JP2019181534A - Laser oscillator and laser processing device using the same - Google Patents

Abstract

To provide a laser oscillator, in which a light emission part can be switched or an output ratio of an allocated laser beam can be changed.SOLUTION: A laser oscillator 10 comprises at least a plurality of laser modules 11 which emit laser beams LB1-LB4 of TE polarization respectively and a beam coupler 12 that couples and emits the plurality of laser beams. The beam coupler 12 has: a plurality of light emitting parts LI1-LI4, a 1/2 wavelength plate HWP1 that varies the laser beams from the TE polarization to TM polarization, and a polarization beam splitter PBS3 that transmits the laser beams of the TE polarization therethrough, while reflecting the laser beams of the TM polarization. The 1/2 wavelength plate HWP1 is arranged on optical paths of the laser beams LB3 and LB4, and the laser beams LB3 and LB4 are reflected on the polarization beam splitter PBS3, while the laser beams LB1 and LB2 are transmitted through the polarization beam splitter PBS3.SELECTED DRAWING: Figure 2

Description

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

  In recent years, a laser processing apparatus equipped with a high-power laser oscillator has been widely used for cutting and welding metals. In particular, a laser oscillator having an output of 4 kW or more is often used for cutting a thick metal plate. On the other hand, a laser oscillator with an output of 2 kW or less is often used for cutting a thin metal plate or laser marking. As described above, although the appropriate laser output varies depending on the processing application, since the laser processing apparatus is expensive, one laser processing apparatus is often used for many purposes.

  However, when a laser beam having an output of 2 kW is emitted using a laser oscillator having an output of 4 kW, only half of the original ability is used, which is inefficient.

  Therefore, conventionally, a laser beam emitted from a high-power laser is scanned by a mirror held by a galvano mirror and introduced into different optical fibers, and the laser beam incident time on the optical fiber is controlled to obtain a desired value. A technique for emitting a laser beam in a time-division manner with a duty ratio has been proposed (see, for example, Patent Document 1).

Japanese Patent No. 3004625

  However, in the prior art disclosed in Patent Document 1, high-precision control is required to couple a laser beam scanned by a mirror to an optical fiber. In addition, a scanner such as a galvanometer mirror that scans a laser beam is expensive and large. Furthermore, in this prior art, it was not possible to distribute and emit the laser beam at the same time.

  The present invention has been made in view of the above points, and an object of the present invention is to provide a laser oscillator and a laser processing apparatus using the laser oscillator that enable switching of a light emitting portion or distribution of a laser beam with a simple configuration and operation. There is.

  To achieve the above object, a laser oscillator according to the present invention includes a plurality of laser modules each emitting a laser beam whose main polarization state is a first polarization state, and a plurality of laser beams emitted from the plurality of laser modules. Are combined to emit one or more laser beams, and the laser beam emitted from the beam combiner is condensed so as to have a predetermined beam diameter and guided to a transmission fiber. A condensing unit, wherein the beam combiner changes the incident laser beam from the first polarization state to a second polarization state different from the first polarization state; A polarization beam splitter that transmits a laser beam having one polarization state and reflects a laser beam having the second polarization state; and A plurality of light emitting portions from which laser beams combined in the chamber are emitted, and one polarizing member and the other polarizing member each have a predetermined position and an optical path on the optical path of at least one laser beam. And at least one of the plurality of laser beams travels in a first direction and is incident on the polarization beam splitter, while at least one of the plurality of laser beams is incident on the polarization beam splitter. The laser beam travels in a second direction intersecting the first direction, is incident on the polarization beam splitter, and is at a predetermined position on the optical path of at least one laser beam traveling in the first direction. One polarizing member is arranged, or the other polarizing member is arranged at a predetermined position on the optical path of at least one laser beam traveling in the second direction, The laser beam transmitted through one polarizing member or the other polarizing member is reflected by the polarizing beam splitter in a direction different from the traveling direction of the first or second direction until it enters the polarizing beam splitter. On the other hand, the laser beam that does not pass through the one polarizing member or the other polarizing member passes through the polarizing beam splitter.

  According to this configuration, the light emitting portion from which the laser beam LB is emitted can be switched or the laser beam can be distributed by a simple operation of placing one polarizing member or another polarizing member on the optical path of the predetermined laser beam. It becomes possible to do. Further, a half-wave plate well known as one and other polarizing members can be used.

  Another laser oscillator according to the present invention combines a plurality of laser modules each emitting a laser beam whose main polarization state is the first polarization state, and a plurality of laser beams emitted from the plurality of laser modules. A beam combiner for emitting one or more laser beams, and a condensing unit for condensing the laser beam emitted from the beam combiner so as to have a predetermined beam diameter and guiding it to a transmission fiber The beam combiner includes: a plurality of polarization members that change an incident laser beam from the first polarization state to a second polarization state different from the first polarization state; and the first polarization A polarization beam splitter that transmits a laser beam having a state while reflecting a laser beam having the second polarization state, and is coupled in the beam combiner. A plurality of light emitting portions from which the laser beam is emitted, and the polarizing member is movable between a predetermined position on the optical path of the at least one laser beam and a predetermined position outside the optical path. Provided, at least one of the plurality of laser beams travels in a first direction, and at least two laser beams travel in a second direction intersecting the first direction and are polarized The polarizing member is disposed on each optical path of at least two laser beams that enter the beam splitter and travel in the second direction, so that at least two light emitting units among the plurality of light emitting units are provided. A laser beam is emitted from.

  According to this configuration, the light emitting unit from which the laser beam is emitted can be switched or the laser beam can be distributed by a simple operation of arranging the polarizing members on the optical paths of the predetermined laser beams. It becomes possible. Further, a half-wave plate well known as a polarizing member can be used.

  In addition to the configuration of the laser oscillator described above, the laser beam emitted from the beam combiner to the outside of the beam combiner may be combined with the condensing unit. The transmission fiber is coupled to each of the plurality of condensing units.

  According to this configuration, a plurality of laser beams generated by the laser oscillator can be simultaneously emitted to the outside, and one or more laser beams generated by the laser oscillator can be emitted toward different locations. .

  The laser processing apparatus according to the present invention includes at least another laser oscillator described above, a laser beam emission head attached to each of emission ends of the plurality of transmission fibers, and a control unit that controls the operation of the polarization member. It is characterized by having.

  According to this configuration, switching of the laser beam and distribution of the laser beam can be performed easily, so that the productivity of the laser processing step can be improved.

  As described above, according to the laser oscillator of the present invention, the laser beam can be switched and the laser beam can be distributed with a simple configuration and operation. Further, according to the laser processing apparatus of the present invention, the switching of the laser beam and the distribution of the laser beam can be easily performed, so that the productivity of the laser processing process can be improved.

It is a schematic diagram which shows the structure of the laser processing apparatus which concerns on Embodiment 1 of this invention. It is a schematic diagram which shows the internal structure of a beam combiner. It is a schematic diagram which shows the internal structure of the beam combiner at the time of switching a laser beam emission part. It is a schematic diagram which shows the internal structure of the beam combiner at the time of laser beam distribution. It is a schematic diagram which shows the internal structure of the beam combiner at the time of changing the output ratio of the distributed laser beam. It is a schematic diagram which shows the internal structure of the beam combiner at the time of the laser beam distribution which concerns on Embodiment 2 of this invention. It is another schematic diagram which shows the internal structure of the beam combiner at the time of changing the output ratio of the distributed laser beam. It is another schematic diagram which shows the internal structure of the beam combiner at the time of changing the output ratio of the distributed laser beam further. It is a figure which shows the usage example of the laser processing apparatus which concerns on Embodiment 3 of this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The following description of the preferred embodiments is merely exemplary in nature and is in no way intended to limit the invention, its application, or its application.

(Embodiment 1)
[Configuration of laser processing equipment]
1 shows the configuration of the laser processing apparatus according to the present embodiment, FIG. 2 shows a schematic diagram of the internal configuration of the beam combiner, and FIG. 3 shows the internal configuration of the beam combiner when the laser beam emitting section is switched. The schematic diagram of each is shown.

  The laser processing apparatus 100 includes a laser oscillator 10, laser beam emitting heads 30 and 31, transmission fibers 40 and 41, and a control unit 50. End portions of the laser oscillator 10 and the transmission fibers 40 and 41 where the laser beam LB is incident (hereinafter simply referred to as incident ends. Further, the end portions of the transmission fibers 40 and 41 where the laser beam is emitted are hereinafter simply referred to as emission ends. Is housed in the housing 70. The laser oscillator 10 performs laser oscillation when power is supplied from a power source (not shown).

  The laser oscillator 10 includes a plurality of laser modules 11, a beam combiner 12, and a plurality of condensing units 20. The laser module 11 includes a plurality of laser diodes or laser arrays that emit laser beams having different wavelengths, and the laser beam synthesized in the laser module 11 is emitted from each laser module 11. Note that the main polarization state of each of the laser beams LB1 to LB4 (see FIG. 2) emitted from the plurality of laser modules 11 is TE polarization (first polarization state) at the time of emission from the laser module 11. The polarization ratio (TE polarized light component intensity / total light intensity) is about 95% to 97%.

  The laser beams LB1 to LB4 are combined into one or more laser beams in the beam combiner 12 (hereinafter, simply referred to as a combined laser beam). As will be described later, when a plurality of combined laser beams are generated simultaneously by switching or distributing the optical path of the laser beam in the beam combiner 12, the beam combiner 12 applies to the plurality of condensing units 20 respectively. A combined laser beam is emitted. The above optical path switching operation will be described in detail later. The laser beam LB incident on the condensing unit 20 is condensed by a condensing lens (not shown) disposed inside the condensing unit 20, and the beam diameter is reduced at a predetermined magnification and transmitted. The light enters the fiber 40 or 41 and is emitted from the laser beam emission head 30 or 31. With the laser oscillator 10 having such a configuration, a high-power laser processing apparatus 100 having a laser beam output exceeding several kW can be obtained. In addition, the laser oscillator 10 in this embodiment is equipped with four laser modules 11 having a laser output of 1 kW, and the maximum output is 4 kW. However, the present invention is not particularly limited to this, and the individual outputs of the laser modules 11 and the number of the laser modules 11 mounted on the laser oscillator 10 can be appropriately changed according to the required specifications of the laser processing apparatus 100.

  The beam combiner 12 has a plurality of light incident portions LI1 to LI4 and a plurality of light emitting portions LO1 and LO2. The light emitting portions LI1 to LI4 are provided on the same surface of the beam combiner 12, and the light emitting portions LO1 and LO2 are provided on another surface of the beam combiner 12, respectively. As shown in FIGS. 2 and 3, the beam combiner 12 includes a plurality of mirrors (light reflecting members) M1 to M5, a plurality of polarizing beam splitters PBS1 to PBS3, and a half-wave plate HWP1 (one of them). A polarizing member), HWP2 (another polarizing member), and beam dampers DP1 and DP2. Of these, the half-wave plates HWP 1 and HWP 2 are configured to be movable within the beam combiner 12. The half-wave plates HWP1 and HWP2 are polarization members that emit by changing the polarization state of the incident laser beam. Note that illustration and description of the actuator that moves the half-wave plates HWP1 and HWP2 are omitted.

  The condensing unit 20 has a condensing lens (not shown) inside, and the condensing lens has a spot diameter smaller than the core diameter of each transmission fiber at the incident end of the transmission fiber 40 or 41. The laser beam LB is condensed so that The condensing unit 20 has a connector (not shown), and the incident end of the transmission fiber 40 or 41 is connected to the connector. Further, in the condensing unit 20, depending on the number of laser beams that are combined within the beam combiner 12 and emitted outside the beam combiner 12, or according to the number of light emitting portions of the beam combiner 12. A condenser lens is provided on the optical path of the laser beam emitted from the beam combiner 12. Other optical components such as a collimator lens for beam shaping may be arranged on the optical path of each laser beam.

  In the following description, the traveling direction of the laser beam LB toward the condenser lens unit 20 is the X direction, the arrangement direction of the plurality of laser modules 11 is the Y direction, and the direction orthogonal to the X direction and the Y direction is the Z direction. Sometimes called.

  The transmission fiber 40 or 41 transmits the laser beam LB received from the condensing unit 20 to the laser beam emission head 30 or 31. Although not shown, the clads 40 and 41 are provided with a clad having a refractive index lower than that of the core around the core, and the surface of the clad is covered with a coating.

  The laser beam emission head 30 or 31 irradiates a workpiece (not shown) with the laser beam LB transmitted by the transmission fiber 40 or 41.

  The control unit 50 controls the laser oscillation of the laser oscillator 10. Specifically, the laser oscillation of each laser module 11 is controlled by supplying control signals such as output voltage and on-time to a power source (not shown) connected to the laser oscillator 10. It is also possible to individually control laser oscillation for each laser module 11. For example, the laser oscillation output, on-time, etc. may be varied for each laser module 11. The control unit 50 is connected to the operations of the half-wave plates HWP1, HWP2 and other optical components disposed in the beam combiner 12, specifically, to the half-wave plates HWP1, HWP2, etc. The operation of an actuator (not shown) is controlled. The control unit 50 may control the operation of a manipulator (not shown) to which the laser beam emitting head 30 is attached.

[Switching operation of laser beam emission part]
As shown in FIGS. 2 and 3, in the laser oscillator 10 according to the present embodiment, it is possible to switch which of the light emitting portions LO1 and LO2 emits the laser beam LB emitted from the beam combiner 12. . Thereby, it is possible to switch between emitting the laser beam LB from the laser beam emitting head 30 or emitting it from the laser beam emitting head 31. This will be described in detail below.

  First, consider the case where the laser beam LB is emitted from the light emitting portion LO1. As shown in FIG. 2, the laser beams LB1 to LB4 incident into the beam combiner 12 from the light incident portions LI1 to LI4 respectively travel in the same direction, in this case, the Z direction. Of these, the laser beam LB1 is reflected by the mirror M1, travels to the mirror M2, is changed again by the mirror M2, and travels again in the Z direction. The laser beam LB2 passes through the vicinity of the mirror M2, travels straight in the Z direction, and enters the polarization beam splitter PBS1 together with the laser beam LB1. Note that immediately before entering the polarization beam splitter PBS1, the laser beam LB1 travels in parallel with the optical path of the laser beam LB2 at a predetermined interval.

  Of the laser beams LB1 and LB2 incident on the polarization beam splitter PBS1, components other than the TEE polarization component, that is, TM polarization (second polarization state) component are reflected by the polarization beam splitter PBS1 and incident on the beam damper DP1. Is absorbed. As a result, the laser beams LB1 and LB2 that pass through the polarization beam splitter PBS1 have only TE polarization components.

  On the other hand, the laser beam LB3 is reflected by the mirror M3, travels in the Y direction, and travels toward the polarization beam splitter PBS2. The laser beam LB4 is reflected by the mirror M4, travels in the Y direction in parallel to the optical path of the laser beam LB3, with a predetermined interval, passes through the vicinity of the mirror M3, and travels toward the polarization beam splitter PBS2.

  Of the laser beams LB3 and LB4 incident on the polarization beam splitter PBS2, the TM polarization component is reflected by the polarization beam splitter PBS2 and incident on the beam damper DP2 and absorbed. As a result, the laser beams LB3 and LB4 that pass through the polarization beam splitter PBS2 have only TE polarization components.

  The laser beams LB1 and LB2 that have passed through the polarization beam splitter PBS1 are incident on the polarization beam splitter PBS3. The laser beams LB1 and LB2 pass through the polarization beam splitter PBS and go directly to the light emitting portion LO1.

  On the other hand, when the half-wave plate HWP1 is arranged on the optical path of the laser beams LB3 and LB4 transmitted through the polarization beam splitter PBS2, the polarization state of the laser beams LB3 and LB4 is changed. That is, the state is changed from the TE polarization to another polarization state, in this case, the TM polarization state. The laser beams LB3 and LB4 changed to TM polarized light are reflected by the polarization beam splitter PBS3. Here, the polarization beam splitter PBS3 is arranged to change the traveling direction of the laser beams LB3 and LB4 from the Y direction to the Z direction. That is, they are arranged so as to form an angle of 45 ° with the traveling direction of the laser beams LB3 and LB4. Further, the polarization beam splitter PBS3 is arranged so as to form an angle of 45 ° with the traveling direction of the laser beams LB1 and LB2. For this reason, the laser beams LB3 and LB4 reflected by the polarization beam splitter PBS3 travel in the Z direction and go directly to the light emitting portion LO1.

  Here, either one of the laser beams LB1 and LB2 after passing through the polarization beam splitter PBS3 and one of the laser beams LB3 and LB4 after being reflected by the polarization beam splitter PBS3 have the same optical axis. Each part in the beam combiner 12 is arrange | positioned so that it may become. Further, the other of the laser beams LB1 and LB2 after passing through the polarization beam splitter PBS3 and the other of the laser beams LB3 and LB4 after being reflected by the polarization beam splitter PBS3 have the same optical axis. Each part in the coupler 12 is arranged. In the present embodiment, as shown in FIG. 2, the laser beam LB1 and the laser beam LB4 have the same optical axis from the polarization beam splitter PBS3 to the light emitting portion LO1, and the laser beam LB2 and the laser beam The arrangement of the light incident portions LI1 to LI4, the mirrors M1 to M4, and the polarization beam splitter PBS3 is determined so that the beam LB3 has the same optical axis.

  By making the laser beams LB1 to LB4 incident on the polarization beam splitter PBS3 in this way, the laser beams LB1 to LB4 are combined with one laser beam LB and emitted from the light emitting portion LO1. In this case, in the laser processing apparatus 100 shown in FIG. 1, the laser beam LB emitted from the condensing unit 20 is emitted from the laser beam emitting head 30 through the transmission fiber 40.

  Next, consider a case where the laser beam LB is emitted from the light emitting portion LO2. As shown in FIG. 3, the arrangement of the light incident portions LI1 to LI4, the mirrors M1 to M4, the polarization beam splitters PBS1 to PBS3, and the beam dampers DP1 and DP2 is the same as that shown in FIG. Further, the optical paths of the laser beams LB1 and LB2 immediately after passing through the polarizing beam splitter PBS1 and the optical paths of the laser beams LB3 and LB4 immediately after passing through the polarizing beam splitter PBS2 are the same as shown in FIG. On the other hand, as shown in FIG. 3, the half-wave plate HWP1 is retracted out of the optical path of the laser beams LB3 and LB4, while the half-wave plate HWP2 moves and passes through the polarization beam splitter PBS1 to be polarized. They are arranged on the optical path of the laser beams LB1 and LB2 until they enter the beam splitter PBS3. As a result, the laser beams LB3 and LB4 pass through the polarization beam splitter PBS3 and go straight in the Y direction, while the laser beams LB1 and LB2 changed to TM polarized light by the half-wave plate HWP2 are transmitted by the polarization beam splitter PBS3. Reflected, the traveling direction is changed from the Z direction to the Y direction, and the vehicle travels straight.

  As shown in FIG. 3, the laser beam LB1 reflected by the polarization beam splitter PBS3 and the laser beam LB4 transmitted through the polarization beam splitter PBS3 have the same optical axis and are reflected by the polarization beam splitter PBS3. The arrangement of the light incident portions LI1 to LI4, the mirrors M1 to M4, and the polarization beam splitter PBS3 is determined so that the laser beam LB2 and the laser beam LB3 transmitted through the polarization beam splitter PBS4 have the same optical axis.

  Thus, the laser beams LB1 to LB4 combined by the polarization beam splitter PBS3 are combined by one laser beam LB and reflected by the mirror M5. The mirror M5 is provided at a predetermined interval in the Y direction from the polarizing beam splitter PBS3, in this case, an interval corresponding to the interval in the Y direction between the light emitting portions LO1 and LO2. The laser beam LB reflected by the mirror M5 is emitted from the light emitting portion LO2. In this case, in the laser processing apparatus 100 shown in FIG. 1, the laser beam LB emitted from the condensing unit 20 is emitted from the laser beam emission head 31 through the transmission fiber 41.

[Laser beam distribution and output ratio change operation]
FIG. 4 is a schematic diagram of the internal configuration of the beam combiner when the laser beam is distributed according to the present embodiment, and FIG. 5 is a schematic diagram of the internal configuration of the beam combiner when the output ratio of the distributed laser beam is changed. Each figure is shown. The beam combiner 12 shown in FIGS. 4 and 5 is the same as the beam combiner 12 shown in FIGS. 2 and 3, and the internal structure is the same as the structure shown in FIGS.

  By arranging the half-wave plates HWP1 and HWP2, especially by moving the HWP2 to a predetermined position, the laser beam can be emitted from both the light emitting portions LO1 and LO2, and the output ratio thereof can be changed. Can do. This will be described in detail below.

  First, consider a case where laser beams LBA and LBB having the same output are emitted from the light emitting portions LO1 and LO2, respectively. As shown in FIG. 4, the optical paths of the laser beams LB1 and LB2 until immediately after passing through the polarizing beam splitter PBS1 and the optical paths of the laser beams LB3 and LB4 immediately after passing through the polarizing beam splitter PBS2 are shown in FIGS. It is the same.

  On the other hand, as shown in FIG. 4, the half-wave plate HWP1 is disposed on the optical path of the laser beams LB3 and LB4 until it passes through the polarization beam splitter PBS2 and enters the polarization beam splitter PBS3. A / 2 wavelength plate HWP2 is disposed on the optical path of the laser beams LB1 and LB2 until it passes through the polarizing beam splitter PBS1 and enters the polarizing beam splitter PBS3. Since the laser beams LB3 and LB4 are changed to TM polarized light by the half-wave plate HWP1, the laser beams LB3 and LB4 are reflected by the polarization beam splitter PBS3, travel straight in the Z direction, and travel toward the light emitting section LO1. Further, since the laser beams LB1 and LB2 are also changed to TM polarized light by the half-wave plate HWP2, the laser beams LB1 and LB2 are reflected by the polarization beam splitter PBS3, go straight in the Y direction, and go to the mirror M5. The laser beams LB1 and LB2 reflected by the mirror M5 have their traveling directions changed from the Y direction to the Z direction and headed toward the light emitting section LO2. In the polarization beam splitter PBS3, the reflection surface on which the laser beams LB1 and LB2 are reflected is opposite to the reflection surface on which the laser beams LB3 and LB4 are reflected.

  As a result, the laser beam LBA obtained by combining the laser beam LB3 and the laser beam LB4 is emitted from the light emitting unit LO1, and the laser beam LBB obtained by combining the laser beam LB1 and the laser beam LB2 is emitted from the light emitting unit LO2. . In the present embodiment, since the laser beams LB1 to LB4 have the same laser output (1 kW), the output ratio between the laser beam LBA emitted from the light emitting portion LO1 and the laser beam LBB emitted from the light emitting portion LO2. Is 1: 1. In this case, in the laser processing apparatus 100 shown in FIG. 1, the two laser beams LBA and LBB emitted from the condensing unit 20 are transmitted from the laser beam emitting heads 30 and 31 through the transmission fibers 40 and 41, respectively. Each is output with the same output.

  Next, consider a case where the output ratio between the laser beam LBA emitted from the light emitting portion LO1 and the laser beam LBB emitted from the light emitting portion LO2 is changed. As shown in FIG. 5, the optical paths of the laser beams LB1 and LB2 up to immediately after passing through the polarizing beam splitter PBS1 and the optical paths of the laser beams LB3 and LB4 up to just after passing through the polarizing beam splitter PBS2 are the same as those shown in FIG. It is.

  Here, as in FIG. 4, the half-wave plate HWP1 is disposed on the optical path of the laser beams LB3 and LB4 until it passes through the polarizing beam splitter PBS2 and enters the polarizing beam splitter PBS3. As shown in FIG. 5, the half-wave plate HWP2 is disposed on the optical path of the laser beam LB1 until it passes through the polarization beam splitter PBS1 and enters the polarization beam splitter PBS3. Since the laser beams LB3 and LB4 are changed to TM polarized light by the half-wave plate HWP1, the laser beams LB3 and LB4 are reflected by the polarization beam splitter PBS3, travel straight in the Z direction, and travel toward the light emitting section LO1. Further, since the laser beam LB1 is also changed to TM polarized light by the half-wave plate HWP2, it is reflected by the polarization beam splitter PBS3, travels straight in the Y direction, and travels toward the mirror M5. The laser beams LB1 and LB2 reflected by the mirror M5 have their traveling directions changed from the Y direction to the Z direction and headed toward the light emitting section LO2.

  On the other hand, since the laser beam LB2 does not pass through the half-wave plate HWP2, it is incident on the polarization beam splitter PBS3 as TE polarized light. Therefore, the laser beam LB2 passes through the polarization beam splitter PBS3 as it is and is combined with the laser beams LB3 and LB4. Note that the laser beam LB2 and the laser beam LB3 travel on the same optical axis from the polarization beam splitter PBS3 to the light emitting section LO1.

  As a result, the laser beam LBA combined with the laser beams LB2 to LB4 is emitted from the light emitting portion LO1, and the laser beam LB1 is emitted as the laser beam LBB from the light emitting portion LO2. In the present embodiment, since the laser beams LB1 to LB4 have the same laser output (1 kW), the output ratio between the laser beam LBA emitted from the light emitting portion LO1 and the laser beam LBB emitted from the light emitting portion LO2. Is 3: 1. That is, compared with the case shown in FIG. 4, the laser beam LBA emitted from the emission part LO1 and the laser beam LBB emitted from the light emission part LO2 are distributed with different outputs, that is, with the above output ratio.

  In this case, in the laser processing apparatus 100 shown in FIG. 1, the two laser beams LBA and LBB emitted from the condensing unit 20 are transmitted from the laser beam emitting heads 30 and 31 through the transmission fibers 40 and 41, respectively. The light is emitted at an output ratio of 3: 1.

  Even if the half-wave plate HWP2 is disposed on the optical path of the laser beam LB2 that passes through the polarizing beam splitter PBS1 and enters the polarizing beam splitter PBS3, the laser beams LB1, LB3, and LB4 are similarly provided. The laser beam LBA combined with the laser beam LBA is emitted from the light emitting portion LO2 as the laser beam LBB as the laser beam LBB, and emitted from the light emitting portion LO2 and the laser beam LBA emitted from the light emitting portion LO1. The output ratio with respect to the laser beam LBB is 3: 1. Further, the laser beam LB1 and the laser beam LB4 travel on the same optical axis and are emitted from the light emitting portion LO1 as a part of the laser beam LBA.

[Effects]
As described above, the laser oscillator 10 according to the present embodiment emits the laser modules 11 each of which emits a laser beam whose main polarization state is the TE polarization (first polarization state), and these laser modules 11. A plurality of laser beams LB1 to LB4 combined to emit one or more laser beams LB, and the laser beam LB emitted from the beam combiner 12 has a predetermined beam diameter. And a light collecting unit 20 for condensing and guiding the light to the transmission fibers 40 and / or 41.

  The beam combiner 12 changes the incident laser beam from the light emitting portions LO1 and LO2 from which the laser beam LB combined in the beam combiner 12 is emitted from a TE polarized light to a different TM polarized light (second polarization state). It includes at least half-wave plates HWP1 and HWP2 that are a plurality of polarization members to be changed, and a polarization beam splitter PBS3 that transmits a TE-polarized laser beam and reflects a TM-polarized laser beam.

  The half-wave plate HWP1 (one polarization member) is provided so as to be movable between a predetermined position on at least one optical path of the laser beams LB3 and LB4 and a predetermined position outside the optical path. The wave plate HWP2 (other polarizing member) is provided so as to be movable between a predetermined position on at least one of the laser beams LB1 and LB2 and a predetermined position outside the optical path.

  Among the laser beams LB1 to LB4, the laser beams LB1 and LB2 travel in the Z direction (first direction) and enter the polarization beam splitter PBS3, while the laser beams LB3 and LB4 cross the Z direction. The light travels in the (second direction) and enters the polarization beam splitter PBS3.

  A half-wave plate HWP2 is disposed at a predetermined position on the optical path of at least one of the laser beams LB1 and LB2 traveling in the Z direction, or among the laser beams LB3 and LB4 traveling in the Y direction. By arranging the half-wave plate HWP1 at a predetermined position on the optical path of at least one laser beam, the laser beam transmitted through the half-wave plate HWP1 or HWP2 changes to the TM polarization state. In this case, if the polarization beam splitter PBS3 has a different direction from the previous travel direction, that is, if the travel direction until it enters the polarization beam splitter PBS3 is the Y direction, the polarization beam splitter PBS3 enters the polarization beam splitter PBS3. If the traveling direction is Z direction, it is reflected in the Y direction. On the other hand, the laser beam that does not pass through the half-wave plate HWP1 or HWP2 passes through the polarization beam splitter PBS3.

  By configuring the laser oscillator 10 in this way, the polarizing member ½ HWP1 or HWP2 is arranged on the optical path of the laser beam or is retracted out of the optical path, thereby allowing the plurality of laser beams LB1 to LB1. Of LB4, the number of laser beams having different traveling directions until they enter the polarizing beam splitter PBS3 and traveling directions after the polarizing beam splitter PBS3 can be adjusted. That is, it is possible to change the direction in which the plurality of laser beams LB1 to LB4 are directed, or to change the number ratio of laser beams that are directed in different directions. As a result, it is possible to switch the light emitting portion from which the laser beam LB is emitted among the light emitting portions LO1 and LO2, or to emit the laser beams LBA and LBB simultaneously from the two light emitting portions LO1 and LO2. It becomes. In addition, since an external optical system as disclosed in Patent Document 1 is not used and laser beams can be switched and distributed within the laser oscillator 10, it is possible to suppress an increase in the size of the laser oscillator 10. Moreover, a well-known half wave plate can be used as a polarizing member, and the laser oscillator 10 can be comprised simply. Further, a simple mechanism for moving the half-wave plates HWP1 and HWP2 can be used.

  Further, by inserting the half-wave plate HWP1 or the half-wave plate HWP2 into the optical path of the laser beam that is incident on the polarization beam splitter PBS3 from different directions, the laser beam incident on the polarization beam splitter PBS3 is reflected. Can be controlled. As a result, the laser beam reflected by the polarization beam splitter PBS3 and the laser beam transmitted through the polarization beam splitter PBS3 are combined by the polarization beam splitter PBS3 so as to have the same optical axis, and the light output portions LO1, LO2 The laser beam LB is emitted from at least one light emitting portion.

  By combining the two laser beams with the polarization beam splitter PBS3 so that the optical axes thereof are the same, the beam quality of the laser beam LB combined in the beam combiner 12 can be improved. As described above, the laser beam LB1 travels in parallel to the optical path of the laser beam LB2 with a predetermined interval, and the laser beam LB3 has parallel to the optical path of the laser beam LB4 and has a predetermined interval. It is progressing. Therefore, when the laser beams LB1 to LB4 are emitted from the same light emitting part by simply changing the traveling direction by a mirror or the like, the laser beam LB is a combination of four laser beams LB1 to LB4 whose optical axes are separated from each other. Become a beam. Therefore, the beam diameter of the laser beam LB is greatly expanded, and the spot shape is greatly different from the circular shape.

  When the workpiece is processed with such a laser beam LB, for example, the width of the cut portion may become larger than a desired value, or a desired drilling process may not be performed. Further, if the spot diameter of the laser beam LB is made close to a circle, the number of optical components such as lenses increases, and the laser oscillator 10 may be expensive.

  On the other hand, according to the present embodiment, the laser beam LB is generated with the optical axes of at least two laser beams being the same, so that the optical axes of the laser beams contained therein can be brought close to each other. The beam quality of LB can be improved. Thereby, in the laser processing apparatus 100 using the laser oscillator 10, the processing quality can be improved.

  At least one of the laser beam transmitted through the polarizing beam splitter PBS3 and the laser beam reflected by the polarizing beam splitter PBS3 by the mirror M5 (light reflecting member) provided at a predetermined interval in the Y direction with the polarizing beam splitter PBS3. When one of the light paths is bent and a laser beam that is not incident on another light emitting unit, for example, the mirror M5, is emitted from the light emitting unit LO1, the laser beam incident on the mirror M5 is reflected and is reflected from the light emitting unit LO2. It may be emitted.

  By doing in this way, the light emission part from which the laser beam LB is emitted can be switched with a simple configuration, and the laser beams LBA and LBB can be emitted from the light emission parts LO1 and LO2, respectively.

  Further, among the laser beams LB1 and LB2 traveling in the Z direction, the number of the half-wave plates HWP2 arranged on the optical path is changed, or among the laser beams LB3 and LB4 traveling in the Y direction, By changing the number of half-wave plates HWP1 arranged on the road, the output ratio of the laser beams LBA and LBB emitted from the light emitting portions LO1 and LO2 can be changed.

  The arrangement of the laser oscillator 10 is not limited to the arrangement shown in FIGS. 4 and 5, and the output ratio of the laser beams LBA and LBB emitted from the light emitting portions LO1 and LO2 can also be changed by configuring the laser oscillator 10 in this way. . For example, in the configuration shown in FIG. 2, either the optical path of the laser beam LB3 or the optical path of the laser beam LB4 until the half-wave plate HWP1 passes through the polarizing beam splitter PBS2 and enters the polarizing beam splitter PBS3. In this case, the output ratio between the laser beam LBA emitted from the light emitting portion LO1 and the laser beam LBB emitted from the light emitting portion LO2 is 3: 1 as in the configuration shown in FIG. The beam quality of the laser beam LBA is also the same as that shown in FIG.

  Further, in the configuration shown in FIG. 3, either the optical path of the laser beam LB1 or the optical path of the laser beam LB2 until the half-wave plate HWP2 passes through the polarizing beam splitter PBS1 and enters the polarizing beam splitter PBS3. In this case, the output ratio between the laser beam LBA emitted from the light emitting portion LO1 and the laser beam LBB emitted from the light emitting portion LO2 is 1: 3. The beam quality of the laser beam LBB emitted from the light emitting portion LO2 is equivalent to the beam quality of the laser beam LB emitted from the light emitting portion LO1 shown in FIG.

  Further, among the plurality of laser beams LB1 to LB4, a half-wave plate HWP2 is disposed at a predetermined position on the optical path of the laser beams LB1 and LB2 traveling in the Z direction, and the LB3 and LB3 traveling in the Y direction The laser beams LBA and LBB can be emitted from the light emitting portions LO1 and LO2, respectively, by arranging the half-wave plate HWP1 at a predetermined position on the optical path. In this case, among the laser beams LB1 and LB2 traveling in the Z direction, the number of the half-wave plates HWP2 disposed on the optical path is changed, or among the laser beams LB3 and LB4 traveling in the Y direction, By changing the number of half-wave plates HWP1 arranged on the road, the output ratio of the laser beams LBA and LBB emitted from the light emitting portions LO1 and LO2 can be changed.

  For example, in the configuration shown in FIG. 5, when the half-wave plate HWP1 is retracted from the optical path of the laser beams LB3 and LB4 until it passes through the polarizing beam splitter PBS2 and enters the polarizing beam splitter PBS3, the light emitting unit The output ratio between the laser beam LBA emitted from LO1 and the laser beam LBB emitted from the light emitting portion LO2 is 1: 3. However, in this case, in the laser beam LBB emitted from the light emitting portion LO2, the optical axes of the laser beams LB1, LB3, and LB4 are spaced apart from each other by a predetermined distance. Therefore, the beam quality of the laser beam LBB is as shown in FIG. 5, the beam quality of the laser beam LBA emitted from the light emitting portion LO1 is deteriorated.

  Note that the number of the light incident portions and the light emitting portions can be appropriately changed according to the specifications of the laser oscillator 10 and the like. Accordingly, the output ratio of the laser beam can be changed as appropriate.

  In addition, a plurality of condensing units 20 are provided according to the number of laser beams that are combined in the beam combiner 12 and emitted to the outside of the beam combiner 12, and a transmission fiber is provided in each of the plurality of condensing units 20. Is connected. In the present embodiment, transmission fibers 40 and 41 are connected to the two light collecting units 20, respectively.

  With such a configuration, a plurality of laser beams generated by the laser oscillator 10 can be simultaneously emitted to the outside, and one or more laser beams generated by the laser oscillator 10 are directed to different places. Can be emitted.

  The components other than the TE polarization component of the laser beams LB1 to LB4 are cut by using the polarization beam splitters PBS1 and PBS2 before entering the polarization beam splitter PBS3, so that the light emitting units LO1 and / or LO2 It is possible to prevent an unintended laser beam from being emitted. In addition, the output of the laser beam LB or LBA, LBB emitted from the light emitting portions LO1 and / or LO2 can be accurately defined.

(Embodiment 2)
FIG. 6A is a schematic diagram of the internal configuration of the beam combiner during laser beam distribution according to the present embodiment, and FIG. 6B is the internal configuration of the beam combiner when the output ratio of the distributed laser beam is changed. FIG. 6C is a schematic diagram of the internal configuration of the beam combiner when the output ratio of the distributed laser beam is further changed.

  The configuration shown in the present embodiment is different from the configuration shown in the first embodiment in the following points. First, in the configuration shown in the present embodiment, the number of light emitting portions is increased to three (light emitting portions LO1 to LO3). Further, the mirrors M1, M2, and M5 and the half-wave plate HWP2 are omitted, and instead, polarizing beam splitters PBS4 to PBS6, half-wave plates HWP3 and HWP4, and a beam damper 3 are added. The arrangement of the light emitting portions LI1 to LI4, the mirrors M3 and M4, the polarization beam splitters PBS1 to PBS3, and the beam dampers DP1 and DP2 is the same as that shown in the first embodiment.

  According to the present embodiment, the laser beams LB1 to LB4 respectively incident from the four light incident portions LI1 to LI4 are combined in the beam combiner 12, and from any one of the three light emitting portions LO1 to LO3, or from each of them. Can be emitted. This will be described in detail below.

  As shown in FIG. 6A, the optical path of the laser beam LB2 immediately after passing through the polarizing beam splitter PBS1 and the optical path of the laser beams LB3 and LB4 immediately after passing through the polarizing beam splitter PBS2 are the same as those shown in FIGS. It is.

  On the other hand, as shown in FIG. 6A, the half-wave plate HWP1 is disposed on the optical path of the laser beams LB3 and LB4 until it passes through the polarizing beam splitter PBS2 and enters the polarizing beam splitter PBS3. Since the laser beams LB3 and LB4 are changed to TM polarized light by the half-wave plate HWP1, the laser beams LB3 and LB4 are reflected by the polarization beam splitter PBS3, travel straight in the Z direction, and travel toward the light emitting section LO1. On the other hand, the laser beam LB2 remains TE-polarized light, passes through the polarization beam splitters PBS1 and PBS5 as they are, and travels toward the light emitting portion LO2. Similarly, the laser beam LB1 remains TE-polarized and passes through the polarization beam splitters PBS4 and PBS6 as they are and travels toward the light emitting portion LO3. Note that the TM polarization components included in the laser beams LB1 and LB2 are reflected by the polarization beam splitters PBS1 and PBS4, respectively, and absorbed by the beam dampers DP1 and DP3, respectively.

  As a result, the laser beam LBA obtained by combining the laser beam LB3 and the laser beam LB4 is emitted from the light emitting portion LO1, the laser beam LB2 is emitted from the light emitting portion LO1 as the laser beam LBB, and the laser beam LB1 is emitted as the laser beam LBC. The light is emitted from LO3. In this embodiment, since the laser beams LB1 to LB4 have the same laser output (1 kW), the output ratio of the laser beam LBA, the laser beam LBB, and the laser beam LBC is 2: 1: 1. In this case, in the laser processing apparatus 100 shown in FIG. 1, the three laser beams LBA, LBB, and LBC emitted from the condensing unit 20 are transmitted through the transmission fibers 40 and 41 and the transmission fiber (not shown), respectively. The light is emitted from the beam emission heads 30 and 31 and a laser beam emission head (not shown) at the above output ratio.

  Further, as shown in FIG. 6B, the half-wave plate HWP1 is disposed on the optical path of the laser beam LB4 until it passes through the polarization beam splitter PBS2 and enters the polarization beam splitter PBS3, and 1/2 The wave plate HWP3 is disposed on the optical path of the laser beam LB3 until it passes through the polarizing beam splitter PBS3 and enters the polarizing beam splitter PBS5. Since the laser beam LB4 is changed to TM polarized light by the half-wave plate HWP1, it is reflected by the polarization beam splitter PBS3, travels straight in the Z direction, and travels toward the light emitting portion LO1. On the other hand, since the laser beam LB3 passes through the polarization beam splitter PBS3 and is changed to TM polarization by the half-wave plate HWP3, the laser beam LB3 is reflected by the polarization beam splitter PBS5 and travels straight in the Z direction to the light emitting unit LO2. Head.

  Similar to that shown in FIG. 6A, the laser beam LB2 remains TE-polarized light, passes through the polarization beam splitters PBS1 and PBS5 as it is, and travels toward the light emitting portion LO2. Further, the laser beam LB1 remains TE-polarized light, passes through the polarization beam splitters PBS4 and PBS6 as they are, and travels toward the light emitting portion LO3. The TM polarized light and components contained in the laser beams LB1 and LB2 are reflected by the polarization beam splitters PBS1 and PBS4, respectively, and absorbed by the beam dampers DP1 and DP3, respectively.

  As a result, the laser beam LB4 is converted into the laser beam LBA from the light emitting unit LO1, the laser beam LBB obtained by combining the laser beam LB2 and the laser beam LB3 is combined from the light emitting unit LO2, and the laser beam LB1 is converted into the light emitting unit as the laser beam LBC. The light is emitted from LO3. In this case, the output ratio of the laser beam LBA, the laser beam LBB, and the laser beam LBC is 1: 2: 1. In this case, in the laser processing apparatus 100 shown in FIG. 1, the three laser beams LBA, LBB, and LBC emitted from the condensing unit 20 are transmitted through the transmission fibers 40 and 41 and the transmission fiber (not shown), respectively. The light is emitted from the beam emission heads 30 and 31 and a laser beam emission head (not shown) at the above output ratio.

  Further, as shown in FIG. 6C, the half-wave plate HWP1 is disposed on the optical path of the laser beam LB3 until it passes through the polarization beam splitter PBS2 and enters the polarization beam splitter PBS3. The wave plate HWP4 is disposed on the optical path of the laser beam LB4 until it passes through the polarizing beam splitter PBS5 and enters the polarizing beam splitter PBS6. Since the laser beam LB3 is changed to TM-polarized light by the half-wave plate HWP1, it is reflected by the polarization beam splitter PBS3, travels straight in the Z direction, and travels toward the light emitting portion LO1. On the other hand, the laser beam LB4 passes through the polarization beam splitters PBS3 and PBS5, and is changed to TM polarization by the half-wave plate HWP4. Therefore, the laser beam LB4 is reflected by the polarization beam splitter PBS6 and travels straight in the Z direction. Head for LO3.

  Similar to that shown in FIG. 6A, the laser beam LB2 remains TE-polarized light, passes through the polarization beam splitters PBS1 and PBS5 as it is, and travels toward the light emitting portion LO2. Further, the laser beam LB1 remains TE-polarized light, passes through the polarization beam splitters PBS4 and PBS6 as they are, and travels toward the light emitting portion LO3. The TM polarized light and components contained in the laser beams LB1 and LB2 are reflected by the polarization beam splitters PBS1 and PBS4, respectively, and absorbed by the beam dampers DP1 and DP3, respectively.

  As a result, the laser beam LB3 is converted into the laser beam LBA from the light emitting unit LO1, the laser beam LB2 is converted into the laser beam LBB from the light emitting unit LO2, and the laser beam LBC obtained by combining the laser beam LB1 and the laser beam LB4 is output to the light emitting unit. The light is emitted from LO3. In this case, the output ratio of the laser beam LBA, the laser beam LBB, and the laser beam LBC is 1: 1: 2. In this case, in the laser processing apparatus 100 shown in FIG. 1, the three laser beams LBA, LBB, and LBC emitted from the condensing unit 20 are transmitted through the transmission fibers 40 and 41 and the transmission fiber (not shown), respectively. The light is emitted from the beam emission heads 30 and 31 and a laser beam emission head (not shown) at the above output ratio.

  According to the laser oscillator 10 according to the present embodiment, the same effects as those of the first embodiment can be obtained. Further, the laser beams LBA to LBC can be emitted simultaneously from the three light emitting portions LO1 to LO3, respectively. Further, the output ratio of the laser beams LBA to LBC can also be changed.

  The half-wave plate HWP2 shown in the first embodiment may be provided so as to be movable with respect to the optical path between the polarization beam splitter PBS1 and the polarization beam splitter PBS5 in the laser beam LB2. For example, in the configuration shown in FIG. 6A, the laser beam LB2 is reflected by the polarization beam splitters PBS5 and PBS6, respectively, by being disposed on the half-wave plate HWP2 between the polarization beam splitter PBS1 and the polarization beam splitter PBS5. The laser beam LBC combined with the laser beams LB1 and LB2 is emitted from the light emitting unit LO3 toward the emitting unit LO3. In this case, the output ratio of the laser beam LBA emitted from the emission part LO1 and the laser beam LBC emitted from the light emission part LO3 is 1: 1, and the maximum output of each is 2 kW.

  Further, by retracting the half-wave plate HWP1 out of the optical path of the laser beams LB3 and LB4, the laser beams LB3 and LB4 pass through the polarization beam splitter PBS3 and go straight in the Y direction. At the same time, the laser beams LB3 and LB4 are arranged on the optical path of the laser beams LB3 and LB4 until the half-wave plate HWP3 passes through the polarizing beam splitter PBS3 and enters the polarizing beam splitter PBS5. The light beam is reflected by the polarization beam splitter PBS5, combined with the laser beam LB2, and emitted from the light emitting unit LO2 as the laser beam LBB. In this case, the laser beam LB1 is emitted from the light emitting portion LO3 as the laser beam LBC, and the output ratio of the laser beam LBB to the laser beam LBC is 3: 1.

  The half-wave plate HWP1 is retracted out of the optical path of the laser beams LB3 and LB4, and the laser beam LB3 until the half-wave plate HWP3 passes through the polarization beam splitter PBS3 and enters the polarization beam splitter PBS5. , LB4 on the optical path, and further arranged on the half-wave plate HWP2 between the polarizing beam splitter PBS1 and the polarizing beam splitter PBS5, the laser beams LB1 to LB4 are all coupled to form the laser beam LB. Is emitted from the light emitting portion LO3.

  In the present embodiment, the arrangement of the optical components is not changed, and only the laser beam LB1 or the laser beam LB2 may be used in combination with the laser beam LB3 and the laser beam LB4, or the laser beams LBA to LBC. It is possible to realize a configuration in which the output ratio can be changed. However, there are fewer variations than the configurations shown in FIGS. 6A to 6C.

(Embodiment 3)
FIG. 7 shows a usage example of the laser processing apparatus according to the present embodiment. The laser oscillator 10 and the laser processing apparatus 100 shown in the present embodiment have the same configuration as that shown in the first embodiment. In other words, whether the laser beams LB1 to LB4 are respectively incident on the beam combiner 12 from the four laser modules 11, are combined in the beam combiner 12, and are emitted from either the light emitting portion LO1 or LO2 as the laser beam LB. Are distributed in the beam combiner 12 and emitted from the light emitting portions LO and LO2 as laser beams LBA and LBB, respectively. A laser beam LB or LBA is emitted from the laser beam emission head 30 via the transmission fiber 40, and a laser beam LB or LBB is emitted from the laser beam emission head 31 via the transmission fiber 41. .

  For example, as shown in the upper left and upper right (switching) of FIG. 7, the laser beam LB is emitted in different time zones with respect to the work 60 by switching the light emitting unit and the laser beam emitting head from which the laser beam LB is emitted. Therefore, the operating time of the laser processing apparatus 100 can be improved by eliminating the stop time of the laser oscillator 10 that occurs when the work 60 is carried in and out. Further, as shown in the lower left of FIG. 7 (distribution 1), for example, the laser beams LBA and LBB having the same output are emitted from the laser beam emitting heads 30 and 31, respectively, thereby increasing the number of workpieces 60 processed simultaneously. And productivity in the laser processing step can be improved. Further, as shown in the lower right of FIG. 7 (distribution 2), a low output laser beam LBA is emitted from the laser beam emission head 30, and a high output laser beam LBB is emitted from the laser beam emission head 31, respectively. It is also possible to improve the processing quality of 60. For example, when the workpiece 60 is a metal plate with a plating film, the plating film is removed with a low-power laser beam LBA emitted from the laser beam emission head 30 and then emitted from the laser beam emission head 31. It is possible to weld the workpiece using the high-power laser beam LBB and improve the welding quality of the welded portion.

  The laser oscillator 10 shown in the second embodiment may be mounted on the laser processing apparatus 100. In that case, laser beams are emitted from three laser beam emission heads at different times or simultaneously. Further, the number of light emitting portions in the laser oscillator 10 and the number of transmission fibers and laser beam emitting heads in the laser processing apparatus 100 may be further increased.

  By doing in this way, the number of the workpiece | work 60 which can be processed simultaneously increases, and the productivity of a laser processing process can further be improved.

  The laser oscillator according to the present invention can realize switching of a light emitting portion from which a laser beam is emitted and changing the output ratio of laser beams emitted from a plurality of light emitting portions with a simple configuration, and a large number of different types. This is useful when applied to a laser processing apparatus for processing a workpiece.

DESCRIPTION OF SYMBOLS 10 Laser oscillator 11 Laser module 12 Beam combiner 20 Condensing unit 30,31 Laser beam emission head 40,41 Transmission fiber 50 Control part 60 Work 70 Case 100 Laser processing apparatus DP1-DP3 Beam damper LI1-LI4 Light incident part LO1- LO3 Light emitting part M1 to M5 Mirror (light reflecting member)
HWP1 1/2 wavelength plate (one polarizing member)
HWP2 1/2 wavelength plate (other polarizing member)
HWP3, HWP4 1/2 wavelength plate (polarizing member)

Claims (13)

A plurality of laser modules each emitting a laser beam whose main polarization state is the first polarization state;
A beam combiner that combines a plurality of laser beams emitted from the plurality of laser modules to emit one or more laser beams;
A condensing unit that condenses the laser beam emitted from the beam combiner so as to have a predetermined beam diameter and guides the laser beam to a transmission fiber;
The beam combiner is
A plurality of polarizing members that change the incident laser beam from the first polarization state to a second polarization state different from the first polarization state;
A polarizing beam splitter that transmits the laser beam having the first polarization state, and reflects the laser beam having the second polarization state;
A plurality of light emitting portions from which the laser beam combined in the beam combiner is emitted,
The one polarizing member and the other polarizing member are each provided so as to be movable between a predetermined position on the optical path of at least one laser beam and a predetermined position outside the optical path,
At least one of the plurality of laser beams travels in a first direction and is incident on the polarizing beam splitter, while at least one laser beam intersects the first direction with a second Traveling in the direction and entering the polarizing beam splitter,
The one polarizing member is disposed at a predetermined position on the optical path of at least one laser beam traveling in the first direction, or on the optical path of at least one laser beam traveling in the second direction. When the other polarizing member is arranged at a predetermined position, the laser beam transmitted through the one polarizing member or the other polarizing member is transmitted in the first or second direction by the polarizing beam splitter. A laser beam that is reflected in a direction different from a traveling direction until it enters the polarizing beam splitter, while a laser beam that does not pass through the one polarizing member or the other polarizing member passes through the polarizing beam splitter. Oscillator. The laser oscillator according to claim 1, wherein
The laser beam reflected by the polarization beam splitter and the laser beam transmitted through the polarization beam splitter are combined by the polarization beam splitter so as to have the same optical axis, and at least one light of the plurality of light emitting portions A laser oscillator characterized by being emitted from an emission part. The laser oscillator according to claim 2, wherein
At least one of a laser beam transmitted through the polarizing beam splitter and a laser beam reflected by the polarizing beam splitter by a light reflecting member provided at a predetermined interval in the second direction with respect to the polarizing beam splitter. A laser oscillator, wherein an optical path is bent and emitted from another light emitting part. The laser oscillator according to claim 3, wherein
A laser oscillator, wherein a laser beam is emitted from at least two of the plurality of light emitting portions. The laser oscillator according to claim 4, wherein
Among the plurality of laser beams traveling in the first direction, change the number of the one polarizing member disposed on the optical path, or among the plurality of laser beams traveling in the second direction, A laser oscillator characterized in that the output ratio of the laser beams emitted from at least two light emitting portions can be changed by changing the number of the other polarizing members arranged on the optical path. The laser oscillator according to claim 1, wherein
Among the plurality of laser beams, there are a plurality of laser beams traveling in the first and second directions, respectively.
The one polarizing member is arranged at a predetermined position on the optical path of the plurality of laser beams traveling in the first direction, and at least one of the plurality of laser beams traveling in the second direction A laser oscillator, wherein a laser beam is emitted from at least two of the plurality of light emitting portions by arranging the other polarizing member at a predetermined position on an optical path. The laser oscillator according to claim 6, wherein
Among the plurality of laser beams traveling in the first direction, change the number of the one polarizing member disposed on the optical path, or among the plurality of laser beams traveling in the second direction, A laser oscillator characterized in that the output ratio of the laser beams emitted from at least two light emitting portions can be changed by changing the number of the other polarizing members arranged on the optical path. A plurality of laser modules each emitting a laser beam whose main polarization state is the first polarization state;
A beam combiner that combines a plurality of laser beams emitted from the plurality of laser modules to emit one or more laser beams;
A condensing unit that condenses the laser beam emitted from the beam combiner so as to have a predetermined beam diameter and guides the laser beam to a transmission fiber;
The beam combiner is
A plurality of polarizing members that change the incident laser beam from the first polarization state to a second polarization state different from the first polarization state;
A polarizing beam splitter that transmits the laser beam having the first polarization state, and reflects the laser beam having the second polarization state;
A plurality of light emitting portions from which the laser beam combined in the beam combiner is emitted,
The one polarizing member and the other polarizing member are each provided so as to be movable between a predetermined position on the optical path of at least one laser beam and a predetermined position outside the optical path,
At least one laser beam of the plurality of laser beams travels in a first direction, and at least two laser beams travel in a second direction intersecting the first direction to reach the polarization beam splitter. Incident,
By arranging the one polarizing member and / or the other polarizing member on respective optical paths of at least two laser beams traveling in the second direction, at least two of the plurality of light emitting portions are arranged. A laser oscillator, wherein a laser beam is emitted from a light emitting portion. The laser oscillator according to claim 8, wherein
The laser beam traveling in the second direction and reflected by the polarization beam splitter and the laser beam traveling in the first direction and transmitted through the polarization beam splitter are combined by the polarization beam splitter, A laser oscillator characterized by being emitted from at least one light emitting part among a plurality of light emitting parts. The laser oscillator according to any one of claims 1 to 9,
A plurality of the condensing units are provided in accordance with the number of laser beams coupled within the beam combiner and emitted outside the beam combiner, and the transmission fiber is provided in each of the plurality of condensing units. A laser oscillator characterized by being connected. A laser oscillator according to claim 10;
A laser beam emission head attached to each of the emission ends of the plurality of transmission fibers;
A laser processing apparatus comprising: at least a control unit that controls the operation of the polarizing member. The laser processing apparatus according to claim 11, wherein
A laser processing apparatus, wherein a laser beam emitting head from which a laser beam is emitted can be switched by changing a position of the polarizing member in the beam combiner. The laser processing apparatus according to claim 11 or 12,
A laser processing apparatus configured to change an output ratio of laser beams respectively emitted from a plurality of laser beam emission heads by changing a position of the polarizing member in the beam combiner. .

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