JP2020068351A - Laser processing device - Google Patents

Abstract

To provide a laser processing device capable of suppressing deterioration of a parameter BPP without having an optical element such as a dichroic mirror and performing fine adjustment of an optical element.SOLUTION: A laser processing device that emits laser beams having different wavelengths, comprises: one or more first laser light sources; a plurality of laser light sources having one or more second laser light sources; a plurality of collimator lenses collimating the laser beams each having the wavelength from the plurality of laser light sources; double core fibers including a first core 41, a first clad 42 surrounding the first core; a second core 43 surrounding the first clad, and a second clad 44 surrounding the second core; and a light focus lens that focuses the plurality of laser beams each having the wavelength from the plurality of collimator lenses to the double core fibers. The laser beam from one or more first laser light sources is incident into the first core, and the laser beam from one or more second laser light sources is incident into at least one core of the first core and the second core.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a fiber-coupled laser processing device composed of a plurality of laser diodes.

  In Patent Documents 1 and 2, there is a laser processing method in which the laser is irradiated to the irradiation target object by processing by combining the optical axes of the lasers having two or more wavelengths with a dichroic mirror or the like to combine the wavelengths. Have been described.

  In the case of a laser processing device, laser light is input to a fiber and the light is handled within the laser processing device.

JP, 2008-797, A JP, 2014-24105, A

  However, in the laser processing apparatus, it is necessary to provide an optical element such as a dichroic mirror in order to align the optical axes. Further, it is necessary to finely adjust the optical element in order to align the optical axis.

  When the laser light is guided to the fiber, the parameter BPP (Beam Parameter Products, beam parameter product) representing the laser quality may deteriorate. The parameter BPP is defined by the product of the radius of the beam waist and the half width at half maximum of the divergence angle of the beam. For example, when a laser output having an emitter size of several tens of um is guided to a 400 um fiber, the parameter BPP deteriorates considerably.

  An object of the present invention is to provide a laser processing apparatus that suppresses deterioration of the parameter BPP without providing an optical element such as a dichroic mirror and finely adjusting the optical element.

  According to a first aspect of the laser processing apparatus of the present invention, a plurality of laser beams having different wavelengths are emitted, and one or more first laser light sources and the one or more first laser light sources are sandwiched therebetween. A plurality of laser light sources having a plurality of second laser light sources arranged, and a plurality of collimator lenses provided corresponding to the plurality of laser light sources and collimating laser light of a plurality of wavelengths from the plurality of laser light sources, A double core fiber having a first core, a first clad surrounding the first core, a second core surrounding the first clad and a second clad surrounding the second core; and a plurality of wavelengths collimated by the plurality of collimating lenses. A condenser lens for condensing laser light on the double core fiber, and allowing the laser light from the one or more first laser light sources to enter the first core. Characterized in that for entering the laser light from the plurality of second laser light source to at least one of the core and the second core and the first core.

  According to a second aspect of the present invention, the one or more first laser light sources are laser light sources having the best beam parameter product among the plurality of laser light sources.

  In claim 3, the one or more first laser light sources are fiber lasers, and the plurality of second laser light sources are semiconductor lasers.

  In a fourth aspect of the present invention, the semiconductor laser has a wavelength of 600 μm or less.

  In claim 5, the condensing lens comprises a variable focus lens having a variable focus in accordance with an input control signal, and the first core control signal is applied to the variable focus lens at a first time to obtain the one or more. Laser light from the first laser light source is incident on the first core, and a second core control signal is applied to the focus variable lens at a second time to generate a second laser light from the plurality of second laser light sources. It is characterized by comprising a controller for making the core incident.

  According to the present invention, when laser beams of a plurality of wavelengths from a plurality of laser light sources are coupled to a double core fiber by using a condenser lens, laser beams from one or more first laser light sources are incident on the first core, Laser light from a plurality of second laser light sources arranged so as to sandwich one or more first laser light sources is mainly incident on the second core.

  As a result, the output optical axes of the double core fiber can be aligned. Therefore, the optical element such as a dichroic mirror is not provided and the optical element is not finely adjusted.

  Further, since the beam parameter product BPP is defined by the product of the radius of the beam waist and the half width at half maximum of the divergence angle of the beam, the laser light of the laser light source having a good beam parameter product BPP is input to the first core having a small radius. As a result, the deterioration of the beam parameter product BPP can be suppressed.

It is a block diagram of the double core fiber used for the laser processing apparatus of Example 1 of this invention. 3 is a diagram showing a configuration of a laser processing apparatus of Example 1. FIG. It is a figure which shows the structure of the laser processing apparatus of Example 2. It is a figure which shows the structure of the laser processing apparatus of Example 3. It is a figure which shows the timing chart of the 1st core control signal and 2nd core control signal for changing the spot diameter of the laser processing apparatus of Example 3. It is a figure which shows the laser irradiation area when changing a spot diameter and irradiating a laser in the laser processing apparatus of Example 3.

(Example 1)
1 is a block diagram of a double core fiber used in a laser processing apparatus according to a first embodiment of the present invention. FIG. 2 is a diagram showing the configuration of the laser processing apparatus according to the first embodiment. The laser processing apparatus includes a plurality of laser diodes 1a to 1c, a plurality of collimating lenses 2a to 2c, a condenser lens 3, and a double core fiber 4.

  The plurality of laser diodes 1a to 1c correspond to the plurality of laser light sources of the present invention, are arranged at predetermined intervals, and emit laser light. The plurality of laser diodes 1a to 1c include a laser diode 1c (corresponding to a first laser light source) arranged on the optical axis, and a laser diode 1a arranged in a direction orthogonal to the optical axis so as to sandwich the laser diode 1c. 1b (corresponding to a plurality of second laser light sources).

  The wavelength of the laser light of the laser diode 1c is λ2, and the wavelength of the laser light of the laser diodes 1a and 1b is λ1, which is different from the wavelength λ2 of the laser light of the laser diode 1c.

  The plurality of collimator lenses 2a to 2c are arranged so as to face the plurality of laser diodes 1a to 1c, and the laser beams from the plurality of laser diodes 1a to 1c are collimated and guided to the condenser lens 3.

  In FIG. 1, the number of each of the laser diodes 1a to 1c and the collimating lenses 2a to 2c is three, but the number is not limited to three, and other numbers may be used. .

  The condenser lens 3 condenses the laser light of the plurality of wavelengths λ1 and λ2 from the plurality of collimator lenses 2a to 2c and couples it to the double core fiber 4.

  As shown in FIG. 1, the double core fiber 4 has a columnar shape, and surrounds the first core 41, the first clad 42 surrounding the first core 41, the second core 43 surrounding the first clad 42, and the second core 43 surrounding the first clad 42. It comprises a second cladding 44 and a coating 45 covering the second cladding 44. The first core 41, the first clad 42, the second core 43, the second clad 44, and the coating 45 are arranged concentrically with respect to the optical axis 40.

  The laser light having the wavelength λ2 from the laser diode 1c is incident on the first core 41, and the laser light having the wavelength λ1 from the laser diodes 1a and 1b is mainly incident on the second core 43.

  Further, the laser light from the laser diodes 1a and 1b may be incident on the first core 41, or the laser light from the laser diodes 1a and 1b may be incident on both the first core 41 and the second core 43. good.

  As described above, according to the laser processing apparatus of the first embodiment, when the laser beams of a plurality of wavelengths from the plurality of laser diodes 1a to 1c are coupled to the double core fiber 4 by using the condenser lens 3, the laser processing device is arranged in the central portion. The laser light of wavelength λ2 from the laser diode 1c is incident on the first core 41, and the laser light of wavelength λ1 from the laser diodes 1a and 1b arranged so as to sandwich the laser diode 1c is mainly incident on the second core 43. Let

  Thereby, the optical axes of the outputs of the double core fiber 4 can be aligned. Therefore, the optical element such as a dichroic mirror is not provided and the optical element is not finely adjusted.

  Further, since the beam parameter product BPP is defined by the product of the radius of the beam waist and the half width at half maximum of the divergence angle of the beam, the laser light of the laser diode 1c having a good beam parameter product BPP is transmitted to the first core 41 having a small radius. By inputting, deterioration of the beam parameter product BPP can be suppressed.

(Example 2)
FIG. 3 is a diagram illustrating the configuration of the laser processing apparatus according to the second embodiment. In the laser processing apparatus according to the second embodiment, the laser diodes 1a and 1b are blue semiconductor lasers. A fiber laser 5 is used in place of the laser diode 1c.

  The fiber laser 5 has a better beam parameter product BPP than the semiconductor laser, and by guiding the laser light from the fiber laser 5 to the first core 41, the deterioration of the beam parameter product BPP can be minimized.

  Further, the fiber laser 5 has a higher brightness than the blue semiconductor laser, and it is preferable to arrange one or a plurality of fiber lasers 5 in the central portion and add the brightness.

  When considering laser processing of metals, metals such as gold and copper have a high reflectance at a wavelength of 1 μm (laser wavelength of a fiber laser), while absorptance of 50% or more at wavelengths of 532 nm and 450 nm. have.

  Therefore, by using a laser light source in which a semiconductor laser having a wavelength of 600 nm or less at which the absorption coefficient increases (not necessarily limited to the semiconductor laser) and a fiber laser having high brightness are combined, the processing efficiency is further improved. A laser processing device can be obtained.

  Further, by using the double core fiber 4 and making the wavelength of the laser light passing through the first core 41 and the wavelength of the laser light passing through the second core 43 different, it is possible to easily realize a light source for hybrid laser processing in which the optical axes match. be able to. Also, efficient laser processing can be performed by selecting the optimum combination of wavelengths for the object to be laser processed.

(Example 3)
FIG. 4 is a diagram showing the configuration of the laser processing apparatus according to the third embodiment. The laser processing apparatus of the third embodiment shown in FIG. 4 is characterized in that a variable focus lens 6 is arranged in place of the condenser lens 3 shown in FIG. 1, and a controller 7 is further provided.

  The focus variable lens 6 changes the focus according to a control signal composed of an input voltage. As shown in FIG. 5, the controller 7 applies a first core control signal composed of a voltage to the variable focus lens 6 from time t0 to time t2 to cause the laser light from the laser diode 1c to enter the first core 41. .

  From time t1 to time t2, the controller 7 applies a second core control signal composed of a voltage to the variable focus lens 6 to cause the laser light from the laser diodes 1a and 1b to enter the second core 43.

  From time t1 to time t2, since the first core control signal and the second core control signal are applied to the variable focus lens 6, the spot diameter becomes large. That is, by temporally dividing the laser light passing through the first core 41 and the laser light passing through the second core 43, laser irradiation can be performed by changing the spot diameter after the fiber output. FIG. 6 shows laser irradiation areas AR1, AR2, and AR3 when the laser irradiation is performed by changing the spot diameter. The laser irradiation areas AR1 and AR3 are laser irradiation areas by the laser light passing through the first core 41. The laser irradiation area AR2 is a laser irradiation area by the laser light passing through the first core 41 and the laser light passing through the second core 43.

  INDUSTRIAL APPLICABILITY The present invention can be applied to a fiber coupling type laser processing apparatus including a plurality of lasers.

1a, 1b, 1c Laser diodes 2a to 2c Collimating lens 3 Condensing lens 4 Double core fiber 5 Fiber laser 40 Optical axis 41 First core 42 First clad 43 Second core 44 Second clad 45 Coating

Claims (5)

A plurality of laser beams having different wavelengths, each of which has one or more first laser light sources and a plurality of second laser light sources arranged so as to sandwich the one or more first laser light sources. Laser light source,
A plurality of collimator lenses provided corresponding to the plurality of laser light sources, and collimating laser light of a plurality of wavelengths from the plurality of laser light sources,
A double-core fiber having a first core, a first clad surrounding the first core, a second core surrounding the first clad, and a second clad surrounding the second core;
A condenser lens for condensing the laser light of a plurality of wavelengths collimated by the plurality of collimator lenses on the double core fiber,
Laser light from the one or more first laser light sources is incident on the first core, and laser light from the plurality of second laser light sources is incident on at least one of the first core and the second core. A laser processing device characterized by:   The laser processing apparatus according to claim 1, wherein the one or more first laser light sources are laser light sources having the best beam parameter product among the plurality of laser light sources.   The laser processing device according to claim 1, wherein the one or more first laser light sources are fiber lasers, and the plurality of second laser light sources are semiconductor lasers.   4. The laser processing apparatus according to claim 3, wherein the semiconductor laser has a wavelength of 600 μm or less. The condensing lens comprises a focus variable lens whose focus is variable according to an input control signal,
A first core control signal is applied to the variable focus lens at a first time to cause laser light from the one or more first laser light sources to enter the first core, and a second core control signal is applied to the first core at a second time. 5. The laser processing apparatus according to claim 1, further comprising a controller that applies a laser beam from the plurality of second laser light sources to the second core by applying the variable focus lens to the second core. .

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