WO2016031895A1 - Laser light irradiation device - Google Patents

Laser light irradiation device Download PDF

Info

Publication number
WO2016031895A1
WO2016031895A1 PCT/JP2015/074153 JP2015074153W WO2016031895A1 WO 2016031895 A1 WO2016031895 A1 WO 2016031895A1 JP 2015074153 W JP2015074153 W JP 2015074153W WO 2016031895 A1 WO2016031895 A1 WO 2016031895A1
Authority
WO
WIPO (PCT)
Prior art keywords
laser
laser light
optical fiber
step index
index type
Prior art date
Application number
PCT/JP2015/074153
Other languages
French (fr)
Japanese (ja)
Inventor
森本　政仁
奈良　一孝
昌孝 家垣
龍一郎 湊
齋藤　恒聡
末松　克輝
繁弘 高坂
松下　俊一
Original Assignee
古河電気工業株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 古河電気工業株式会社 filed Critical 古河電気工業株式会社
Priority to JP2016545600A priority Critical patent/JP6640094B2/en
Publication of WO2016031895A1 publication Critical patent/WO2016031895A1/en

Links

Images

Classifications

    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B18/00—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body
    • A61B18/18—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body by applying electromagnetic radiation, e.g. microwaves
    • A61B18/20—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body by applying electromagnetic radiation, e.g. microwaves using laser
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K26/00—Working by laser beam, e.g. welding, cutting or boring
    • B23K26/02—Positioning or observing the workpiece, e.g. with respect to the point of impact; Aligning, aiming or focusing the laser beam
    • B23K26/06—Shaping the laser beam, e.g. by masks or multi-focusing
    • B23K26/064—Shaping the laser beam, e.g. by masks or multi-focusing by means of optical elements, e.g. lenses, mirrors or prisms
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K26/00—Working by laser beam, e.g. welding, cutting or boring
    • B23K26/02—Positioning or observing the workpiece, e.g. with respect to the point of impact; Aligning, aiming or focusing the laser beam
    • B23K26/06—Shaping the laser beam, e.g. by masks or multi-focusing
    • B23K26/073—Shaping the laser spot
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
    • G02B27/09—Beam shaping, e.g. changing the cross-sectional area, not otherwise provided for

Definitions

  • the present invention relates to a laser beam irradiation apparatus.
  • the intensity distribution of the laser beam is approximated by the Gaussian intensity distribution, reflecting the light emission characteristics of the light source and the characteristics of the light guide (for example, optical fiber). Often.
  • a beam having this intensity distribution is generally called a Gaussian beam.
  • a laser beam having a uniform intensity distribution in the irradiated region is required. This is to prevent damage to normal cells while destroying cancer cells. Therefore, in such an application, a Gaussian beam having a peak at the center of the intensity distribution is not preferable. Therefore, various techniques for producing a laser beam having a smooth intensity distribution are known (see, for example, Patent Document 1).
  • the present invention has been made in view of the above, and an object of the present invention is to provide a laser beam irradiation apparatus that improves the smoothness of the intensity distribution of the laser beam without causing an increase in the size of the apparatus. is there.
  • a laser light irradiation apparatus propagates a laser light source unit that emits laser light and laser light emitted from the laser light source unit in a multimode.
  • an objective optical system for enlarging and irradiating the object.
  • the laser light irradiation apparatus is characterized in that, in the above invention, the laser light source unit includes one laser element, and a spectral width of laser light oscillated by the laser element is 3 nm or more and 100 nm or less.
  • the laser light source unit includes a plurality of laser elements, and laser light emitted from the laser light source unit oscillates by the plurality of laser elements. It is a combination of lights, and a spectrum width of a combination of laser beams oscillated by the plurality of laser elements is 3 nm or more and 100 nm or less.
  • the laser beam irradiation apparatus is characterized in that, in the above invention, each of the spectral widths of the laser beam oscillated by the laser element is 3 nm or more and 50 nm or less.
  • the central oscillation wavelengths of the plurality of laser elements are different from each other, and the maximum difference in the central oscillation wavelengths of the plurality of laser elements is 50 nm or less. It is characterized by.
  • the mode disturbance means may have a length of a region of 1 m or more that simultaneously applies lateral pressure, bending, and vibration to the step index type multimode optical fiber.
  • the laser beam irradiation apparatus is characterized in that, in the above invention, the step index type multimode optical fiber has a numerical aperture of 0.15 or more.
  • the laser beam irradiation apparatus is characterized in that, in the above invention, the numerical aperture of the objective optical system is smaller than the numerical aperture of the step index type multimode optical fiber.
  • the laser beam irradiation apparatus has an effect of improving the smoothness of the intensity distribution of the laser beam without causing an increase in the size of the apparatus.
  • FIG. 1 is a diagram showing a schematic configuration of a laser beam irradiation apparatus according to the first embodiment.
  • FIG. 2 is a graph showing an example of a spectrum of laser light oscillated by a Fabry-Perot laser diode.
  • FIG. 3 is a graph showing an example of a spectrum of laser light oscillated by a laser diode having a fiber Bragg grating as an external resonator.
  • FIG. 4 is a graph showing an example of a spectrum in a case where laser beams oscillated by a plurality of laser elements are combined.
  • FIG. 5 is a diagram showing a schematic configuration of a laser light source unit in the laser light irradiation apparatus according to the second embodiment.
  • FIG. 1 is a diagram showing a schematic configuration of a laser beam irradiation apparatus according to the first embodiment.
  • FIG. 2 is a graph showing an example of a spectrum of laser light oscillated by a Fabry-Perot laser diode
  • FIG. 6 is a diagram illustrating a schematic configuration of a laser light source unit in the laser light irradiation apparatus according to the second embodiment.
  • FIG. 7 is a diagram illustrating a schematic configuration of a laser light source unit in the laser light irradiation apparatus according to the second embodiment.
  • FIG. 8 is a diagram illustrating a schematic configuration of a laser light source unit in the laser light irradiation apparatus according to the third embodiment.
  • FIG. 9 is a diagram showing a schematic configuration of mode disturbance means in the laser beam irradiation apparatus according to the fourth embodiment.
  • FIG. 10 is a diagram showing a schematic configuration of mode disturbance means in the laser beam irradiation apparatus according to the fourth embodiment.
  • FIG. 10 is a diagram showing a schematic configuration of mode disturbance means in the laser beam irradiation apparatus according to the fourth embodiment.
  • FIG. 11 is a diagram showing a schematic configuration of mode disturbance means in the laser beam irradiation apparatus according to the fifth embodiment.
  • FIG. 12 is a diagram illustrating a schematic configuration of an objective optical system in the laser light irradiation apparatus according to the sixth embodiment.
  • FIG. 13 is a diagram for explaining the definition of smoothness.
  • FIG. 14 is a diagram illustrating the smoothness in the first verification example.
  • FIG. 15 is a diagram illustrating the smoothness in the first verification example.
  • FIG. 16 is a diagram illustrating the smoothness in the first verification example.
  • FIG. 17 is a diagram illustrating the smoothness in the second verification example.
  • FIG. 18 is a diagram illustrating the smoothness in the second verification example.
  • FIG. 19 is a diagram illustrating the smoothness in the second verification example.
  • FIG. 19 is a diagram illustrating the smoothness in the second verification example.
  • FIG. 20 is a diagram illustrating the smoothness in the third verification example.
  • FIG. 21 is a diagram illustrating the smoothness in the third verification example.
  • FIG. 22 is a diagram illustrating the smoothness in the third verification example.
  • FIG. 23 is a diagram illustrating the smoothness in the fourth verification example.
  • FIG. 24 is a diagram illustrating the smoothness in the fourth verification example.
  • FIG. 25 is a diagram illustrating the smoothness in the fourth verification example.
  • FIG. 26 is a diagram illustrating the smoothness in the fifth verification example.
  • FIG. 27 is a diagram illustrating the smoothness in the fifth verification example.
  • FIG. 28 is a diagram illustrating the smoothness in the fifth verification example.
  • FIG. 29 is a diagram illustrating the smoothness in the verification example 6.
  • FIG. 30 is a diagram illustrating the smoothness in the verification example 6.
  • FIG. 31 is a diagram illustrating the smoothness in the verification example 6.
  • FIG. 32 is a diagram illustrating the smoothness in the seventh verification example.
  • FIG. 33 is a diagram illustrating the smoothness in the seventh verification example.
  • FIG. 34 is a diagram illustrating the smoothness in the seventh verification example.
  • FIG. 1 is a diagram showing a schematic configuration of a laser beam irradiation apparatus according to the first embodiment.
  • the laser light irradiation apparatus 1000 includes a laser light source unit 100, a step index type multimode optical fiber 200, a mode disturbance means 300, and an objective optical system 400.
  • the laser light source unit 100 is a unit for emitting laser light, and includes at least one laser element, preferably a plurality of laser elements.
  • the spectral width of the laser light emitted from the laser light source unit 100 is preferably 3 nm or more and 100 nm or less. If the lower limit of the spectral width is not reached, it is difficult to smooth the intensity distribution of the laser light. On the other hand, if the upper limit of the spectral width is exceeded, the laser light irradiation apparatus 1000 may deviate from the desired wavelength. Because. For example, when the laser beam irradiation apparatus 1000 is used for an application for destroying cancer cells, it is necessary to use laser light having a wavelength in the vicinity of 1480 nm which is the absorption wavelength of water. It will come off.
  • the spectral width of the laser light emitted from the laser light source unit 100 is a wavelength range in which the intensity is reduced by 20 dB from the maximum output intensity of the laser light. Further, when the laser light source unit 100 includes one laser element, it means that the spectral width of the laser light oscillated by the one laser element falls within the above range, and when the laser light source unit 100 includes a plurality of laser elements, It means that the total spectrum width (that is, the width between the maximum value and the minimum value in the case where there are a plurality of wavelengths whose intensity is 20 dB lower than the maximum output intensity of the laser beam) falls within the above range. is doing.
  • the laser light source unit 100 has one laser element, for example, a Fabry-Perot type laser diode may be used. Since the Fabry-Perot type laser diode has a plurality of resonance modes, the laser light of the plurality of resonance modes is used as it is (without limiting the mode with an external resonator or the like) as the output of the laser light source unit 100. be able to.
  • FIG. 2 is a graph showing an example of a spectrum of laser light oscillated by a Fabry-Perot laser diode.
  • the spectral width of the laser light oscillated by the Fabry-Perot laser diode is 13 nm, which is 3 nm to 100 nm. That is, the Fabry-Perot type laser diode having a spectrum as shown in FIG. 2 is suitable as a laser element included in the laser light source unit 100.
  • the laser light source unit 100 When there are a plurality of laser elements provided in the laser light source unit 100, it is preferable to use a Fabry-Perot type laser diode, but it is also possible to use a distributed feedback type laser diode or a laser diode using an external resonator. Note that, even if the spectrum width of the laser light emitted from each laser element is narrow, the combined spectrum width may be 3 nm or more and 100 nm or less.
  • the spectral width of the laser light oscillated by each laser element included in the laser light source unit 100 is preferably 3 nm or more and 50 nm or less. Note that the spectral width of the laser light oscillated by the laser element is a wavelength range in which the intensity is reduced by 20 dB from the maximum output intensity of the laser light.
  • the laser light source unit 100 includes a plurality of laser elements, it is preferable not to include a plurality of the same laser elements, but to configure the respective laser elements to have different center oscillation wavelengths. However, if the center oscillation wavelength is too far away from the desired wavelength as the laser light irradiation apparatus 1000, the maximum difference between the center oscillation wavelengths is preferably 50 nm or less.
  • FIG. 3 is a graph showing an example of a spectrum of laser light oscillated by a laser diode having a fiber Bragg grating as an external resonator.
  • the spectral width of the laser beam is narrower than 3 nm. That is, a Fabry-Perot type laser diode having a spectrum as shown in FIG. 3 is not suitable as a laser element included in the laser light source unit 100.
  • FIG. 4 is a graph showing an example of a spectrum in a case where laser beams oscillated by a plurality of laser elements are combined.
  • the graph shown in FIG. 4 shows an example in which the oscillations of two Fabry-Perot laser diodes are combined.
  • the spectrum width of the combined laser beam is 70 nm, which is 3 nm or more and 100 nm or less.
  • the spectral width of the laser light oscillated by each laser element is also 3 nm or more and 50 nm or less. That is, the two laser elements having a spectrum as shown in FIG. 4 are suitable as laser elements included in the laser light source unit 100.
  • step index type multimode optical fiber 200 and the mode disturbance means 300 will be described.
  • the step index type multimode optical fiber 200 is an optical fiber that propagates laser light emitted from the laser light source unit 100 to the objective optical system 400 in multimode.
  • the step index type multimode optical fiber 200 is an optical fiber that allows laser light to propagate in a plurality of modes, and particularly has a refractive index distribution formed by a core and a clad in a step shape. .
  • the numerical aperture of the step index type multimode optical fiber 200 is 0.15 or more. This is because, as will be described in detail later, it has been experimentally confirmed that the smoothness F is improved when the NA of the step index type multimode optical fiber is large.
  • the mode disturbance means 300 is a means that is provided between the laser light source unit 100 and the objective optical system 400, and simultaneously applies a lateral pressure, bending and vibration to the step index type multimode optical fiber 200.
  • the mode disturbance means 300 gives a disturbance to the mode of the laser beam propagating through the step index type multimode optical fiber 200 by simultaneously applying a lateral pressure, bending and vibration to the step index type multimode optical fiber 200.
  • the step index type multimode optical fiber 200 allows the laser light to propagate in a plurality of modes, but in many cases, the laser light does not propagate in all the allowed modes.
  • the mode disturbance means 300 has a function of changing the coupling state between the laser beam and the mode by giving a disturbance to the step index type multimode optical fiber 200. As a result, a so-called mode shift in which the mode in which the laser light propagates changes occurs, and propagation in a mode that has not been realized is realized. This means that the spatial coherency of the laser light propagating through the step index type multimode optical fiber 200 is reduced.
  • the objective optical system 400 is an optical system for expanding the beam diameter of the laser light emitted from the step index type multimode optical fiber 200 and irradiating the object.
  • the end surface of the step index type multimode optical fiber 200 and the object are arranged in an optically conjugate relationship, and the intensity distribution of the laser light on the end surface of the step index type multimode optical fiber 200 is substantially similar to the object. Projected.
  • the laser light propagating through the step index type multimode optical fiber 200 is propagated in many modes by the mode disturbance means 300 and reaches the end face, so that the smoothness of the intensity distribution at the end face is improved. .
  • speckle noise which is a random interference phenomenon, is also reduced. Therefore, smoothness is improved even when the object is irradiated.
  • a new embodiment can be configured by combining the configurations of different embodiments described below so that a specific example of the laser light source unit 100 and a specific example of the mode disturbance unit 300 are combined.
  • FIGS. 5 to 7 are diagrams showing a schematic configuration of a laser light source unit in the laser light irradiation apparatus according to the second embodiment.
  • the laser light source unit 110 shown in FIGS. 5 to 7 is a specific example of the laser light source unit 100 in the first embodiment.
  • FIG. 5 is a plan view of the laser light source unit 110
  • FIG. 6 is a vertical view of the laser light source unit 110
  • FIG. 7 is an enlarged view of a portion where laser light is combined.
  • the laser light source unit 110 includes a first laser element 111a, a second laser element 111b, and a third laser element 111c.
  • the laser beams oscillated by the laser element 111 b and the third laser element 111 c are directly combined and introduced into the step index type multimode optical fiber 200.
  • the first laser element 111a, the second laser element 111b, and the third laser element 111c are preferably Fabry-Perot laser diodes, but are distributed feedback laser diodes or laser diodes using external resonators. Etc. may be used.
  • the first laser element 111a, the second laser element 111b, and the third laser element 111c have different central oscillation wavelengths, and the maximum difference between the central oscillation wavelengths is 50 nm or less.
  • the spectrum width of each laser beam oscillated by the first laser element 111a, the second laser element 111b, and the third laser element 111c is not less than 3 nm and not more than 50 nm. The width is 3 nm or more and 100 nm or less.
  • the first laser element 111a, the second laser element 111b, and the third laser element 111c are arranged in parallel to each other and emit laser light in the same direction.
  • the laser beams emitted from the first laser element 111a, the second laser element 111b, and the third laser element 111c are respectively a first cylindrical lens 112a, 112b, 112c having a refractive power in a direction perpendicular to the paper surface, and a paper surface horizontal method.
  • the first cylindrical lenses 112a, 112b, and 112c and the second cylindrical lenses 113a, 113b, and 113c are parallel laser beams emitted from the first laser element 111a, the second laser element 111b, and the third laser element 111c. It is for light.
  • the first cylindrical lenses 112a, 112b, and 112c are arranged so as to have refractive power in the direction perpendicular to the paper surface with respect to the laser light.
  • the second cylindrical lenses 113a, 113b, and 113c are arranged so as to have a refractive power in a direction parallel to the paper surface with respect to the laser light.
  • the first laser element 111a, the second laser element 111b, and the third laser element 111c are arranged with a step.
  • the laser beams emitted from the first laser element 111a, the second laser element 111b, and the third laser element 111c are reflected by the mirrors 114a, 114b, and 114c, they are perpendicular to the plane of FIG.
  • the laser beams are different in height from each other and parallel to each other.
  • the laser beams reflected by the mirrors 114a, 114b, and 114c are parallel laser beams having different heights when entering the condenser lens 115.
  • FIG. 7 shows how the laser beams emitted from the first laser element 111 a, the second laser element 111 b, and the third laser element 111 c are combined and introduced into the step index type multimode optical fiber 200.
  • the condensing lens 115 is a lens having a positive refractive power, and is arranged so that the rear focal position substantially coincides with the end face of the step index type multimode optical fiber 200.
  • each of the laser beams L a , L b , and L c is incident on the end face of the step index type multimode optical fiber 200 at an incident angle equal to or smaller than the angle ⁇ 1 .
  • NA 1 the numerical aperture
  • Each laser beam L a , L b , L c having an incident angle of ⁇ 1 or less is coupled to the step index type multimode optical fiber 200.
  • the laser light source unit 110 configured as described above has a step index type multimode optical fiber 200 that propagates laser light emitted from the laser light source unit 110 in a multimode, and a lateral pressure, bending, and vibration in the step index type multimode optical fiber 200.
  • a mode disturbance means 300 that simultaneously applies the above
  • the objective optical system 400 that expands the beam diameter of the laser light emitted from the step index type multimode optical fiber 200 and irradiates the object.
  • Such a laser beam irradiation apparatus is configured.
  • FIG. 8 is a diagram illustrating a schematic configuration of a laser light source unit in the laser light irradiation apparatus according to the third embodiment.
  • the laser light source unit 120 shown in FIG. 8 is a specific example of the laser light source unit 100 in the first embodiment.
  • the laser light source unit 120 includes a first laser element 121a, a second laser element 121b, and a third laser element 121c, and these first laser element 121a and second laser element.
  • the laser light oscillated by 121b and the third laser element 121c is multiplexed in the laser light source unit 120 and connected to the step index type multimode optical fiber 200 in a so-called pigtail configuration.
  • the first laser element 121a, the second laser element 121b, and the third laser element 121c are preferably Fabry-Perot laser diodes, but are distributed feedback laser diodes or laser diodes using external resonators. Etc. may be used.
  • the first laser element 121a, the second laser element 121b, and the third laser element 121c have different central oscillation wavelengths, and the maximum difference between the central oscillation wavelengths is 50 nm or less.
  • the spectrum width of each laser beam oscillated by the first laser element 121a, the second laser element 121b, and the third laser element 121c is not less than 3 nm and not more than 50 nm, and the spectrum when the laser beams are multiplexed is obtained. The width is 3 nm or more and 100 nm or less.
  • the laser beams oscillated by the first laser element 121a, the second laser element 121b, and the third laser element 121c are introduced into the optical multiplexer 123 while propagating through the optical fibers 122a, 122b, and 122c, respectively.
  • the optical multiplexer 123 uses, for example, a wavelength division multiplexing optical coupler.
  • the laser light combined by the optical multiplexer 123 is guided to the outside of the laser light source unit 120 while propagating through the optical fiber 124, and is step index type via the optical connection part 125 constituted by a connector and a fusion connection part.
  • the multimode optical fiber 200 is connected.
  • the optical fibers 122a, 122b, 122c, and 124 are single-mode optical fibers when the first laser element 121a, the second laser element 121b, and the third laser element 121c are single-mode laser elements.
  • the optical multiplexer 123 is a fiber melting type, a filter type, or a waveguide type based on the difference in oscillation wavelength between the first laser element 121a, the second laser element 121b, and the third laser element 121c.
  • a coupler can be selected and used.
  • a configuration in which a polarization beam combiner is used instead of the optical multiplexer 123 may be adopted. Further, when there are more laser beams to be combined, a configuration in which a polarization beam combiner and a wavelength division multiplexing optical multiplexer are used together may be employed.
  • the laser light source unit 120 having the above configuration includes a step index type multimode optical fiber 200 that propagates laser light emitted from the laser light source unit 120 in a multimode, and a lateral pressure, bending, and vibration in the step index type multimode optical fiber 200.
  • a mode disturbance means 300 that simultaneously applies the above
  • the objective optical system 400 that expands the beam diameter of the laser light emitted from the step index type multimode optical fiber 200 and irradiates the object.
  • Such a laser beam irradiation apparatus is configured.
  • FIGS. 9 and 10 are diagrams showing a schematic configuration of the mode disturbance means in the laser beam irradiation apparatus according to the fourth embodiment.
  • the mode disturbance means 310 shown in FIGS. 9 and 10 is a specific example of the mode disturbance means 300 in the first embodiment.
  • FIG. 9 is a partially transparent view of the mode disturbance unit 310
  • FIG. 10 is a side view of the mode disturbance unit 310.
  • the mode disturbance means 310 has a configuration in which the step index type multimode optical fiber 200 arranged in a bundle shape is sandwiched between two sandwich plates 311a and 311b.
  • the two clamping plates 311a and 311b are provided with pressurizing means 312 composed of bolts and nuts, and a lateral pressure is applied to the step index type multimode optical fiber 200 sandwiched between the two clamping plates 311a and 311b. It is configured to be. As shown in FIG. 9, the step index type multimode optical fiber 200 arranged in a bundle shape is arranged in a state having a large number of intersections, so that the side pressure applied from the two sandwiching plates 311a and 311b Is locally changed, and the disturbance is more efficiently applied to the mode of the laser light propagating through the step index type multimode optical fiber 200.
  • the pressurizing means 312 can be constituted by bolts and nuts as shown in the figure. However, if the upper sandwiching plate 311a has a certain weight, the pressurizing means 312a is pressurized by its own weight. Means 312 may be provided. Alternatively, a separate weight or the like can be disposed on the upper clamping plate 311a, and the weight of the weight can be used as the pressurizing unit 312.
  • step index type multimode optical fiber 200 is arranged in a bundle shape, bending is applied to the step index type multimode optical fiber 200.
  • the bending of the step index type multimode optical fiber 200 is a disturbance to the laser light propagating through the step index type multimode optical fiber 200.
  • the sandwiching plates 311a and 311b are provided with a vibration means 313 so that vibration is applied to the step index type multimode optical fiber 200 sandwiched between the two sandwiching plates 311a and 311b.
  • the vibration unit 313 is a vibration motor that generates vibration of about 200 Hz, for example.
  • the vibration with respect to the step index type multimode optical fiber 200 is a disturbance to the laser light propagating through the step index type multimode optical fiber 200.
  • the length of the step index type multi-mode optical fiber 200 arranged in a bundle is preferably 1 m or more.
  • the length of the region in which the mode disturbance means 310 simultaneously applies lateral pressure, bending and vibration to the step index type multimode optical fiber 200 is 1 m or more, which is sufficient for the mode of laser light propagating through the step index type multimode optical fiber 200. This is to give a disturbance.
  • the step index type multimode optical fiber 200 is wound with a radius of about 3 cm, the number of windings is about six.
  • the mode disturbance means 310 having the above configuration includes a laser light source unit 100 that emits laser light, a step index type multimode optical fiber 200 that propagates laser light emitted from the laser light source unit 100 in a multimode, and a step index type.
  • the laser beam irradiation apparatus according to the fourth embodiment is configured by using together with the objective optical system 400 that expands the beam diameter of the laser beam emitted from the multimode optical fiber 200 and irradiates the object.
  • FIG. 11 is a diagram showing a schematic configuration of mode disturbance means in the laser beam irradiation apparatus according to the fifth embodiment.
  • the mode disturbance means 320 shown in FIG. 11 is a specific example of the mode disturbance means 300 in the first embodiment.
  • the mode disturbance means 320 includes bobbins 321a and 321b, tension means 322a and 322b, and vibration means 323. As shown in FIG. 11, the mode disturbance means 320 has a configuration that uses a so-called optical fiber polarization controller.
  • the vibration means 323 is an actuator composed of, for example, an electric motor and a gear.
  • An optical fiber polarization controller is a polarization controller that controls polarization using birefringence when an optical fiber is bent.
  • the mode disturbance means 320 diverts this optical fiber type polarization controller and applies lateral pressure, bending and vibration to the step index type multimode optical fiber 200 simultaneously.
  • the step index type multimode optical fiber 200 is wound around bobbins 321a and 321b while being given a constant tension by tension means 322a and 322b. Thereby, the step index type multimode optical fiber 200 receives a side pressure from the bobbins 321a and 321b. Further, the bobbins 321a and 321b are configured to rotate around the shafts 321aa and 321ba, respectively. The bobbin 321a and 321b rotate around the shafts 321aa and 321ba, respectively. Will be twisted and subjected to lateral pressure and bending.
  • the step index type multimode optical fiber 200 is wound around the bobbins 321a and 321b so that the step index type multimode optical fibers 200 have intersections. Thereby, a strong lateral pressure and bending are applied locally at the intersection of the step index type multimode optical fibers 200.
  • the bobbins 321a and 321b are rotated around the shafts 321aa and 321ba by the vibration means 323, respectively, and vibration or peristalsis is applied. As a result, vibration or vibration is also applied to the step index type multimode optical fiber 200 wound around the bobbins 321a and 321b.
  • the mode disturbance means 320 having the above configuration includes a laser light source unit 100 that emits laser light, a step index type multimode optical fiber 200 that propagates laser light emitted from the laser light source unit 100 in a multimode, and a step index type.
  • the laser beam irradiation apparatus according to the fifth embodiment is configured by using together with the objective optical system 400 that expands the beam diameter of the laser beam emitted from the multimode optical fiber 200 and irradiates the object.
  • FIG. 12 is a diagram illustrating a schematic configuration of an objective optical system in the laser light irradiation apparatus according to the sixth embodiment.
  • An objective optical system 410 shown in FIG. 12 is a specific example of the objective optical system 400 in the first embodiment.
  • the objective optical system 410 includes an objective lens 411.
  • the objective lens 411 is a lens for enlarging the intensity distribution of the laser light on the end face of the step index type multimode optical fiber 200 to a substantially similar shape and projecting it onto the object. That is, the front focal position of the objective lens 411 is arranged so as to coincide with the end face of the step index type multimode optical fiber 200, and the rear focal position of the objective lens 411 coincides with the object.
  • NA 2 the numerical aperture of the objective lens 411 is smaller than the numerical aperture (NA 1 ) of the step index type multimode optical fiber 200.
  • NA 1 the numerical aperture of the step index type multimode optical fiber 200.
  • the above numerical aperture relationship is a state in which so-called vignetting occurs. That is, a part of the outer periphery of the laser light emitted from the end face of the step index type multimode optical fiber 200 cannot pass through the objective lens 411 and cannot reach the object. In general, it is not preferable that vignetting occurs. However, the objective optical system 410 intentionally generates vignetting so that the intensity distribution of the laser light projected onto the object is closer to a rectangle. Shaped into shape.
  • the objective optical system 410 having the above configuration includes a laser light source unit 100 that emits laser light, a step index type multimode optical fiber 200 that propagates laser light emitted from the laser light source unit 100 in a multimode, and a step index type.
  • the laser beam irradiation apparatus according to the sixth embodiment is configured by using the multimode optical fiber 200 together with the mode disturbance means 300 that simultaneously applies a lateral pressure, bending, and vibration.
  • FIG. 13 is a diagram for explaining the definition of smoothness.
  • an example of the intensity distribution of laser light is indicated by a solid line, and a Gaussian intensity distribution is indicated by a broken line as a comparative intensity distribution.
  • the average power P is the average value of the intensity of the laser beam in the range of 0.8 times the full width W of the intensity distribution of the laser beam.
  • the full width W is a wavelength range where the intensity is reduced by 20 dB from the maximum output intensity of the laser beam.
  • the vertical axis of the graph shown in FIG. 13 is an arbitrary unit (au) of the linear scale, and the full width W corresponds to the wavelength range at a position where the vertical axis is reduced to 1% of the maximum intensity.
  • the fluctuation width ⁇ P with respect to the average power is the difference between the peak-to-peak of the intensity of the laser beam in the range of 0.8 times the total width W of the intensity distribution of the laser beam.
  • the smoothness F increases as the unevenness in the intensity distribution of the laser beam increases. Further, even if the laser light intensity distribution approaches the Gaussian intensity distribution, the smoothness F increases. Therefore, it can be determined that the smaller the smoothness F defined above, the greater the effect of the present invention.
  • Verification Example 1 is an example in the case of using a laser beam having a narrow spectrum width as shown in FIG. In the mode disturbance means, vibration, lateral pressure and bending are applied simultaneously.
  • the numerical index of the used step index type multimode optical fiber is 0.15, and the numerical aperture of the objective optical system is 0.15.
  • FIG. 14 to 16 are diagrams showing the smoothness in the first verification example.
  • FIG. 14 is a 3D graph showing the intensity distribution of the laser light in Verification Example 1
  • FIG. 15 is a planar image showing the intensity distribution of the laser light in Verification Example 1
  • FIG. It is a graph which shows intensity distribution of a Y section.
  • Verification example 2 is an example in the case of using a laser beam having a narrow spectrum width as shown in FIG. In the mode disturbance means, vibration, lateral pressure and bending are applied simultaneously. Moreover, the numerical aperture of the used step index type multimode optical fiber is 0.22, and the numerical aperture of the objective optical system is 0.22.
  • FIG. 17 to 19 are diagrams showing the smoothness in the verification example 2.
  • FIG. 17 is a 3D graph showing the intensity distribution of the laser beam in Verification Example 2
  • FIG. 18 is a planar image showing the intensity distribution of the laser beam in Verification Example 2
  • FIG. It is a graph which shows intensity distribution of a Y section.
  • Verification Example 3 is an example in the case of using a combination of a plurality of laser beams having a wide spectrum width as shown in FIG. In the mode disturbance means, only vibration is given. Moreover, the numerical aperture of the used step index type multimode optical fiber is 0.22, and the numerical aperture of the objective optical system is 0.22.
  • FIG. 20 to 22 are diagrams illustrating the smoothness in the third verification example.
  • FIG. 20 is a 3D graph showing the intensity distribution of the laser beam in Verification Example 3
  • FIG. 21 is a planar image showing the intensity distribution of the laser beam in Verification Example 3
  • FIG. It is a graph which shows intensity distribution of a Y section.
  • Verification Example 4 is an example in the case of using a combination of a plurality of laser beams having a wide spectrum width as shown in FIG. In the mode disturbance means, only vibration and bending are given. Moreover, the numerical aperture of the used step index type multimode optical fiber is 0.22, and the numerical aperture of the objective optical system is 0.22.
  • FIG. 23 to 25 are diagrams showing the smoothness in the fourth verification example.
  • FIG. 23 is a 3D graph showing the intensity distribution of the laser light in Verification Example 4
  • FIG. 24 is a planar image showing the intensity distribution of the laser light in Verification Example 4
  • FIG. 25 is an X cross-section in FIG. It is a graph which shows intensity distribution of a Y section.
  • the smoothness F is improved by applying not only vibration but also bending to the step index type multimode optical fiber.
  • Verification Example 5 is an example in the case of using a combination of a plurality of laser beams having a wide spectrum width as shown in FIG. In the mode disturbance means, vibration, bending and lateral pressure are applied simultaneously. Moreover, the numerical aperture of the used step index type multimode optical fiber is 0.22, and the numerical aperture of the objective optical system is 0.22.
  • FIGS. 26 to 28 are diagrams showing the smoothness in the fifth verification example.
  • FIG. 26 is a 3D graph showing the intensity distribution of the laser light in Verification Example 5
  • FIG. 27 is a plane image showing the intensity distribution of the laser light in Verification Example 5
  • FIG. It is a graph which shows intensity distribution of a Y section.
  • the smoothness F is improved by applying not only vibration and bending but also a lateral pressure to the step index type multimode optical fiber.
  • Verification example 6 is an example in the case of using a combination of a plurality of laser beams having a wide spectrum width as shown in FIG. In the mode disturbance means, vibration, bending and lateral pressure are applied simultaneously.
  • the step index type multimode optical fiber used has a numerical aperture of 0.22, and the objective optical system has a numerical aperture of 0.18.
  • FIG. 29 to 31 are diagrams showing the smoothness in the verification example 6.
  • FIG. 29 is a 3D graph showing the intensity distribution of laser light in Verification Example 6
  • FIG. 30 is a planar image showing the intensity distribution of laser light in Verification Example 6, and
  • FIG. It is a graph which shows intensity distribution of a Y section.
  • Verification example 7 is an example in the case of using a combination of a plurality of laser beams having a wide spectrum width as shown in FIG. In the mode disturbance means, vibration, bending and lateral pressure are applied simultaneously. Moreover, the numerical aperture of the used step index type multimode optical fiber is 0.22, and the numerical aperture of the objective optical system is 0.24.
  • FIG. 32 to 34 are diagrams showing the smoothness in the verification example 7.
  • FIG. FIG. 32 is a 3D graph showing the intensity distribution of the laser beam in Verification Example 7
  • FIG. 33 is a planar image showing the intensity distribution of the laser beam in Verification Example 7, and
  • FIG. It is a graph which shows intensity distribution of a Y section.
  • the laser beam irradiation apparatus including the mode disturbance means for simultaneously applying the lateral pressure, bending, and vibration to the step index type multimode optical fiber has only vibration in the step index type multimode optical fiber.
  • the effect of improving the smoothness of the intensity distribution of the laser beam is greater than that of the laser beam irradiation apparatus that includes the mode disturbance unit that provides vibration or the mode disturbance unit that applies only vibration and bending to the step index type multimode optical fiber.
  • the laser beam irradiation apparatus in which the spectral width of the laser beam emitted from the laser light source unit is 3 nm to 100 nm is a laser emitted from the laser light source unit.
  • the effect of improving the smoothness of the intensity distribution of the laser beam is greater than that of a laser beam irradiation apparatus having a spectral width of light smaller than 3 nm.
  • the laser beam irradiation apparatus in which the numerical aperture of the step index type multimode optical fiber is 0.15 or more is the numerical aperture of the step index type multimode optical fiber.
  • the effect of improving the smoothness of the intensity distribution of the laser beam is greater than that of a laser beam irradiation apparatus having a diameter of less than 0.15.
  • the laser beam irradiation apparatus in which the numerical aperture of the objective optical system is smaller than the numerical aperture of the step index type multi-mode optical fiber has the numerical aperture of the objective optical system of the step index type.
  • the effect of improving the smoothness is greater than that of a laser beam irradiation apparatus having a numerical aperture smaller than that of the multimode optical fiber.
  • the laser light irradiation apparatus is useful in the industrial field in which an object is irradiated with high-intensity laser light.
  • Laser light irradiation device 100 110, 120 Laser light source unit 111a, 121a First laser element 111b, 121b Second laser element 111c, 121c Third laser element 112a, 112b, 112c First cylindrical lens 113a, 113b , 113c Second cylindrical lens 114a, 114b, 114c Mirror 115 Condensing lens 122a, 122b, 122c, 124 Optical fiber 123 Optical multiplexer 125 Optical connection part 200 Step index type multimode optical fiber 300, 310, 320 Mode disturbance means 311a, 311b Clamping plate 312 Pressurizing means 313, 323 Vibration means 321a, 321b Bobbins 322a, 322b Tensioning means 400, 410 Objective optical system 411 Objective lens

Landscapes

  • Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Engineering & Computer Science (AREA)
  • Health & Medical Sciences (AREA)
  • Surgery (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Mechanical Engineering (AREA)
  • Plasma & Fusion (AREA)
  • Heart & Thoracic Surgery (AREA)
  • Molecular Biology (AREA)
  • General Physics & Mathematics (AREA)
  • Nuclear Medicine, Radiotherapy & Molecular Imaging (AREA)
  • Biomedical Technology (AREA)
  • Electromagnetism (AREA)
  • Medical Informatics (AREA)
  • Otolaryngology (AREA)
  • Animal Behavior & Ethology (AREA)
  • General Health & Medical Sciences (AREA)
  • Public Health (AREA)
  • Veterinary Medicine (AREA)
  • Laser Beam Processing (AREA)
  • Lasers (AREA)
  • Laser Surgery Devices (AREA)

Abstract

A laser light irradiation device is provided with: a laser light source unit which emits laser light; a step-index multimode optical fiber which propagates the laser light emitted from the laser light source unit in multiple modes; a mode disturbance means which simultaneously applies lateral pressure, bending, and vibration to the step-index multimode optical fiber; and an object optical system which enlarges the beam diameter of the laser light emitted from the step-index multimode optical fiber and irradiates an object therewith.

Description

レーザ光照射装置Laser beam irradiation device
　本発明は、レーザ光照射装置に関する。 The present invention relates to a laser beam irradiation apparatus.
　従来、高強度のレーザ光を対象物に照射するレーザ光照明装置が多く使用されている。近年では、工業分野に限らず医療分野でも、レーザメスやレーザアブレーションによってがん細胞を破壊するなどの用途にてレーザ光照射装置が用いられ始めている。このようなレーザ光照射装置の応用は今後も発展し、加工や治療などに留まらず新しい応用を生み出すと考えられている。 Conventionally, many laser light illumination devices that irradiate an object with high-intensity laser light have been used. In recent years, laser light irradiation apparatuses have begun to be used not only in the industrial field but also in the medical field for purposes such as destroying cancer cells by laser scalpel or laser ablation. The application of such a laser beam irradiation apparatus will continue to develop in the future, and it is thought that new applications will be created in addition to processing and treatment.
　一般的に、コヒーレント光であるレーザ光のビームを作製すると、光源の発光特性や導光路（例えば光ファイバなど）の特性を反映して、レーザ光の強度分布はガウシアン強度分布で近似される形状となることが多い。この強度分布を有するビームは一般にガウシアンビームと呼ばれている。 Generally, when a laser beam, which is coherent light, is produced, the intensity distribution of the laser beam is approximated by the Gaussian intensity distribution, reflecting the light emission characteristics of the light source and the characteristics of the light guide (for example, optical fiber). Often. A beam having this intensity distribution is generally called a Gaussian beam.
　ところで、例えばがん細胞を破壊する用途などでは、照射領域にて均等な強度分布を有するレーザ光が求められている。がん細胞を破壊しつつも正常な細胞を傷つけないようにするためである。したがって、このような用途では、強度分布が中心にピークを持つガウシアンビームは好ましくない。そこで、平滑な強度分布を持つレーザ光のビームを作製するための技術が各種知られている（例えば特許文献１参照）。 By the way, for the purpose of destroying cancer cells, for example, a laser beam having a uniform intensity distribution in the irradiated region is required. This is to prevent damage to normal cells while destroying cancer cells. Therefore, in such an application, a Gaussian beam having a peak at the center of the intensity distribution is not preferable. Therefore, various techniques for producing a laser beam having a smooth intensity distribution are known (see, for example, Patent Document 1).
特開２００５－０４６２４７号公報JP 2005-046247 A
　しかしながら、強度分布を平滑化したレーザ光のビームを実現するには特殊な光学レンズ系の組み合わせや、特殊なモードの励振装置とレンズ系や、空間光変調装置などが必要となる。結果、レーザ光照射装置の出射部が大型化するなどの問題が発生することがあった。 However, in order to realize a laser beam having a smooth intensity distribution, a special optical lens system combination, a special mode excitation device and lens system, a spatial light modulator, and the like are required. As a result, problems such as an increase in the size of the emission part of the laser beam irradiation apparatus may occur.
　本発明は、上記に鑑みてなされたものであって、その目的は、装置の大型化を招来することなく、レーザ光の強度分布の平滑性を向上させたレーザ光照射装置を提供することにある。 The present invention has been made in view of the above, and an object of the present invention is to provide a laser beam irradiation apparatus that improves the smoothness of the intensity distribution of the laser beam without causing an increase in the size of the apparatus. is there.
　上述した課題を解決し、目的を達成するために、本発明に係るレーザ光照射装置は、レーザ光を出射するレーザ光源ユニットと、前記レーザ光源ユニットから出射されたレーザ光をマルチモードで伝搬するステップインデックス型マルチモード光ファイバと、前記ステップインデックス型マルチモード光ファイバに側圧と曲げと振動とを同時に与えるモード外乱手段と、前記ステップインデックス型マルチモード光ファイバから出射されるレーザ光のビーム径を拡大して対象物に照射する対物光学系とを備えることを特徴とする。 In order to solve the above-described problems and achieve the object, a laser light irradiation apparatus according to the present invention propagates a laser light source unit that emits laser light and laser light emitted from the laser light source unit in a multimode. A step index type multimode optical fiber, mode disturbance means for simultaneously applying lateral pressure, bending and vibration to the step index type multimode optical fiber, and a beam diameter of laser light emitted from the step index type multimode optical fiber. And an objective optical system for enlarging and irradiating the object.
　また、本発明に係るレーザ光照射装置は、上記発明において、前記レーザ光源ユニットは、一つのレーザ素子を備え、前記レーザ素子が発振するレーザ光のスペクトル幅が３ｎｍ以上１００ｎｍ以下であることを特徴とする。 The laser light irradiation apparatus according to the present invention is characterized in that, in the above invention, the laser light source unit includes one laser element, and a spectral width of laser light oscillated by the laser element is 3 nm or more and 100 nm or less. And
　また、本発明に係るレーザ光照射装置は、上記発明において、前記レーザ光源ユニットは、複数のレーザ素子を備え、前記レーザ光源ユニットから出射されるレーザ光は、前記複数のレーザ素子が発振するレーザ光を合波したものであり、前記複数のレーザ素子が発振するレーザ光を合波したもののスペクトル幅が３ｎｍ以上１００ｎｍ以下であることを特徴とする。 In the laser beam irradiation apparatus according to the present invention as set forth in the invention described above, the laser light source unit includes a plurality of laser elements, and laser light emitted from the laser light source unit oscillates by the plurality of laser elements. It is a combination of lights, and a spectrum width of a combination of laser beams oscillated by the plurality of laser elements is 3 nm or more and 100 nm or less.
　また、本発明に係るレーザ光照射装置は、上記発明において、前記レーザ素子が発振するレーザ光のスペクトル幅の各々が３ｎｍ以上５０ｎｍ以下であることを特徴とする。 The laser beam irradiation apparatus according to the present invention is characterized in that, in the above invention, each of the spectral widths of the laser beam oscillated by the laser element is 3 nm or more and 50 nm or less.
　また、本発明に係るレーザ光照射装置は、上記発明において、前記複数のレーザ素子の中心発振波長が相互に異なり、前記複数のレーザ素子の中心発振波長における差の最大値が５０ｎｍ以下であることを特徴とする。 In the laser beam irradiation apparatus according to the present invention, in the above invention, the central oscillation wavelengths of the plurality of laser elements are different from each other, and the maximum difference in the central oscillation wavelengths of the plurality of laser elements is 50 nm or less. It is characterized by.
　また、本発明に係るレーザ光照射装置は、上記発明において、前記モード外乱手段が前記ステップインデックス型マルチモード光ファイバに側圧と曲げと振動とを同時に与える領域の長さが１ｍ以上であることを特徴とする。 In the laser beam irradiation apparatus according to the present invention, in the above-described invention, the mode disturbance means may have a length of a region of 1 m or more that simultaneously applies lateral pressure, bending, and vibration to the step index type multimode optical fiber. Features.
　また、本発明に係るレーザ光照射装置は、上記発明において、前記ステップインデックス型マルチモード光ファイバの開口数は０．１５以上であることを特徴とする。 The laser beam irradiation apparatus according to the present invention is characterized in that, in the above invention, the step index type multimode optical fiber has a numerical aperture of 0.15 or more.
　また、本発明に係るレーザ光照射装置は、上記発明において、前記対物光学系の開口数が前記ステップインデックス型マルチモード光ファイバの開口数よりも小さいことを特徴とする。 The laser beam irradiation apparatus according to the present invention is characterized in that, in the above invention, the numerical aperture of the objective optical system is smaller than the numerical aperture of the step index type multimode optical fiber.
　本発明に係るレーザ光照射装置は、装置の大型化を招来することなく、レーザ光の強度分布の平滑性を向上させるという効果を奏する。 The laser beam irradiation apparatus according to the present invention has an effect of improving the smoothness of the intensity distribution of the laser beam without causing an increase in the size of the apparatus.
図１は、第１実施形態に係るレーザ光照射装置の概略構成を示す図である。FIG. 1 is a diagram showing a schematic configuration of a laser beam irradiation apparatus according to the first embodiment. 図２は、ファブリペロー型のレーザダイオードが発振するレーザ光のスペクトルの例を示すグラフである。FIG. 2 is a graph showing an example of a spectrum of laser light oscillated by a Fabry-Perot laser diode. 図３は、ファイバブラッググレーティングを外部共振器として備えるレーザダイオードが発振するレーザ光のスペクトルの例を示すグラフである。FIG. 3 is a graph showing an example of a spectrum of laser light oscillated by a laser diode having a fiber Bragg grating as an external resonator. 図４は、複数のレーザ素子が発振するレーザ光を合波した場合のスペクトルの例を示すグラフである。FIG. 4 is a graph showing an example of a spectrum in a case where laser beams oscillated by a plurality of laser elements are combined. 図５は、第２実施形態に係るレーザ光照射装置におけるレーザ光源ユニットの概略構成を示す図である。FIG. 5 is a diagram showing a schematic configuration of a laser light source unit in the laser light irradiation apparatus according to the second embodiment. 図６は、第２実施形態に係るレーザ光照射装置におけるレーザ光源ユニットの概略構成を示す図である。FIG. 6 is a diagram illustrating a schematic configuration of a laser light source unit in the laser light irradiation apparatus according to the second embodiment. 図７は、第２実施形態に係るレーザ光照射装置におけるレーザ光源ユニットの概略構成を示す図である。FIG. 7 is a diagram illustrating a schematic configuration of a laser light source unit in the laser light irradiation apparatus according to the second embodiment. 図８は、第３実施形態に係るレーザ光照射装置におけるレーザ光源ユニットの概略構成を示す図である。FIG. 8 is a diagram illustrating a schematic configuration of a laser light source unit in the laser light irradiation apparatus according to the third embodiment. 図９は、第４実施形態に係るレーザ光照射装置におけるモード外乱手段の概略構成を示す図である。FIG. 9 is a diagram showing a schematic configuration of mode disturbance means in the laser beam irradiation apparatus according to the fourth embodiment. 図１０は、第４実施形態に係るレーザ光照射装置におけるモード外乱手段の概略構成を示す図である。FIG. 10 is a diagram showing a schematic configuration of mode disturbance means in the laser beam irradiation apparatus according to the fourth embodiment. 図１１は、第５実施形態に係るレーザ光照射装置におけるモード外乱手段の概略構成を示す図である。FIG. 11 is a diagram showing a schematic configuration of mode disturbance means in the laser beam irradiation apparatus according to the fifth embodiment. 図１２は、第６実施形態に係るレーザ光照射装置における対物光学系の概略構成を示す図である。FIG. 12 is a diagram illustrating a schematic configuration of an objective optical system in the laser light irradiation apparatus according to the sixth embodiment. 図１３は、平滑性の定義を説明する図である。FIG. 13 is a diagram for explaining the definition of smoothness. 図１４は、検証例１における平滑性を示す図である。FIG. 14 is a diagram illustrating the smoothness in the first verification example. 図１５は、検証例１における平滑性を示す図である。FIG. 15 is a diagram illustrating the smoothness in the first verification example. 図１６は、検証例１における平滑性を示す図である。FIG. 16 is a diagram illustrating the smoothness in the first verification example. 図１７は、検証例２における平滑性を示す図である。FIG. 17 is a diagram illustrating the smoothness in the second verification example. 図１８は、検証例２における平滑性を示す図である。FIG. 18 is a diagram illustrating the smoothness in the second verification example. 図１９は、検証例２における平滑性を示す図である。FIG. 19 is a diagram illustrating the smoothness in the second verification example. 図２０は、検証例３における平滑性を示す図である。FIG. 20 is a diagram illustrating the smoothness in the third verification example. 図２１は、検証例３における平滑性を示す図である。FIG. 21 is a diagram illustrating the smoothness in the third verification example. 図２２は、検証例３における平滑性を示す図である。FIG. 22 is a diagram illustrating the smoothness in the third verification example. 図２３は、検証例４における平滑性を示す図である。FIG. 23 is a diagram illustrating the smoothness in the fourth verification example. 図２４は、検証例４における平滑性を示す図である。FIG. 24 is a diagram illustrating the smoothness in the fourth verification example. 図２５は、検証例４における平滑性を示す図である。FIG. 25 is a diagram illustrating the smoothness in the fourth verification example. 図２６は、検証例５における平滑性を示す図である。FIG. 26 is a diagram illustrating the smoothness in the fifth verification example. 図２７は、検証例５における平滑性を示す図である。FIG. 27 is a diagram illustrating the smoothness in the fifth verification example. 図２８は、検証例５における平滑性を示す図である。FIG. 28 is a diagram illustrating the smoothness in the fifth verification example. 図２９は、検証例６における平滑性を示す図である。FIG. 29 is a diagram illustrating the smoothness in the verification example 6. 図３０は、検証例６における平滑性を示す図である。FIG. 30 is a diagram illustrating the smoothness in the verification example 6. 図３１は、検証例６における平滑性を示す図である。FIG. 31 is a diagram illustrating the smoothness in the verification example 6. 図３２は、検証例７における平滑性を示す図である。FIG. 32 is a diagram illustrating the smoothness in the seventh verification example. 図３３は、検証例７における平滑性を示す図である。FIG. 33 is a diagram illustrating the smoothness in the seventh verification example. 図３４は、検証例７における平滑性を示す図である。FIG. 34 is a diagram illustrating the smoothness in the seventh verification example.
　以下に、本発明に係るレーザ光照射装置の実施形態を図面に基づいて詳細に説明する。なお、以下の実施形態により本発明が限定されるものではない。 Hereinafter, an embodiment of a laser beam irradiation apparatus according to the present invention will be described in detail with reference to the drawings. In addition, this invention is not limited by the following embodiment.
（第１実施形態）
　図１は、第１実施形態に係るレーザ光照射装置の概略構成を示す図である。図１に示されるように、レーザ光照射装置１０００は、レーザ光源ユニット１００と、ステップインデックス型マルチモード光ファイバ２００と、モード外乱手段３００と、対物光学系４００とを備えている。 (First embodiment)
FIG. 1 is a diagram showing a schematic configuration of a laser beam irradiation apparatus according to the first embodiment. As shown in FIG. 1, the laser light irradiation apparatus 1000 includes a laser light source unit 100, a step index type multimode optical fiber 200, a mode disturbance means 300, and an objective optical system 400.
　レーザ光源ユニット１００は、レーザ光を出射するためのユニットであり、少なくとも１つのレーザ素子、好ましくは複数のレーザ素子を備えている。レーザ光源ユニット１００が出射するレーザ光のスペクトル幅は、３ｎｍ以上１００ｎｍ以下とすることが好ましい。このスペクトル幅の下限を下回ると、レーザ光の強度分布を平滑化することが困難となり、一方、このスペクトル幅の上限を上回ると、レーザ光照射装置１０００としての所望波長から外れてしまう場合があるからである。レーザ光照射装置１０００を例えばがん細胞を破壊する用途に使う場合などは、水の吸収波長である１４８０ｎｍ近傍の波長のレーザ光を用いる必要があり、上記スペクトル幅の上限を上回ると当該用途から外れてしまう。 The laser light source unit 100 is a unit for emitting laser light, and includes at least one laser element, preferably a plurality of laser elements. The spectral width of the laser light emitted from the laser light source unit 100 is preferably 3 nm or more and 100 nm or less. If the lower limit of the spectral width is not reached, it is difficult to smooth the intensity distribution of the laser light. On the other hand, if the upper limit of the spectral width is exceeded, the laser light irradiation apparatus 1000 may deviate from the desired wavelength. Because. For example, when the laser beam irradiation apparatus 1000 is used for an application for destroying cancer cells, it is necessary to use laser light having a wavelength in the vicinity of 1480 nm which is the absorption wavelength of water. It will come off.
　なお、レーザ光源ユニット１００が出射するレーザ光のスペクトル幅とは、レーザ光の最大出力強度から２０ｄＢ低下した強度となる波長範囲である。また、レーザ光源ユニット１００が一つのレーザ素子を備えている場合、当該１つのレーザ素子が発振するレーザ光のスペクトル幅が上記範囲となることを意味し、複数のレーザ素子を備えている場合、合波した全体のスペクトル幅（すなわち、レーザ光の最大出力強度から２０ｄＢ低下した強度となる波長が複数ある場合は、その最大値と最小値との間の幅）が上記範囲となることを意味している。 The spectral width of the laser light emitted from the laser light source unit 100 is a wavelength range in which the intensity is reduced by 20 dB from the maximum output intensity of the laser light. Further, when the laser light source unit 100 includes one laser element, it means that the spectral width of the laser light oscillated by the one laser element falls within the above range, and when the laser light source unit 100 includes a plurality of laser elements, It means that the total spectrum width (that is, the width between the maximum value and the minimum value in the case where there are a plurality of wavelengths whose intensity is 20 dB lower than the maximum output intensity of the laser beam) falls within the above range. is doing.
　レーザ光源ユニット１００が備えるレーザ素子が一つの場合、例えばファブリペロー型のレーザダイオードを用いることが考えられる。ファブリペロー型のレーザダイオードは、複数の共振モードを有しているので、これら複数の共振モードのレーザ光をそのまま（外部共振器等でモードを制限せずに）レーザ光源ユニット１００の出力として用いることができる。 When the laser light source unit 100 has one laser element, for example, a Fabry-Perot type laser diode may be used. Since the Fabry-Perot type laser diode has a plurality of resonance modes, the laser light of the plurality of resonance modes is used as it is (without limiting the mode with an external resonator or the like) as the output of the laser light source unit 100. be able to.
　図２は、ファブリペロー型のレーザダイオードが発振するレーザ光のスペクトルの例を示すグラフである。図２に示される例では、ファブリペロー型のレーザダイオードが発振するレーザ光のスペクトル幅が１３ｎｍであり、３ｎｍ以上１００ｎｍ以下となっている。つまり、図２に示されるようなスペクトルを有するファブリペロー型のレーザダイオードは、レーザ光源ユニット１００が備えるレーザ素子として好適なものとなっている。 FIG. 2 is a graph showing an example of a spectrum of laser light oscillated by a Fabry-Perot laser diode. In the example shown in FIG. 2, the spectral width of the laser light oscillated by the Fabry-Perot laser diode is 13 nm, which is 3 nm to 100 nm. That is, the Fabry-Perot type laser diode having a spectrum as shown in FIG. 2 is suitable as a laser element included in the laser light source unit 100.
　レーザ光源ユニット１００が備えるレーザ素子が複数の場合、ファブリペロー型のレーザダイオードを用いることが好ましいが、分布帰還型のレーザダイオードや外部共振器を用いたレーザダイオードなどを用いることも可能である。なお、たとえ各レーザ素子から出射されるレーザ光のスペクトル幅が狭いものであっても、合波された全体のスペクトル幅が３ｎｍ以上１００ｎｍ以下となっていればよい。 When there are a plurality of laser elements provided in the laser light source unit 100, it is preferable to use a Fabry-Perot type laser diode, but it is also possible to use a distributed feedback type laser diode or a laser diode using an external resonator. Note that, even if the spectrum width of the laser light emitted from each laser element is narrow, the combined spectrum width may be 3 nm or more and 100 nm or less.
　しかしながら、複数のレーザ素子のうち１つであっても、そのレーザ素子から出射されるレーザ光のスペクトル幅が極端に狭い場合は、レーザ光の強度分布を平滑化することが困難となる。具体的には、レーザ光源ユニット１００が備える各レーザ素子が発振するレーザ光のスペクトル幅が３ｎｍ以上５０ｎｍ以下であることが好ましい。なお、レーザ素子が発振するレーザ光のスペクトル幅とは、レーザ光の最大出力強度から２０ｄＢ低下した強度となる波長範囲である。 However, even if one of the plurality of laser elements is used, if the spectral width of the laser light emitted from the laser element is extremely narrow, it is difficult to smooth the intensity distribution of the laser light. Specifically, the spectral width of the laser light oscillated by each laser element included in the laser light source unit 100 is preferably 3 nm or more and 50 nm or less. Note that the spectral width of the laser light oscillated by the laser element is a wavelength range in which the intensity is reduced by 20 dB from the maximum output intensity of the laser light.
　また、レーザ光源ユニット１００が備えるレーザ素子が複数の場合、同一のレーザ素子を複数備えるのではなく、各レーザ素子の中心発振波長が相互に異なるように構成することが好ましい。ただし、中心発振波長があまりに離れてしまっていると、レーザ光照射装置１０００としての所望波長から外れてしまうので、各中心発振波長の差の最大値は、５０ｎｍ以下となっていることが好ましい。 Further, when the laser light source unit 100 includes a plurality of laser elements, it is preferable not to include a plurality of the same laser elements, but to configure the respective laser elements to have different center oscillation wavelengths. However, if the center oscillation wavelength is too far away from the desired wavelength as the laser light irradiation apparatus 1000, the maximum difference between the center oscillation wavelengths is preferably 50 nm or less.
　図３は、ファイバブラッググレーティングを外部共振器として備えるレーザダイオードが発振するレーザ光のスペクトルの例を示すグラフである。図３に示される例では、レーザ光のスペクトル幅が３ｎｍより狭くなっている。つまり、図３に示されるようにスペクトルを有するファブリペロー型のレーザダイオードは、レーザ光源ユニット１００が備えるレーザ素子として適さない。 FIG. 3 is a graph showing an example of a spectrum of laser light oscillated by a laser diode having a fiber Bragg grating as an external resonator. In the example shown in FIG. 3, the spectral width of the laser beam is narrower than 3 nm. That is, a Fabry-Perot type laser diode having a spectrum as shown in FIG. 3 is not suitable as a laser element included in the laser light source unit 100.
　図４は、複数のレーザ素子が発振するレーザ光を合波した場合のスペクトルの例を示すグラフである。なお、図４に示されるグラフは、２つのファブリペロー型のレーザダイオードの発振を合波した例を示している。図４に示される例では、合波されたレーザ光のスペクトル幅が７０ｎｍであり、３ｎｍ以上１００ｎｍ以下となっている。また、各レーザ素子が発振するレーザ光のスペクトル幅も３ｎｍ以上５０ｎｍ以下となっている。つまり、図４に示されるようなスペクトルを有する２つのレーザ素子は、レーザ光源ユニット１００が備えるレーザ素子として好適なものとなっている。 FIG. 4 is a graph showing an example of a spectrum in a case where laser beams oscillated by a plurality of laser elements are combined. The graph shown in FIG. 4 shows an example in which the oscillations of two Fabry-Perot laser diodes are combined. In the example shown in FIG. 4, the spectrum width of the combined laser beam is 70 nm, which is 3 nm or more and 100 nm or less. The spectral width of the laser light oscillated by each laser element is also 3 nm or more and 50 nm or less. That is, the two laser elements having a spectrum as shown in FIG. 4 are suitable as laser elements included in the laser light source unit 100.
　ここで、図１の参照にもどり、ステップインデックス型マルチモード光ファイバ２００およびモード外乱手段３００の説明を行う。 Here, referring back to FIG. 1, the step index type multimode optical fiber 200 and the mode disturbance means 300 will be described.
　図１に示されるように、ステップインデックス型マルチモード光ファイバ２００は、レーザ光源ユニット１００から出射されたレーザ光を対物光学系４００までマルチモードで伝搬する光ファイバである。ステップインデックス型マルチモード光ファイバ２００とは、複数のモードでレーザ光を伝搬することを許容する光ファイバであって、特にコアおよびクラッドが形成する屈折率分布がステップ形状となっているものをいう。 As shown in FIG. 1, the step index type multimode optical fiber 200 is an optical fiber that propagates laser light emitted from the laser light source unit 100 to the objective optical system 400 in multimode. The step index type multimode optical fiber 200 is an optical fiber that allows laser light to propagate in a plurality of modes, and particularly has a refractive index distribution formed by a core and a clad in a step shape. .
　ステップインデックス型マルチモード光ファイバ２００の開口数は０．１５以上であることが好ましい。後に詳述するように、ステップインデックス型マルチモード光ファイバのＮＡが大きい方が、平滑性Ｆは向上することが実験によって確かめられたからである。 It is preferable that the numerical aperture of the step index type multimode optical fiber 200 is 0.15 or more. This is because, as will be described in detail later, it has been experimentally confirmed that the smoothness F is improved when the NA of the step index type multimode optical fiber is large.
　モード外乱手段３００は、レーザ光源ユニット１００と対物光学系４００との間に設けられ、ステップインデックス型マルチモード光ファイバ２００に側圧と曲げと振動とを同時に与える手段である。モード外乱手段３００は、ステップインデックス型マルチモード光ファイバ２００に側圧と曲げと振動とを同時に与えることにより、ステップインデックス型マルチモード光ファイバ２００を伝搬しているレーザ光のモードに外乱を与える。 The mode disturbance means 300 is a means that is provided between the laser light source unit 100 and the objective optical system 400, and simultaneously applies a lateral pressure, bending and vibration to the step index type multimode optical fiber 200. The mode disturbance means 300 gives a disturbance to the mode of the laser beam propagating through the step index type multimode optical fiber 200 by simultaneously applying a lateral pressure, bending and vibration to the step index type multimode optical fiber 200.
　ステップインデックス型マルチモード光ファイバ２００は、複数のモードでレーザ光を伝搬することを許容しているが、多くの場合、許容されるすべてのモードでレーザ光が伝搬されているわけではない。モード外乱手段３００は、ステップインデックス型マルチモード光ファイバ２００に外乱を与えることによって、レーザ光とモードとの結合状態を変化させる作用を有する。結果、レーザ光が伝搬するモードが変更するいわゆるモードシフトが発生し、実現されていなかったモードでの伝搬が実現することとなる。なお、このことは、ステップインデックス型マルチモード光ファイバ２００を伝搬しているレーザ光の空間的コヒーレンシーが低下していることを意味する。 The step index type multimode optical fiber 200 allows the laser light to propagate in a plurality of modes, but in many cases, the laser light does not propagate in all the allowed modes. The mode disturbance means 300 has a function of changing the coupling state between the laser beam and the mode by giving a disturbance to the step index type multimode optical fiber 200. As a result, a so-called mode shift in which the mode in which the laser light propagates changes occurs, and propagation in a mode that has not been realized is realized. This means that the spatial coherency of the laser light propagating through the step index type multimode optical fiber 200 is reduced.
　対物光学系４００は、ステップインデックス型マルチモード光ファイバ２００から出射されるレーザ光のビーム径を拡大して対象物に照射するための光学系である。ステップインデックス型マルチモード光ファイバ２００の端面と対象物とは、光学的共役関係に配置されており、ステップインデックス型マルチモード光ファイバ２００の端面におけるレーザ光の強度分布がほぼ相似形に対象物に投影される。 The objective optical system 400 is an optical system for expanding the beam diameter of the laser light emitted from the step index type multimode optical fiber 200 and irradiating the object. The end surface of the step index type multimode optical fiber 200 and the object are arranged in an optically conjugate relationship, and the intensity distribution of the laser light on the end surface of the step index type multimode optical fiber 200 is substantially similar to the object. Projected.
　上述のように、ステップインデックス型マルチモード光ファイバ２００を伝搬するレーザ光は、モード外乱手段３００によって数多くのモードで伝搬されて端面に到達するので、端面における強度分布の平滑性が向上している。また、空間的コヒーレンシーが低下しているので、ランダムな干渉現象であるいわゆるスペックルノイズも低減されている。よって、対象物に照射された状況でも、平滑性が向上される。 As described above, the laser light propagating through the step index type multimode optical fiber 200 is propagated in many modes by the mode disturbance means 300 and reaches the end face, so that the smoothness of the intensity distribution at the end face is improved. . In addition, since spatial coherency is reduced, so-called speckle noise, which is a random interference phenomenon, is also reduced. Therefore, smoothness is improved even when the object is irradiated.
　以下に、上記説明した第１実施形態の各構成を具体化した実施形態について説明する。以下では、具体化された各構成の部分のみの説明を行うが、説明を省略した部分は、第１実施形態と同一の構成であるものとする。また、例えばレーザ光源ユニット１００の具体例とモード外乱手段３００の具体例とを組み合わせるように、以下で説明する異なる実施形態の構成を組み合わせて新たな実施形態を構成することも可能である。 Hereinafter, an embodiment that embodies each configuration of the first embodiment described above will be described. In the following, only the specific parts of the components will be described. However, the parts that are not described here are the same as those in the first embodiment. In addition, for example, a new embodiment can be configured by combining the configurations of different embodiments described below so that a specific example of the laser light source unit 100 and a specific example of the mode disturbance unit 300 are combined.
（第２実施形態）
　図５～図７は、第２実施形態に係るレーザ光照射装置におけるレーザ光源ユニットの概略構成を示す図である。図５～図７に示されるレーザ光源ユニット１１０は、第１実施形態におけるレーザ光源ユニット１００の具体例となっている。図５は、レーザ光源ユニット１１０の平面構成図であり、図６は、レーザ光源ユニット１１０の垂直面視図であり、図７は、レーザ光の合波部分の拡大図である。 (Second Embodiment)
5 to 7 are diagrams showing a schematic configuration of a laser light source unit in the laser light irradiation apparatus according to the second embodiment. The laser light source unit 110 shown in FIGS. 5 to 7 is a specific example of the laser light source unit 100 in the first embodiment. FIG. 5 is a plan view of the laser light source unit 110, FIG. 6 is a vertical view of the laser light source unit 110, and FIG. 7 is an enlarged view of a portion where laser light is combined.
　図５および図６に示されるように、レーザ光源ユニット１１０は、第１のレーザ素子１１１ａ、第２のレーザ素子１１１ｂおよび第３のレーザ素子１１１ｃを備え、これら第１のレーザ素子１１１ａ、第２のレーザ素子１１１ｂおよび第３のレーザ素子１１１ｃが発振するレーザ光が直接合波されてステップインデックス型マルチモード光ファイバ２００に導入される構成である。 As shown in FIG. 5 and FIG. 6, the laser light source unit 110 includes a first laser element 111a, a second laser element 111b, and a third laser element 111c. In this configuration, the laser beams oscillated by the laser element 111 b and the third laser element 111 c are directly combined and introduced into the step index type multimode optical fiber 200.
　第１のレーザ素子１１１ａ、第２のレーザ素子１１１ｂおよび第３のレーザ素子１１１ｃは、ファブリペロー型のレーザダイオードとすることが好ましいが、分布帰還型のレーザダイオードや外部共振器を用いたレーザダイオードなどを用いてもよい。第１のレーザ素子１１１ａ、第２のレーザ素子１１１ｂおよび第３のレーザ素子１１１ｃは、中心発振波長が相互に異なり、各中心発振波長の差の最大値は、５０ｎｍ以下となっている。また、第１のレーザ素子１１１ａ、第２のレーザ素子１１１ｂおよび第３のレーザ素子１１１ｃが発振する各レーザ光のスペクトル幅は、３ｎｍ以上５０ｎｍ以下であり、各レーザ光を合波した際のスペクトル幅は、３ｎｍ以上１００ｎｍ以下である。 The first laser element 111a, the second laser element 111b, and the third laser element 111c are preferably Fabry-Perot laser diodes, but are distributed feedback laser diodes or laser diodes using external resonators. Etc. may be used. The first laser element 111a, the second laser element 111b, and the third laser element 111c have different central oscillation wavelengths, and the maximum difference between the central oscillation wavelengths is 50 nm or less. The spectrum width of each laser beam oscillated by the first laser element 111a, the second laser element 111b, and the third laser element 111c is not less than 3 nm and not more than 50 nm. The width is 3 nm or more and 100 nm or less.
　図５に示されるように、第１のレーザ素子１１１ａ、第２のレーザ素子１１１ｂおよび第３のレーザ素子１１１ｃは、互いに平行に配置され、同一方向にレーザ光を出射する。第１のレーザ素子１１１ａ、第２のレーザ素子１１１ｂおよび第３のレーザ素子１１１ｃから出射したレーザ光は、それぞれ紙面垂直方向の屈折力を有する第１のシリンドリカルレンズ１１２ａ，１１２ｂ，１１２ｃと紙面水平方法の屈折力を有する第２のシリンドリカルレンズ１１３ａ，１１３ｂ，１１３ｃとを透過し、ミラー１１４ａ，１１４ｂ，１１４ｃにて反射されることによって、ステップインデックス型マルチモード光ファイバ２００方向に偏向される。 As shown in FIG. 5, the first laser element 111a, the second laser element 111b, and the third laser element 111c are arranged in parallel to each other and emit laser light in the same direction. The laser beams emitted from the first laser element 111a, the second laser element 111b, and the third laser element 111c are respectively a first cylindrical lens 112a, 112b, 112c having a refractive power in a direction perpendicular to the paper surface, and a paper surface horizontal method. Is transmitted through the second cylindrical lenses 113a, 113b, and 113c having a refractive power of 1 and reflected by the mirrors 114a, 114b, and 114c, and deflected in the direction of the step index type multimode optical fiber 200.
　第１のシリンドリカルレンズ１１２ａ，１１２ｂ，１１２ｃおよび第２のシリンドリカルレンズ１１３ａ，１１３ｂ，１１３ｃは、第１のレーザ素子１１１ａ、第２のレーザ素子１１１ｂおよび第３のレーザ素子１１１ｃから出射するレーザ光を平行光にするためのものである。第１のシリンドリカルレンズ１１２ａ，１１２ｂ，１１２ｃは、当該レーザ光に対して紙面に垂直方向に屈折力を有するように配置されている。第２のシリンドリカルレンズ１１３ａ，１１３ｂ，１１３ｃは、当該レーザ光に対して紙面に平行方向に屈折力を有するように配置されている。 The first cylindrical lenses 112a, 112b, and 112c and the second cylindrical lenses 113a, 113b, and 113c are parallel laser beams emitted from the first laser element 111a, the second laser element 111b, and the third laser element 111c. It is for light. The first cylindrical lenses 112a, 112b, and 112c are arranged so as to have refractive power in the direction perpendicular to the paper surface with respect to the laser light. The second cylindrical lenses 113a, 113b, and 113c are arranged so as to have a refractive power in a direction parallel to the paper surface with respect to the laser light.
　図６に示されるように、第１のレーザ素子１１１ａ、第２のレーザ素子１１１ｂおよび第３のレーザ素子１１１ｃは、段差を付けて配置されている。これにより、第１のレーザ素子１１１ａ、第２のレーザ素子１１１ｂおよび第３のレーザ素子１１１ｃから出射した各レーザ光がミラー１１４ａ，１１４ｂ，１１４ｃにて反射される際には、図５における紙面垂直方向で互いに高さが異なり、かつ互いに平行なレーザ光になる。また、各ミラー１１４ａ，１１４ｂ，１１４ｃにて反射されたレーザ光は、集光レンズ１１５に入射する際には、互いに高さが異なる平行なレーザ光となっている。 As shown in FIG. 6, the first laser element 111a, the second laser element 111b, and the third laser element 111c are arranged with a step. As a result, when the laser beams emitted from the first laser element 111a, the second laser element 111b, and the third laser element 111c are reflected by the mirrors 114a, 114b, and 114c, they are perpendicular to the plane of FIG. The laser beams are different in height from each other and parallel to each other. The laser beams reflected by the mirrors 114a, 114b, and 114c are parallel laser beams having different heights when entering the condenser lens 115.
　図７は、第１のレーザ素子１１１ａ、第２のレーザ素子１１１ｂおよび第３のレーザ素子１１１ｃから出射した各レーザ光が合波されてステップインデックス型マルチモード光ファイバ２００に導入される様子を示している。図７に示されるように、集光レンズ１１５は正の屈折力を有するレンズであり、後側焦点位置がステップインデックス型マルチモード光ファイバ２００の端面にほぼ一致するように配置されている。 FIG. 7 shows how the laser beams emitted from the first laser element 111 a, the second laser element 111 b, and the third laser element 111 c are combined and introduced into the step index type multimode optical fiber 200. ing. As shown in FIG. 7, the condensing lens 115 is a lens having a positive refractive power, and is arranged so that the rear focal position substantially coincides with the end face of the step index type multimode optical fiber 200.
　一方、第１のレーザ素子１１１ａから出射したレーザ光Ｌａと、第２のレーザ素子１１１ｂから出射したレーザ光Ｌｂと、第３のレーザ素子１１１ｃから出射したレーザ光Ｌｃとは、互いに段差を有する平行なレーザ光となっている。したがって、集光レンズ１１５を透過したレーザ光Ｌａ，Ｌｂ，Ｌｃは、ステップインデックス型マルチモード光ファイバ２００の端面近傍にて交差することとなる。 On the other hand, the laser beam L a emitted from the first laser element 111a, the laser beam L b emitted from the second laser element 111b, the laser beam L c emitted from the third laser element 111c, a step with each other It is a parallel laser beam having Therefore, the laser beams L a , L b , and L c that have passed through the condenser lens 115 intersect in the vicinity of the end surface of the step index type multimode optical fiber 200.
　さらに、各レーザ光Ｌａ，Ｌｂ，Ｌｃは、ステップインデックス型マルチモード光ファイバ２００の端面に角度θ１以下の入射角度で入射している。ここで、角度θ１は、ステップインデックス型マルチモード光ファイバ２００に固有の定数である開口数（ＮＡ１）で定まる角度であり、ＮＡ１＝ｓｉｎθ１の関係を有する。入射角度がθ１以下である各レーザ光Ｌａ，Ｌｂ，Ｌｃは、ステップインデックス型マルチモード光ファイバ２００に結合されることとなる。 Further, each of the laser beams L a , L b , and L c is incident on the end face of the step index type multimode optical fiber 200 at an incident angle equal to or smaller than the angle θ 1 . Here, the angle θ 1 is an angle determined by the numerical aperture (NA 1 ), which is a constant unique to the step index type multimode optical fiber 200, and has a relationship of NA 1 = sin θ 1 . Each laser beam L a , L b , L c having an incident angle of θ 1 or less is coupled to the step index type multimode optical fiber 200.
　以上の構成のレーザ光源ユニット１１０は、レーザ光源ユニット１１０から出射されたレーザ光をマルチモードで伝搬するステップインデックス型マルチモード光ファイバ２００と、ステップインデックス型マルチモード光ファイバ２００に側圧と曲げと振動とを同時に与えるモード外乱手段３００と、ステップインデックス型マルチモード光ファイバ２００から出射されるレーザ光のビーム径を拡大して対象物に照射する対物光学系４００と共に用いることにより、第２実施形態に係るレーザ光照射装置を構成する。 The laser light source unit 110 configured as described above has a step index type multimode optical fiber 200 that propagates laser light emitted from the laser light source unit 110 in a multimode, and a lateral pressure, bending, and vibration in the step index type multimode optical fiber 200. Are used together with the mode disturbance means 300 that simultaneously applies the above and the objective optical system 400 that expands the beam diameter of the laser light emitted from the step index type multimode optical fiber 200 and irradiates the object. Such a laser beam irradiation apparatus is configured.
（第３実施形態）
　図８は、第３実施形態に係るレーザ光照射装置におけるレーザ光源ユニットの概略構成を示す図である。図８に示されるレーザ光源ユニット１２０は、第１実施形態におけるレーザ光源ユニット１００の具体例となっている。 (Third embodiment)
FIG. 8 is a diagram illustrating a schematic configuration of a laser light source unit in the laser light irradiation apparatus according to the third embodiment. The laser light source unit 120 shown in FIG. 8 is a specific example of the laser light source unit 100 in the first embodiment.
　図８に示されるように、レーザ光源ユニット１２０は、第１のレーザ素子１２１ａ、第２のレーザ素子１２１ｂおよび第３のレーザ素子１２１ｃを備え、これら第１のレーザ素子１２１ａ、第２のレーザ素子１２１ｂおよび第３のレーザ素子１２１ｃが発振するレーザ光をレーザ光源ユニット１２０内で合波し、いわゆるピグテールの構成でステップインデックス型マルチモード光ファイバ２００に接続する構成である。 As shown in FIG. 8, the laser light source unit 120 includes a first laser element 121a, a second laser element 121b, and a third laser element 121c, and these first laser element 121a and second laser element. The laser light oscillated by 121b and the third laser element 121c is multiplexed in the laser light source unit 120 and connected to the step index type multimode optical fiber 200 in a so-called pigtail configuration.
　第１のレーザ素子１２１ａ、第２のレーザ素子１２１ｂおよび第３のレーザ素子１２１ｃは、ファブリペロー型のレーザダイオードとすることが好ましいが、分布帰還型のレーザダイオードや外部共振器を用いたレーザダイオードなどを用いてもよい。第１のレーザ素子１２１ａ、第２のレーザ素子１２１ｂおよび第３のレーザ素子１２１ｃは、中心発振波長が相互に異なり、各中心発振波長の差の最大値は、５０ｎｍ以下となっている。また、第１のレーザ素子１２１ａ、第２のレーザ素子１２１ｂおよび第３のレーザ素子１２１ｃが発振する各レーザ光のスペクトル幅は、３ｎｍ以上５０ｎｍ以下であり、各レーザ光を合波した際のスペクトル幅は、３ｎｍ以上１００ｎｍ以下である。 The first laser element 121a, the second laser element 121b, and the third laser element 121c are preferably Fabry-Perot laser diodes, but are distributed feedback laser diodes or laser diodes using external resonators. Etc. may be used. The first laser element 121a, the second laser element 121b, and the third laser element 121c have different central oscillation wavelengths, and the maximum difference between the central oscillation wavelengths is 50 nm or less. The spectrum width of each laser beam oscillated by the first laser element 121a, the second laser element 121b, and the third laser element 121c is not less than 3 nm and not more than 50 nm, and the spectrum when the laser beams are multiplexed is obtained. The width is 3 nm or more and 100 nm or less.
　第１のレーザ素子１２１ａ、第２のレーザ素子１２１ｂおよび第３のレーザ素子１２１ｃが発振したレーザ光は、それぞれ光ファイバ１２２ａ，１２２ｂ，１２２ｃを伝搬しながら、光合波器１２３へ導入される。光合波器１２３は、例えば波長分割多重方式の光カプラを用いる。光合波器１２３によって合波されたレーザ光は光ファイバ１２４を伝搬しながら、レーザ光源ユニット１２０の外部へ導出され、コネクタや融着接続部により構成される光接続部１２５を介してステップインデックス型マルチモード光ファイバ２００へ接続される。 The laser beams oscillated by the first laser element 121a, the second laser element 121b, and the third laser element 121c are introduced into the optical multiplexer 123 while propagating through the optical fibers 122a, 122b, and 122c, respectively. The optical multiplexer 123 uses, for example, a wavelength division multiplexing optical coupler. The laser light combined by the optical multiplexer 123 is guided to the outside of the laser light source unit 120 while propagating through the optical fiber 124, and is step index type via the optical connection part 125 constituted by a connector and a fusion connection part. The multimode optical fiber 200 is connected.
　なお、光ファイバ１２２ａ，１２２ｂ，１２２ｃ，１２４は、第１のレーザ素子１２１ａ、第２のレーザ素子１２１ｂおよび第３のレーザ素子１２１ｃがシングルモードレーザ素子である場合は、シングルモードの光ファイバとすることができるが、マルチモードレーザ素子である場合は、ステップインデックス型マルチモード光ファイバ２００に多くのモードで導入することができるという観点では、マルチモードの光ファイバを用いることが好ましい。また、光合波器１２３は、第１のレーザ素子１２１ａ、第２のレーザ素子１２１ｂおよび第３のレーザ素子１２１ｃの発振波長の相違度合に基づいて、ファイバ溶融型やフィルタ型、または導波路型のカプラを選択して用いることができる。さらに、合波するレーザ光が２つの場合は、光合波器１２３の代わりに偏波合成器を利用する構成としてもよい。さらには、合波するレーザ光がさらに多い場合は、偏波合成器と波長分割多重式の光合波器とを併用する構成としてもよい。 Note that the optical fibers 122a, 122b, 122c, and 124 are single-mode optical fibers when the first laser element 121a, the second laser element 121b, and the third laser element 121c are single-mode laser elements. However, in the case of a multimode laser element, it is preferable to use a multimode optical fiber from the viewpoint that it can be introduced into the step index type multimode optical fiber 200 in many modes. Further, the optical multiplexer 123 is a fiber melting type, a filter type, or a waveguide type based on the difference in oscillation wavelength between the first laser element 121a, the second laser element 121b, and the third laser element 121c. A coupler can be selected and used. Furthermore, when there are two laser beams to be combined, a configuration in which a polarization beam combiner is used instead of the optical multiplexer 123 may be adopted. Further, when there are more laser beams to be combined, a configuration in which a polarization beam combiner and a wavelength division multiplexing optical multiplexer are used together may be employed.
　以上の構成のレーザ光源ユニット１２０は、レーザ光源ユニット１２０から出射されたレーザ光をマルチモードで伝搬するステップインデックス型マルチモード光ファイバ２００と、ステップインデックス型マルチモード光ファイバ２００に側圧と曲げと振動とを同時に与えるモード外乱手段３００と、ステップインデックス型マルチモード光ファイバ２００から出射されるレーザ光のビーム径を拡大して対象物に照射する対物光学系４００と共に用いることにより、第３実施形態に係るレーザ光照射装置を構成する。 The laser light source unit 120 having the above configuration includes a step index type multimode optical fiber 200 that propagates laser light emitted from the laser light source unit 120 in a multimode, and a lateral pressure, bending, and vibration in the step index type multimode optical fiber 200. Are used together with the mode disturbance means 300 that simultaneously applies the above and the objective optical system 400 that expands the beam diameter of the laser light emitted from the step index type multimode optical fiber 200 and irradiates the object. Such a laser beam irradiation apparatus is configured.
（第４実施形態）
　図９および図１０は、第４実施形態に係るレーザ光照射装置におけるモード外乱手段の概略構成を示す図である。図９および図１０に示されるモード外乱手段３１０は、第１実施形態におけるモード外乱手段３００の具体例となっている。図９は、モード外乱手段３１０の部分透過図であり、図１０は、モード外乱手段３１０の側面図である。 (Fourth embodiment)
9 and 10 are diagrams showing a schematic configuration of the mode disturbance means in the laser beam irradiation apparatus according to the fourth embodiment. The mode disturbance means 310 shown in FIGS. 9 and 10 is a specific example of the mode disturbance means 300 in the first embodiment. FIG. 9 is a partially transparent view of the mode disturbance unit 310, and FIG. 10 is a side view of the mode disturbance unit 310.
　図９および図１０に示されるように、モード外乱手段３１０は、巻き束状に配置したステップインデックス型マルチモード光ファイバ２００を２枚の挟持板３１１ａ，３１１ｂで挟持した構成となっている。 As shown in FIGS. 9 and 10, the mode disturbance means 310 has a configuration in which the step index type multimode optical fiber 200 arranged in a bundle shape is sandwiched between two sandwich plates 311a and 311b.
　２枚の挟持板３１１ａ，３１１ｂには、ボルトおよびナットで構成される加圧手段３１２が設けられ、２枚の挟持板３１１ａ，３１１ｂに挟持されたステップインデックス型マルチモード光ファイバ２００に側圧が加えられるように構成されている。図９に示されるように、巻き束状に配置したステップインデックス型マルチモード光ファイバ２００は、多数の交点を有する状態で配置されているので、２枚の挟持板３１１ａ，３１１ｂから印加された側圧が局所的に変化の付けられたものとなり、ステップインデックス型マルチモード光ファイバ２００を伝搬するレーザ光のモードに対してより効率よく外乱を与えることができるように構成されている。 The two clamping plates 311a and 311b are provided with pressurizing means 312 composed of bolts and nuts, and a lateral pressure is applied to the step index type multimode optical fiber 200 sandwiched between the two clamping plates 311a and 311b. It is configured to be. As shown in FIG. 9, the step index type multimode optical fiber 200 arranged in a bundle shape is arranged in a state having a large number of intersections, so that the side pressure applied from the two sandwiching plates 311a and 311b Is locally changed, and the disturbance is more efficiently applied to the mode of the laser light propagating through the step index type multimode optical fiber 200.
　なお、加圧手段３１２は、図に示されるようなボルトおよびナットで構成することもできるが、上側の挟持板３１１ａがある程度の重量を有しているならば、挟持板３１１ａの自重をもって加圧手段３１２とすることができる。また、別途の重り等を上側の挟持板３１１ａの上に配置し、当該重りの重量をもって加圧手段３１２とすることもできる。 The pressurizing means 312 can be constituted by bolts and nuts as shown in the figure. However, if the upper sandwiching plate 311a has a certain weight, the pressurizing means 312a is pressurized by its own weight. Means 312 may be provided. Alternatively, a separate weight or the like can be disposed on the upper clamping plate 311a, and the weight of the weight can be used as the pressurizing unit 312.
　また、ステップインデックス型マルチモード光ファイバ２００は、巻き束状に配置されているので、ステップインデックス型マルチモード光ファイバ２００に曲げが印加されている。ステップインデックス型マルチモード光ファイバ２００に対する曲げは、ステップインデックス型マルチモード光ファイバ２００を伝搬するレーザ光に対する外乱となっている。 Further, since the step index type multimode optical fiber 200 is arranged in a bundle shape, bending is applied to the step index type multimode optical fiber 200. The bending of the step index type multimode optical fiber 200 is a disturbance to the laser light propagating through the step index type multimode optical fiber 200.
　さらに、挟持板３１１ａ，３１１ｂには、振動手段３１３が設けられ、２枚の挟持板３１１ａ，３１１ｂに挟持されたステップインデックス型マルチモード光ファイバ２００に振動が加えられるように構成されている。振動手段３１３は、例えば２００Ｈｚ程度の振動を発生させる振動モータである。ステップインデックス型マルチモード光ファイバ２００に対する振動は、ステップインデックス型マルチモード光ファイバ２００を伝搬するレーザ光に対する外乱となっている。 Furthermore, the sandwiching plates 311a and 311b are provided with a vibration means 313 so that vibration is applied to the step index type multimode optical fiber 200 sandwiched between the two sandwiching plates 311a and 311b. The vibration unit 313 is a vibration motor that generates vibration of about 200 Hz, for example. The vibration with respect to the step index type multimode optical fiber 200 is a disturbance to the laser light propagating through the step index type multimode optical fiber 200.
　巻き束状に配置されたステップインデックス型マルチモード光ファイバ２００の長さは１ｍ以上であることが好ましい。モード外乱手段３１０がステップインデックス型マルチモード光ファイバ２００に側圧と曲げと振動とを同時に与える領域の長さを１ｍ以上とし、ステップインデックス型マルチモード光ファイバ２００を伝搬するレーザ光のモードに十分な外乱を与えるためである。例えば、半径３ｃｍ程度の大きさでステップインデックス型マルチモード光ファイバ２００を巻き束にした場合、６巻程度の巻き束である。 The length of the step index type multi-mode optical fiber 200 arranged in a bundle is preferably 1 m or more. The length of the region in which the mode disturbance means 310 simultaneously applies lateral pressure, bending and vibration to the step index type multimode optical fiber 200 is 1 m or more, which is sufficient for the mode of laser light propagating through the step index type multimode optical fiber 200. This is to give a disturbance. For example, when the step index type multimode optical fiber 200 is wound with a radius of about 3 cm, the number of windings is about six.
　以上の構成のモード外乱手段３１０は、レーザ光を出射するレーザ光源ユニット１００と、レーザ光源ユニット１００から出射されたレーザ光をマルチモードで伝搬するステップインデックス型マルチモード光ファイバ２００と、ステップインデックス型マルチモード光ファイバ２００から出射されるレーザ光のビーム径を拡大して対象物に照射する対物光学系４００と共に用いることにより、第４実施形態に係るレーザ光照射装置を構成する。 The mode disturbance means 310 having the above configuration includes a laser light source unit 100 that emits laser light, a step index type multimode optical fiber 200 that propagates laser light emitted from the laser light source unit 100 in a multimode, and a step index type. The laser beam irradiation apparatus according to the fourth embodiment is configured by using together with the objective optical system 400 that expands the beam diameter of the laser beam emitted from the multimode optical fiber 200 and irradiates the object.
（第５実施形態）
　図１１は、第５実施形態に係るレーザ光照射装置におけるモード外乱手段の概略構成を示す図である。図１１に示されるモード外乱手段３２０は、第１実施形態におけるモード外乱手段３００の具体例となっている。 (Fifth embodiment)
FIG. 11 is a diagram showing a schematic configuration of mode disturbance means in the laser beam irradiation apparatus according to the fifth embodiment. The mode disturbance means 320 shown in FIG. 11 is a specific example of the mode disturbance means 300 in the first embodiment.
　図１１に示されるように、モード外乱手段３２０は、ボビン３２１ａ，３２１ｂと張力手段３２２ａ，３２２ｂと振動手段３２３とを備えている。図１１に示されるように、モード外乱手段３２０は、いわゆる光ファイバ型偏波コントローラを流用した構成となっている。振動手段３２３はたとえば電動モータとギヤとで構成されたアクチュエータである。 As shown in FIG. 11, the mode disturbance means 320 includes bobbins 321a and 321b, tension means 322a and 322b, and vibration means 323. As shown in FIG. 11, the mode disturbance means 320 has a configuration that uses a so-called optical fiber polarization controller. The vibration means 323 is an actuator composed of, for example, an electric motor and a gear.
　光ファイバ型偏波コントローラとは、光ファイバを曲げる際の複屈折を利用して偏波を制御する偏波コントローラである。モード外乱手段３２０は、この光ファイバ型偏波コントローラを流用し、ステップインデックス型マルチモード光ファイバ２００に側圧と曲げと振動とを同時に与える。 An optical fiber polarization controller is a polarization controller that controls polarization using birefringence when an optical fiber is bent. The mode disturbance means 320 diverts this optical fiber type polarization controller and applies lateral pressure, bending and vibration to the step index type multimode optical fiber 200 simultaneously.
　図１１に示されるように、ステップインデックス型マルチモード光ファイバ２００は、張力手段３２２ａ，３２２ｂによって一定の張力を与えられながらボビン３２１ａ，３２１ｂに巻きつけられている。これにより、ステップインデックス型マルチモード光ファイバ２００は、ボビン３２１ａ，３２１ｂから側圧を受けることになる。さらに、ボビン３２１ａ，３２１ｂはそれぞれ軸３２１ａａ，３２１ｂａの回りに回転できるように構成されており、ボビン３２１ａ，３２１ｂがそれぞれ軸３２１ａａ，３２１ｂａの回りに回転することにより、ステップインデックス型マルチモード光ファイバ２００は捻られて側圧および曲げを受けることになる。 As shown in FIG. 11, the step index type multimode optical fiber 200 is wound around bobbins 321a and 321b while being given a constant tension by tension means 322a and 322b. Thereby, the step index type multimode optical fiber 200 receives a side pressure from the bobbins 321a and 321b. Further, the bobbins 321a and 321b are configured to rotate around the shafts 321aa and 321ba, respectively. The bobbin 321a and 321b rotate around the shafts 321aa and 321ba, respectively. Will be twisted and subjected to lateral pressure and bending.
　また、図１１に示されるように、ステップインデックス型マルチモード光ファイバ２００同士が交点を有するよう、ステップインデックス型マルチモード光ファイバ２００がボビン３２１ａ，３２１ｂに巻きつけられている。これにより、ステップインデックス型マルチモード光ファイバ２００同士の交点で、局所的に強い側圧および曲げが印加されている。 As shown in FIG. 11, the step index type multimode optical fiber 200 is wound around the bobbins 321a and 321b so that the step index type multimode optical fibers 200 have intersections. Thereby, a strong lateral pressure and bending are applied locally at the intersection of the step index type multimode optical fibers 200.
　さらに、図１１に示されるように、振動手段３２３によって、ボビン３２１ａ，３２１ｂはそれぞれ軸３２１ａａ，３２１ｂａの回りに回転され、振動または搖動が印加されている。これにより、ボビン３２１ａ，３２１ｂに巻きつけられたステップインデックス型マルチモード光ファイバ２００も振動または搖動が印加されている。 Furthermore, as shown in FIG. 11, the bobbins 321a and 321b are rotated around the shafts 321aa and 321ba by the vibration means 323, respectively, and vibration or peristalsis is applied. As a result, vibration or vibration is also applied to the step index type multimode optical fiber 200 wound around the bobbins 321a and 321b.
　以上の構成のモード外乱手段３２０は、レーザ光を出射するレーザ光源ユニット１００と、レーザ光源ユニット１００から出射されたレーザ光をマルチモードで伝搬するステップインデックス型マルチモード光ファイバ２００と、ステップインデックス型マルチモード光ファイバ２００から出射されるレーザ光のビーム径を拡大して対象物に照射する対物光学系４００と共に用いることにより、第５実施形態に係るレーザ光照射装置を構成する。 The mode disturbance means 320 having the above configuration includes a laser light source unit 100 that emits laser light, a step index type multimode optical fiber 200 that propagates laser light emitted from the laser light source unit 100 in a multimode, and a step index type. The laser beam irradiation apparatus according to the fifth embodiment is configured by using together with the objective optical system 400 that expands the beam diameter of the laser beam emitted from the multimode optical fiber 200 and irradiates the object.
（第６実施形態）
　図１２は、第６実施形態に係るレーザ光照射装置における対物光学系の概略構成を示す図である。図１２に示される対物光学系４１０は、第１実施形態における対物光学系４００の具体例となっている。 (Sixth embodiment)
FIG. 12 is a diagram illustrating a schematic configuration of an objective optical system in the laser light irradiation apparatus according to the sixth embodiment. An objective optical system 410 shown in FIG. 12 is a specific example of the objective optical system 400 in the first embodiment.
　図１２に示されるように、対物光学系４１０は、対物レンズ４１１を備えている。対物レンズ４１１は、ステップインデックス型マルチモード光ファイバ２００の端面におけるレーザ光の強度分布をほぼ相似形に拡大し、対象物に投影するためのレンズである。すなわち、対物レンズ４１１の前側焦点位置がステップインデックス型マルチモード光ファイバ２００の端面に一致し、かつ、対物レンズ４１１の後側焦点位置が対象物に一致するように配置されている。 As shown in FIG. 12, the objective optical system 410 includes an objective lens 411. The objective lens 411 is a lens for enlarging the intensity distribution of the laser light on the end face of the step index type multimode optical fiber 200 to a substantially similar shape and projecting it onto the object. That is, the front focal position of the objective lens 411 is arranged so as to coincide with the end face of the step index type multimode optical fiber 200, and the rear focal position of the objective lens 411 coincides with the object.
　ここで、対物レンズ４１１の開口数（ＮＡ２）は、ステップインデックス型マルチモード光ファイバ２００の開口数（ＮＡ１）よりも小さい。図１２の角度θ１とθ２との関係で表現すれば、角度θ２は角度θ１よりも小さい。先述のように、ＮＡ１＝ｓｉｎθ１，ＮＡ２＝ｓｉｎθ２の関係が成立しているからである。 Here, the numerical aperture (NA 2 ) of the objective lens 411 is smaller than the numerical aperture (NA 1 ) of the step index type multimode optical fiber 200. Expressed by the relationship between the angles θ 1 and θ 2 in FIG. 12, the angle θ 2 is smaller than the angle θ 1 . This is because the relationship of NA 1 = sin θ 1 and NA 2 = sin θ 2 is established as described above.
　上記開口数の関係は、いわゆるケラレが発生してしまう状態である。すなわち、ステップインデックス型マルチモード光ファイバ２００の端面から出射されるレーザ光のうちビーム外周の一部は、対物レンズ４１１を透過することができず、対象物まで到達することができない。一般的に、ケラレが発生することは好ましくないとされているが、対物光学系４１０は、意図的にケラレを発生させることにより、対象物に投影されるレーザ光の強度分布をより矩形に近い形状に整形している。 The above numerical aperture relationship is a state in which so-called vignetting occurs. That is, a part of the outer periphery of the laser light emitted from the end face of the step index type multimode optical fiber 200 cannot pass through the objective lens 411 and cannot reach the object. In general, it is not preferable that vignetting occurs. However, the objective optical system 410 intentionally generates vignetting so that the intensity distribution of the laser light projected onto the object is closer to a rectangle. Shaped into shape.
　以上の構成の対物光学系４１０は、レーザ光を出射するレーザ光源ユニット１００と、レーザ光源ユニット１００から出射されたレーザ光をマルチモードで伝搬するステップインデックス型マルチモード光ファイバ２００と、ステップインデックス型マルチモード光ファイバ２００に側圧と曲げと振動とを同時に与えるモード外乱手段３００と共に用いることにより、第６実施形態に係るレーザ光照射装置を構成する。 The objective optical system 410 having the above configuration includes a laser light source unit 100 that emits laser light, a step index type multimode optical fiber 200 that propagates laser light emitted from the laser light source unit 100 in a multimode, and a step index type. The laser beam irradiation apparatus according to the sixth embodiment is configured by using the multimode optical fiber 200 together with the mode disturbance means 300 that simultaneously applies a lateral pressure, bending, and vibration.
（効果の検証例）
　以下、上記説明した本発明の実施形態に係るレーザ光照射装置における効果の検証例について説明する。まず、効果の測定に用いる平滑性の定義を行う。 (Effectiveness verification example)
Hereinafter, a verification example of the effect in the laser beam irradiation apparatus according to the embodiment of the present invention described above will be described. First, the smoothness used for measuring the effect is defined.
　図１３は、平滑性の定義を説明する図である。図１３に示されるグラフには、レーザ光の強度分布の例が実線で記載され、比較となる強度分布としてガウシアン強度分布が破線で記載されている。 FIG. 13 is a diagram for explaining the definition of smoothness. In the graph shown in FIG. 13, an example of the intensity distribution of laser light is indicated by a solid line, and a Gaussian intensity distribution is indicated by a broken line as a comparative intensity distribution.
　以下の効果の検証で用いられる平滑性Ｆは、平均パワーＰと平均パワーに対する変動幅δＰとの比で表される。すなわち、平滑性Ｆは、Ｆ＝δＰ／Ｐの関係式で定義される。 The smoothness F used in the verification of the following effects is represented by the ratio of the average power P and the fluctuation range δP with respect to the average power. That is, the smoothness F is defined by the relational expression of F = δP / P.
　図１３に示されるように、平均パワーＰとは、レーザ光の強度分布の全幅Ｗの０．８倍の範囲におけるレーザ光の強度の平均値である。ここで、全幅Ｗとは、レーザ光の最大出力強度から２０ｄＢ低下した強度となる波長範囲である。なお、図１３に示されるグラフの縦軸は、リニアスケールの任意単位（ａ．ｕ．）であり、全幅Ｗは、縦軸に関して最大強度の１％に低下した位置の波長範囲に対応している。また、平均パワーに対する変動幅δＰとは、レーザ光の強度分布の全幅Ｗの０．８倍の範囲におけるレーザ光の強度のピーク・トゥー・ピークの差である。 As shown in FIG. 13, the average power P is the average value of the intensity of the laser beam in the range of 0.8 times the full width W of the intensity distribution of the laser beam. Here, the full width W is a wavelength range where the intensity is reduced by 20 dB from the maximum output intensity of the laser beam. The vertical axis of the graph shown in FIG. 13 is an arbitrary unit (au) of the linear scale, and the full width W corresponds to the wavelength range at a position where the vertical axis is reduced to 1% of the maximum intensity. Yes. The fluctuation width δP with respect to the average power is the difference between the peak-to-peak of the intensity of the laser beam in the range of 0.8 times the total width W of the intensity distribution of the laser beam.
　図１３から解るように、レーザ光の強度分布における凹凸が大きくなる程、平滑性Ｆが大きくなる。また、レーザ光の強度分布がガウシアン強度分布に近づいても、平滑性Ｆが大きくなる。したがって、上記定義の平滑性Ｆが小さい程、本発明の効果が大きいと判断できる。 As can be seen from FIG. 13, the smoothness F increases as the unevenness in the intensity distribution of the laser beam increases. Further, even if the laser light intensity distribution approaches the Gaussian intensity distribution, the smoothness F increases. Therefore, it can be determined that the smaller the smoothness F defined above, the greater the effect of the present invention.
（検証例１）
　検証例１は、図３に示したようにスペクトル幅が狭いレーザ光を用いた場合の例である。なお、モード外乱手段では、振動と側圧と曲げとを同時に与えている。また、使用したステップインデックス型マルチモード光ファイバの開口数は０．１５であり、対物光学系の開口数は０．１５である。 (Verification example 1)
Verification Example 1 is an example in the case of using a laser beam having a narrow spectrum width as shown in FIG. In the mode disturbance means, vibration, lateral pressure and bending are applied simultaneously. The numerical index of the used step index type multimode optical fiber is 0.15, and the numerical aperture of the objective optical system is 0.15.
　図１４～図１６は、検証例１における平滑性を示す図である。図１４は、検証例１におけるレーザ光の強度分布を示す３Ｄグラフであり、図１５は、検証例１におけるレーザ光の強度分布を示す平面画像であり、図１６は、図１５におけるＸ断面およびＹ断面の強度分布を示すグラフである。 14 to 16 are diagrams showing the smoothness in the first verification example. FIG. 14 is a 3D graph showing the intensity distribution of the laser light in Verification Example 1, FIG. 15 is a planar image showing the intensity distribution of the laser light in Verification Example 1, and FIG. It is a graph which shows intensity distribution of a Y section.
　図１４～図１６を参照すると解るように、検証例１におけるレーザ光の強度分布は、スペックルの発生が観察される。また、検証例１におけるレーザ光の強度分布の平滑性Ｆを計算すると、Ｆ＝約２０％であった。 As can be seen from FIG. 14 to FIG. 16, in the intensity distribution of the laser light in the verification example 1, occurrence of speckle is observed. Further, when the smoothness F of the intensity distribution of the laser light in the verification example 1 was calculated, F = about 20%.
（検証例２）
　検証例２は、図３に示したようにスペクトル幅が狭いレーザ光を用いた場合の例である。なお、モード外乱手段では、振動と側圧と曲げとを同時に与えている。また、使用したステップインデックス型マルチモード光ファイバの開口数は０．２２であり、対物光学系の開口数は０．２２である。 (Verification example 2)
Verification example 2 is an example in the case of using a laser beam having a narrow spectrum width as shown in FIG. In the mode disturbance means, vibration, lateral pressure and bending are applied simultaneously. Moreover, the numerical aperture of the used step index type multimode optical fiber is 0.22, and the numerical aperture of the objective optical system is 0.22.
　図１７～図１９は、検証例２における平滑性を示す図である。図１７は、検証例２におけるレーザ光の強度分布を示す３Ｄグラフであり、図１８は、検証例２におけるレーザ光の強度分布を示す平面画像であり、図１９は、図１８におけるＸ断面およびＹ断面の強度分布を示すグラフである。 17 to 19 are diagrams showing the smoothness in the verification example 2. FIG. 17 is a 3D graph showing the intensity distribution of the laser beam in Verification Example 2, FIG. 18 is a planar image showing the intensity distribution of the laser beam in Verification Example 2, and FIG. It is a graph which shows intensity distribution of a Y section.
　図１７～図１９を参照すると解るように、検証例２におけるレーザ光の強度分布は、スペックルは少ないが、ガウシアン強度分布に近い形状である。また、検証例２におけるレーザ光の強度分布の平滑性Ｆを計算すると、Ｆ＝約１５％であった。 As can be seen from FIG. 17 to FIG. 19, the intensity distribution of the laser light in the verification example 2 has a shape close to the Gaussian intensity distribution although the speckle is small. Further, when the smoothness F of the intensity distribution of the laser beam in the verification example 2 was calculated, F = about 15%.
　ここで、検証例１と検証例２とを比較すると、ステップインデックス型マルチモード光ファイバのＮＡが大きい方が、平滑性Ｆは向上することが解る。 Here, comparing the verification example 1 and the verification example 2, it can be seen that the smoothness F is improved when the NA of the step index type multimode optical fiber is large.
（検証例３）
　検証例３は、図４に示したようにスペクトル幅が広い複数のレーザ光を合波したものを用いた場合の例である。なお、モード外乱手段では、振動のみを与えている。また、使用したステップインデックス型マルチモード光ファイバの開口数は０．２２であり、対物光学系の開口数は０．２２である。 (Verification Example 3)
Verification example 3 is an example in the case of using a combination of a plurality of laser beams having a wide spectrum width as shown in FIG. In the mode disturbance means, only vibration is given. Moreover, the numerical aperture of the used step index type multimode optical fiber is 0.22, and the numerical aperture of the objective optical system is 0.22.
　図２０～図２２は、検証例３における平滑性を示す図である。図２０は、検証例３におけるレーザ光の強度分布を示す３Ｄグラフであり、図２１は、検証例３におけるレーザ光の強度分布を示す平面画像であり、図２２は、図２１におけるＸ断面およびＹ断面の強度分布を示すグラフである。 20 to 22 are diagrams illustrating the smoothness in the third verification example. FIG. 20 is a 3D graph showing the intensity distribution of the laser beam in Verification Example 3, FIG. 21 is a planar image showing the intensity distribution of the laser beam in Verification Example 3, and FIG. It is a graph which shows intensity distribution of a Y section.
　図２０～図２２を参照すると解るように、検証例３におけるレーザ光の強度分布は、スペックルの発生が観察される。また、検証例３におけるレーザ光の強度分布の平滑性Ｆを計算すると、Ｆ＝約１５％であった。 As can be seen from FIG. 20 to FIG. 22, the speckle generation is observed in the intensity distribution of the laser light in the verification example 3. Further, when the smoothness F of the intensity distribution of the laser beam in the verification example 3 was calculated, F = about 15%.
（検証例４）
　検証例４は、図４に示したようにスペクトル幅が広い複数のレーザ光を合波したものを用いた場合の例である。なお、モード外乱手段では、振動と曲げのみを与えている。また、使用したステップインデックス型マルチモード光ファイバの開口数は０．２２であり、対物光学系の開口数は０．２２である。 (Verification Example 4)
Verification example 4 is an example in the case of using a combination of a plurality of laser beams having a wide spectrum width as shown in FIG. In the mode disturbance means, only vibration and bending are given. Moreover, the numerical aperture of the used step index type multimode optical fiber is 0.22, and the numerical aperture of the objective optical system is 0.22.
　図２３～図２５は、検証例４における平滑性を示す図である。図２３は、検証例４におけるレーザ光の強度分布を示す３Ｄグラフであり、図２４は、検証例４におけるレーザ光の強度分布を示す平面画像であり、図２５は、図２４におけるＸ断面およびＹ断面の強度分布を示すグラフである。 23 to 25 are diagrams showing the smoothness in the fourth verification example. FIG. 23 is a 3D graph showing the intensity distribution of the laser light in Verification Example 4, FIG. 24 is a planar image showing the intensity distribution of the laser light in Verification Example 4, and FIG. 25 is an X cross-section in FIG. It is a graph which shows intensity distribution of a Y section.
　図２３～図２５を参照すると解るように、検証例４におけるレーザ光の強度分布は、スペックルが十分に除去されていない。また、検証例４におけるレーザ光の強度分布の平滑性Ｆを計算すると、Ｆ＝約１２％であった。 As can be seen from FIG. 23 to FIG. 25, the speckles are not sufficiently removed in the intensity distribution of the laser light in the verification example 4. Further, when the smoothness F of the intensity distribution of the laser light in the verification example 4 was calculated, F = about 12%.
　ここで、検証例３と検証例４とを比較すると、ステップインデックス型マルチモード光ファイバに振動のみならず曲げも印加する方が、平滑性Ｆは向上することが解る。 Here, comparing the verification example 3 and the verification example 4, it is understood that the smoothness F is improved by applying not only vibration but also bending to the step index type multimode optical fiber.
（検証例５）
　検証例５は、図４に示したようにスペクトル幅が広い複数のレーザ光を合波したものを用いた場合の例である。なお、モード外乱手段では、振動と曲げと側圧とを同時に与えている。また、使用したステップインデックス型マルチモード光ファイバの開口数は０．２２であり、対物光学系の開口数は０．２２である。 (Verification Example 5)
Verification example 5 is an example in the case of using a combination of a plurality of laser beams having a wide spectrum width as shown in FIG. In the mode disturbance means, vibration, bending and lateral pressure are applied simultaneously. Moreover, the numerical aperture of the used step index type multimode optical fiber is 0.22, and the numerical aperture of the objective optical system is 0.22.
　図２６～図２８は、検証例５における平滑性を示す図である。図２６は、検証例５におけるレーザ光の強度分布を示す３Ｄグラフであり、図２７は、検証例５におけるレーザ光の強度分布を示す平面画像であり、図２８は、図２７におけるＸ断面およびＹ断面の強度分布を示すグラフである。 FIGS. 26 to 28 are diagrams showing the smoothness in the fifth verification example. FIG. 26 is a 3D graph showing the intensity distribution of the laser light in Verification Example 5, FIG. 27 is a plane image showing the intensity distribution of the laser light in Verification Example 5, and FIG. It is a graph which shows intensity distribution of a Y section.
　図２６～図２８を参照すると解るように、検証例５におけるレーザ光の強度分布は、スペックルが十分に除去されており、平滑性が良い。また、検証例５におけるレーザ光の強度分布の平滑性Ｆを計算すると、Ｆ＝約１０％であった。 As can be seen from FIGS. 26 to 28, in the intensity distribution of the laser light in the verification example 5, speckles are sufficiently removed and smoothness is good. Further, when the smoothness F of the intensity distribution of the laser light in the verification example 5 was calculated, F = about 10%.
　ここで、検証例４と検証例５とを比較すると、ステップインデックス型マルチモード光ファイバに振動および曲げのみならず側圧も印加する方が、平滑性Ｆは向上することが解る。 Here, comparing the verification example 4 and the verification example 5, it is understood that the smoothness F is improved by applying not only vibration and bending but also a lateral pressure to the step index type multimode optical fiber.
（検証例６）
　検証例６は、図４に示したようにスペクトル幅が広い複数のレーザ光を合波したものを用いた場合の例である。なお、モード外乱手段では、振動と曲げと側圧とを同時に与えている。また、使用したステップインデックス型マルチモード光ファイバの開口数は０．２２であり、対物光学系の開口数は０．１８である。 (Verification Example 6)
Verification example 6 is an example in the case of using a combination of a plurality of laser beams having a wide spectrum width as shown in FIG. In the mode disturbance means, vibration, bending and lateral pressure are applied simultaneously. The step index type multimode optical fiber used has a numerical aperture of 0.22, and the objective optical system has a numerical aperture of 0.18.
　図２９～図３１は、検証例６における平滑性を示す図である。図２９は、検証例６におけるレーザ光の強度分布を示す３Ｄグラフであり、図３０は、検証例６におけるレーザ光の強度分布を示す平面画像であり、図３１は、図３０におけるＸ断面およびＹ断面の強度分布を示すグラフである。 29 to 31 are diagrams showing the smoothness in the verification example 6. FIG. 29 is a 3D graph showing the intensity distribution of laser light in Verification Example 6, FIG. 30 is a planar image showing the intensity distribution of laser light in Verification Example 6, and FIG. It is a graph which shows intensity distribution of a Y section.
　図２９～図３１を参照すると解るように、検証例６におけるレーザ光の強度分布は、スペックルが十分に除去されており、かつ、強度分布の両端部における光強度が低下しているので、切れの良い矩形形状となっている。また、検証例６におけるレーザ光の強度分布の平滑性Ｆを計算すると、Ｆ＝約８％であった。 As can be seen with reference to FIGS. 29 to 31, in the intensity distribution of the laser light in the verification example 6, the speckle is sufficiently removed, and the light intensity at both ends of the intensity distribution is reduced. It has a well-cut rectangular shape. Further, when the smoothness F of the intensity distribution of the laser beam in the verification example 6 was calculated, F = about 8%.
　ここで、検証例５と検証例６とを比較すると、ステップインデックス型マルチモード光ファイバの開口数よりも対物光学系の開口数を小さくする方が、平滑性Ｆは向上することが解る。 Here, comparing the verification example 5 and the verification example 6, it can be seen that the smoothness F is improved when the numerical aperture of the objective optical system is made smaller than the numerical aperture of the step index type multimode optical fiber.
（検証例７）
　検証例７は、図４に示したようにスペクトル幅が広い複数のレーザ光を合波したものを用いた場合の例である。なお、モード外乱手段では、振動と曲げと側圧とを同時に与えている。また、使用したステップインデックス型マルチモード光ファイバの開口数は０．２２であり、対物光学系の開口数は０．２４である。 (Verification example 7)
Verification example 7 is an example in the case of using a combination of a plurality of laser beams having a wide spectrum width as shown in FIG. In the mode disturbance means, vibration, bending and lateral pressure are applied simultaneously. Moreover, the numerical aperture of the used step index type multimode optical fiber is 0.22, and the numerical aperture of the objective optical system is 0.24.
　図３２～図３４は、検証例７における平滑性を示す図である。図３２は、検証例７におけるレーザ光の強度分布を示す３Ｄグラフであり、図３３は、検証例７におけるレーザ光の強度分布を示す平面画像であり、図３４は、図３３におけるＸ断面およびＹ断面の強度分布を示すグラフである。 32 to 34 are diagrams showing the smoothness in the verification example 7. FIG. FIG. 32 is a 3D graph showing the intensity distribution of the laser beam in Verification Example 7, FIG. 33 is a planar image showing the intensity distribution of the laser beam in Verification Example 7, and FIG. It is a graph which shows intensity distribution of a Y section.
　図３２～図３４を参照すると解るように、検証例７におけるレーザ光の強度分布は、強度分布の両端部における光強度が増加し、全体としてガウシアン強度分布に近い形状となっている。さらに、本来とは異なるレーザ光まで結合されてしまい、平滑性も犠牲になっている。また、検証例７におけるレーザ光の強度分布の平滑性Ｆを計算すると、Ｆ＝約１２％であった。 As can be seen from FIG. 32 to FIG. 34, the intensity distribution of the laser light in the verification example 7 has a shape close to the Gaussian intensity distribution as a whole as the light intensity increases at both ends of the intensity distribution. Further, even laser light different from the original is coupled, and the smoothness is sacrificed. Further, when the smoothness F of the intensity distribution of the laser beam in the verification example 7 was calculated, F = about 12%.
　ここで、検証例６と検証例７とを比較すると、ステップインデックス型マルチモード光ファイバの開口数よりも対物光学系の開口数を小さくする方が、平滑性Ｆは向上することが解る。 Here, comparing the verification example 6 and the verification example 7, it can be seen that the smoothness F is improved when the numerical aperture of the objective optical system is made smaller than the numerical aperture of the step index type multimode optical fiber.
（検証例のまとめ）
　検証例３～５を比較すると解るように、ステップインデックス型マルチモード光ファイバに側圧と曲げと振動とを同時に与えるモード外乱手段を備えるレーザ光照射装置は、ステップインデックス型マルチモード光ファイバに振動のみを与えるモード外乱手段、またはステップインデックス型マルチモード光ファイバに振動および曲げのみを与えるモード外乱手段を備えるレーザ光照射装置よりも、レーザ光の強度分布の平滑性を向上させる効果が大きい。 (Summary of verification examples)
As can be seen by comparing the verification examples 3 to 5, the laser beam irradiation apparatus including the mode disturbance means for simultaneously applying the lateral pressure, bending, and vibration to the step index type multimode optical fiber has only vibration in the step index type multimode optical fiber. The effect of improving the smoothness of the intensity distribution of the laser beam is greater than that of the laser beam irradiation apparatus that includes the mode disturbance unit that provides vibration or the mode disturbance unit that applies only vibration and bending to the step index type multimode optical fiber.
　また、検証例２と検証例５とを比較すると解るように、レーザ光源ユニットから出射されるレーザ光のスペクトル幅が３ｎｍ以上１００ｎｍ以下であるレーザ光照射装置は、レーザ光源ユニットから出射されるレーザ光のスペクトル幅が３ｎｍより小さいレーザ光照射装置よりも、レーザ光の強度分布の平滑性を向上させる効果が大きい。 As can be seen from a comparison between verification example 2 and verification example 5, the laser beam irradiation apparatus in which the spectral width of the laser beam emitted from the laser light source unit is 3 nm to 100 nm is a laser emitted from the laser light source unit. The effect of improving the smoothness of the intensity distribution of the laser beam is greater than that of a laser beam irradiation apparatus having a spectral width of light smaller than 3 nm.
　さらに、検証例１と検証例２とを比較すると解るように、ステップインデックス型マルチモード光ファイバの開口数が０．１５以上であるレーザ光照射装置は、ステップインデックス型マルチモード光ファイバの開口数が０．１５より小さいレーザ光照射装置よりも、レーザ光の強度分布の平滑性を向上させる効果が大きい。 Further, as can be seen from a comparison between the verification example 1 and the verification example 2, the laser beam irradiation apparatus in which the numerical aperture of the step index type multimode optical fiber is 0.15 or more is the numerical aperture of the step index type multimode optical fiber. The effect of improving the smoothness of the intensity distribution of the laser beam is greater than that of a laser beam irradiation apparatus having a diameter of less than 0.15.
　さらに、検証例５～７を比較すると解るように、対物光学系の開口数がステップインデックス型マルチモード光ファイバの開口数よりも小さいレーザ光照射装置は、対物光学系の開口数がステップインデックス型マルチモード光ファイバの開口数よりも小さいレーザ光照射装置よりも平滑性を向上させる効果が大きい。 Further, as can be seen by comparing the verification examples 5 to 7, the laser beam irradiation apparatus in which the numerical aperture of the objective optical system is smaller than the numerical aperture of the step index type multi-mode optical fiber has the numerical aperture of the objective optical system of the step index type. The effect of improving the smoothness is greater than that of a laser beam irradiation apparatus having a numerical aperture smaller than that of the multimode optical fiber.
　以上のように、本発明に係るレーザ光照射装置は、高強度のレーザ光を対象物に照射する産業分野に有用である。 As described above, the laser light irradiation apparatus according to the present invention is useful in the industrial field in which an object is irradiated with high-intensity laser light.
　１０００　レーザ光照射装置
　１００，１１０，１２０　レーザ光源ユニット
　１１１ａ，１２１ａ　第１のレーザ素子
　１１１ｂ，１２１ｂ　第２のレーザ素子
　１１１ｃ，１２１ｃ　第３のレーザ素子
　１１２ａ，１１２ｂ，１１２ｃ　第１のシリンドリカルレンズ
　１１３ａ，１１３ｂ，１１３ｃ　第２のシリンドリカルレンズ
　１１４ａ，１１４ｂ，１１４ｃ　ミラー
　１１５　集光レンズ
　１２２ａ，１２２ｂ，１２２ｃ，１２４　光ファイバ
　１２３　光合波器
　１２５　光接続部
　２００　ステップインデックス型マルチモード光ファイバ
　３００，３１０，３２０　モード外乱手段
　３１１ａ，３１１ｂ　挟持板
　３１２　加圧手段
　３１３，３２３　振動手段
　３２１ａ，３２１ｂ　ボビン
　３２２ａ，３２２ｂ　張力手段
　４００，４１０　対物光学系
　４１１　対物レンズ 1000 Laser light irradiation device 100, 110, 120 Laser light source unit 111a, 121a First laser element 111b, 121b Second laser element 111c, 121c Third laser element 112a, 112b, 112c First cylindrical lens 113a, 113b , 113c Second cylindrical lens 114a, 114b, 114c Mirror 115 Condensing lens 122a, 122b, 122c, 124 Optical fiber 123 Optical multiplexer 125 Optical connection part 200 Step index type multimode optical fiber 300, 310, 320 Mode disturbance means 311a, 311b Clamping plate 312 Pressurizing means 313, 323 Vibration means 321a, 321b Bobbins 322a, 322b Tensioning means 400, 410 Objective optical system 411 Objective lens

Claims (8)

  1. 　レーザ光を出射するレーザ光源ユニットと、
    　前記レーザ光源ユニットから出射されたレーザ光をマルチモードで伝搬するステップインデックス型マルチモード光ファイバと、
    　前記ステップインデックス型マルチモード光ファイバに側圧と曲げと振動とを同時に与えるモード外乱手段と、
    　前記ステップインデックス型マルチモード光ファイバから出射されるレーザ光のビーム径を拡大して対象物に照射する対物光学系と、
    　を備えることを特徴とするレーザ光照射装置。     A laser light source unit for emitting laser light;
    A step index type multimode optical fiber that propagates the laser light emitted from the laser light source unit in a multimode;
    Mode disturbance means for simultaneously applying lateral pressure, bending and vibration to the step index type multimode optical fiber;
    An objective optical system for irradiating an object with an enlarged beam diameter of laser light emitted from the step index type multimode optical fiber;
    A laser beam irradiation apparatus comprising:
  2. 　前記レーザ光源ユニットは、一つのレーザ素子を備え、
    　前記レーザ素子が発振するレーザ光のスペクトル幅が３ｎｍ以上１００ｎｍ以下であることを特徴とする請求項１に記載のレーザ光照射装置。     The laser light source unit includes one laser element,
    The laser beam irradiation apparatus according to claim 1, wherein the laser beam oscillated by the laser element has a spectral width of 3 nm to 100 nm.
  3. 　前記レーザ光源ユニットは、複数のレーザ素子を備え、
    　前記レーザ光源ユニットから出射されるレーザ光は、前記複数のレーザ素子が発振するレーザ光を合波したものであり、
    　前記複数のレーザ素子が発振するレーザ光を合波したもののスペクトル幅が３ｎｍ以上１００ｎｍ以下であることを特徴とする請求項１に記載のレーザ光照射装置。     The laser light source unit includes a plurality of laser elements,
    The laser beam emitted from the laser light source unit is a combination of laser beams oscillated by the plurality of laser elements,
    2. The laser beam irradiation apparatus according to claim 1, wherein a spectrum width of a combination of laser beams oscillated by the plurality of laser elements is 3 nm or more and 100 nm or less.
  4. 　前記レーザ素子が発振するレーザ光のスペクトル幅の各々が３ｎｍ以上５０ｎｍ以下であることを特徴とする請求項３に記載のレーザ光照射装置。 4. The laser beam irradiation apparatus according to claim 3, wherein each of the spectral widths of the laser beams oscillated by the laser element is 3 nm or more and 50 nm or less.
  5. 　前記複数のレーザ素子の中心発振波長が相互に異なり、前記複数のレーザ素子の中心発振波長における差の最大値が５０ｎｍ以下であることを特徴とする請求項３または請求項４に記載のレーザ光照射装置。 5. The laser beam according to claim 3, wherein central oscillation wavelengths of the plurality of laser elements are different from each other, and a maximum difference in central oscillation wavelengths of the plurality of laser elements is 50 nm or less. Irradiation device.
  6. 　前記モード外乱手段が前記ステップインデックス型マルチモード光ファイバに側圧と曲げと振動とを同時に与える領域の長さが１ｍ以上であることを特徴とする請求項１～５の何れか１つに記載のレーザ光照射装置。 The length of a region in which the mode disturbance means applies lateral pressure, bending, and vibration simultaneously to the step index type multimode optical fiber is 1 m or more, according to any one of claims 1 to 5. Laser light irradiation device.
  7. 　前記ステップインデックス型マルチモード光ファイバの開口数は０．１５以上であることを特徴とする請求項１～６の何れか１つに記載のレーザ光照射装置。 The laser beam irradiation apparatus according to any one of claims 1 to 6, wherein the step index type multimode optical fiber has a numerical aperture of 0.15 or more.
  8. 　前記対物光学系の開口数が前記ステップインデックス型マルチモード光ファイバの開口数よりも小さいことを特徴とする請求項１～７の何れか１つに記載のレーザ光照射装置。 8. The laser light irradiation apparatus according to claim 1, wherein the numerical aperture of the objective optical system is smaller than the numerical aperture of the step index type multimode optical fiber.
PCT/JP2015/074153 2014-08-28 2015-08-27 Laser light irradiation device WO2016031895A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2016545600A JP6640094B2 (en) 2014-08-28 2015-08-27 Laser light irradiation device

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2014-174621 2014-08-28
JP2014174621 2014-08-28

Publications (1)

Publication Number Publication Date
WO2016031895A1 true WO2016031895A1 (en) 2016-03-03

Family

ID=55399780

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2015/074153 WO2016031895A1 (en) 2014-08-28 2015-08-27 Laser light irradiation device

Country Status (2)

Country Link
JP (1) JP6640094B2 (en)
WO (1) WO2016031895A1 (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20200354261A1 (en) * 2016-09-29 2020-11-12 Nlight, Inc. Optical fiber bending mechanisms
US20220404648A1 (en) * 2016-09-29 2022-12-22 Nlight, Inc. Methods of and systems for processing using adjustable beam characteristics

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS62148922A (en) * 1985-12-23 1987-07-02 Nippon Telegr & Teleph Corp <Ntt> Optical fiber type device for changing attitude of optical polarized wave
JPH11500541A (en) * 1995-11-23 1999-01-12 ナショナル インスティチュート オブ テクノロジー アンド クオリティ Uniform laser beam using multi-dimensional and double bending of optical fiber, method for generating the same, and apparatus for generating the same
JP3059875U (en) * 1998-12-07 1999-07-13 工業技術院長 Arbitrary shape uniform radiation heating jig
JP2000019453A (en) * 1998-07-07 2000-01-21 Ishikawajima Harima Heavy Ind Co Ltd Beam profile uniformalizing device, optical fiber joining device, and exposure device
WO2007007388A1 (en) * 2005-07-11 2007-01-18 Mitsubishi Denki Kabushiki Kaisha Lighting apparatus

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0868954A (en) * 1994-08-29 1996-03-12 Furukawa Electric Co Ltd:The Method for imparting fluctuation to light signal
JP2003156698A (en) * 2001-11-22 2003-05-30 Toshiba Corp Laser light source device
US7366210B2 (en) * 2005-11-18 2008-04-29 Jds Uniphase Corporation Single spatial mode output multi-mode interference laser diode with external cavity
JP2010060912A (en) * 2008-09-04 2010-03-18 Mitsubishi Electric Corp Image display device
JP2010172651A (en) * 2009-02-02 2010-08-12 Fujifilm Corp Endoscope and endoscope system

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS62148922A (en) * 1985-12-23 1987-07-02 Nippon Telegr & Teleph Corp <Ntt> Optical fiber type device for changing attitude of optical polarized wave
JPH11500541A (en) * 1995-11-23 1999-01-12 ナショナル インスティチュート オブ テクノロジー アンド クオリティ Uniform laser beam using multi-dimensional and double bending of optical fiber, method for generating the same, and apparatus for generating the same
JP2000019453A (en) * 1998-07-07 2000-01-21 Ishikawajima Harima Heavy Ind Co Ltd Beam profile uniformalizing device, optical fiber joining device, and exposure device
JP3059875U (en) * 1998-12-07 1999-07-13 工業技術院長 Arbitrary shape uniform radiation heating jig
WO2007007388A1 (en) * 2005-07-11 2007-01-18 Mitsubishi Denki Kabushiki Kaisha Lighting apparatus

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20200354261A1 (en) * 2016-09-29 2020-11-12 Nlight, Inc. Optical fiber bending mechanisms
US20220404648A1 (en) * 2016-09-29 2022-12-22 Nlight, Inc. Methods of and systems for processing using adjustable beam characteristics
US11858842B2 (en) 2016-09-29 2024-01-02 Nlight, Inc. Optical fiber bending mechanisms
US11886053B2 (en) 2016-09-29 2024-01-30 Nlight, Inc. Methods of and systems for processing using adjustable beam characteristics
US11886052B2 (en) 2016-09-29 2024-01-30 Nlight, Inc Adjustable beam characteristics
JP7481846B2 (en) 2016-09-29 2024-05-13 エヌライト， インコーポレイテッド Systems and methods for beam characteristic modification - Patents.com

Also Published As

Publication number Publication date
JPWO2016031895A1 (en) 2017-06-15
JP6640094B2 (en) 2020-02-05

Similar Documents

Publication Publication Date Title
JP7167066B2 (en) Fiber coupling device for changing beam properties
US7292749B2 (en) System for electromagnetic field conversion
CN109792129B (en) Monolithic Visible Wavelength Fiber Laser
JP5113668B2 (en) Laser equipment
US10732439B2 (en) Fiber-coupled device for varying beam characteristics
JP5156385B2 (en) Laser light source device and image display device
EP3058628B1 (en) Method and apparatus for generating high power laser light
KR101083677B1 (en) apparatus of controlling speckle contrast of light
JP2015072955A (en) Spectrum beam coupling fiber laser device
JP5224445B2 (en) Laser light source device
JP6640094B2 (en) Laser light irradiation device
JP4886269B2 (en) Medical laser equipment
US9001850B2 (en) Excitation unit for a fiber laser
JP6744357B2 (en) Laser oscillator
JP6227212B1 (en) Laser oscillator
KR101400512B1 (en) An alignment method of grating pair based pulse stretcher at chirped pulse amplification system
WO2012117569A1 (en) Laser processing device
JP7430711B2 (en) Apparatus and method for transmitting and controlling light beams
JP2011128639A (en) Speckle removing light source and lighting device
JP2021006902A (en) Radiation delivery apparatus for microscope systems
JP6628777B2 (en) Reflectors, fiber resonators, and fiber lasers
JP2015087729A (en) Wavelength conversion laser device
JP2010032667A (en) Laser light source module and method of manufacturing the same
JP6763121B2 (en) Laser device
JP2018194789A (en) Optical component and laser apparatus

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 15836184

Country of ref document: EP

Kind code of ref document: A1

ENP Entry into the national phase

Ref document number: 2016545600

Country of ref document: JP

Kind code of ref document: A

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 15836184

Country of ref document: EP

Kind code of ref document: A1