparatus 100 according to the first and second embodiments. The laser processing apparatus 100 of this example focuses the focused beam 102 on the optical fiber core 62. The laser processing apparatus 100 of this example is different from the laser processing apparatus 100 according to the third embodiment in that a convex lens 48 is provided as a condenser lens. Thereby, the number of cylindrical lenses can be reduced.

The optical fiber 60 has an optical fiber core 62 having a numerical aperture NA = sin (Θ) and a radius CR. The focal length F _x2 of the convex lens 48 in the first direction is a divergence angle Θ _x from the total number K of emitters 28 in the X-axis direction, emitter width W _x , pitch P, and the focal length in the X-axis direction is E _x1 . The width ΣB _x of the laser beam in the X-axis direction is
[Equation 24]
B _x = (E _x1 · sin (Θ _x / 2)) · 2 + W _x
[Equation 25]
ΣB _x = P · (K−1) + (E _x1 · sin (Θ _x / 2)) · 2 + W _x
Then,
[Equation 26]
F _x2 ≧ ΣB _x / (2 · sin (Θ))
Meet. Thereby, the condensed beam 102 is incident without damaging the optical fiber 60.

When the laser light 21 emitted from the n semiconductor laser bars 26 among the N stacked semiconductor laser bars 26 is branched, the focal length F _y2 of the convex lens 48 in the Y-axis direction is the Y-axis direction focal length F _y2 of the focused beam 102. represented by the following equation using the beam width .SIGMA.B _y.
[Equation 27]
F _y2 ≧ ΣB _y / (2 · sin (Θ))
Here, the beam width ΣB _y is
B _y = (E _y1 · sin (Θ _y / 2)) · 2 + W _y
Because
ΣB _y = S _y · (n−1) + B _y
It is. Thereby, the condensed beam 102 is incident without damaging the optical fiber 60.

When F _x2 ≧ F _y2 , the focal length of the convex lens 48 is F _x2 that satisfies the formula (26), and
When the distance from the incident surface of the optical fiber core 62 is C _c , the position of the convex lens 48 is
2 · F _x2 ≧ C _c ≧ (1-2 · CR / ΣB _x ) · F _x2
Meet.

On the other hand, if F _x2 <F _y2 ,
The focal length of the convex lens 48 is F _y2 that satisfies Equation (27), and
2 · F _y2 ≧ C _c ≧ (1-2 · CR / ΣB _y ) · F _y2
Meet.

In one example, the optical fiber 60 satisfies the numerical aperture NA = sin (Θ) = 0.22 and CR = 0.3 mm. In the semiconductor laser bar 26 of this example, 12 is the number of X-axis direction of the emitter 28, the pitch P of the X-axis direction width _{W x} is 0.2 mm, the X-axis direction of the emitter 28 is 0.4 mm, the emitter 28 The length W _y in the Y-axis direction is 0.01 mm. The laser light 21 emitted from each emitter 28 diverges into a two-dimensional ellipsoidal shape. The divergence angles of the laser light 21 emitted from the twelve emitters 28 in this example are Θ _y = 30 ° and Θ _x = 8 °.

Therefore, B _x , ΣB _x and F _x2 are as follows.
B _x = 0.395mm
ΣB _x = P · (K−1) + B _x = 0.4 · (12−1) + 0.395 = 4.79
F _x2 ≧ ΣB _x /(2·sin(Θ))=4.795/(2×0.22)=10.9
From the above, the distance _{C c} of the optical fiber core 62a and the convex lens 48 is represented by the following formula.
2 · F _x2 ≧ C _c ≧ (1-2 · CR / ΣB _x ) · F _x2
Therefore, _{C c} satisfies the following equation.
21.8 ≧ C _c ≧ 9.5

Here, C _c = 11 mm, and C _x is approximately the same as the focal length F _x2 = 10.9 mm. Further, since the numerical aperture NA of the optical fiber 60 = sin (Θ) = 0.22 and CR = 0.3 mm, B _y = 0.32 mm and ΣB _y = 2.7 mm. Therefore, F _y2 is expressed by the following equation.
F _y2 = ΣB _y /(2·sin(Θ))=2.7/(2×0.22)=6.13

Position C _c of the convex lens 48, the distance C _y from the incident core surface is set so as to satisfy the following equation.
2 · 6.13 ≧ C _c ≧ (1-2 · 0.3 / 2.7) · 6.13
12.26 ≧ C _c ≧ 0.126
From the request in the X-axis direction and the request in the Y-axis direction, the distance C _c from the incident core surface of the convex lens 48 with the focal length F _x2 = 10.9 mm satisfies the following expression.
12.26 ≧ C _c ≧ 9.5

Therefore, the distance C _c from the incident core surface of the convex lens 48 with the focal length F _x2 = 10.9 mm may be selected as 11 mm. Focal length of the convex lens 48, and by appropriately selecting the distance C _c from the incident core surface of the convex lens 48, the fiber end faces two required cylindrical lens set at one convex lens 48 can be incident without damage focused beam 102 .

[Example 5]
FIG. 7 shows an example of the configuration of the laser processing apparatus 100 according to the fifth embodiment. The laser processing apparatus 100 according to the present example is different from the laser processing apparatus 100 according to the first and second embodiments in that the laser processing apparatus 100 includes L × N optical fibers 60.

  The laser processing apparatus 100 of this example is an example in which the configuration according to Example 1 in which the semiconductor laser bars 26 are branched into L pieces is expanded when N layers of semiconductor laser bars 26 are stacked. The laser processing apparatus 100 of this example focuses the focused beam 102 on L × N optical fiber cores 62. However, the number of incident sides of the optical fiber 60 may be L. On the other hand, the number of radiation side fibers 66 is L × N, and the number of irradiation heads 80 is also L × N.

  In the laser processing apparatus 100 of this example, L heating beams 104 are formed from one semiconductor laser bar 26 and further laminated on an N layer. Thereby, the laser processing apparatus 100 can process the processing material 110 with a larger number of heating beams 104. The laser processing apparatus 100 of this example is particularly advantageous when a large number of holes are formed at one time.

  The adjustment unit 50 may include a Pockel cell element. The Pockel cell element rotates the polarization plane of the focused beam 102 by applying a voltage. As a result, the transmitted focused beam 102 can be turned on and off. As a result, the continuous focused beam 102 can be converted into pulsed light in a wide frequency range from several Hz to several MHz. The adjusting unit 50 can adjust the transmission intensity by adjusting the on / off ratio. Thereby, the intensity of the heating beam 104 is adjusted. The pulse frequency and on / off ratio of the heating beam 104 can be controlled by an external voltage source. When the Pockel cell element is used, the cut light is emitted in a direction different from the main direction, and therefore a damper for absorbing the cut focused beam 102 is provided.

As described above, the laser processing apparatus 100 generates the heating beam 104 using the semiconductor laser apparatus 20 instead of the CO ₂ gas laser. The laser processing apparatus 100 of this example can simultaneously provide a large number of high-intensity heating beams 104 of several tens of W to several KW. The laser processing apparatus 100 can generate the heating beam 104 having various shapes such as a polygonal shape and an oval shape by appropriately changing the optical system. The laser processing apparatus 100 can generate a heating beam 104 such as a top hat type irradiation intensity, a bell type irradiation intensity, or an irradiation intensity distribution combining a top hat type and a bell type. The laser processing apparatus 100 can change the shape and irradiation intensity distribution for each heating beam 104.

The laser processing apparatus 100 includes only one cooling unit 15. Realizes a cooling system with high temperature control accuracy of cooling water. Whereas the CO ₂ laser processing apparatus has a size of several meters, the laser processing apparatus 100 of the present example suffices with an installation-occupied area of several tens of centimeters even for high intensity output of several KW class. The energy conversion efficiency of the laser processing apparatus 100 is as extremely high as 40% or more, and energy saving can be realized.

  The lifetime of the semiconductor laser device 20 has reached several hundred thousand hours or more. By using the semiconductor laser device 20, the laser processing apparatus 100 can withstand a severe use environment in which the heating beam 104 is turned on and off. Therefore, the laser processing apparatus 100 is excellent as a laser processing apparatus for mass production. The laser processing apparatus 100 can change the continuous light heating beam 104 from a few Hz to a pulse beam of MHz by using the adjustment unit 50. The laser processing apparatus 100 can change the characteristics of the plurality of heating beams 104 independently.

  As mentioned above, although this invention was demonstrated using embodiment, the technical scope of this invention is not limited to the range as described in the said embodiment. It will be apparent to those skilled in the art that various modifications or improvements can be added to the above-described embodiment. It is apparent from the scope of the claims that the embodiments added with such changes or improvements can be included in the technical scope of the present invention.

  The order of execution of each process such as operations, procedures, steps, and stages in the apparatus, system, program, and method shown in the claims, the description, and the drawings is particularly “before” or “prior to”. It should be noted that the output can be realized in any order unless the output of the previous process is used in the subsequent process. Regarding the operation flow in the claims, the description, and the drawings, even if it is described using “first”, “next”, etc. for convenience, it means that it is essential to carry out in this order. It is not a thing.

DESCRIPTION OF SYMBOLS 10 ... Power supply, 12 ... Power supply, 15 ... Cooling part, 20 ... Semiconductor laser apparatus, 21 ... Laser beam, 22 ... Input / output terminal, 24 ... Input / output terminal, 26 ... Semiconductor laser bar, 28 ... Emitter, 30 ... First optical system, 32 ... Cylindrical lens, 34 ... Micro lens, 40 ... Second optical system, 42 ... Micro Lens: 44 ... Cylindrical lens, 46 ... Cylindrical lens, 48 ... Convex lens, 50 ... Adjustment unit, 52 ... Damper, 55 ... Control unit, 60 ... Optical fiber, 62 ... Optical fiber core, 64 ... Optical fiber cladding, 66 ... Radiation side fiber, 70 ... Optical converter, 80 ... Irradiation head, 100 ... Laser processing device, 102 ... Focused beam, 104 ... Heating beam, 110 ... processing material, 112 ... hole, 120 ... semiconductor laser device, 121 ... laser light, 122 ... input / output terminal, 124 ... input / output terminal, 130 ... -1st optical system, 140 ... 2nd optical system, 150 ... Sensor part, 155 ... Control part, 170 ... Optical conversion part

Claims (28)

A semiconductor laser device for irradiating a plurality of laser beams;
An optical converter for condensing the plurality of laser beams into L condensed beams;
L optical fibers for receiving the L condensed beams;
With
The semiconductor laser device has N semiconductor laser bars,
Each of the N semiconductor laser bars has a plurality of emitters that emit the plurality of laser beams,
L is an integer of 2 or more, and N is an integer of 1 or more. The optical converter is
A first optical system for converting a component in a first direction of the plurality of laser beams and a component in a second direction different from the first direction into parallel light parallel to the traveling direction of the laser beams;
The laser processing apparatus according to claim 1, further comprising: a second optical system that condenses the plurality of laser beams converted into parallel light into the L condensed beams. The first optical system has a microlens,
The microlens is
When the divergence angle Θ _x from the plurality of emitters in the first direction, the emitter width W _x , the pitch P, and the focal length in the first direction are E _x1 ,
(E _x1 · sin (Θ _x / 2)) · 2 + W _x ≦ P
Including a plurality of lenses satisfying
The laser processing apparatus according to claim 2, wherein the plurality of lenses are arranged in the first direction corresponding to the plurality of emitters. The optical fiber has an optical fiber core having a numerical aperture NA = sin (Θ) and a radius CR;
The second optical system condenses k laser beams emitted from k emitters per one condensed beam on the optical fiber core,
The focal length F _{x2 in} the first direction of the second optical system is
A divergence angle Θ _x from the plurality of emitters in the first direction, an emitter width W _x , a pitch P, and a focal length in the first direction as E _x1 ,
The width ΣB _x of the laser beam in the first direction is
B _x = (E _x1 · sin (Θ _x / 2)) · 2 + W _x
ΣB _x = P · (k−1) + (E _x1 · sin (Θ _x / 2)) · 2 + W _x
As
F _x2 ≧ ΣB _x / (2 · sin (Θ))
And
If the position of the second optical system is the distance from the incident surface of the optical fiber core is C _x,
2 · F _x2 ≧ C _x ≧ (1-2 · CR / ΣB _x ) · F _x2
The laser processing apparatus according to claim 2 or 3, wherein: The optical fiber has an optical fiber core with a numerical aperture NA = sin (Θ) and a radius CR;
Condensing k laser beams emitted from emitters arranged in the first direction of the semiconductor laser bar on the optical fiber;
The focal length F _y2 of the second optical system in the second direction is
The width B _y of the _focused beam in the second direction is _expressed as B _y = E _y1 (2 · sin (Θ _y / 2)).
As
F _y2 ≧ B _y / (2 · sin (Θ))
The filling,
If the position of the second optical system, the distance from the incident surface of the optical fiber core is C _y,
2 · F _y2 ≧ C _y ≧ (1-2 · CR / B _y ) · F _y2
The laser processing apparatus according to any one of claims 2 to 4. The semiconductor laser device includes:
The semiconductor laser bar in which k emitters are arranged in the first direction is constituted by one semiconductor laser device in which N pieces are arranged in the second direction.
When the number of emitters used for one focused beam is k,
K × N ≧ k × L (K, k, N are integers of 1 or more)
The laser processing apparatus according to any one of claims 2 to 5, wherein: The plurality of emitters are arranged in a predetermined first direction,
The N semiconductor laser bars are stacked in a second direction different from the first direction,
The laser processing apparatus according to claim 2, wherein the semiconductor laser device emits the laser light in a third direction different from the first direction and the second direction. The first optical system has a cylindrical lens,
The cylindrical lens is
The divergence angle Θ _y in the second direction of the laser light emitted from the plurality of emitters, the emitter width W _y , the pitch of the N semiconductor laser bars S _y , and the second of the cylindrical lens If the focal length in the direction is E _y1 ,
(E _y1 · sin (Θ _y / 2)) · 2 + W _y ≦ S _y
The laser processing apparatus according to claim 7, wherein: 3. The second optical system makes the focused beam obtained by collecting the laser beam from the n semiconductor laser bars out of N stacked semiconductor laser bars incident on one optical fiber. The laser processing apparatus as described in any one of 8-8. The optical fiber has an optical fiber core having a numerical aperture NA = sin (Θ) and a radius CR;
The second optical system includes a cylindrical lens that branches the semiconductor laser bar emitted by the n-layer semiconductor laser bars from the N stacked semiconductor laser bars and focuses the light on the optical fiber core,
The focal length F _y2 of the cylindrical lens in the second direction is
The beam width ΣB _y in the second direction of the focused beam is
B _y = (E _y1 · sin (Θ _y / 2)) · 2 + W _y
ΣB _y = S _y · (n−1) + B _y
As
F _y2 ≧ ΣB _y / (2 · sin (Θ))
The filling,
The position of the cylindrical lens, when the distance from the incident surface of the optical fiber core is C _y,
2 · F _y2 ≧ C _y ≧ (1-2 · CR / ΣB _y ) · F _y2
The laser processing apparatus according to claim 9. The optical fiber has an optical fiber core having a numerical aperture NA = sin (Θ) and a radius CR;
The second optical system focuses k laser beams emitted from k emitters per one focused beam onto the optical fiber core as the focused beam, and the second optical system Having a convex lens,
The focal length F _x2 of the convex lens in the first direction is
The divergence angle Θ _x from the plurality of emitters in the first direction, the emitter width W _x , the pitch P, the total number of emitters K, and the focal length in the first direction as E _x1 ,
The width ΣB _x of the laser beam in the first direction is
B _x = (E _x1 · sin (Θ _x / 2)) · 2 + W _x
ΣB _x = P · (K−1) + (E _x1 · sin (Θ _x / 2)) · 2 + W _x
As
F _x2 ≧ ΣB _x / (2 · sin (Θ))
The filling,
The convex lens branches the laser light emitted by the n-layer semiconductor laser bars among the N stacked semiconductor laser bars, and focuses the light on the optical fiber core.
The focal length F _y2 in the second direction is the beam width ΣB _y in the second direction of the focused beam,
B _y = (E _y1 · sin (Θ _y / 2)) · 2 + W _y
ΣB _y = S _y · (n−1) + B _y
As
F _y2 ≧ ΣB _y / (2 · sin (Θ))
The filling,
If F _x2 ≧ F _y2 ,
When the distance from the incident surface of the optical fiber core is C _c , the position of the convex lens is
2 · F _x2 ≧ C _c ≧ (1-2 · CR / ΣB _x ) · F _x2
The filling,
If F _x2 <F _y2 ,
2 · F _y2 ≧ C _c ≧ (1-2 · CR / ΣB _y ) · F _y2
The laser processing apparatus according to claim 9, wherein: When the diameter of the optical fiber including the optical fiber core, the optical fiber cladding, and the sheath is Fmax,
The width of the focused beam is B _y , the focal length of the second optical system in the second direction is F _y2, and the pitch of the N semiconductor laser bars is S _y .
The minimum distance CD of the optical fiber is
CD = F _y2 · (2 · sin (Θ) + S _y · (n−1))
F _y2 = ΣB _y / (2 · sin (Θ))
But,
CD ≧ Fmax
The second optical system is composed of the optical fiber core, the optical fiber cladding, and the exterior that collect the laser light from the n semiconductor laser bars among the N stacked semiconductor laser bars. The laser processing apparatus according to claim 2, wherein the laser processing apparatus is incident on a single optical fiber. The optical fiber is on the incident side of the focused beam,
L optical fiber cores;
An optical fiber clad covering the L optical fiber cores in common;
The laser processing apparatus according to any one of claims 1 to 12. The optical fiber is on the radiation side of the focused beam,
L independent optical fiber cores;
The laser processing apparatus according to any one of claims 1 to 13, further comprising: L optical fiber claddings that cover the optical fiber core. The laser processing apparatus according to any one of claims 1 to 14, wherein the optical fiber has an optical fiber core having an oval cross section on an incident side. The laser processing apparatus according to any one of claims 1 to 15, wherein the optical fiber has an optical fiber core having a polygonal cross section on an incident side. The laser processing apparatus according to any one of claims 1 to 16, further comprising L irradiation heads for processing an irradiation intensity distribution of the L heating beams emitted from the radiation surfaces of the L optical fibers. The irradiation head irradiates a heating beam whose irradiation intensity distribution on a two-dimensional surface orthogonal to the traveling direction of the heating beam is a bell-shaped irradiation intensity distribution with the maximum intensity at the center of the two-dimensional surface of the heating beam. The laser processing apparatus according to claim 17. The laser processing apparatus according to claim 17, wherein the irradiation head irradiates a heating beam having a top-hat type irradiation intensity distribution in which an irradiation intensity distribution on a two-dimensional plane orthogonal to a traveling direction of the heating beam is substantially uniform. . In the irradiation head, the irradiation intensity distribution on the two-dimensional plane orthogonal to the traveling direction of the heating beam is a top hat type irradiation intensity distribution in one direction and a bell type irradiation intensity distribution in the other direction. The laser processing apparatus according to claim 17, which irradiates a beam. The L irradiation heads include two or more irradiation heads arranged at non-equal intervals on the same circumference centered on an irradiation region by the heating beam. Laser processing equipment. The L irradiation heads are:
A first irradiation head for irradiating the heating beam;
The laser processing apparatus according to any one of claims 17 to 20, further comprising: a second irradiation head disposed in a region other than the same circumference around the irradiation region of the first irradiation head by the heating beam. A single cooling unit for supplying cooling water to the semiconductor laser device;
The semiconductor laser device includes:
The laser processing apparatus according to claim 1, further comprising: a single second input / output terminal that flows in and out of the cooling water from the single cooling unit. An adjustment unit for adjusting the intensity of the L focused beams;
The laser according to any one of claims 1 to 23, wherein the adjustment unit includes a Pockel cell element that converts a L focused beam having continuous intensity into a focused beam having discontinuous intensity. Processing equipment. The laser processing apparatus according to claim 24, wherein the adjustment unit includes a Pockel cell element that attenuates the intensity of the L focused beams. An adjustment unit for adjusting the intensity of the L focused beams;
The laser processing apparatus according to any one of claims 1 to 23, further comprising: a first control unit that adjusts the intensity of each of the L focused beams by controlling the position of the adjustment unit. The adjustment unit is
The laser processing apparatus according to claim 26, further comprising a damper that attenuates the intensity of the L focused beams. A sensor unit that detects the intensity of a specific focused beam among the L focused beams;
The control apparatus according to claim 1, further comprising: a second control unit that adjusts the intensity of the focused beam by controlling power supplied to the semiconductor laser device that emits the specific focused beam. Laser processing equipment.