JP5717989B2 - Laser equipment - Google Patents

Description

  The present invention relates to a laser device using a surface emitting laser array element.

  Conventionally, a laser apparatus using a surface emitting laser array element in which a plurality of surface emitting laser elements are arranged on a substrate has been disclosed (see, for example, Patent Documents 1 and 2). In this laser apparatus, each laser beam outputted from each surface emitting laser element constituting the surface emitting laser array element is focused on one optical fiber by a diffractive lens provided corresponding to each surface emitting laser element and output. Like to do. A surface emitting laser element is low in cost and is unlikely to cause catastrophic optical damage (COD), which is a problem with stripe lasers. Therefore, a laser device using this is expected to be a low-cost, reliable and high-power laser device. Has been.

US Pat. No. 6,888,871 JP 2006-91285 A

K.Takaki, N.Iwai, K.Hiraiwa, S.Imai, H.Shimizu, T.kageyama, Y.kawakita, N.Tsukiji and A.Kasukawa, "A recorded 62% PCE and low series and thermal resistance VCSEL with a double intra-cavity structure ", The 21st IEEE International Semiconductor Laser Conference (ISCL2008, September 14-18, 2008, Sorrent, Italy), Postdeadline Papers, PD1.1.)

  By the way, when a high-power laser device using a surface-emitting laser array element is put into practical use, the light-emitting efficiency of each surface-emitting laser element is high and the electro-optical conversion efficiency is high in order to reduce power consumption. It is requested. In order to increase the luminous efficiency of the surface emitting laser element, it is necessary to select an appropriate aperture size. Here, the aperture is an opening left for current injection in a structure in which current injection into the active layer is restricted by a technique such as selective oxidation. That is, if the aperture size is too small, the element resistance increases and the light emission efficiency decreases. On the other hand, if the aperture size is too large, the current flow becomes non-uniform due to the concentration of the current around the periphery of the aperture, and the luminous efficiency also decreases. Therefore, it is necessary to optimize the aperture size in order to realize a surface emitting laser element with high emission efficiency. For example, Non-Patent Document 1 discloses a surface emitting laser element having an aperture size optimized for high light emission efficiency. As described above, the surface-emitting laser element with high emission efficiency generates little heat, so that deterioration of the element is suppressed and reliability is increased.

  However, as in Non-Patent Document 1, a surface emitting laser element having an aperture size optimized for high emission efficiency has a multi-mode laser oscillation transverse mode, and the laser beam shape has a plurality of peaks. Become. When the beam shape of the laser beam output from each surface emitting laser element has such a plurality of peaks, the beam shape of the laser beam focused on these laser beams also has a plurality of peaks, which is preferable for practical use. There was no problem.

  For example, when the focused laser beam has a bimodal beam shape in which the center of the beam cross section is recessed and has two peaks around it, the light intensity density at the center is reduced. As a result, even if this laser beam is coupled to an optical fiber as pumping light for an optical fiber laser, the pumping efficiency is expected from the total light intensity of the laser beam because the light intensity density at the center of the optical fiber is small. May be lower than the efficiency. Also, in the case of laser processing, when directly irradiating laser light onto a processing target, it is difficult to obtain good processing conditions because the light intensity distribution in the beam is non-uniform.

  The present invention has been made in view of the above, and an object of the present invention is to provide a laser apparatus capable of outputting laser light having a beam shape that is practically preferable.

  In order to solve the above-described problems and achieve the object, a laser apparatus according to the present invention includes a surface-emitting laser array element having a plurality of surface-emitting laser elements arranged on a substrate and outputting multimode laser light. A shaping optical element that is arranged separately from the surface emitting laser array element, shapes the shape of each laser beam output from the plurality of surface emitting laser elements, and makes each laser beam a parallel beam. Features.

  In the laser device according to the present invention, in the above invention, the shaping optical element includes at least a first optical element for shaping a beam shape of each laser beam and each laser beam shaped by the first optical element. And a second optical element for making parallel light.

  In the laser device according to the present invention as set forth in the invention described above, the second optical element further shapes each laser beam shaped by the first optical element.

  The laser device according to the present invention is characterized in that, in the above invention, the shaping optical element shapes the beam shape of each laser beam so as to eliminate the deviation of the light intensity distribution in the beam section. To do.

  In the laser device according to the present invention as set forth in the invention described above, the shaping optical element shapes the beam shape of each laser beam into a single peak shape.

  Further, the laser device according to the present invention is the above-mentioned invention, wherein the focusing optical element that focuses each laser beam that has been converted into parallel light by the shaping optical element and the light that is combined with each laser beam that is focused by the focusing optical element. And a fiber.

  In the laser device according to the present invention as set forth in the invention described above, the focusing optical element corrects a wavelength distribution of each laser beam caused by a temperature distribution in a substrate surface of the surface emitting laser array element. And

  In the laser device according to the present invention as set forth in the invention described above, the shaping optical element or the focusing optical element includes a diffractive lens.

  According to the present invention, it is possible to realize a laser apparatus that outputs laser light having a beam shape that is practically preferable.

FIG. 1 is a schematic configuration diagram of a laser apparatus according to an embodiment. FIG. 2 is a schematic configuration diagram of a main part of the laser apparatus shown in FIG. FIG. 3 is a schematic plan view of the surface emitting laser array element shown in FIG. FIG. 4 is a diagram showing the beam shape of laser light output from the surface emitting laser element at different driving currents. FIG. 5 is a diagram showing the relationship between the drive current and the beam divergence angle. FIG. 6 is a schematic plan view of the first optical element shown in FIG. FIG. 7 is a schematic partial cross-sectional view along the radius of the first optical element for explaining the characteristics of the first optical element. FIG. 8 is a diagram for explaining shaping, collimation, and focusing of the laser beam output from the surface emitting laser element. FIG. 9 is a diagram for explaining the beam angle θ of the laser beam output from the surface emitting laser element. FIG. 10 is a diagram for explaining a change in the beam angle θ by the first optical element and the second optical element in the design example. FIG. 11 is a diagram illustrating a beam shape of laser light immediately before entering the first optical element in the design example. FIG. 12 is a diagram illustrating a beam shape of laser light immediately after being emitted from the second optical element in the design example. FIG. 13 is a schematic plan view of a preferred embodiment of the focusing optical element.

  Embodiments of a laser apparatus according to the present invention will be described below in detail with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment)
FIG. 1 is a schematic configuration diagram of a laser apparatus according to an embodiment of the present invention. As shown in FIG. 1, the laser device 100 includes a surface emitting laser array element 20 placed on a base 11 of a housing 10 and a housing 10 provided with radiation fins 12 so as to cover the outer periphery. In the main body 13, an optical element group 30 that is spaced apart from the surface emitting laser array element 20, an auxiliary condensing lens 40 attached to one end of the protrusion 14 of the housing 10, and other protrusions 14. And an optical fiber 50 inserted and fixed at one end of the optical fiber.

  The surface emitting laser array element 20 outputs high-intensity laser light LL. The optical element group 30 and the auxiliary condensing lens 40 are for optically coupling the laser light LL to the optical fiber 50. The optical fiber 50 outputs the laser light LL to the outside.

  The base unit 11 includes a cooling mechanism 11 a for cooling the surface emitting laser array element 20. As the cooling mechanism 11a, for example, a water-cooled pipe using a microchannel, an air-cooled fin, a heat pipe, or a Peltier element can be used. Further, the heat radiation fin 12 suppresses the temperature rise of the casing 10 due to the component of the laser light LL that is not coupled to the optical fiber 50, for example, the energy of scattered light.

  Next, optical elements of the laser device 100 will be described. FIG. 2 is a schematic configuration diagram of a main part of the laser apparatus 100 shown in FIG. As shown in FIG. 2, the surface emitting laser array element 20 has 16 surface emitting laser elements 22 arranged in a 4 × 4 two-dimensional square lattice pattern on a substrate 21.

  The optical element group 30 includes a first optical element array 31, a second optical element array 32, and a focusing optical element 33. These optical elements constitute the optical element group 30 in a separated state or an integrated state.

  The first optical element array 31 has a plurality of first optical elements 31 a arranged in correspondence with the surface emitting laser elements 22 of the surface emitting laser array element 20. The second optical element array 32 also has a plurality of second optical elements 32 a arranged in correspondence with the surface emitting laser elements 22. The laser light LL1 output from the surface emitting laser element 22 is a first optical element 31a corresponding to the first optical element array 31, a second optical element 32a corresponding to the second optical element array 32, a focusing optical element 33, and an auxiliary element. The light passes through the condenser lens 40 in order and reaches the optical fiber 50.

  Here, each 1st optical element 31a has a function which shapes the beam shape of each laser beam LL1 which each surface emitting laser element 22 output. In addition, each second optical element 32a has a function of further shaping the beam shape of each laser beam LL1 shaped by each first optical element 31a and making each laser beam LL1 parallel light. That is, a shaping optical element for shaping and collimating the beam shape of the laser beam LL1 is realized by a combination of each first optical element 31a and each second optical element 32a. The focusing optical element 33 has a function of focusing the laser light LL that is a bundle of the laser lights LL1 that are converted into parallel light by the second optical elements 32a. Each of these optical elements will be described in detail later.

  Next, each component shown in FIG. 2 will be specifically described. First, the surface emitting laser array element 20 will be described.

  FIG. 3 is a schematic plan view of the surface emitting laser array element 20 shown in FIG. The 16 surface-emitting laser elements 22 arranged on the substrate 21 are surface-emitting laser elements having a structure disclosed in Non-Patent Document 1, for example, and having a high emission efficiency, and have an aperture of about 10 μm in diameter. To output laser light having a wavelength of about 900 to 1100 nm. The output laser light travels while the beam diameter is widened. Further, as the current-light output characteristics of the surface emitting laser element 22, when the threshold current is 1 to 2 mA and the drive current is a CW (continuous wave) current, the light output rolls over at about 20 mA. When the drive current is a pulse current, the light output does not roll over even at about 30 mA, and the light output further increases. For use in later description, an inner region A1 and an outer region A2 are defined in the region where the surface emitting laser elements 22 are arranged on the substrate 21.

  FIG. 4 is a diagram showing the beam shape of the laser light output from the surface emitting laser element at different driving currents using a far field pattern (FFP). 4A shows a case where the drive current is a CW current near the threshold current, FIG. 4B shows a case where the drive current is 10 mA, and FIG. 4C shows a case where the pulse current is 30 mA. ing. Here, a beam shape spread angle (a width between opposing arrows in FIG. 4) at a position where the light intensity of the beam shape is ½ of the maximum value is defined as a beam spread angle. FIG. 5 is a diagram showing the relationship between the drive current and the beam divergence angle.

  As shown in FIGS. 4 and 5, in the surface emitting laser element 22, the transverse mode becomes a multi-mode oscillation state as the drive current is increased from FIG. 4A to FIG. While extending from 11 degrees to about 13 degrees, a plurality of peaks are separated, resulting in a more prominent bimodal type. Further, in FIG. 4C, a higher order transverse mode is generated, and a new peak is generated at the center.

  Next, the first optical element 31a and the second optical element 32a will be specifically described. FIG. 6 is a schematic plan view of the first optical element 31a shown in FIG. FIG. 7 is a schematic partial cross-sectional view along the radius of the first optical element 31a for explaining the characteristics of the first optical element 31a. As shown in FIGS. 6 and 7, the first optical element 31a is a diffractive lens in which a diffraction grating is formed concentrically. This diffraction grating has a pattern in which the angle of the diffraction surface varies depending on the distance from the center.

  Here, as shown in FIG. 7, the light L1 incident on the diffraction surface 31aa having a small angle has a large diffraction angle. As a result, since the light L1 travels while being widely dispersed and spread, the light intensity per unit angle becomes weak. On the other hand, the light L2 incident on the diffraction surface 31ab having a large angle has a small diffraction angle. As a result, the light L2 travels without spreading so much that the light intensity per unit angle does not become weak. The first optical element 31a has a function of shaping the intensity distribution of the laser beam LL1 input to the first optical element 31a, that is, the beam shape, by using diffraction gratings having different diffraction surface angles.

  The second optical element 32a also has a diffraction grating formed concentrically like the first optical element 31a shown in FIGS. 6 and 7, but the pattern of the diffraction grating is different from that of the first optical element 31a. The laser beam LL1 input to the second optical element 32a is shaped to have a function of shaping the beam shape and making it parallel light.

  Next, the shaping, collimation, and focusing of the laser beam LL1 output from the surface emitting laser element 22 will be described with reference to FIG. First, the beam shape of the laser beam LL1 output from the surface emitting laser element 22 has a shape of a multimode oscillation state having a plurality of peaks like the shape P1 schematically shown. Further, the beam shape of the laser beam LL1 immediately before entering the first optical element 31a has a shape in which the shape P1 is further expanded, such as the shape P2.

  Here, in the first optical element 31a, the light is dispersed and weakened at the position corresponding to the high light intensity in the shape P2, and the intensity of the diffracted light is not weakened at the position corresponding to the low light intensity. A diffraction grating pattern is designed. Therefore, the first optical element 31a changes the beam shape of the laser beam LL1 to the deviation of the light intensity distribution in the beam cross section (that is, the peak portion of the light intensity caused by the mode and the valley where the light intensity located between the peaks is weak. Shape so that the difference in intensity from the above part is eliminated. As a result, the beam shape of the laser beam LL1 immediately before entering the second optical element 32a has a shape with a flatter light intensity distribution like the shape P3.

  Next, in accordance with the shape P3, the second optical element 32a shapes the beam shape of the laser light LL1 so as to further eliminate the deviation of the light intensity distribution, and makes the diffraction grating pattern so as to be parallel light. Is designed. As a result, the laser beam LL1 emitted from the second optical element 32a has a more flat beam shape and becomes parallel light. The maximum value of the deviation of the light intensity distribution is preferably within 20% of the average value of the light intensity distribution between the peaks located at both ends of the beam shape.

  It is preferable to increase the area of the first optical element 31a by increasing the area occupied by the first optical element 31a in the first optical element array 31. If the area of the first optical element 31a is large, it is possible to realize a diffractive lens with higher complexity and performance with a predetermined processing accuracy when processing the diffractive lens. Moreover, since the light intensity density of the incident laser beam LL1 can be lowered by increasing the first optical element 31a, the occurrence of local optical damage of the first optical element 31a can be suppressed. . Similarly, it is preferable to increase the area of the second optical element 32a as well.

  In order to increase the areas of the first optical element 31a and the second optical element 32a, it is necessary to increase the separation distance of the first optical element array 31 and the second optical element array 32 from the surface emitting laser array element 20 as much as possible. preferable. This separation distance is set to such a distance that the beams of the laser beams LL1 emitted from the adjacent surface emitting laser elements 22 do not intersect each other. For example, when the surface emitting laser elements 22 having apertures with a diameter of about 10 μm are arranged at a pitch of 100 μm, if the beam divergence angle of the laser light LL1 is 15 degrees, the surface emitting laser elements 22 are separated from the surface emitting laser array element 20 by 350 μm. The beam diameter of the laser beam LL1 is 100 μm. In this case, the separation distance of the second optical element array 32 from the surface emitting laser array element 20 is set to about 350 μm or less.

  Next, the focusing optical element 33 focuses the laser beam LL1 emitted from the second optical element 32a. The beam shape of the focused laser beam LL1 has a flat and narrow shape like the shape P4. Further, the focusing optical element 33 is output from each surface emitting laser element 22 of the surface emitting laser array element 20, and each laser beam LL1 shaped and collimated by the corresponding first optical element 31a and second optical element 32a. Are bundled on the optical fiber 50 through the auxiliary condenser lens 40 as laser light LL.

  As the auxiliary condenser lens 40, an aspherical lens or a plano-convex lens can be used. The optical fiber 50 has a core diameter as small as 200 μm or less, and further 100 μm or less. Here, as described above, in the laser apparatus 100, the temperature of the housing 10 is suppressed from being increased by the radiation fins 12. However, even if the temperature rises, the use of the auxiliary condensing lens 40 increases the robustness (robustness) against the optical axis fluctuation due to the temperature rise. As a result, the laser beam LL can be optically coupled more stably to the optical fiber 50 having a small core diameter and a small NA (Numerical Aperture). Further, since both the auxiliary condensing lens 40 and the optical fiber 50 are attached to the protruding portion 14 of the housing 10, the relative position thereof is less likely to change even when the temperature of the housing 10 rises, and is more stable. Optical coupling can be realized.

  Each laser beam LL1 output from each surface emitting laser element 22 has a low light intensity of, for example, about 10 mW, and therefore is incident on the first optical element 31a, the second optical element 32a, and the focusing optical element 33. The light intensity density of each of the laser beams LL1 is low. Further, by increasing the arrangement pitch of the surface emitting laser elements 22 in the surface emitting laser array 20, the distance between the first optical element array 31 and the second optical element array 32 from the surface emitting laser array element 20 is increased. Since the areas of the first optical element 31a and the second optical element 32a can be increased, the light intensity density can be further reduced. Therefore, as a material of these optical elements, low-cost materials such as glass and optical resin that are easy to process even with low heat resistance, or a hybrid material of glass and optical resin can be used. In addition, since the auxiliary | assistant condensing lens 40 has the high light intensity of the incident laser beam LL, what consists of material with high heat resistance, such as quartz glass, for example is preferable.

  As described above, the laser apparatus 100 outputs each laser beam LL1 output from each surface emitting laser element 22 of the surface emitting laser array element 20 from the optical fiber 50 to the outside as a focused high-intensity laser beam LL. Can be output.

  This laser device 100 can be suitably used as an excitation light source for an optical fiber laser, for example, when the wavelength of the laser beam LL to be output is in the 980 nm band. If the wavelength is 1064 nm, it can be used as an alternative light source for the YAG laser. Further, it can be used as a fundamental light source for generating wavelength-converted light having a wavelength of 532 nm, 350 nm, 260 nm or the like in combination with a wavelength conversion element.

  Next, design examples of the first optical element 31a and the second optical element 32a will be described. This design was performed by simulation calculation using the ray tracing method. FIG. 9 is a diagram for explaining the beam angle θ of the laser beam output from the surface emitting laser element 22. As shown in FIG. 9, the beam angle θ refers to a straight line (laser beam optical axis X) extending perpendicularly from the reference position with the center of the aperture of the surface emitting laser element 22 as the reference position (origin). This represents the tilt angle in the traveling direction of the laser beam, and represents the half of the beam divergence angle. Further, the clockwise direction on the paper with respect to the optical axis X is defined as the negative direction of the position, and the counterclockwise direction on the paper surface is defined as the positive direction of the angle. The diameters of the first optical element 31a and the second optical element 32a are both 100 μm.

  FIG. 10 is a diagram for explaining a change in the beam angle θ by the first optical element 31a and the second optical element 32a in the present design example. As shown in FIG. 10, in the first optical element 31a and the second optical element 32a in this design, the beam angle θ is predetermined with respect to the position on the diameter of the first optical element 31a when entering the first optical element 31a. Designed so that the laser beam that changes linearly with the inclination of the beam angle θ is zero, that is, the laser beam is parallel light regardless of the position when the laser beam is emitted from the second optical element 32a. Has been. In addition, the shape of the light emitted from the first optical element 31a and the beam angle θ inside the second optical element 32a is the first optical element for shaping the beam shape or shaping the beam shape and making the laser beam parallel. This is generated by setting the diffraction grating patterns of 31a and the second optical element 32a.

  Here, the shaping optical element formed by combining the first optical element 31a of the combination of the first optical element 31a and the second optical element 32a of the present design example has a beam shape having a plurality of peaks as shown in FIG. A laser beam was incident. Then, it was confirmed that the second optical element 32a can emit laser light having a very flat beam shape in which the deviation of the light intensity distribution in the beam cross section as shown in FIG. 12 is eliminated.

  This design example is an example, and the design of the first optical element 31a and the second optical element 32a has a light intensity distribution that matches the beam shape of the laser light LL1 during the operation of the surface emitting laser element 22. What is necessary is just to design so that deviation can be eliminated.

  Next, a preferable aspect of the focusing optical element 33 will be described. The focusing optical element 33 is preferably configured to correct the wavelength distribution of the laser light output from each surface emitting laser element 22 due to the temperature distribution in the surface of the substrate 21 of the surface emitting laser array element 20.

  This will be specifically described below. As shown in FIG. 3, since the surface emitting laser element 22 existing in the inner area A1 in the surface of the substrate 21 is surrounded by another surface emitting laser element 22, the other surface emitting laser is operated during operation. Due to the inflow of heat generated by the element 22, the element temperature becomes higher than that of the surface emitting laser element 22 present in the outer region A2. The element temperature is distributed, for example, from 50 ° C. to 80 ° C. within the substrate surface according to the number of elements, the array shape, and the array interval. The temperature coefficient of the laser oscillation wavelength of the surface emitting laser element 22 is, for example, about 0.07 nm / ° C. Therefore, the wavelength of the laser beam of the surface emitting laser element 22 in the inner region A1 is shifted to the longer wavelength side due to the temperature rise of the element. As a result, the wavelength of each laser beam LL1 has a wavelength distribution due to the temperature distribution in the surface of the substrate 21. Therefore, it is preferable to use a focusing optical element 33 configured to correct this wavelength distribution.

  FIG. 13 is a schematic plan view of a preferred embodiment of the focusing optical element 33. As shown in FIG. 13, the focusing optical element 33 is a diffractive lens, and a diffraction grating pattern is formed in accordance with the shapes of the inner region A1 and the outer region A2. The angle of the diffraction surface of this diffraction grating is set so as to focus each laser beam LL1 from each surface emitting laser element 22 and to correct the wavelength distribution of this laser beam LL1. Accordingly, the focusing optical element 33 can couple each laser beam LL1 from each surface emitting laser element 22 to the optical fiber 50 with high coupling efficiency regardless of its wavelength distribution. In a diffractive lens, the longer the wavelength, the larger the diffraction angle. Therefore, in order to correct the long wavelength shift, the angle of the diffractive surface of the diffractive lens may be relatively reduced.

  The present invention is not limited to the above embodiment. For example, the first optical element or the second optical element may be a diffractive lens or an aspheric lens having a rectangular cross section. The focusing optical element may be a diffractive lens or an aspheric lens having a rectangular cross section, or a plano-convex lens. Further, the first optical element and the second optical element may be configured to shape the beam shape of the laser light into a single peak type such as a Gaussian shape. Alternatively, the beam shape of the laser beam may be shaped only by the first optical element, and the second optical element may only convert the laser beam into parallel light. Further, instead of the combination of the first optical element and the second optical element, the shaping of the laser beam and the parallel light may be performed with only one shaping optical element.

  Further, the number of surface emitting laser elements included in the surface emitting laser array element is not particularly limited, and can be, for example, 100 to 10,000. When the light output of each surface emitting laser element is 10 mW, the light output having an intensity of about 1 W can be obtained by arranging the surface emitting laser elements in 10 × 10. Further, an optical output with an intensity of about 10 W can be obtained with an arrangement of 30 × 30, and an intensity of about 100 W with an arrangement of 100 × 100. When the arrangement pitch of the surface emitting laser elements is 100 μm, the chip size of the surface emitting laser array element is 1 mm square in the 10 × 10 arrangement, 3 mm square in the 30 × 30 arrangement, and 10 mm square in the 100 × 100 arrangement, Both are very small compared to the light output. Further, the arrangement shape of the surface emitting laser elements is not limited to a square lattice shape, and may be, for example, a triangular lattice shape, a circular shape, or a honeycomb shape. The optical fiber may be a lens whose tip is processed. When a lens-processed optical fiber is used, the auxiliary condensing lens may be omitted.

DESCRIPTION OF SYMBOLS 10 Housing | casing 11 Base part 11a Cooling mechanism 12 Radiation fin 13 Main body part 14 Protrusion part 20 Surface emitting laser array element 21 Substrate 22 Surface emitting laser element 30 Optical element group 31 1st optical element array 31a 1st optical element 31aa, 31ab Diffraction surface 32 2nd optical element array 32a 2nd optical element 33 Focusing optical element 40 Auxiliary condensing lens 50 Optical fiber 100 Laser apparatus A1 Inner area A2 Outer area L1, L2 Light LL, LL1 Laser light P1-P4 Shape X Optical axis

Claims (8)

A surface-emitting laser array element having a plurality of surface-emitting laser elements arranged on a substrate and outputting multimode laser light having a bimodal beam shape;
A shaping optical element that is arranged apart from the surface emitting laser array element, shapes the beam shape of each laser beam output from the plurality of surface emitting laser elements, and makes each laser beam parallel light;
The shaping optical element includes a first optical element that shapes a beam shape of each laser beam;
A second optical element that converts each laser beam shaped by the first optical element into at least parallel light;
With
The separation distance between the first optical element and the second optical element from the surface emitting laser array element is a distance that prevents the laser beams emitted from the adjacent surface emitting laser elements from crossing each other . The laser apparatus is characterized in that the separation distance is increased by increasing the arrangement pitch of the plurality of surface emitting laser elements so that the laser beams do not cross each other .   The laser device according to claim 1, wherein the second optical element further shapes each laser beam shaped by the first optical element.   The laser device according to claim 2, wherein the first optical element expands a beam shape of the laser light while maintaining a state where the laser light beams do not intersect with each other.   The laser according to any one of claims 1 to 3, wherein the shaping optical element shapes the beam shape of each laser beam so as to eliminate the deviation of the light intensity distribution in the beam cross section. apparatus.   The laser apparatus according to claim 1, wherein the shaping optical element shapes the beam shape of each laser beam into a single peak shape. A focusing optical element that focuses each laser beam that has been made into parallel light by the shaping optical element;
An optical fiber to which each laser beam focused by the focusing optical element is coupled;
The laser device according to claim 1, comprising:   The laser apparatus according to claim 6, wherein the focusing optical element corrects a wavelength distribution of each laser beam caused by a temperature distribution in a substrate surface of the surface emitting laser array element.   The laser apparatus according to claim 6, wherein the shaping optical element or the focusing optical element includes a diffractive lens.

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