JP2017168772A - Laser oscillator and laser processing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laser oscillator that is easy to handle and stable in the position and angle of the optical axis of an externally emitted laser beam, and to provide a laser processing device having such a laser oscillator.SOLUTION: A laser oscillator 400 comprises: a source-light emission part 410 having a source light LD 411; a preamplifier part 420 having a first laser fiber 423 and a first exciting LD 424; a power amplifying part 430 having a second laser fiber 434 and a second exciting LD 435; a laser beam emission part 440 having an isolator 442 provided with an emission end 443; and a housing 470 having a mounting base 471 and accommodating the source-light emission part 410, the preamplifier part 420, the power amplifying part 430, and the laser beam emission part 440. The isolator 442 provided with an emission end 443 is located on the mounting base 471.SELECTED DRAWING: Figure 13

Description

  The present invention relates to a laser oscillator and a laser processing apparatus.

  In order to cut an object to be processed such as a semiconductor wafer into a plurality of chips, there is known a laser processing apparatus that forms a modified region inside the object to be processed along a predetermined cutting line set in a lattice shape ( For example, see Patent Document 1).

Japanese Patent No. 5456510

  The laser oscillator mounted on the laser processing apparatus as described above is preferably easy to handle so that it can be easily replaced. In particular, when a modified region is formed inside a workpiece, severe laser light irradiation conditions are required compared to ablation processing, welding processing, etc. It is desirable that the position and angle of the optical axis of laser light emitted from the oscillator to the outside be stable.

  An object of the present invention is to provide a laser oscillator that is easy to handle and has a stable position and angle of the optical axis of laser light emitted to the outside, and a laser processing apparatus including such a laser oscillator. And

  A laser oscillator according to the present invention includes a seed light emitting unit having a seed light source that emits laser light that is seed light, a first laser fiber that propagates the laser light emitted from the seed light emitting unit, and a first laser fiber. A first amplifier unit having a first excitation light source that emits first excitation light for excitation, a second laser fiber for propagating the laser light amplified by the first amplifier unit, and for exciting the second laser fiber A second amplifier unit having a second excitation light source that emits the second excitation light, and a laser beam emitting unit having an optical component provided with an emission end for emitting the laser light amplified by the second amplifier unit to the outside; And a housing that contains a seed light emitting portion, a first amplifier portion, a second amplifier portion, and a laser light emitting portion, and the optical component is disposed on the mounting base.

  In this laser oscillator, a seed light emitting unit, a first amplifier unit, a second amplifier unit, and a laser beam emitting unit are housed in a casing. Therefore, handling of the laser oscillator is easy. In addition, an optical component having an emission end is disposed on a mounting base of the housing. As a result, for example, when a laser oscillator is mounted on a laser processing apparatus via a mounting base, vibrations are generated in the laser processing apparatus, or a housing or the like is caused by a change in the operating environment temperature of the laser processing apparatus. Even if it is deformed, the position and angle of the emission end are difficult to shift. Therefore, the position and angle of the optical axis of the laser beam emitted from the laser oscillator to the outside are stabilized.

  The laser oscillator of the present invention includes a first support plate that is housed in a housing and at least a first laser fiber is disposed, and a second support plate that is housed in the housing and is disposed at least a second laser fiber. Further, it may be provided. According to this, the first laser fiber and the second laser fiber can be appropriately supported in the housing.

  In the laser oscillator of the present invention, the second support plate may be provided with a refrigerant flow path, and the first excitation light source and the second excitation light source may be disposed on the second support plate. According to this, in addition to the second laser fiber that is likely to generate heat, the first excitation light source and the second excitation light source that are likely to generate heat can be efficiently cooled in a small space.

  In the laser oscillator of the present invention, the second support plate may be disposed above the mounting base, and the first support plate may be disposed above the second support plate. According to this, the footprint of the laser oscillator can be reduced while simplifying the arrangement of the optical path of the laser light from the first amplifier section to the laser light emitting section via the second amplifier section.

  In the laser oscillator according to the present invention, the housing is detachable from the first part that houses the first amplifier part, the second amplifier part, and the laser light emitting part, and is detachable from the first part, and contains the seed light emitting part. And a second portion to be included. According to this, the seed light emitting part can be easily maintained by attaching / detaching the second part to / from the first part.

  The laser oscillator according to the present invention may further include a support member that is provided on the mounting base and has a support surface on which a fiber for propagating laser light from the second amplifier section to the laser light emitting section is disposed. According to this, since the fiber for propagating the amplified laser beam can be appropriately supported (while maintaining the necessary bending diameter), it is possible to prevent a situation in which the laser beam leaks from the fiber. .

  The laser processing apparatus of the present invention includes the laser oscillator, an output adjustment unit that adjusts the output of the laser beam emitted from the emission end of the laser oscillator, and an optical axis of the laser beam that has passed through the output adjustment unit. A mirror unit having a mirror, a mounting base of a laser oscillator, a mounting plate to which an output adjustment unit and a mirror unit are mounted, a device frame to which a mounting plate is mounted, and a support that is mounted on the device frame and supports a workpiece. And a laser condensing unit that is attached to the apparatus frame so as to be movable with respect to the mirror unit, and condenses the laser light that has passed through the mirror unit onto the object to be processed.

  In this laser processing apparatus, since the laser condensing unit is attached to the apparatus frame so as to be movable, it is not necessary to move the laser oscillator. Therefore, the stability of the position and angle of the optical axis of the laser light emitted from the laser oscillator can be more reliably maintained, and the processing object can be irradiated with the laser light under severe irradiation conditions.

  According to the present invention, it is possible to provide a laser oscillator that is easy to handle and has a stable position and angle of the optical axis of laser light emitted to the outside, and a laser processing apparatus including such a laser oscillator. Is possible.

It is a schematic block diagram of the laser processing apparatus used for formation of a modification area | region. It is a top view of the processing target object used as the object of formation of a modification field. It is sectional drawing along the III-III line of the workpiece of FIG. It is a top view of the processing target after laser processing. It is sectional drawing along the VV line of the workpiece of FIG. It is sectional drawing along the VI-VI line of the processing target object of FIG. It is a perspective view of the laser processing apparatus of an embodiment. It is a perspective view of the processing target attached to the support stand of the laser processing apparatus of FIG. It is sectional drawing of the laser output part along XY plane of FIG. It is a perspective view of a part of laser output part and laser condensing part in the laser processing apparatus of FIG. It is a figure which shows the optical arrangement | positioning relationship of (lambda) / 2 wavelength plate unit and polarizing plate unit in the laser output part of FIG. (A) is a figure which shows the polarization direction in (lambda) / 2 wavelength plate unit of the laser output part of FIG. 9, (b) is a figure which shows the polarization direction in the polarizing plate unit of the laser output part of FIG. It is a figure showing the whole laser oscillator composition of an embodiment. It is a front view of the laser oscillator of an embodiment. It is a figure which shows the internal structure of the laser oscillator of FIG. It is a figure which shows the internal structure of the laser oscillator of FIG. It is a figure which shows the internal structure of the laser oscillator of FIG. It is a figure which shows the internal structure of the laser oscillator of FIG. It is a figure which shows the internal structure of the laser oscillator of FIG. It is a figure which shows the internal structure of the laser oscillator of FIG. (A) is a figure which shows the whole structure of the 1st modification of the laser oscillator of embodiment, (b) is a figure which shows the whole structure of the 2nd modification of the laser oscillator of embodiment, (c) is It is a figure which shows the whole structure of the 3rd modification of the laser oscillator of embodiment.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In addition, in each figure, the same code | symbol is attached | subjected to the same or an equivalent part, and the overlapping description is abbreviate | omitted.

  In the laser processing apparatus (described later) of the embodiment, the modified region is formed in the processing object along the planned cutting line by condensing the laser beam on the processing object. First, the formation of the modified region will be described with reference to FIGS.

  As shown in FIG. 1, a laser processing apparatus 100 includes a laser light source 101 that oscillates a laser beam L, a dichroic mirror 103 that is arranged to change the direction of the optical axis (optical path) of the laser beam L by 90 °, and And a condensing lens 105 for condensing the laser light L. Further, the laser processing apparatus 100 includes a support base 107 for supporting the workpiece 1 irradiated with the laser light L condensed by the condensing lens 105, and a stage 111 for moving the support base 107. , A laser light source control unit 102 for controlling the laser light source 101 to adjust the output, pulse width, pulse waveform, and the like of the laser light L, and a stage control unit 115 for controlling the movement of the stage 111.

  In the laser processing apparatus 100, the laser light L emitted from the laser light source 101 is changed in the direction of its optical axis by 90 ° by the dichroic mirror 103, and is placed inside the processing object 1 placed on the support base 107. The light is condensed by the condensing lens 105. At the same time, the stage 111 is moved, and the workpiece 1 is moved relative to the laser beam L along the planned cutting line 5. Thereby, a modified region along the planned cutting line 5 is formed on the workpiece 1. Here, the stage 111 is moved in order to move the laser light L relatively, but the condensing lens 105 may be moved, or both of them may be moved.

  As the processing object 1, a plate-like member (for example, a substrate, a wafer, or the like) including a semiconductor substrate formed of a semiconductor material, a piezoelectric substrate formed of a piezoelectric material, or the like is used. As shown in FIG. 2, a scheduled cutting line 5 for cutting the workpiece 1 is set in the workpiece 1. The planned cutting line 5 is a virtual line extending linearly. When the modified region is formed inside the workpiece 1, the laser beam L is cut in a state where the condensing point (condensing position) P is aligned with the inside of the workpiece 1 as shown in FIG. 3. It moves relatively along the planned line 5 (that is, in the direction of arrow A in FIG. 2). Thereby, as shown in FIGS. 4, 5, and 6, the modified region 7 is formed on the workpiece 1 along the planned cutting line 5, and the modified region formed along the planned cutting line 5. 7 becomes the cutting start region 8.

  The condensing point P is a part where the laser light L is condensed. The planned cutting line 5 is not limited to a straight line, but may be a curved line, a three-dimensional shape in which these lines are combined, or a coordinate designated. The planned cutting line 5 is not limited to a virtual line but may be a line actually drawn on the surface 3 of the workpiece 1. The modified region 7 may be formed continuously or intermittently. The modified region 7 may be in the form of a line or a dot. In short, the modified region 7 only needs to be formed at least inside the workpiece 1. In addition, a crack may be formed starting from the modified region 7, and the crack and the modified region 7 may be exposed on the outer surface (front surface 3, back surface, or outer peripheral surface) of the workpiece 1. . The laser light incident surface when forming the modified region 7 is not limited to the front surface 3 of the workpiece 1 and may be the back surface of the workpiece 1.

  Incidentally, when the modified region 7 is formed inside the workpiece 1, the laser light L passes through the workpiece 1 and is near the condensing point P located inside the workpiece 1. Especially absorbed. Thereby, the modified region 7 is formed in the workpiece 1 (that is, internal absorption laser processing). In this case, since the laser beam L is hardly absorbed by the surface 3 of the workpiece 1, the surface 3 of the workpiece 1 is not melted. On the other hand, when the modified region 7 is formed on the surface 3 of the workpiece 1, the laser light L is absorbed particularly near the condensing point P located on the surface 3 and melted and removed from the surface 3. Then, removal portions such as holes and grooves are formed (surface absorption laser processing).

  The modified region 7 is a region where the density, refractive index, mechanical strength, and other physical characteristics are different from the surroundings. Examples of the modified region 7 include a melt treatment region (meaning at least one of a region once solidified after melting, a region in a molten state, and a region in a state of being resolidified from melting), a crack region, and the like. In addition, there are a dielectric breakdown region, a refractive index change region, and the like, and there is a region in which these are mixed. Further, the modified region 7 includes a region where the density of the modified region 7 in the material of the workpiece 1 is changed compared to the density of the non-modified region, and a region where lattice defects are formed. When the material of the workpiece 1 is single crystal silicon, the modified region 7 can be said to be a high dislocation density region.

The area where the density of the melt processing area, the refractive index changing area, the density of the modified area 7 is changed as compared with the density of the non-modified area, and the area where lattice defects are formed are further included in the interior of these areas or the modified areas. In some cases, cracks (cracks, microcracks) are included in the interface between the region 7 and the non-modified region. The included crack may be formed over the entire surface of the modified region 7, or may be formed in only a part or a plurality of parts. The workpiece 1 includes a substrate made of a crystal material having a crystal structure. For example, the workpiece 1 includes a substrate formed of at least one of gallium nitride (GaN), silicon (Si), silicon carbide (SiC), LiTaO ₃ , and sapphire (Al ₂ O ₃ ). In other words, the workpiece 1 includes, for example, a gallium nitride substrate, a silicon substrate, a SiC substrate, a LiTaO ₃ substrate, or a sapphire substrate. The crystal material may be either an anisotropic crystal or an isotropic crystal. Moreover, the workpiece 1 may include a substrate made of an amorphous material having an amorphous structure (amorphous structure), for example, a glass substrate.

In the embodiment, the modified region 7 can be formed by forming a plurality of modified spots (processing marks) along the planned cutting line 5. In this case, the modified region 7 is formed by collecting a plurality of modified spots. The modified spot is a modified portion formed by one pulse shot of pulsed laser light (that is, one pulse of laser irradiation: laser shot). Examples of the modified spot include a crack spot, a melting treatment spot, a refractive index change spot, or a mixture of at least one of these. For the modified spot, the size and length of cracks to be generated are appropriately determined in consideration of the required cutting accuracy, required flatness of the cut surface, thickness, type, crystal orientation, etc. of the workpiece 1. Can be controlled. In the embodiment, the modified spot can be formed as the modified region 7 along the planned cutting line 5.
[Laser Processing Apparatus of Embodiment]

Next, the laser processing apparatus of the embodiment will be described. In the following description, directions orthogonal to each other in the horizontal plane are defined as an X-axis direction and a Y-axis direction, and a vertical direction is defined as a Z-axis direction.
[Overall configuration of laser processing equipment]

  As shown in FIG. 7, the laser processing apparatus 200 includes an apparatus frame 210, a first moving mechanism 220, a support base (supporting unit) 230, and a second moving mechanism 240. Further, the laser processing apparatus 200 includes a laser output unit 300, a laser condensing unit 500, and a control unit 600.

  The first moving mechanism 220 is attached to the device frame 210. The first moving mechanism 220 includes a first rail unit 221, a second rail unit 222, and a movable base 223. The first rail unit 221 is attached to the device frame 210. The first rail unit 221 is provided with a pair of rails 221a and 221b extending along the Y-axis direction. The second rail unit 222 is attached to the pair of rails 221a and 221b of the first rail unit 221 so as to be movable along the Y-axis direction. The second rail unit 222 is provided with a pair of rails 222a and 222b extending along the X-axis direction. The movable base 223 is attached to the pair of rails 222a and 222b of the second rail unit 222 so as to be movable along the X-axis direction. The movable base 223 can rotate around an axis parallel to the Z-axis direction as a center line.

  The support base 230 is attached to the movable base 223. The support base 230 supports the workpiece 1. The workpiece 1 includes, for example, a plurality of functional elements (a light receiving element such as a photodiode, a light emitting element such as a laser diode, or a circuit element formed as a circuit) on the surface side of a substrate made of a semiconductor material such as silicon. It is formed in a matrix. When the workpiece 1 is supported on the support base 230, for example, the surface 1a (a plurality of functional elements) of the workpiece 1 is formed on the film 12 stretched on the annular frame 11 as shown in FIG. Side surface) is affixed. The support base 230 supports the workpiece 1 by holding the frame 11 with a clamp and adsorbing the film 12 with a vacuum chuck table. On the support base 230, a plurality of cutting lines 5 a parallel to each other and a plurality of cutting lines 5 b parallel to each other are set on the workpiece 1 in a lattice shape so as to pass between adjacent functional elements. The

  As shown in FIG. 7, the support base 230 is moved along the Y-axis direction by the operation of the second rail unit 222 in the first moving mechanism 220. Further, the support base 230 is moved along the X-axis direction when the movable base 223 operates in the first moving mechanism 220. Further, the support base 230 is rotated about the axis parallel to the Z-axis direction as the center line by the movement of the movable base 223 in the first moving mechanism 220. As described above, the support base 230 is attached to the apparatus frame 210 so as to be movable along the X-axis direction and the Y-axis direction and to be rotatable about an axis parallel to the Z-axis direction.

  The laser output unit 300 is attached to the apparatus frame 210. The laser condensing unit 500 is attached to the apparatus frame 210 via the second moving mechanism 240. The laser condensing unit 500 is moved along the Z-axis direction by the operation of the second moving mechanism 240. As described above, the laser condensing unit 500 is attached to the apparatus frame 210 so as to be movable along the Z-axis direction with respect to the laser output unit 300.

  The control unit 600 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and the like. The control unit 600 controls the operation of each unit of the laser processing apparatus 200.

  As an example, in the laser processing apparatus 200, a modified region is formed inside the processing target 1 along each scheduled cutting line 5a, 5b (see FIG. 8) as follows.

  First, the processing object 1 is supported on the support base 230 so that the back surface 1b (see FIG. 8) of the processing object 1 becomes a laser light incident surface, and each scheduled cutting line 5a of the processing object 1 is in the X-axis direction. In a direction parallel to Subsequently, the laser condensing unit is moved by the second moving mechanism 240 so that the condensing point of the laser light L is located at a position separated from the laser light incident surface of the processing object 1 by a predetermined distance inside the processing object 1. 500 is moved. Subsequently, the focusing point of the laser beam L relatively moves along each scheduled cutting line 5a while the distance between the laser beam incident surface of the workpiece 1 and the focusing point of the laser beam L is maintained constant. Be made. As a result, a modified region is formed in the workpiece 1 along each planned cutting line 5a.

  When the formation of the modified region along each scheduled cutting line 5a is completed, the support base 230 is rotated by the first moving mechanism 220, and each scheduled cutting line 5b of the workpiece 1 is parallel to the X-axis direction. To suit. Subsequently, the laser condensing unit is moved by the second moving mechanism 240 so that the condensing point of the laser light L is located at a position separated from the laser light incident surface of the processing object 1 by a predetermined distance inside the processing object 1. 500 is moved. Subsequently, the focusing point of the laser beam L relatively moves along each scheduled cutting line 5b while the distance between the laser beam incident surface of the workpiece 1 and the focusing point of the laser beam L is maintained constant. Be made. As a result, a modified region is formed in the workpiece 1 along each planned cutting line 5b.

  Thus, in the laser processing apparatus 200, the direction parallel to the X-axis direction is the processing direction (scanning direction of the laser light L). The relative movement of the condensing point of the laser beam L along each planned cutting line 5a and the relative movement of the condensing point of the laser beam L along each planned cutting line 5b are the first moving mechanism. This is implemented by moving the support base 230 along the X-axis direction by 220. Further, the relative movement of the condensing point of the laser beam L between each scheduled cutting line 5a and the relative movement of the condensing point of the laser beam L between each scheduled cutting line 5b are performed by the first moving mechanism 220. This is implemented by moving the support base 230 along the Y-axis direction.

  As shown in FIG. 9, the laser output unit 300 includes a mounting plate 301, a cover 302, and a plurality of mirrors 303 and 304. Further, the laser output unit 300 includes a laser oscillator 400, a shutter 320, a λ / 2 wavelength plate unit (output adjustment unit, polarization direction adjustment unit) 330, and a polarizing plate unit (output adjustment unit, polarization direction adjustment unit) 340. A beam expander (laser beam collimating unit) 350 and a mirror unit 360.

  The mounting plate 301 supports a plurality of mirrors 303 and 304, a laser oscillator 400, a shutter 320, a λ / 2 wavelength plate unit 330, a polarizing plate unit 340, a beam expander 350, and a mirror unit 360. The plurality of mirrors 303 and 304, the laser oscillator 400, the shutter 320, the λ / 2 wavelength plate unit 330, the polarizing plate unit 340, the beam expander 350, and the mirror unit 360 are attached to the main surface 301 a of the attachment plate 301. The mounting plate 301 is a plate-like member and can be attached to and detached from the apparatus frame 210 (see FIG. 7). The laser output unit 300 is attached to the apparatus frame 210 via the attachment plate 301. That is, the laser output unit 300 can be attached to and detached from the apparatus frame 210.

  The cover 302 includes a plurality of mirrors 303 and 304, a laser oscillator 400, a shutter 320, a λ / 2 wavelength plate unit 330, a polarizing plate unit 340, a beam expander 350, and a mirror unit 360 on the main surface 301 a of the mounting plate 301. Covering. The cover 302 can be attached to and detached from the mounting plate 301.

  The laser oscillator 400 oscillates linearly polarized laser light L in the X-axis direction. As will be described later, the laser oscillator 400 is configured as a MOPA (Master Oscillator Power Amplifier) type fiber laser. Therefore, in the laser oscillator 400, the output of the laser beam L is switched at a high speed by switching the output of the seed light LD (Laser Diode / semiconductor laser) and the pumping LD. The wavelength of the laser light L emitted from the laser oscillator 400 is included in any of the wavelength bands of 500 to 550 nm, 1000 to 1150 nm, or 1300 to 1400 nm, for example. Laser light L having a wavelength band of 500 to 550 nm is suitable for internal absorption laser processing for a substrate made of sapphire, for example. The laser light L in each wavelength band of 1000 to 1150 nm and 1300 to 1400 nm is suitable for internal absorption laser processing for a substrate made of silicon, for example. The polarization direction of the laser light L emitted from the laser oscillator 400 is, for example, a direction parallel to the Y-axis direction. The laser light L emitted from the laser oscillator 400 is reflected by the mirror 303 and enters the shutter 320 along the Y-axis direction.

  The shutter 320 opens and closes the optical path of the laser light L by a mechanical mechanism. As described above, ON / OFF switching of the output of the laser light L from the laser output unit 300 is performed by switching ON / OFF of the output of the laser light L in the laser oscillator 400, but a shutter 320 is provided. For example, the laser output L is prevented from being unexpectedly emitted from the laser output unit 300. The laser light L that has passed through the shutter 320 is reflected by the mirror 304 and sequentially enters the λ / 2 wavelength plate unit 330 and the polarizing plate unit 340 along the X-axis direction.

  The λ / 2 wavelength plate unit 330 and the polarizing plate unit 340 function as an output adjusting unit that adjusts the output (light intensity) of the laser light L. Further, the λ / 2 wavelength plate unit 330 and the polarizing plate unit 340 function as a polarization direction adjusting unit that adjusts the polarization direction of the laser light L. Details of these will be described later. The laser light L that has sequentially passed through the λ / 2 wavelength plate unit 330 and the polarizing plate unit 340 enters the beam expander 350 along the X-axis direction.

  The beam expander 350 collimates the laser light L while adjusting the diameter of the laser light L. The laser light L that has passed through the beam expander 350 enters the mirror unit 360 along the X-axis direction.

  The mirror unit 360 includes a support base 361 and a plurality of mirrors 362 and 363. The support base 361 supports a plurality of mirrors 362 and 363. The support base 361 is attached to the attachment plate 301 so that the position can be adjusted along the X-axis direction and the Y-axis direction. The mirror 362 reflects the laser light L that has passed through the beam expander 350 in the Y-axis direction. The mirror 362 is attached to the support base 361 so that the reflection surface thereof can be adjusted in angle around an axis parallel to the Z axis, for example. The mirror 363 reflects the laser light L reflected by the mirror 362 in the Z-axis direction. The mirror 363 is attached to the support base 361 so that the reflection surface thereof can be angle-adjusted around an axis parallel to the X-axis, for example, and the position can be adjusted along the Y-axis direction. The laser light L reflected by the mirror 363 passes through the opening 361a formed in the support base 361 and enters the laser condensing unit 500 (see FIG. 7) along the Z-axis direction. That is, the emission direction of the laser light L from the laser output unit 300 is coincident with the moving direction of the laser condensing unit 500.

  As described above, each of the mirrors 362 and 363 has a mechanism for adjusting the angle of the reflecting surface. In the mirror unit 360, the position adjustment of the support base 361 with respect to the mounting plate 301, the position adjustment of the mirror 363 with respect to the support base 361, and the angle adjustment of the reflection surfaces of the mirrors 362 and 363 are performed. The position and angle of the optical axis of the emitted laser light L are matched with the laser condensing unit 500. That is, the plurality of mirrors 362 and 363 are configured to adjust the optical axis of the laser light L emitted from the laser output unit 300.

  The laser condensing unit 500 condenses the laser light L that has passed through the mirror unit 360 onto the workpiece 1. As shown in FIG. 10, the laser condensing unit 500 has a housing 501. A second moving mechanism 240 is attached to the side surface of the housing 501. The casing 501 is provided with a cylindrical light incident portion 501a so as to face the opening 361a of the mirror unit 360 in the Z-axis direction. The light incident part 501 a causes the laser light L emitted from the laser output part 300 to enter the housing 501. The mirror unit 360 and the light incident unit 501a are moved when the laser condensing unit 500 is moved along the Z-axis direction by the second moving mechanism 240 (that is, the laser condensing unit 500 is moved with respect to the mirror unit 360). They are separated from each other by a distance that does not contact each other (when moved).

  Although not shown, a mirror, a reflective spatial light modulator, and a 4f lens unit are arranged in the housing 501. The housing 501 is provided with a condensing lens unit (condensing optical system), a driving mechanism, and a pair of distance measuring sensors.

  The laser light L that has traveled into the housing 501 along the Z-axis direction is reflected by the mirror in a direction parallel to the XY plane, and enters the reflective spatial light modulator. The reflective spatial light modulator reflects the laser light L along the XY plane while modulating the laser light L reflected by the mirror. The reflective spatial light modulator is, for example, a reflective liquid crystal (LCOS) spatial light modulator (SLM).

  Here, in a plane parallel to the XY plane, the optical axis of the laser light L incident on the reflective spatial light modulator and the optical axis of the laser light L emitted from the reflective spatial light modulator are acute angles. An angle α is formed. This is because the incident angle and the reflection angle of the laser beam L are suppressed to suppress the decrease in diffraction efficiency, and the performance of the reflective spatial light modulator is sufficiently exhibited. In the reflective spatial light modulator, the laser light L is reflected as P-polarized light. This is because, in the case where liquid crystal is used for the light modulation layer of the reflective spatial light modulator, the plane parallel to the plane including the optical axis of the laser beam L entering and exiting the reflective spatial light modulator is used. This is because when the liquid crystal is aligned so that the liquid crystal molecules are tilted, phase modulation is performed on the laser light L in a state where the rotation of the polarization plane is suppressed (see, for example, Japanese Patent No. 3878758). .

  The 4f lens unit constitutes a double-sided telecentric optical system in which the reflection surface of the reflective spatial light modulator and the entrance pupil surface of the condenser lens unit are in an imaging relationship. As a result, the image of the laser beam L on the reflecting surface of the reflective spatial light modulator (the image of the laser beam L modulated by the reflective spatial light modulator) is transferred to the entrance pupil plane of the condenser lens unit ( Imaging).

  The condenser lens unit is attached to the housing 501 via a drive mechanism. The condensing lens unit condenses the laser light L onto the workpiece 1 (see FIG. 7) supported by the support base 230. The driving mechanism moves the condenser lens unit along the Z-axis direction by the driving force of the piezoelectric element.

  The pair of distance measuring sensors are attached to the housing 501 so as to be positioned on both sides of the condenser lens unit in the X-axis direction. Each distance measuring sensor emits distance measuring light (for example, laser light) to the laser light incident surface of the workpiece 1 (see FIG. 7) supported by the support base 230, and the laser light incident surface. By detecting the distance measuring light reflected by, displacement data of the laser light incident surface of the workpiece 1 is acquired.

In the laser processing apparatus 200, as described above, the direction parallel to the X-axis direction is the processing direction (scanning direction of the laser light L). Therefore, when the condensing point of the laser beam L is moved relatively along the respective cutting scheduled lines 5a and 5b, the distance measurement that precedes the condensing lens unit among the pair of distance measuring sensors. The sensor acquires displacement data of the laser light incident surface of the workpiece 1 along the respective scheduled cutting lines 5a and 5b. Then, the driving mechanism has a condensing lens based on the displacement data acquired by the distance measuring sensor so that the distance between the laser light incident surface of the workpiece 1 and the condensing point of the laser light L is maintained constant. The unit is moved along the Z-axis direction.
[Λ / 2 wavelength plate unit and polarizing plate unit]

  As described above, in the laser condensing unit 500, the optical axis of the laser light L incident on the reflective spatial light modulator and the laser light emitted from the reflective spatial light modulator in a plane parallel to the XY plane. The optical axis of L forms an angle α that is an acute angle. On the other hand, as shown in FIG. 9, in the laser output unit 300, the optical path of the laser light L is set along the X-axis direction or the Y-axis direction. Therefore, in the laser output unit 300, the λ / 2 wavelength plate unit 330 and the polarizing plate unit 340 are not only used as an output adjustment unit that adjusts the output of the laser light L, but also a polarization direction that adjusts the polarization direction of the laser light L. It is also necessary to function as an adjustment unit.

  As shown in FIG. 11, the λ / 2 wavelength plate unit 330 includes a holder 331 and a λ / 2 wavelength plate 332. The holder 331 holds the λ / 2 wavelength plate 332 so that the λ / 2 wavelength plate 332 can be rotated about an axis (first axis) XL parallel to the X-axis direction as a center line. The λ / 2 wavelength plate 332 rotates the polarization direction by an angle 2θ with the axis XL as a center line when the laser beam L is incident with the polarization direction inclined by an angle θ with respect to its optical axis (for example, fast axis). Thus, the laser beam L is emitted (see FIG. 12A).

  The polarizing plate unit 340 includes a holder 341, a polarizing plate (polarizing member) 342, and an optical path correction plate (optical path correcting member) 343. The holder 341 holds the polarizing plate 342 and the optical path correction plate 343 so that the polarizing plate 342 and the optical path correction plate 343 can rotate together with the axis line (second axis) XL as a center line. The light incident surface and light output surface of the polarizing plate 342 are inclined by a predetermined angle (for example, Brewster angle). When the laser light L is incident, the polarizing plate 342 transmits the P-polarized component of the laser light L that matches the polarization axis of the polarizing plate 342, and reflects or absorbs the S-polarized component of the laser light L (FIG. 12). (See (b)). The light incident surface and the light emitting surface of the optical path correction plate 343 are inclined to the opposite side to the light incident surface and the light emitting surface of the polarizing plate 342. The optical path correction plate 343 returns the optical axis of the laser beam L off the axis XL by passing through the polarizing plate 342 to the axis XL.

  In the polarizing plate unit 340, the polarizing plate 342 and the optical path correction plate 343 are integrally rotated with the axis XL as the center line, and as shown in FIG. 12B, polarized light is polarized in a direction parallel to the Y-axis direction. The polarization axis of the plate 342 is tilted by an angle α. Thereby, the polarization direction of the laser light L emitted from the polarizing plate unit 340 is inclined by an angle α with respect to the direction parallel to the Y-axis direction. As a result, the laser beam L is reflected as P-polarized light in the reflective spatial light modulator of the laser condensing unit 500.

  12B, the polarization direction of the laser light L incident on the polarizing plate unit 340 is adjusted, and the light intensity of the laser light L emitted from the polarizing plate unit 340 is adjusted. Adjustment of the polarization direction of the laser light L incident on the polarizing plate unit 340 is performed by rotating the λ / 2 wavelength plate 332 around the axis XL in the λ / 2 wavelength plate unit 330 as shown in FIG. As shown, the angle of the optical axis of the λ / 2 wavelength plate 332 with respect to the polarization direction of the laser light L incident on the λ / 2 wavelength plate 332 (for example, the direction parallel to the Y-axis direction) is adjusted. Is done.

As described above, in the laser output unit 300, the λ / 2 wavelength plate unit 330 and the polarizing plate unit 340 are not only used as an output adjustment unit (in the above-described example, an output attenuation unit) that adjusts the output of the laser light L. Also, it functions as a polarization direction adjusting unit that adjusts the polarization direction of the laser light L.
[Laser Oscillator of Embodiment]

  As shown in FIG. 13, the laser oscillator 400 includes a seed light emitting unit 410, a preamplifier unit (first amplifier unit) 420, a power amplifier unit (second amplifier unit) 430, a laser beam emitting unit 440, It has. The laser oscillator 400 is configured as a MOPA fiber laser.

  The seed light emitting unit 410 has a seed light LD (seed light source) 411. The seed light LD 411 is driven by a pulse generator, and oscillates the laser light L which is seed light. The laser light L emitted from the seed light LD411 is propagated to the preamplifier unit 420 by the fiber F1 and the fiber cable FC1. The laser beam L has a predetermined wavelength (for example, 1098 nm).

  The preamplifier unit 420 includes an isolator 421, a cladding mode stripper 422, a first laser fiber 423, for example, one first excitation LD (first excitation light source) 424, and a combiner 425. In the preamplifier unit 420, the laser light L is propagated to the first laser fiber 423 through the fibers F3, F4, and F5, amplified by the first laser fiber 423, and then propagated to the power amplifier unit 430 through the fibers F6 and F7. It is done.

  The first excitation LD 424 emits first excitation light PL1 having a predetermined wavelength (for example, 915 nm) for exciting the first laser fiber 423. The first excitation light PL1 emitted from the first excitation LD 424 is propagated to the combiner 425 through the fiber F21. The combiner 425 couples the first excitation light PL1 to the fiber F6 between the fiber F6 and the fiber F7. The first excitation light PL1 coupled to the fiber F6 is incident on the first laser fiber 423, and travels in the direction opposite to the traveling direction of the laser light L in the first laser fiber 423. Thus, the preamplifier unit 420 employs a backward pumping configuration.

  The first laser fiber 423 amplifies the laser light L by propagating the laser light L emitted from the seed light emitting unit 410 while being excited by the first excitation light PL1. The isolator 421 blocks return light (light traveling toward the seed light emitting unit 410) between the fiber F3 and the fiber F4. The cladding mode stripper 422 removes the first excitation light PL1 that has not been absorbed by the first laser fiber 423 between the fiber F5 and the first laser fiber 423.

  The power amplifier unit 430 includes an isolator 431, a bandpass filter 432, a cladding mode stripper 433, a second laser fiber 434, and a plurality of (here, six) second pumping LDs (second pumping light sources) 435, for example. , And a combiner 436. In the power amplifier section 430, the laser light L is propagated to the second laser fiber 434 through the fibers F8, F9, and F10, amplified by the second laser fiber 434, and then the laser light emitting section through the fibers F11, F12, and F13. 440 is propagated.

  Each second excitation LD 435 emits second excitation light PL2 having a predetermined wavelength (for example, 915 nm) for exciting the second laser fiber 434. The second pumping light PL2 emitted from each second pumping LD 435 is propagated to the combiner 436 by the fiber F22. The combiner 436 couples the second excitation light PL2 to the fiber F11 between the fiber F11 and the fiber F12. The second pumping light PL2 coupled to the fiber F11 enters the second laser fiber 434, and travels in the direction opposite to the traveling direction of the laser light L in the second laser fiber 434. Thus, the power amplifier unit 430 employs a backward pumping configuration.

  The second laser fiber 434 amplifies the laser light L by propagating the laser light L amplified by the preamplifier unit 420 while being excited by the second excitation light PL2. The isolator 431 blocks return light (light traveling toward the preamplifier unit 420) between the fiber F7 and the fiber F8. The band pass filter 432 removes ASE (Amplified Spontaneous Emission) light generated in the preamplifier unit 420. The clad mode stripper 433 removes the second pumping light PL2 that has not been absorbed by the second laser fiber 434 between the fiber F10 and the second laser fiber 434.

  The laser beam emitting unit 440 includes a collimator 441 and an isolator (optical component) 442. The collimator 441 collimates the laser beam L emitted from the emission end of the fiber F13. The isolator 442 blocks return light (light traveling in the laser oscillator 400). The exit end of the isolator 442 constitutes an exit end 443 that emits the laser light L amplified by the power amplifier unit 430 to the outside.

  In the laser oscillator 400, the output of the laser light L emitted from the seed light emitting unit 410, the output of the laser light L amplified by the preamplifier unit 420, the output of the laser light L amplified by the power amplifier unit 430, and the power amplifier The output of the return light at the unit 430 is monitored. Further, the output of the first excitation light PL1 emitted from the first excitation LD 424 and the output of the second excitation light PL2 emitted from the plurality of second excitation LDs 435 are monitored.

  A part of the laser light L emitted from the seed light emitting unit 410 enters the fiber F31 via a coupler 451 provided between the fibers F4 and F5, and enters the PD (light receiving element) 452 by the fiber F31. Propagated and detected by PD452. The output of the laser light L emitted from the seed light emitting unit 410 is monitored based on a signal outputted from the PD 452.

  A part of the laser light L amplified by the preamplifier unit 420 is incident on the fiber F32 via the coupler 454 provided between the fibers F9 and F10, and is propagated to the PD (light receiving element) 455 by the fiber F32. And detected by PD455. The output of the laser light L amplified by the preamplifier unit 420 is monitored based on the signal output from the PD 455.

  A part of the laser light L amplified by the power amplifier unit 430 enters the fiber F34 via the coupler 458 provided between the fibers F12 and F13, and propagates to the PD (light receiving element) 459 by the fiber F34. And detected by PD459. The output of the laser beam L amplified by the power amplifier unit 430 is monitored based on the signal output from the PD 459.

  When return light (light traveling toward the bandpass filter 432) is generated in the second laser fiber 434 of the power amplifier unit 430, a part of the return light is incident on the fiber F33 via the coupler 454, and the fiber F33. Is propagated to PD456 and detected by PD456. The output of the return light from the power amplifier unit 430 is monitored based on the signal output from the PD 456.

  A part of the first pumping light PL1 emitted from the first pumping LD 424 is incident on the PD 453 disposed at the junction between the fiber F6 and the first laser fiber 423, and is detected by the PD 453. The output of the first excitation light PL1 emitted from the first excitation LD 424 is monitored based on the signal output from the PD 453.

  A part of the second excitation light PL2 emitted from the plurality of second excitation LDs 435 is incident on the PD 457 disposed at the junction between the fiber F11 and the second laser fiber 434 and detected by the PD 457. The output of the second excitation light PL2 emitted from the plurality of second excitation LDs 435 is monitored based on the signal output from the PD 457.

  As shown in FIG. 14, the laser oscillator 400 includes a first support plate 461, a second support plate 462, and a housing 470. A mounting base 471 is provided in the housing 470. The housing 470 includes a first portion 470a and a second portion 470b. The second part 470b is detachable from the first part 470a. As an example, the first portion 470a has a rectangular parallelepiped shape, and the mounting base 471 is configured by the lower wall of the first portion 470a. The second portion 470b has a rectangular parallelepiped shape and is attached to the upper surface of the first portion 470a.

  The first portion 470a accommodates the preamplifier unit 420, the power amplifier unit 430, and the laser beam emitting unit 440. The second portion 470b accommodates the seed light emitting portion 410. The fiber cable FC1 for propagating the laser light L from the seed light emitting unit 410 to the preamplifier unit 420 is stretched between the first portion 470a and the second portion 470b (see FIG. 9).

  The first support plate 461 and the second support plate 462 are accommodated in the first portion 470a so as to face each other (that is, the thickness directions of the first support plate 461 and the second support plate 462 are mutually different). The first support plate 461 and the second support plate 462 are disposed so as to coincide with each other when viewed from the thickness direction. The second support plate 462 is disposed on the upper side with respect to the mounting base 471. The first support plate 461 is disposed on the upper side with respect to the second support plate 462. More specifically, the surface 471a of the mounting base 471 and the back surface 462b of the second support plate 462 are opposed to each other through a space, and the surface 462a of the second support plate 462 and the back surface 461b of the first support plate 461 are opposed to each other. Are opposed to each other through a space. The first support plate 461 and the second support plate 462 are each supported by a column (not shown) or the like.

  The laser oscillator 400 includes the mounting plate 301 via the mounting base 471 in a state where the back surface 471b of the mounting base 471 is in contact with the main surface 301a of the mounting plate 301 and the emission end 443 of the laser light emitting unit 440 faces the mirror 303. (See FIG. 9). That is, the laser oscillator 400 can be attached to and detached from the mounting plate 301 (and thus the apparatus frame 210).

  As shown in FIG. 15 (see FIG. 13), the surface 461a of the first support plate 461 includes a fiber connector 401, an isolator 421, a coupler 451, a cladding mode stripper 422, a first laser fiber 423, a PD 453, a combiner 425, An isolator 431, a band pass filter 432, and a coupler 454 are attached. The fiber connector 401 connects the fiber cable FC1 and the fiber F3 to each other. The first laser fiber 423 is held by a fiber reel (not shown). The fiber F10 that propagates the laser light L to the second laser fiber 434 passes from the surface 461a of the first support plate 461 to the surface 462a of the second support plate 462 via a notch 461c formed in the first support plate 461. It is extended.

  As shown in FIGS. 16 and 17, the front surface 462 a, the back surface 462 b, and the side surface 462 c of the second support plate 462 are formed by the second laser fiber 434 and the plurality of second excitation LDs 435 of the power amplifier unit 430 and the preamplifier unit 420. This is an arrangement surface of the first excitation LD 424 and the like. 17 is a view of the configuration of the back surface 462b side of the second support plate 462 viewed from the front surface 462a side of the second support plate 462. In FIG. 17, the configuration of the front surface 462a side of the second support plate 462 is shown. It is omitted.

  As shown in FIG. 16 (see FIG. 13), a cladding mode stripper 433, a second laser fiber 434, a PD457, a combiner 436, a coupler 458, and a PD459 are attached to the surface 462a of the second support plate 462. The second laser fiber 434 is held by a fiber reel (not shown). The fiber F13 for propagating the laser light L to the laser light emitting portion 440 extends from the surface 462a of the second support plate 462 to the surface 471a of the mounting base 471 through a notch 462e formed in the second support plate 462. doing.

  PDs 452, 455, 456 and a first excitation LD 424 are attached to the side surface 462c of the second support plate 462. A fiber F31 for propagating a part of the laser light L to the PD 452, a fiber F32 for propagating a part of the laser light L to the PD 455, and a fiber F33 for propagating the return light to the PD 456 include the first support plate 461 and the housing 470. It extends from the surface 461a of the first support plate 461 to the side surface 462c of the second support plate 462 via a gap formed between the inner surface of the first portion 470a. The fiber F21 for propagating the first excitation light PL1 to the combiner 425 is a side surface 462c of the second support plate 462 via a gap formed between the first support plate 461 and the inner surface of the first portion 470a of the housing 470. To the surface 461a of the first support plate 461.

  As shown in FIG. 17, a plurality of second excitation LDs 435 are attached to the back surface 462 b of the second support plate 462. The fiber F22 for propagating the second excitation light PL2 to the combiner 436 extends from the back surface 462b of the second support plate 462 to the surface 462a of the second support plate 462 through a notch 462d formed in the second support plate 462. Exist.

  As shown in FIGS. 16 and 17, a pipe 462 f is embedded in the second support plate 462. Cooling water (refrigerant) W is circulated and supplied to the pipe 462f. Thereby, the 2nd support plate 462 functions as a cooling plate in which the flow path of the cooling water W was provided. In the laser oscillator 400, the first laser fiber 423 of the preamplifier unit 420 is disposed on the first support plate 461, while the second laser fiber 434 and the plurality of second pumping LDs 435 of the power amplifier unit 430 and the preamplifier unit are included. 420 first excitation LDs 424 are arranged on the second support plate 462. As a result, the second laser fiber 434 and the plurality of second pumping LDs 435 in the power amplifier unit 430 and the first pumping LD 424 in the preamplifier unit 420 are cooled.

  As shown in FIG. 18, a support member 402, a collimator 441, and an isolator 442 are attached to the surface 471 a of the attachment base 471. That is, the laser beam emitting portion 440 is disposed on the mounting base 471. As shown in FIG. 19, a recess 471 c is formed on the back surface 471 b of the mounting base 471. Processing boards 403 and 404 for signals output from the PDs 452, 455, 456, 457, and 459, and a memory board 405 are attached to the inner surface of the recess 471c. 19 is a view of the configuration of the mounting base 471 on the back surface 471b side as viewed from the surface 471a side of the mounting base 471. In FIG. 19, the configuration of the mounting base 471 on the surface 471a side is omitted.

As shown in FIG. 20, the support member 402 has a support surface 402a. A fiber F13 for propagating the laser beam L from the power amplifier unit 430 to the laser beam emitting unit 440 is disposed on the support surface 402a. More specifically, the support surface 402a extends from immediately below the notch 462e formed in the second support plate 462 (see FIGS. 16 and 18) toward the incident end of the collimator 441. It is inclined so as to be located on the lower side as it approaches.
[Operation and Effect of Embodiment]

  The laser oscillator 400 includes a seed light emitting unit 410 having a seed light LD 411 that emits laser light L that is seed light, a first laser fiber 423 that propagates the laser light L emitted from the seed light emitting unit 410, and a first laser fiber 423. A preamplifier unit 420 having a first excitation LD 424 that emits a first excitation light PL1 for exciting one laser fiber 423; a second laser fiber 434 that propagates the laser light L amplified by the preamplifier unit 420; A power amplifier unit 430 having a second pumping LD 435 that emits second pumping light PL2 for pumping the laser fiber 434 and an emitting end 443 that emits the laser light L amplified by the power amplifier unit 430 to the outside are provided. A laser beam emitting part 440 having an isolator 442 and a mounting base 471, Pump unit 420 includes a housing 470 that houses the power amplifier 430 and the laser beam emitting unit 440, a. The isolator 442 provided with the emission end 443 is disposed on the mounting base 471.

  In the laser oscillator 400, the seed light emitting unit 410, the preamplifier unit 420, the power amplifier unit 430, and the laser light emitting unit 440 are accommodated in the housing 470. Therefore, the laser oscillator 400 can be easily handled. In addition, an isolator 442 provided with an emission end 443 is disposed on a mounting base 471 included in the housing 470. As a result, for example, when the laser oscillator 400 is mounted on the laser processing apparatus 200 via the mounting base 471, vibration is generated in the laser processing apparatus 200, or the operating environment temperature of the laser processing apparatus 200 is changed. Even if the housing 470 or the like is deformed, the position and angle of the emission end 443 are difficult to shift. Therefore, the position and angle of the optical axis of the laser beam L emitted from the laser oscillator 400 to the outside are stabilized. In particular, when a modified region is formed inside the workpiece 1, since severe irradiation conditions of the laser beam L are required as compared with the case where ablation processing, welding processing, or the like is performed, a laser is required. It is desirable that the position and angle of the optical axis of the laser beam L emitted from the oscillator 400 be stable.

  In the laser oscillator 400, at least the first laser fiber 423 is disposed on the first support plate 461 accommodated in the housing 470, and at least the second laser fiber is disposed on the second support plate 462 accommodated in the housing 470. 434 is arranged. Accordingly, the first laser fiber 423 and the second laser fiber 434 can be appropriately supported in the housing 470.

  In the laser oscillator 400, the flow path of the cooling water W is provided in the second support plate 462, and the first excitation LD 424 and the second excitation LD 435 are disposed on the second support plate 462. Thereby, in addition to the second laser fiber 434 that easily generates heat, the first pumping LD 424 and the second pumping LD 435 that easily generate heat can be efficiently cooled in a small space.

  In the laser oscillator 400, the second support plate 462 is disposed above the mounting base 471, and the first support plate 461 is disposed above the second support plate 462. Thereby, the footprint of the laser oscillator 400 can be reduced while simplifying the arrangement of the optical path of the laser beam L from the preamplifier unit 420 to the laser beam emitting unit 440 via the power amplifier unit 430.

  In the laser oscillator 400, the housing 470 is detachable from the first part 470 a that houses the preamplifier unit 420, the power amplifier unit 430, and the laser beam emitting unit 440, and the seed light emitting unit 410. And a second portion 470b that accommodates the container. Thereby, the seed light emission part 410 can be easily maintained by attaching and detaching the 2nd part 470b with respect to the 1st part 470a.

  In the laser oscillator 400, a fiber F13 for propagating the laser beam L from the power amplifier unit 430 to the laser beam emitting unit 440 is disposed on the support surface 402a of the support member 402 provided on the mounting base 471. As a result, the fiber F13 for propagating the amplified laser light L can be appropriately supported (while maintaining the required bending diameter), so that a situation in which the laser light L leaks from the fiber F13 can be prevented. it can.

  In the laser processing apparatus 200, since the laser condensing unit 500 is attached to the apparatus frame 210 so as to be movable, it is not necessary to move the laser oscillator 400. Therefore, the stability of the position and angle of the optical axis of the laser beam L emitted from the laser oscillator 400 can be more reliably maintained, and the workpiece 1 is irradiated with the laser beam L under severe irradiation conditions. be able to.

  The laser oscillator 400 includes a seed light emitting unit 410 having a seed light LD 411 that emits laser light L that is seed light, a first laser fiber 423 that propagates the laser light L emitted from the seed light emitting unit 410, And a preamplifier unit 420 having a first excitation LD 424 for emitting a first excitation light PL1 for exciting the first laser fiber 423, a second laser fiber 434 for propagating the laser light L amplified by the preamplifier unit 420, and A power amplifier unit 430 having a second pumping LD 435 that emits second pumping light PL2 for pumping the second laser fiber 434, and an emitting end 443 that emits the laser light L amplified by the power amplifier unit 430 to the outside. A laser beam emitting portion 440 having an isolator 442 provided, and a first laser fiber 423 arranged in the first Comprises a lifting plate 461, a second laser fiber 434, first excitation LD424 and a second excitation LD435 is arranged, a second support plate 462 flow path of the cooling water W is provided, a. The first support plate 461 and the second support plate 462 face each other (that is, the thickness directions of the first support plate 461 and the second support plate 462 coincide with each other and are viewed from the thickness direction). In some cases, the first support plate 461 and the second support plate 462 are arranged so as to overlap each other.

  In the laser oscillator 400, in addition to the cooling of the second laser fiber 434 that is likely to generate heat, the cooling of the first excitation LD 424 and the second excitation LD 435 that is likely to generate heat is the second in which the flow path of the cooling water W is provided. Implemented by support plate 462. In addition, the first support plate 461 on which the first laser fiber 423 is disposed is disposed so as to face the second support plate 462. Thereby, the preamplifier unit 420 and the power amplifier unit 430 which are laser amplification units can be reduced in size.

  In the laser oscillator 400, the front surface 462a, the back surface 462b, and the side surface 462c of the second support plate 462 serve as arrangement surfaces for the second laser fiber 434, the first excitation LD 424, the second excitation LD 435, and the like. Thereby, the front surface 462a, the back surface 462b, and the side surface 462c of the second support plate 462 functioning as a cooling plate can be effectively used, and the enlargement of the second support plate 462 can be reliably suppressed.

  In the laser oscillator 400, a seed light emitting unit 410, a preamplifier unit 420, a power amplifier unit 430, a laser beam emitting unit 440, a first support plate 461 and a second support plate 462 are housed in a housing 470. Thereby, handling of the laser oscillator 400 becomes easy.

  In the laser oscillator 400, each of the PDs 452, 455, and 459 for detecting a part of the laser light L is disposed on a second support plate 462 that functions as a cooling plate. Thereby, each PD452, 455, 459 can be operated at an appropriate temperature. In particular, when Si (silicon) photodiodes are used for the PDs 452, 455, and 459, and the wavelength of the laser light L to be detected is 1098 nm, the PDs 452, 455, and 459 are arranged on the second support plate 462. It is important to maintain a stable sensitivity for a wavelength of 1098 nm. When a Si photodiode is used for the PD 453 and the wavelength of the first excitation light PL1 to be detected is 915 nm, even if the temperature of the PD 453 rises slightly, stable sensitivity to the wavelength of 915 nm is obtained. Therefore, the necessity to arrange the PD 453 on the second support plate 462 is low.

  The laser processing apparatus 200 includes a laser oscillator 400 that can reduce the size of the laser amplification unit. Thereby, the enlargement of the laser processing apparatus 200 can be suppressed.

  In the laser output unit 300, the laser oscillator 400, the λ / 2 wavelength plate unit 330, the polarizing plate unit 340, and the mirror unit 360 are disposed on the main surface 301 a of the mounting plate 301. Accordingly, the laser output unit 300 can be easily attached to and detached from the laser processing apparatus 200 by attaching and detaching the attachment plate 301 to the apparatus frame 210 of the laser processing apparatus 200. The optical path of the laser light L from the laser oscillator 400 to the mirror unit 360 via the λ / 2 wavelength plate unit 330 and the polarizing plate unit 340 is set along a plane parallel to the main surface 301 a of the mounting plate 301. The mirror unit 360 emits the laser light L to the outside along the direction intersecting the plane. Thereby, for example, when the emission direction of the laser beam L is along the vertical direction, the laser output unit 300 is lowered, so that the laser output unit 300 can be easily attached to and detached from the laser processing apparatus 200. . Further, the mirror unit 360 includes mirrors 362 and 363 for adjusting the optical axis of the laser light L. Thereby, when the laser output part 300 is attached to the apparatus frame 210 of the laser processing apparatus 200, the position and angle of the optical axis of the laser light L incident on the laser condensing part 500 can be adjusted. As described above, the laser output unit 300 can be easily attached to and detached from the laser processing apparatus 200.

If the optical component provided with the emission end 443 in the laser beam emission part 440 is arranged on the attachment base 471, for example, when the laser oscillator 400 is mounted on the laser processing apparatus 200 via the attachment base 471, Even if vibration occurs in the laser processing apparatus 200 or the housing 470 or the like is deformed due to a change in the operating environment temperature of the laser processing apparatus 200, the position and angle of the emission end 443 are difficult to shift. Therefore, if the optical component provided with the emitting end 443 in the laser beam emitting portion 440 is disposed on the mounting base 471, the position and angle of the optical axis of the laser beam L emitted from the laser oscillator 400 to the outside are stabilized. . As an example, as shown in FIG. 21A, even if the preamplifier unit 420 and the power amplifier unit 430 are arranged in parallel along the horizontal direction on the laser beam emitting unit 440, or FIG. ) And (c), even if the laser beam emitting section 440, the preamplifier section 420, and the power amplifier section 430 are arranged side by side in the horizontal direction, the laser beam emitting section 440 is provided with an emitting end 443. If the optical component is arranged on the mounting base 471, the position and angle of the optical axis of the laser beam L emitted from the laser oscillator 400 to the outside are stabilized.
[Modification]

  As mentioned above, although embodiment of this invention was described, this invention is not limited to embodiment mentioned above. For example, in the above-described embodiment, the configuration of backward pumping is employed in the preamplifier unit 420. However, in the first laser fiber 423, the first pumping light PL1 travels in the same direction as the traveling direction of the laser light L. A configuration may be employed. Similarly, in the above-described embodiment, the configuration of backward pumping is employed in the power amplifier unit 430. However, in the second laser fiber 434, the second pumping light PL2 travels in the same direction as the traveling direction of the laser light L. An excitation configuration may be employed.

  The laser oscillator of the present invention is not limited to the laser processing apparatus 200 that forms the modified region inside the workpiece 1 but is mounted on a laser processing apparatus that performs other laser processing such as ablation processing and welding processing. It is also possible to do.

  In the laser processing apparatus 200, a polarizing member other than the polarizing plate 342 may be provided in the polarizing plate unit 340. As an example, a cube-shaped polarizing member may be used instead of the polarizing plate 342 and the optical path correction plate 343. The cube-shaped polarizing member is a member having a rectangular parallelepiped shape, and the side surfaces of the member facing each other are a light incident surface and a light emitting surface, and a layer having a polarizing plate function is provided therebetween. It is a member.

  In the laser processing apparatus 200, the axis line around which the λ / 2 wave plate 332 rotates and the axis line around which the polarizing plate 342 rotates do not have to coincide with each other.

  In the laser processing apparatus 200, the laser output unit 300 has the mirrors 362 and 363 for adjusting the optical axis of the laser light L emitted from the laser output unit 300. It suffices to have at least one mirror for adjusting the optical axis of the laser beam L.

  DESCRIPTION OF SYMBOLS 1 ... Processing object, 200 ... Laser processing apparatus, 210 ... Apparatus frame, 230 ... Support stand (support part), 301 ... Mounting plate, 330 ... (lambda) / 2 wavelength plate unit (output adjustment part), 340 ... Polarizing plate unit (Output adjustment unit) 360 ... Mirror unit, 362, 363 ... Mirror, 400 ... Laser oscillator, 402 ... Support member, 402a ... Support surface, 410 ... Seed light emitting part, 411 ... Seed light LD (seed light source), 420 ... Preamplifier part (first amplifier part), 423 ... First laser fiber, 424 ... First excitation LD (first excitation light source), 430 ... Power amplifier part (second amplifier part), 434 ... Second laser fiber, 435 ... second excitation LD (second excitation light source), 440 ... laser light emitting part, 442 ... isolator (optical component), 443 ... emission end, 461 ... first support plate, 462 ... first Support plate, 470 ... housing, 470a ... first part, 470b ... second part, 471 ... mounting base, 500 ... laser focusing part, FC1 ... fiber cable, F13 ... fiber, L ... laser light, PL1 ... first Excitation light, PL2 ... second excitation light, W ... cooling water (refrigerant).

Claims (7)

A seed light emitting unit having a seed light source for emitting laser light as seed light;
A first amplifier unit having a first laser fiber that propagates the laser light emitted from the seed light emitting unit, and a first excitation light source that emits first excitation light for exciting the first laser fiber;
A second amplifier unit including a second laser fiber that propagates the laser light amplified by the first amplifier unit, and a second excitation light source that emits second excitation light for exciting the second laser fiber;
A laser beam emitting unit having an optical component provided with an emitting end for emitting the laser beam amplified by the second amplifier unit to the outside;
A housing having a mounting base and housing the seed light emitting unit, the first amplifier unit, the second amplifier unit, and the laser beam emitting unit;
The optical component is a laser oscillator disposed on the mounting base. A first support plate housed in the housing and at least disposed with the first laser fiber;
2. The laser oscillator according to claim 1, further comprising: a second support plate housed in the housing and having at least the second laser fiber disposed thereon. The second support plate is provided with a refrigerant flow path,
The laser oscillator according to claim 2, wherein the first excitation light source and the second excitation light source are arranged on the second support plate. The second support plate is disposed above the mounting base;
The laser oscillator according to claim 2, wherein the first support plate is disposed on an upper side with respect to the second support plate. The housing is
A first portion housing the first amplifier section, the second amplifier section and the laser beam emitting section;
The laser oscillator according to any one of claims 1 to 4, further comprising: a second part that is detachable from the first part and accommodates the seed light emitting unit.   6. The support member according to claim 1, further comprising a support member provided on the mounting base and having a support surface on which a fiber for propagating the laser beam from the second amplifier unit to the laser beam emitting unit is disposed. The laser oscillator described. A laser oscillator according to any one of claims 1 to 6;
An output adjustment unit for adjusting the output of the laser beam emitted from the emission end of the laser oscillator;
A mirror unit having a mirror for adjusting the optical axis of the laser beam that has passed through the output adjusting unit;
The mounting base of the laser oscillator, the output adjusting unit and the mounting plate to which the mirror unit is mounted;
A device frame to which the mounting plate is attached;
A support portion attached to the apparatus frame and supporting a workpiece;
A laser processing apparatus, comprising: a laser condensing unit that is attached to the apparatus frame so as to be movable with respect to the mirror unit, and condenses the laser light that has passed through the mirror unit onto the object to be processed.

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