JP7258091B2 - Laser oscillator and laser processing equipment - Google Patents

Description

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

In order to cut a workpiece such as a semiconductor wafer into a plurality of chips, there is known a laser processing apparatus that forms a modified region inside the workpiece along grid-like cutting lines ( For example, see Patent Document 1).

Japanese Patent No. 5456510

In the laser oscillator mounted on the laser processing apparatus as described above, it is desirable that the footprint is small, but the laser amplification section tends to be larger than the laser light emission section.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a laser oscillator capable of reducing the size of a laser amplifier, and a laser processing apparatus having such a laser oscillator.

A laser oscillator according to the present invention includes a seed light emitting section having a seed light source for emitting laser light as seed light, a first laser fiber for propagating the laser light emitted from the seed light emitting section, and a first laser fiber. A first amplifier section having a first pumping light source that emits first pumping light for pumping, a second laser fiber that propagates the laser light amplified by the first amplifier section, and for pumping the second laser fiber a second amplifier unit having a second pumping light source that emits the second pumping light of; , a first support plate on which the first laser fiber is arranged, a second support plate on which the second laser fiber, the first excitation light source and the second excitation light source are arranged, and a coolant flow path is provided; The first support plate and the second support plate are arranged to face each other.

In this laser oscillator, in addition to cooling the second laser fiber, which easily generates heat, the first excitation light source and the second excitation light source, which tend to generate heat, are cooled by the second support plate provided with coolant flow paths. be implemented. Moreover, the first support plate on which the first laser fiber is arranged faces the second support plate (that is, the thickness directions of the first support plate and the second support plate are aligned with each other and the thickness are arranged such that the first support plate and the second support plate overlap each other when viewed from the vertical direction. As a result, it is possible to reduce the size of the first amplifier section and the second amplifier section, which are laser amplifier sections.

In the laser oscillator of the present invention, the front surface and the rear surface of the second support plate may be surfaces on which the second laser fiber, the first excitation light source and the second excitation light source are arranged. According to this, it is possible to effectively utilize the front surface and the rear surface of the second support plate, and to suppress the enlargement of the second support plate.

In the laser oscillator of the present invention, the side surface of the second support plate may be the placement surface. According to this, the side surface of the second support plate can be effectively used to more reliably suppress the increase in size of the second support plate.

The laser oscillator of the present invention may further include a housing that accommodates the seed light emitting section, the first amplifier section, the second amplifier section, the laser light emitting section, the first support plate, and the second support plate. This facilitates handling of the laser oscillator.

The laser oscillator of the present invention includes a first housing that houses a seed light emitting section, a first amplifier section, a second amplifier section, a first support plate, and a second support plate, and a second housing that houses a laser light emitting section. and a fiber cable stretched between the first housing and the second housing for propagating the laser light from the second amplifier section to the laser light emitting section. According to this, the degree of freedom in disposing the laser light emitting section with respect to the first amplifier section and the second amplifier section, which are laser amplifier sections, is improved.

The laser oscillator of the present invention has at least a position between the seed light source and the first laser fiber, a position between the first laser fiber and the second laser fiber, and a position between the second laser fiber and the optical component. At one position, it may further comprise at least one light receiving element for detecting part of the laser light, the at least one light receiving element being arranged on the second support plate. According to this, the light receiving element can be operated at an appropriate temperature.

The laser processing apparatus of the present invention comprises the laser oscillator, an output adjusting section for adjusting the output of the laser light emitted from the output end of the laser oscillator, and an optical axis for adjusting the optical axis of the laser light that has passed through the output adjusting section. A mirror unit having a mirror, a mounting plate to which a laser oscillator, an output adjustment section and a mirror unit are attached, a device frame to which the mounting plate is attached, a support portion attached to the device frame for supporting a workpiece, a laser condensing section 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.

Since this laser processing apparatus includes a laser oscillator that can reduce the size of the laser amplifying section, it is possible to suppress an increase in the size of the laser processing apparatus.

ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to provide the laser oscillator which can achieve size reduction of a laser amplification part, and the laser processing apparatus provided with such a laser oscillator.

1 is a schematic configuration diagram of a laser processing apparatus used for forming a modified region; FIG. FIG. 4 is a plan view of a workpiece to be processed to form a modified region; FIG. 3 is a cross-sectional view along line III-III of the workpiece of FIG. 2; FIG. 2 is a plan view of an object to be processed after laser processing; FIG. 5 is a cross-sectional view of the workpiece of FIG. 4 taken along line VV; FIG. 5 is a cross-sectional view of the workpiece of FIG. 4 taken along line VI-VI; 1 is a perspective view of a laser processing apparatus according to a first embodiment; FIG. 8 is a perspective view of an object to be processed attached to a support base of the laser processing apparatus of FIG. 7; FIG. FIG. 8 is a cross-sectional view of the laser output portion along the XY plane of FIG. 7; FIG. 8 is a perspective view of part of a laser output unit and a laser condensing unit in the laser processing apparatus of FIG. 7; FIG. 10 is a diagram showing an optical arrangement relationship between a λ/2 wavelength plate unit and a polarizing plate unit in the laser output section of FIG. 9; 10A is a diagram showing the polarization directions in a λ/2 wavelength plate unit of the laser output section in FIG. 9, and FIG. 10B is a diagram showing the polarization directions in the polarizing plate unit of the laser output section in FIG. 9. FIG. It is a figure which shows the whole structure of the laser oscillator of 1st Embodiment. 1 is a front view of a laser oscillator according to a first embodiment; FIG. 15 is a diagram showing the internal configuration of the laser oscillator of FIG. 14; FIG. 15 is a diagram showing the internal configuration of the laser oscillator of FIG. 14; FIG. 15 is a diagram showing the internal configuration of the laser oscillator of FIG. 14; FIG. 15 is a diagram showing the internal configuration of the laser oscillator of FIG. 14; FIG. 15 is a diagram showing the internal configuration of the laser oscillator of FIG. 14; FIG. 15 is a diagram showing the internal configuration of the laser oscillator of FIG. 14; FIG. (a) is a diagram showing the overall configuration of a first modification of the laser oscillator of the first embodiment, (b) is a diagram showing the overall configuration of a second modification of the laser oscillator of the first embodiment, (c) is a diagram showing the overall configuration of a third modification of the laser oscillator of the first embodiment. It is a front view of the laser oscillator of 2nd Embodiment. 23 is a diagram showing the internal configuration of the laser oscillator of FIG. 22; FIG. 23 is a diagram showing the internal configuration of the laser oscillator of FIG. 22; FIG. 23 is a diagram showing the internal configuration of the laser oscillator of FIG. 22; FIG.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In each figure, the same or corresponding parts are denoted by the same reference numerals, and redundant explanations are omitted.

In the laser processing apparatus (described later) of the first embodiment, a modified region is formed in the object along the planned cutting line by focusing the laser beam on the object. Therefore, first, the formation of the modified region will be described with reference to FIGS. 1 to 6. FIG.

As shown in FIG. 1, the laser processing apparatus 100 includes a laser light source 101 that pulse-oscillates a laser beam L, and a dichroic mirror 103 arranged to change the direction of the optical axis (optical path) of the laser beam L by 90°. , and a condensing lens 105 for condensing the laser light L. The laser processing apparatus 100 also includes a support table 107 for supporting the workpiece 1 irradiated with the laser beam L condensed by the condensing lens 105, and a stage 111 for moving the support table 107. , a laser light source control unit 102 for controlling the laser light source 101 to adjust the output, pulse width, pulse waveform, etc. 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 beam L emitted from the laser light source 101 has its optical axis direction changed by 90° by the dichroic mirror 103, and enters the workpiece 1 placed on the support table 107. The light is condensed by the condensing lens 105 . Along with this, the stage 111 is moved, and the workpiece 1 is relatively moved along the planned cutting line 5 with respect to the laser beam L. As a result, a modified region along the line to cut 5 is formed in the workpiece 1 . Although the stage 111 is moved here to relatively move the laser light L, the condenser lens 105 may be moved, or both of them may be moved.

As the object 1 to be processed, a plate-like member (for example, a substrate, a wafer, etc.) including a semiconductor substrate made of a semiconductor material, a piezoelectric substrate made of a piezoelectric material, or the like is used. As shown in FIG. 2, a line to cut 5 for cutting the object 1 is set on the object 1 . The planned cutting line 5 is a straight imaginary line. When forming the modified region inside the object 1, as shown in FIG. It is relatively moved along the planned line 5 (that is, in the direction of arrow A in FIG. 2). As a result, as shown in FIGS. 4, 5 and 6, a modified region 7 is formed in the workpiece 1 along the line to cut 5, and the modified region formed along the line to cut 5 7 becomes the cutting starting point region 8 .

The condensing point P is a point where the laser light L is condensed. The line to cut 5 is not limited to a straight line, but may be a curved line, a three-dimensional combination of these lines, or a coordinate-designated line. The planned cutting line 5 may be a line actually drawn on the surface 3 of the workpiece 1 instead of a virtual line. The modified region 7 may be formed continuously or intermittently. The modified regions 7 may be linear or dotted, and the point is that the modified regions 7 should be formed at least inside the object 1 to be processed. 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 beam incident surface for forming the modified region 7 is not limited to the front surface 3 of the object 1 to be processed, and may be the rear surface of the object 1 to be processed.

Incidentally, when forming the modified region 7 inside the object 1, the laser light L is transmitted through the object 1 and near the condensing point P located inside the object 1. especially absorbed. As a result, the modified region 7 is formed in the object 1 (that is, internal absorption laser processing). In this case, since the surface 3 of the object 1 hardly absorbs the laser beam L, the surface 3 of the object 1 is not melted. On the other hand, when forming the modified region 7 on the surface 3 of the workpiece 1, the laser beam L is particularly absorbed in the vicinity of the focal point P located on the surface 3, melted and removed from the surface 3. , holes and grooves are formed (surface absorption laser processing).

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

The melt-processed region, the refractive index changing region, the region where the density of the modified region 7 is changed compared to the density of the non-modified region, and the region where lattice defects are formed, are further divided into the inside of these regions and the modified region. The interface between the region 7 and the non-modified region may contain cracks (cracks, microcracks). The included cracks may extend over the entire surface of the modified region 7, or may be formed only in a portion or in a plurality of portions. The workpiece 1 includes a substrate made of a crystalline material having a crystalline structure. For example, the workpiece 1 includes a substrate made 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 crystalline material may be either an anisotropic crystal or an isotropic crystal. In addition, the workpiece 1 may include a substrate made of an amorphous material having an amorphous structure (amorphous structure), such as a glass substrate.

In the embodiment, the modified region 7 can be formed by forming a plurality of modified spots (processing marks) along the line to cut 5 . In this case, a plurality of modified spots gather to form the modified region 7 . A modified spot is a modified portion formed by one pulse shot of pulsed laser light (that is, one pulse of laser irradiation: laser shot). Modified spots include crack spots, melted spots, refractive index change spots, or a mixture of at least one of these. Regarding the modified spot, considering the required cutting accuracy, the required flatness of the cut surface, the thickness, type, crystal orientation, etc. of the workpiece 1, the size and the length of the generated crack are appropriately adjusted. can be controlled. Further, in the embodiment, a modified spot can be formed as the modified region 7 along the line to cut 5 .
[Laser processing apparatus of the first embodiment]

Next, the laser processing apparatus of the first embodiment will be explained. In the following description, directions perpendicular to each other in the horizontal plane are the X-axis direction and the Y-axis direction, and the vertical direction is the Z-axis direction.
[Overall Configuration of Laser Processing Device]

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

The first moving mechanism 220 is attached to the device frame 210 . The first moving mechanism 220 has 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 a 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 a 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 is rotatable about an axis parallel to the Z-axis direction.

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 (light receiving elements such as photodiodes, light emitting elements such as laser diodes, or circuit elements formed as circuits) on the surface side of a substrate made of a semiconductor material such as silicon. It is formed in a matrix. When the object to be processed 1 is supported by the support table 230, as shown in FIG. side) is affixed. The support table 230 supports the object 1 by holding the frame 11 with a clamp and sucking the film 12 with a vacuum chuck table. On the support table 230, a plurality of parallel lines to cut 5a and a plurality of lines to cut 5b parallel to each other are set in a grid pattern so as to pass between adjacent functional elements. be.

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

The laser output section 300 is attached to the device frame 210 . The laser focusing unit 500 is attached to the device frame 210 via the second moving mechanism 240 . The laser focusing unit 500 is moved along the Z-axis direction by the operation of the second moving mechanism 240 . In this manner, the laser condensing section 500 is attached to the device frame 210 so as to be movable along the Z-axis direction with respect to the laser output section 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 section 600 controls the operation of each section of the laser processing apparatus 200 .

As an example, in the laser processing apparatus 200, a modified region is formed inside the object 1 along the lines to cut 5a and 5b (see FIG. 8) as follows.

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

Thus, in the laser processing apparatus 200, the direction parallel to the X-axis direction is the processing direction (the scanning direction of the laser beam L). The relative movement of the focal point of the laser light L along each line to cut 5a and the relative movement of the focal point of the laser light L along each line to cut 5b are performed by the first moving mechanism This is done by moving the support base 230 along the X-axis direction by means of 220 . In addition, the relative movement of the focal point of the laser light L between the lines to cut 5a and the relative movement of the focal point of the laser light L between the lines to cut 5b are performed by the first moving mechanism 220. It is implemented by moving the support base 230 along the Y-axis direction.

As shown in FIG. 9, the laser output section 300 has a mounting plate 301, a cover 302 and a plurality of mirrors 303,304. 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 .

Mounting plate 301 supports a plurality of mirrors 303 , 304 , laser oscillator 400 , shutter 320 , λ/2 wavelength plate unit 330 , polarizer unit 340 , beam expander 350 and mirror unit 360 . A plurality of mirrors 303 and 304 , laser oscillator 400 , shutter 320 , λ/2 wavelength plate unit 330 , polarizing plate unit 340 , beam expander 350 and mirror unit 360 are attached to main surface 301 a of attachment plate 301 . The mounting plate 301 is a plate-like member, and is detachable from the apparatus frame 210 (see FIG. 7). The laser output section 300 is attached to the device frame 210 via an attachment plate 301 . In other words, the laser output section 300 is detachable with respect to the device frame 210 .

Cover 302 covers a plurality of mirrors 303 and 304, laser oscillator 400, shutter 320, λ/2 wavelength plate unit 330, polarizing plate unit 340, beam expander 350 and mirror unit 360 on main surface 301a of mounting plate 301. covering. The cover 302 is removable from the mounting plate 301 .

The laser oscillator 400 pulse-oscillates linearly polarized laser light L along 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 light L is switched ON/OFF at high speed by switching ON/OFF 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 one of the wavelength bands of 500 to 550 nm, 1000 to 1150 nm, or 1300 to 1400 nm, for example. A laser beam L in a wavelength band of 500 to 550 nm is suitable for internal absorption laser processing of a substrate made of sapphire, for example. Laser light L in wavelength bands of 1000 to 1150 nm and 1300 to 1400 nm is suitable for internal absorption laser processing of a substrate made of silicon, for example. The polarization direction of the laser light L emitted from the laser oscillator 400 is parallel to the Y-axis direction, for example. A laser beam 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. ON/OFF switching of the output of the laser light L from the laser output unit 300 is performed by switching ON/OFF the output of the laser light L in the laser oscillator 400 as described above. As a result, the laser light L is prevented from being emitted unexpectedly from the laser output unit 300, for example. 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 adjustment section that adjusts the output (light intensity) of the laser light L. Also, the λ/2 wavelength plate unit 330 and the polarizing plate unit 340 function as a polarization direction adjusting section that adjusts the polarization direction of the laser light L. FIG. 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 is incident on the beam expander 350 along the X-axis direction.

The beam expander 350 parallelizes the laser light L while adjusting the diameter of the laser light L. FIG. The laser light L that has passed through the beam expander 350 is incident on the mirror unit 360 along the X-axis direction.

The mirror unit 360 has a support base 361 and a plurality of mirrors 362 and 363 . A support base 361 supports a plurality of mirrors 362 and 363 . The support base 361 is attached to the mounting plate 301 so as to be positionally adjustable 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 its reflecting surface can be angularly adjusted around an axis parallel to the Z-axis. 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 its reflective surface is angularly adjustable around an axis parallel to the X-axis and positionally adjustable along the Y-axis. The laser beam L reflected by the mirror 363 passes through an opening 361a formed in the support base 361 and enters the laser focusing unit 500 (see FIG. 7) along the Z-axis direction. In other words, the direction in which the laser beam L is emitted by the laser output section 300 matches the moving direction of the laser condensing section 500 .

As described above, each mirror 362, 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 reflecting surfaces of the mirrors 362 and 363 are performed. The position and angle of the optical axis of the emitted laser light L are aligned with the laser condensing section 500 . In other words, the multiple mirrors 362 and 363 are configured to adjust the optical axis of the laser light L emitted from the laser output section 300 .

The laser condensing unit 500 converges the laser light L that has passed through the mirror unit 360 onto the workpiece 1 . As shown in FIG. 10 , the laser focusing section 500 has a housing 501 . A second moving mechanism 240 is attached to the side surface of the housing 501 . The housing 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 portion 501 a causes the laser light L emitted from the laser output portion 300 to enter the housing 501 . The mirror unit 360 and the light incident part 501a are separated when the second moving mechanism 240 moves the laser focusing part 500 along the Z-axis direction (that is, when the laser focusing part 500 moves relative to the mirror unit 360). are separated from each other by a distance that they do not touch each other (when moved).

Although illustration is omitted, a mirror, a reflective spatial light modulator, and a 4f lens unit are arranged in the housing 501 . In addition, a condensing lens unit (condensing optical system), a driving mechanism, and a pair of distance measuring sensors are attached to the housing 501 .

The laser beam L that has traveled into the housing 501 along the Z-axis direction is reflected by a mirror in a direction parallel to the XY plane and enters the reflective spatial light modulator. The reflective spatial light modulator modulates the laser light L reflected by the mirror and reflects the laser light L along the XY plane. The reflective spatial light modulator is, for example, a reflective liquid crystal (LCOS: Liquid Crystal on Silicon) spatial light modulator (SLM: Spatial Light Modulator).

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 form an acute angle. form an angle α. This is because the incident angle and the reflection angle of the laser light L are suppressed to suppress the deterioration of the diffraction efficiency, and the performance of the reflective spatial light modulator is fully exhibited. Also, in the reflective spatial light modulator, the laser light L is reflected as P-polarized light. This is because, when liquid crystal is used for the light modulation layer of the reflective spatial light modulator, in a plane parallel to the plane containing the optical axis of the laser light L entering and exiting the reflective spatial light modulator. This is because when the liquid crystal is oriented so that the liquid crystal molecules are tilted, the laser light L is phase-modulated while the rotation of the plane of polarization is suppressed (see, for example, Japanese Patent No. 3878758). .

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

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 table 230 . The driving mechanism moves the condensing lens unit along the Z-axis direction by the driving force of the piezoelectric element.

A pair of ranging 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 light for distance measurement (for example, laser light) to the laser light incident surface of the workpiece 1 (see FIG. 7) supported by the support table 230, and detects the laser light incident surface. Displacement data of the laser beam incident surface of the workpiece 1 is acquired by detecting the light for distance measurement reflected by .

In the laser processing apparatus 200, as described above, the direction parallel to the X-axis direction is the processing direction (the scanning direction of the laser beam L). Therefore, when the condensing point of the laser beam L is relatively moved along each of the planned cutting lines 5a and 5b, the distance measuring sensor of the pair of distance measuring sensors that precedes the condenser lens unit relatively A sensor acquires the displacement data of the laser beam incident surface of the workpiece 1 along each of the planned cutting lines 5a and 5b. Then, in order to maintain a constant distance between the laser beam incident surface of the workpiece 1 and the focal point of the laser beam L, the driving mechanism moves the condenser lens based on the displacement data acquired by the distance measuring sensor. Move the unit along the Z-axis.
[λ/2 Wave Plate Unit and Polarizing Plate Unit]

As described above, in the laser focusing 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 are arranged in a plane parallel to the XY plane. and the optical axis of L form an acute angle α. On the other hand, as shown in FIG. 9, in the laser output section 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 section 300, the λ/2 wavelength plate unit 330 and the polarizing plate unit 340 are used not only as an output adjustment section for adjusting the output of the laser light L, but also as a polarization direction for adjusting the polarization direction of the laser light L. It also needs to function as a coordinator.

As shown in FIG. 11, the λ/2 wavelength plate unit 330 has 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 rotate about an axis (first axis) XL parallel to the X-axis direction. The λ/2 wavelength plate 332 rotates the polarization direction by an angle 2θ about the axis line XL when the laser light L is incident with the polarization direction inclined by an angle θ with respect to the optical axis (for example, the fast axis). to emit laser light L (see FIG. 12(a)).

The polarizing plate unit 340 has a holder 341 , a polarizing plate (polarizing member) 342 , and an optical path correction plate (optical path correction member) 343 . The holder 341 holds the polarizing plate 342 and the optical path correcting plate 343 so that the polarizing plate 342 and the optical path correcting plate 343 are integrally rotatable about the axis (second axis) XL as the center line. The light incident surface and the light exit surface of the polarizing plate 342 are inclined by a predetermined angle (eg Brewster's angle). When the laser light L is incident on the polarizing plate 342, 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 (see FIG. 12). (b)). The light incident surface and the light exit surface of the optical path correction plate 343 are inclined opposite to the light incident surface and the light exit surface of the polarizing plate 342 . The optical path correction plate 343 returns the optical axis of the laser light L that has deviated from 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 about the axis XL, and as shown in FIG. The polarization axis of plate 342 is tilted by angle α. As a result, the polarization direction of the laser light L emitted from the polarizing plate unit 340 is tilted 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 at the reflective spatial light modulator of the laser focusing unit 500 .

Further, as shown in FIG. 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 wave plate 332 about the axis line XL in the λ/2 wave plate unit 330, as shown in FIG. 12(a). By adjusting the angle of the optical axis of the λ/2 wave plate 332 with respect to the polarization direction of the laser light L incident on the λ/2 wave plate 332 (for example, the direction parallel to the Y-axis direction), be done.

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

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

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

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

The first pumping LD 424 emits first pumping light PL<b>1 with a predetermined wavelength (for example, 915 nm) for exciting the first laser fiber 423 . The first pumping light PL1 emitted from the first pumping LD 424 is propagated to the combiner 425 through the fiber F21. Combiner 425 couples first pump light PL1 to fiber F6 between fibers F6 and F7. The first pumping light PL1 coupled to the fiber F6 enters 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 . In this way, preamplifier section 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 section 410 while being excited by the first pumping light PL1. The isolator 421 blocks return light (light traveling toward the seed light emitting section 410 side) between the fibers F3 and F4. The cladding mode stripper 422 removes the first pumping 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, for example, a plurality (here, six) of second pumping LDs (second pumping light sources) 435. , and a combiner 436 . In the power amplifier section 430, the laser light L is propagated through the fibers F8, F9, and F10 to the second laser fiber 434, amplified by the second laser fiber 434, and then transmitted through the fibers F11, F12, and F13 to the laser light emission section. 440 is propagated.

Each second pumping LD 435 emits second pumping light PL2 of a predetermined wavelength (915 nm, for example) for exciting the second laser fiber 434 . 2nd pumping light PL2 emitted from each 2nd pumping LD435 is propagated to the combiner 436 by the fiber F22. A combiner 436 couples the second pumping light PL2 to the fiber F11 between the fibers F11 and F12. The second excitation light PL2 coupled to the fiber F11 enters the second laser fiber 434 and travels in the second laser fiber 434 in the direction opposite to the traveling direction of the laser light L. As shown in FIG. In this way, the power amplifier section 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 section 420 while being excited by the second pumping light PL2. The isolator 431 blocks return light (light traveling toward the preamplifier section 420) between the fibers F7 and F8. A bandpass filter 432 removes ASE (Amplified Spontaneous Emission) light generated in the preamplifier section 420 . The cladding 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 light emitting section 440 has a collimator 441 and an isolator (optical component) 442 . The collimator 441 collimates the laser light L emitted from the emission end of the fiber F13. The isolator 442 blocks return light (light traveling into the laser oscillator 400). An emission end of the isolator 442 constitutes an emission end 443 that emits the laser light L amplified by the power amplifier section 430 to the outside.

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

A part of the laser light L emitted from the seed light emitting part 410 enters the fiber F31 through the coupler 451 provided between the fiber F4 and the fiber F5, and is transmitted to the PD (light receiving element) 452 by the fiber F31. It is propagated and detected by PD452. The output of the laser light L emitted from the seed light emitting section 410 is monitored based on the signal output from the PD 452 .

A part of the laser light L amplified by the preamplifier section 420 enters the fiber F32 through the coupler 454 provided between the fiber F9 and the fiber F10, and propagates to the PD (light receiving element) 455 through the fiber F32. detected by PD455. The output of laser light L amplified by preamplifier section 420 is monitored based on the signal output from PD 455 .

Part of the laser light L amplified by the power amplifier unit 430 enters the fiber F34 via the coupler 458 provided between the fiber F12 and the fiber F13, and propagates to the PD (photodetector) 459 through the fiber F34. detected by PD459. The output of laser light L amplified by power amplifier section 430 is monitored based on the signal output from PD 459 .

When return light (light traveling toward the band-pass filter 432 side) is generated in the second laser fiber 434 of the power amplifier unit 430, part of the return light enters the fiber F33 via the coupler 454 and enters the fiber F33. is propagated to PD 456 by and detected by PD 456 . The output of the returned light from the power amplifier section 430 is monitored based on the signal output from the PD 456 .

Part of the first excitation light PL1 emitted from the first excitation LD424 is incident on the PD453 arranged at the junction between the fiber F6 and the first laser fiber 423 and detected by the PD453. The output of the first pumping light PL1 emitted from the first pumping LD424 is monitored based on the signal output from the PD453.

A part of the second pumping light PL2 emitted from the plurality of second pumping LDs 435 is incident on the PD 457 arranged at the junction between the fiber F11 and the second laser fiber 434 and detected by the PD 457 . The output of the second pumping light PL2 emitted from the multiple second pumping 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. As shown in FIG. A mounting base 471 is provided on the housing 470 . The housing 470 has a first portion 470a and a second portion 470b. The second portion 470b is detachable from the first portion 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 470 a accommodates the preamplifier section 420 , the power amplifier section 430 and the laser light emitting section 440 . The second portion 470b accommodates the seed light emitting portion 410. As shown in FIG. A fiber cable FC1 for propagating the laser light L from the seed light emitting section 410 to the preamplifier section 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 are arranged such that the first support plate 461 and the second support plate 462 overlap each other when viewed from the thickness direction. The second support plate 462 is arranged above the mounting base 471 . The first support plate 461 is arranged above the second support plate 462 . More specifically, the front surface 471a of the mounting base 471 and the rear surface 462b of the second support plate 462 are opposed to each other with a space therebetween, and the front surface 462a of the second support plate 462 and the rear surface 461b of the first support plate 461 face each other. are opposed to each other through a space. The first support plate 461 and the second support plate 462 are respectively supported by columns (not shown) or the like.

The laser oscillator 400 is attached to the mounting plate 301 via the mounting base 471 in a state in which the rear surface 471b of the mounting base 471 is in contact with the principal surface 301a of the mounting plate 301 and the emission end 443 of the laser beam emitting portion 440 is directed toward the mirror 303. (see Figure 9). In other words, the laser oscillator 400 is attachable/detachable to/from the mounting plate 301 (and thus the device 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 bandpass filter 432 and a coupler 454 are attached. A 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 for propagating the laser light L to the second laser fiber 434 extends from the surface 461a of the first support plate 461 to the surface 462a of the second support plate 462 through the notch 461c formed in the first support plate 461. extended.

As shown in FIGS. 16 and 17, a front surface 462a, a back surface 462b and a side surface 462c of the second support plate 462 are the second laser fiber 434 and the plurality of second pumping LDs 435 of the power amplifier section 430 and the preamplifier section 420. 1 is an arrangement surface of the first pumping LD 424 and the like. 17 is a view of the configuration of the rear surface 462b side of the second support plate 462 as viewed from the front surface 462a side of the second support plate 462. In FIG. omitted.

As shown in FIG. 16 (see FIG. 13), a cladding mode stripper 433, a second laser fiber 434, a PD 457, a combiner 436, a coupler 458 and a PD 459 are attached to the surface 462a of the second support plate 462. FIG. The second laser fiber 434 is held by a fiber reel (not shown). The fiber F13 that propagates 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. are doing.

PDs 452 , 455 , 456 and a first excitation LD 424 are attached to a side surface 462 c of the second support plate 462 . A fiber F31 that propagates part of the laser light L to the PD 452, a fiber F32 that propagates a part of the laser light L to the PD 455, and a fiber F33 that propagates the return light to the PD 456 are connected between 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 pumping light PL1 to the combiner 425 passes through the gap formed between the first support plate 461 and the inner surface of the first portion 470a of the housing 470 to the side surface 462c of the second support plate 462. to the surface 461 a of the first support plate 461 .

As shown in FIG. 17 , a plurality of second excitation LDs 435 are attached to the rear surface 462 b of the second support plate 462 . The fiber F22 that propagates the second pumping light PL2 to the combiner 436 extends from the rear surface 462b of the second support plate 462 to the front surface 462a of the second support plate 462 via a notch 462d formed in the second support plate 462. exist.

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

As shown in FIG. 18, the support member 402, the collimator 441 and the isolator 442 are attached to the surface 471a of the attachment base 471. As shown in FIG. That is, the laser light emitting portion 440 is arranged on the mounting base 471 . As shown in FIG. 19, a concave portion 471c is formed on the rear surface 471b of the mounting base 471. As shown in FIG. Signal processing boards 403 and 404 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 rear surface 471b side of the mounting base 471 as viewed from the front surface 471a side of the mounting base 471, and the configuration of the front surface 471a side of the mounting base 471 is omitted in FIG.

As shown in FIG. 20, the support member 402 has a support surface 402a. A fiber F13 for propagating the laser light L from the power amplifier section 430 to the laser light emitting section 440 is arranged on the supporting surface 402a. More specifically, the support surface 402a extends from directly 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 that it is located on the lower side as it approaches .
[Actions and effects of the first embodiment]

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

In the laser oscillator 400, in addition to cooling the second laser fiber 434 that easily generates heat, the cooling of the first pumping LD 424 and the second pumping LD 435 that easily generate heat is performed by cooling the second laser fiber 434 in which the cooling water W flow path is provided. Implemented by support plate 462 . Moreover, the first support plate 461 on which the first laser fiber 423 is arranged is arranged so as to face the second support plate 462 . As a result, the size of the preamplifier section 420 and the power amplifier section 430, which are laser amplifier sections, can be reduced.

In the laser oscillator 400, the surface 462a, the back surface 462b and the side surface 462c of the second support plate 462 are arranged surfaces for the second laser fiber 434, the first pumping LD424, the second pumping LD435 and the like. As a result, the front surface 462a, the rear surface 462b, and the side surfaces 462c of the second support plate 462, which function as cooling plates, can be effectively used to reliably prevent the second support plate 462 from increasing in size.

In laser oscillator 400 , seed light emitting section 410 , preamplifier section 420 , power amplifier section 430 , laser light emitting section 440 , first support plate 461 and second support plate 462 are housed in housing 470 . This facilitates handling of the laser oscillator 400 .

In laser oscillator 400, PDs 452, 455, and 459 that detect part of laser light L are arranged on second support plate 462 that functions as a cooling plate. Thereby, each PD 452, 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. is important to maintain stable sensitivity to the 1098 nm wavelength. 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, the sensitivity is stable with respect to the wavelength of 915 nm. is maintained, there is less need to place the PD 453 on the second support plate 462 .

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

In addition, the laser oscillator 400 includes a seed light emitting section 410 having a seed light LD 411 for emitting a laser light L as seed light, a first laser fiber 423 for propagating the laser light L emitted from the seed light emitting section 410, and a preamplifier section 420 having a first pumping LD 424 that emits the first pumping light PL1 for pumping the first laser fiber 423, a second laser fiber 434 that propagates the laser light L amplified by the preamplifier section 420, and A power amplifier section 430 having a second pumping LD 435 that emits a second pumping light PL2 for pumping a second laser fiber 434, and an emission end 443 that emits laser light L amplified by the power amplifier section 430 to the outside. A laser light emitting section 440 having an isolator 442 provided thereon, and a housing 470 having a mounting base 471 and housing the seed light emitting section 410, the preamplifier section 420, the power amplifier section 430, and the laser light emitting section 440. Prepare. The isolator 442 provided with the output end 443 is arranged on the mounting base 471 .

In the laser oscillator 400 , the seed light emitting section 410 , the preamplifier section 420 , the power amplifier section 430 and the laser light emitting section 440 are accommodated in the housing 470 . Therefore, handling of the laser oscillator 400 is easy. Also, an isolator 442 provided with an output end 443 is arranged on a mounting base 471 of 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, vibrations may occur in the laser processing apparatus 200, or due to changes in the operating environment temperature of the laser processing apparatus 200. Even if the housing 470 or the like is deformed due to deformation, the position and angle of the output end 443 are unlikely to shift. Therefore, the position and angle of the optical axis of the laser light L emitted from the laser oscillator 400 are stabilized. Particularly in the case of forming a modified region inside the object 1, severer irradiation conditions for the laser beam L are required than in the case of performing ablation processing, welding processing, or the like. It is desirable that the position and angle of the optical axis of the laser light L emitted from the oscillator 400 to the outside be stable.

In the laser oscillator 400, at least the first laser fiber 423 is arranged in the first support plate 461 housed in the housing 470, and at least the second laser fiber 423 is arranged in the second support plate 462 housed in the housing 470. 434 are arranged. Thereby, the first laser fiber 423 and the second laser fiber 434 can be properly supported inside the housing 470 .

In the laser oscillator 400 , a flow path for cooling water W is provided in the second support plate 462 , and the first pumping LD 424 and the second pumping LD 435 are arranged on the second support plate 462 . This makes it possible to efficiently cool the first pumping LD 424 and the second pumping LD 435, which tend to generate heat, in addition to the second laser fiber 434, which tends to generate heat, in a small space.

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

In the laser oscillator 400, the housing 470 includes a first portion 470a that houses the preamplifier section 420, the power amplifier section 430, and the laser light emitting section 440, and is detachable from the first section 470a. and a second portion 470b that accommodates the . Thus, by attaching and detaching the second portion 470b to and from the first portion 470a, maintenance of the seed light emitting portion 410 can be facilitated.

In the laser oscillator 400 , the fiber F<b>13 that propagates the laser light L from the power amplifier section 430 to the laser light emitting section 440 is arranged on the support surface 402 a of the support member 402 provided on the mounting base 471 . As a result, the fiber F13 that propagates the amplified laser light L can be properly supported (while maintaining the required bending diameter), so that the laser light L can be prevented from leaking from the fiber F13. can.

In the laser processing apparatus 200, since the laser condensing section 500 is mounted on the apparatus frame 210 so as to be movable, the laser oscillator 400 does not need to be moved. Therefore, the stability of the position and angle of the optical axis of the laser light L emitted from the laser oscillator 400 to the outside can be more reliably maintained, and the laser light L can be applied to the workpiece 1 under severe irradiation conditions. be able to.

Also, in the laser output section 300 , the laser oscillator 400 , the λ/2 wavelength plate unit 330 , the polarizing plate unit 340 and the mirror unit 360 are arranged on the main surface 301 a of the mounting plate 301 . Accordingly, by attaching and detaching the mounting plate 301 to and from the device frame 210 of the laser processing device 200 , the laser output section 300 can be easily attached and detached to and from the laser processing device 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 301a of the mounting plate 301. , and the mirror unit 360 emits the laser light L to the outside along the direction intersecting with the plane. As a result, for example, when the emission direction of the laser light L is along the vertical direction, the laser output unit 300 can be easily attached to and detached from the laser processing apparatus 200 because the height of the laser output unit 300 is reduced. . Furthermore, the mirror unit 360 has mirrors 362 and 363 for adjusting the optical axis of the laser beam L. As shown in FIG. Accordingly, when the laser output unit 300 is attached to the device frame 210 of the laser processing device 200, the position and angle of the optical axis of the laser light L incident on the laser condensing unit 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 .

Note that if the optical component provided with the output end 443 in the laser beam output unit 440 is arranged on the mounting base 471, for example, when the laser oscillator 400 is mounted on the laser processing apparatus 200 via the mounting base 471, Even if the laser processing apparatus 200 vibrates or the housing 470 or the like is deformed due to changes in the operating environment temperature of the laser processing apparatus 200 or the like, the position and angle of the output end 443 are unlikely to shift. Therefore, if the optical component provided with the emission end 443 in the laser beam emission section 440 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. . As an example, as shown in (a) of FIG. 21, the preamplifier section 420 and the power amplifier section 430 may be arranged in parallel along the horizontal direction on the laser light emitting section 440, or (b) of FIG. ) and (c), even if the laser light emitting section 440, the preamplifier section 420, and the power amplifier section 430 are arranged in parallel along the horizontal direction, the laser light emitting section 440 does not have the 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 light L emitted from the laser oscillator 400 to the outside are stabilized.
[Laser Oscillator of Second Embodiment]

The laser oscillator 400 of the second embodiment is mainly different from the laser oscillator 400 of the first embodiment described above in that it includes a first housing 470, a second housing 480, and a fiber cable FC2. there is As shown in FIG. 22 , the first housing 470 accommodates the seed light emitting section 410 , the preamplifier section 420 , the power amplifier section 430 , the first support plate 461 and the second support plate 462 . The second housing 480 accommodates the laser light emitting section 440 . The fiber cable FC2 is stretched between the first housing 470 and the second housing 480 and propagates the laser light L from the power amplifier section 430 to the laser light emitting section 440 .

As shown in FIG. 23, the signal processing boards 403 and 404 output from the PDs 452, 455, 456, 457 and 459 and the memory board 405 are attached to the rear surface 461b of the first support plate 461. As shown in FIG. The configuration of the surface 461a side of the first support plate 461 is the same as that of the laser oscillator 400 of the first embodiment described above. 23 is a view of the configuration of the rear surface 461b side of the first support plate 461 as viewed from the front surface 461a side of the first support plate 461. In FIG. omitted.

As shown in FIG. 24, the fiber F13 that propagates the laser light L from the power amplifier section 430 to the laser light emitting section 440 is connected to the fiber cable FC2. The configuration of the front surface 462a side and the configuration of the rear surface 462b side of the second support plate 462 are the same as those of the laser oscillator 400 of the first embodiment described above.

As shown in FIG. 25, the collimator 441 and the isolator 442 are attached to the surface 481a of the attachment base 481 of the second housing 480. As shown in FIG. Laser light L propagated by fiber cable FC2 is propagated to collimator 441 by fiber F14.

According to the laser oscillator 400 configured as described above, the degree of freedom of arrangement of the laser light emitting section 440 with respect to the preamplifier section 420 and the power amplifier section 430, which are laser amplifying sections, is improved.
[Modification]

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments. For example, in the above-described embodiment, the preamplifier unit 420 employs a backward pumping configuration. configurations may be employed. Similarly, in the above-described embodiment, the power amplifier unit 430 employs a backward pumping configuration. Configurations of excitation may be employed.

Further, the laser oscillator of the present invention is not limited to the laser processing apparatus 200 that forms a modified region inside the workpiece 1, but is installed in a laser processing apparatus that performs other laser processing such as ablation processing, welding processing, etc. It is also possible to

Further, in the laser processing apparatus 200 , the polarizing plate unit 340 may be provided with a polarizing member other than the polarizing plate 342 . As an example, instead of the polarizing plate 342 and the optical path correction plate 343, a cubic polarizing member may be used. A cubic polarizing member is a member having a rectangular parallelepiped shape, in which side surfaces of the member facing each other are a light incident surface and a light emitting surface, and a layer functioning as a polarizing plate is provided between them. It is a member.

Further, in the laser processing apparatus 200, the axis along which the λ/2 wavelength plate 332 rotates and the axis along which the polarizing plate 342 rotates may not coincide with each other.

Further, in the laser processing apparatus 200, the laser output section 300 has the mirrors 362 and 363 for adjusting the optical axis of the laser light L emitted from the laser output section 300. At least one mirror may be provided for adjusting the optical axis of the laser beam L to be emitted.

DESCRIPTION OF SYMBOLS 1... Object to be processed, 200... Laser processing apparatus, 210... Apparatus frame, 230... Support stand (support part), 301... Mounting plate, 330... λ/2 wavelength plate unit (output adjustment part), 340... Polarizing plate unit (output adjusting unit) 360 mirror unit 362, 363 mirror 400 laser oscillator 410 seed light emitting unit 411 seed light LD (seed light source) 420 preamplifier unit (first amplifier unit) 423... First laser fiber 424... First pumping LD (first pumping light source) 430... Power amplifier unit (second amplifier unit) 434... Second laser fiber 435... Second pumping LD (second pumping light source) ), 440...Laser light emitting part, 442...Isolator (optical component), 443...Emitting end, 452, 455, 459...PD (light receiving element), 461...First supporting plate, 462...Second supporting plate, 462a... Front surface 462b Back surface 462c Side surface 470 Housing First housing 480 Second housing 500 Laser focusing unit FC2 Fiber cable 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, which is seed light;
a first amplifier section having a first laser fiber for propagating the laser light emitted from the seed light emitting section and a first excitation light source for emitting first excitation light for exciting the first laser fiber;
a second amplifier unit having a second laser fiber for propagating the laser light amplified by the first amplifier unit and a second pumping light source for emitting a second pumping light for pumping the second laser fiber;
a laser light emitting section having an optical component provided with an emitting end for emitting the laser light amplified by the second amplifier section to the outside;
a housing that accommodates the seed light emitting unit, the first amplifier unit, the second amplifier unit, and the laser light emitting unit;
The housing is
a first portion housing the first amplifier section, the second amplifier section, and the laser light emitting section;
a second portion that is detachable from the upper surface of the first portion and that accommodates the seed light emitting portion;
The lower wall of the first portion forms a mounting base,
The laser oscillator , wherein the laser light emitting section is arranged on the mounting base within the first portion . a first support plate on which the first laser fiber is arranged;
a second support plate on which the second laser fiber, the first excitation light source and the second excitation light source are arranged and a coolant flow path is provided;
a fiber cable for propagating the laser light from the seed light emitting unit to the first amplifier unit,
the housing further houses the first support plate and the second support plate;
The first support plate and the second support plate are arranged to face each other,
The optical component is arranged so as to overlap the first support plate and the second support plate when viewed from the respective thickness directions of the first support plate and the second support plate,
The output end of the optical component faces the outside of the housing in the housing,
the first portion houses the first support plate and the second support plate;
2. The laser oscillator according to claim 1, wherein said fiber cable is stretched between said first portion and said second portion. 3. The laser oscillator according to claim 2, wherein a front surface and a back surface of said second support plate are surfaces on which said second laser fiber, said first excitation light source and said second excitation light source are arranged. 4. The laser oscillator according to claim 3, wherein the side surface of said second support plate is said placement surface. at least one of a position between the seed light source and the first laser fiber, a position between the first laser fiber and the second laser fiber, and a position between the second laser fiber and the optical component further comprising at least one light receiving element that detects a portion of the laser light at one position;
5. The laser oscillator according to claim 2, wherein said at least one light receiving element is arranged on said second support plate. 6. The laser oscillator according to claim 1, wherein said optical component is an isolator for blocking return light. a laser oscillator according to any one of claims 1 to 6 ;
an output adjustment unit that adjusts the output of the laser light 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 adjustment unit;
a mounting plate to which the laser oscillator, the output adjustment section and the mirror unit are mounted;
a device frame to which the mounting plate is attached;
a support part that is attached to the apparatus frame and supports the object to be processed;
and a laser beam condensing unit attached to the apparatus frame so as to be movable with respect to the mirror unit, the laser condensing unit condensing the laser beam that has passed through the mirror unit onto the object to be processed.

Images