JP2008021900A - Laser condensing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a laser condensing device capable of increasing the density of luminous flux without crowding a plurality of semiconductor laser arrays, by suppressing diffusion to long- and short-axis directions wherein the luminous flux is formed of a plurality of laser beams emitted from the semiconductor laser array. <P>SOLUTION: The laser condensing device has: a laser unit 36 composed of the semiconductor laser array 31 and a long-axis collimating lens 35; and a condensing duct 65 having duct width Wg and duct thickness Tg, and one end face formed on a reflection surface MM that has a prescribed angle θ to a duct upper surface MU and orthogonally crosses a duct side MS. A plurality of condensing units are used, where the emission of the laser unit opposes the upper surface of the duct, and the laser unit is arranged to the condensing duct so that the luminous flux reflecting on the reflection surface is guided in the condensing duct in the longitudinal direction of the duct. Each condensing duct is superposed in the thickness direction of the duct, so that the longitudinal direction of the duct coincides, and the emission surface MR of each condensing duct is positioned on the same plane. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a laser condensing device that condenses laser light, and more particularly to a laser condensing device that condenses a light beam of a semiconductor laser emitted from a semiconductor laser array.

In recent years, semiconductor lasers have a high oscillation efficiency (˜50%), and therefore there is an increasing need for using them as excitation light for solid-state lasers or as direct processing light sources. Also, semiconductor laser manufacturers have provided a semiconductor laser array in which a plurality of emitters (light emitting portions) are arranged one-dimensionally, or a semiconductor laser in which a plurality of emitters (light emitting portions) are arranged in a two-dimensional manner by stacking semiconductor laser arrays. The stack is commercialized.
For example, a general semiconductor laser array is obtained by mounting a semiconductor laser chip having an external dimension of about 10 mm in length, about 0.2 mm in thickness, and about 1 mm in width to a heat sink, and about 1 μm in length in the thickness direction. In the vertical direction, about 10 light emitting portions having a pitch of about 500 μm are integrated. Then, a laser beam with an output of about 2 W is emitted from one light emitting unit. If these are condensed to increase the power density and used as excitation light or directly as a processing light source, metal welding, drilling, cutting, etc. can be performed.

In a general semiconductor laser array (light emitting portions are one-dimensionally arranged), as shown in the example of FIG. 1A, the laser light L1 emitted from the light emitting portions (31a to 31h) is in the major axis direction and the minor axis direction. It progresses while spreading in an almost elliptical shape. As shown in the example of FIG. 1B, the major axis direction spread angle θf is about several tens of degrees (for example, 30 to 40 degrees), and the minor axis direction spread angle θs is several degrees (for example, 3 degrees). ~ 4 degrees). In addition, as described above, the dimensions of the light emitting units (31a to 31h) are about 1 μm in the major axis direction and about 100 to 200 μm in the minor axis direction in a general semiconductor laser array. In the following description, light (laser light L1 emitted from the light emitting part 31a and light emitted from the light emitting part 31b) is a combination of laser lights emitted from the respective light emitting parts (in this case, 31a to 31h) of the semiconductor laser array. The light that combines the laser light L1 and the laser light L1 emitted from the light emitting section 31h) will be referred to as “light beam”.
The condensing property of the laser light depends on the beam parameter product indicated by “beam diameter * divergence angle”. In the case of the semiconductor laser array as described above, the beam parameter product in the major axis direction is about 0.2 mm · mrad, The beam parameter product in the short axis direction is 200 mm · mrad. For this reason, when condensing, it is relatively easy to condense in the long axis direction, but it is relatively difficult to condense in the short axis direction.

For example, in the prior art described in Patent Document 1, each light beam from a plurality of semiconductor laser arrays is converted into parallel light, and each light beam is made to be in the same direction using a reflecting member for each semiconductor laser array. The density of the laser beam is increased along the long axis direction.
Further, in the prior art described in Patent Document 2, a semiconductor laser stack in which semiconductor laser arrays are stacked in the major axis direction is used, and a collimating lens in the major axis direction is provided in each semiconductor laser array, so that the luminous flux is about the major axis direction. The light beams are converted into parallel light and arranged so that the interval in the major axis direction of each light beam is shortened using a light reflecting surface prepared for each light beam to increase the density of the laser light.
In the prior art described in Patent Document 3 and Patent Document 4, each semiconductor laser array is provided with a long-axis collimating lens, and the light beam is converted into parallel light in the long-axis direction. Two sets of stacked units in which plates are alternately stacked in the major axis direction are used. The other set of light beams is devised so that the light beams arranged in the major axis direction emitted from one set of stacked units enter the gap portion formed by the cooling plate.
JP 2001-044574 A JP 2001-215443 A JP 2003-124558 A Japanese Patent Laid-Open No. 11-072743

As described above, the laser beam emitted from the semiconductor laser array has a large divergence angle in the major axis direction where the beam parameter product is relatively small, but is relatively easy to collect light. It is also easy to convert to However, although the divergence angle is small in the minor axis direction, the beam parameter product is relatively large, it is difficult to arrange the collimating lens, and it is also difficult to convert it into parallel light.
In the prior art described in Patent Document 1, the divergence angle (for example, 30 to 40 degrees) in the long axis direction of the light beam is a non-negligible size, and is converted into the long axis direction using a collimator. The divergence angle in the minor axis direction (for example, 3 to 4 degrees) is ignored, and the minor axis direction is originally treated as parallel light without using a collimator in the minor axis direction. This is not preferable because the laser beam propagates through the space from the semiconductor laser array to the reflecting member and beyond the reflecting member, and the longer the distance, the lower the laser beam density due to the spread angle in the minor axis direction. . Further, when increasing the output using a plurality of semiconductor laser arrays, the semiconductor laser arrays are arranged to face each other, and a reflecting member is prepared accordingly (FIG. 5 of Patent Document 1), and the semiconductor laser array is radial. And an example in which a reflecting member is prepared in accordance therewith (FIG. 6 of Patent Document 1). In the example of being arranged opposite to each other, if the number of semiconductor laser arrays is increased, the length of the light beam after being reflected by the reflecting member is increased, and the influence of the spread angle in the minor axis direction is increased, which is not preferable. Further, in the example of the radial arrangement, the number of semiconductor laser arrays is spatially limited, and a desired number of semiconductor laser arrays may not be arranged.

  In the prior art described in Patent Document 2, as in Patent Document 1, the light beam is converted into parallel light in the long axis direction, but the spread angle (for example, 3 degrees to 4 degrees) of the light beam in the short axis direction is converted. Therefore, the minor axis direction is originally treated as parallel light without using a collimator in the minor axis direction. In this case, the laser light propagates through the space from the semiconductor laser array to the light reflecting surface and beyond the light reflecting surface, and the laser light density decreases due to the spread angle in the short axis direction as the distance increases. It is not preferable.

Also, in the prior art described in Patent Document 3 and Patent Document 4, as a result of stacking the semiconductor laser arrays in the long axis direction in order to increase the density of the laser light, it is impossible to dissipate heat. Since the array and the water cooling plate are alternately stacked, and a water cooling device is required, the cost increases. Similarly to Patent Documents 1 and 2, the light beam is converted into parallel light in the major axis direction, but the spread angle (for example, 3 to 4 degrees) of the light beam in the minor axis direction is ignored and the minor axis is ignored. Without using a directional collimator in particular, the minor axis direction is originally treated as parallel light. This is not preferable because the laser beam propagates through the space from the semiconductor laser array to the reflecting surface and beyond the reflecting surface, and the laser beam density decreases due to the spread angle in the short axis direction as the distance increases. .
The present invention has been devised in view of such points, and suppresses diffusion in the major axis direction and the minor axis direction with respect to a light beam by a plurality of laser beams emitted from the semiconductor laser array, and thereby a plurality of semiconductors. It is an object of the present invention to provide a laser condensing device that can increase the density of light flux without concentrating the laser array.

As means for solving the above-mentioned problems, a first invention of the present invention is a laser condensing device as described in claim 1.
The laser condensing device according to claim 1 is a semiconductor laser array in which a plurality of light emitting portions that emit laser light that travels while spreading in a short axis direction and a long axis direction orthogonal to each other are arranged in a line in the short axis direction; A long-axis collimating lens that is provided at a position facing the plurality of light-emitting portions and converts laser light emitted from the plurality of light-emitting portions into parallel light with respect to the long-axis direction. The incident laser beam can be transmitted, the duct width corresponding to the length in the minor axis direction of the light beam by the plurality of laser beams emitted from the laser unit, and the length in the major axis direction of the light beam The corresponding duct thicknesses are formed to be constant, and the length in the duct longitudinal direction orthogonal to the duct width direction and the duct thickness direction is formed to an arbitrary length. Oh One end face is formed on a reflecting surface having a predetermined angle with respect to the upper surface of the duct including the duct width direction and the duct longitudinal direction and orthogonal to the duct side surface including the duct thickness direction and the duct longitudinal direction. An optical duct.
And the light emitting portion of the laser unit and the duct upper surface of the condensing duct are opposed so that the duct width direction of the condensing duct coincides with the short axis direction of the laser unit, and from the laser unit The emitted light beam is applied to the reflecting surface from the inside of the light collecting duct, and the light beam reflected by the reflecting surface is guided to the light collecting duct in the longitudinal direction of the duct through the light collecting duct. The laser unit is disposed, and the laser unit and the light collecting duct constitute a light collecting unit.
The light collecting unit includes a plurality of the light collecting units, and the light collecting ducts of the light collecting units are overlapped in the duct thickness direction so that the duct longitudinal directions coincide with each other. It has a structure where it is overlapped so as to be located on the same plane.

The second invention of the present invention is the laser condensing device as described in claim 2.
According to a second aspect of the present invention, there is provided a laser condensing device comprising: a semiconductor laser array in which a plurality of light emitting portions that emit laser light that travels while spreading in a short axis direction and a long axis direction perpendicular to each other are arranged in a line in the short axis direction; A long-axis collimating lens that is provided at a position facing the plurality of light-emitting portions and converts laser light emitted from the plurality of light-emitting portions into parallel light with respect to the long-axis direction. The incident laser beam can be transmitted, the duct width corresponding to the length in the minor axis direction of the light beam by the plurality of laser beams emitted from the laser unit, and the length in the major axis direction of the light beam The corresponding duct thicknesses are formed to be constant, and the length in the duct longitudinal direction orthogonal to the duct width direction and the duct thickness direction is formed to an arbitrary length. Oh One end face is formed on a reflecting surface having a predetermined angle with respect to the duct side surface including the duct thickness direction and the duct longitudinal direction and orthogonal to the duct upper surface including the duct width direction and the duct longitudinal direction. An optical duct.
And the light emitting part of the laser unit and the duct side surface of the condensing duct are made to face each other so that the longitudinal direction of the condensing duct coincides with the short axis direction of the laser unit, and from the laser unit The emitted light beam is applied to the reflecting surface from the inside of the light collecting duct, and the light beam reflected by the reflecting surface is guided to the light collecting duct in the longitudinal direction of the duct through the light collecting duct. The laser unit is disposed, and the laser unit and the light collecting duct constitute a light collecting unit.
The light collecting unit includes a plurality of the light collecting units, and the light collecting ducts of the light collecting units are overlapped in the duct thickness direction so that the duct longitudinal directions coincide with each other. It has a structure where it is overlapped so as to be located on the same plane.

A third invention of the present invention is the laser condensing device as described in the third aspect.
A laser condensing device according to claim 3 is the laser condensing device according to claim 1 or 2, wherein the condensing duct overlapped in the thickness direction according to claim 1 or 2, The condensing duct is integrally formed so as to have the same shape as the above.
Or the condensing duct is shape | molded by dividing | segmenting with respect to the longitudinal direction so that it may become the same shape as the condensing duct piled up in the thickness direction of Claim 1 or Claim 2.

According to a fourth aspect of the present invention, there is provided the laser condensing device as set forth in the fourth aspect.
The laser condensing device according to claim 4 is the laser condensing device according to any one of claims 1 to 3, wherein the length of the condensing duct of each condensing unit in the longitudinal direction is an arbitrary length. Thus, a plurality of the semiconductor laser arrays are arranged at intervals according to the heat generation amount and fixed to the heat radiating plate, and the heat radiating plate is provided with a heat radiating fin, and a cooling fan is provided facing the heat radiating fin. Is provided.

If the laser condensing device according to claim 1 is used, the light beam emitted from the semiconductor laser array can be guided to the inside of the light collecting duct, and the light beam can be totally reflected inside the light collecting duct and transmitted. It is possible to suppress the diffusion of the light beam in the long axis direction and the short axis direction and confine the light beam in the light collecting duct for transmission.
Also, since the length of the condensing duct can be set arbitrarily, even if the condensing ducts are overlapped using a plurality of condensing units in order to increase the density of the luminous flux, the interval between the semiconductor laser arrays is increased. Since it can be set freely, the density of the light beam can be increased without making the semiconductor laser array dense.

The laser condensing device according to claim 2 is different from claim 1 in that the shape of the condensing duct and the arrangement position of the semiconductor laser array with respect to the condensing duct are changed to obtain the same effect as in the first aspect. A laser condensing device capable of performing
This suppresses diffusion in the major axis direction and minor axis direction of the luminous flux from the plurality of laser beams emitted from the semiconductor laser array, and increases the density of the luminous flux without concentrating the plurality of semiconductor laser arrays. Can do.

  According to the laser condensing device of claim 3, the overlapping is performed in the duct thickness direction so that the duct longitudinal directions are coincident with each other, and the other end face is placed on the same plane. Thus, the light collecting duct having the same function as that of the light collecting duct can be realized, and the degree of freedom of the manufacturing method is improved.

  In addition, according to the laser condensing device of the fourth aspect, the interval between the semiconductor laser arrays can be freely set even though the luminous flux can be increased in density, and is constituted by the heat radiation fin, the heat radiation plate, and the cooling fan. Since the air can be cooled by the air cooling mechanism, the apparatus can be downsized and realized at a lower cost.

The best mode for carrying out the present invention will be described below with reference to the drawings.
FIG. 2 shows an example of a schematic external view of the laser oscillation device 10 using the laser condensing device 68 of the present invention. Each figure in FIG. 2 is a rear view, a plan view, respectively, from the upper left to the right. A front view is shown, and a lower view shows a side view.

● [Appearance and structure of laser oscillator 10 (FIGS. 2 to 4)]
As shown in FIG. 2, the laser oscillation device 10 is accommodated in a substantially box-shaped housing (case), and is placed on a horizontal surface by a leg portion 10 </ b> S.
An intake port 10N for taking in cooling air is provided on the rear surface 10B (corresponding to one side surface) of the housing, and cooling air is supplied to the front surface 10F (corresponding to the side surface facing one side surface) of the housing. An exhaust port 10E for discharging is provided. The front panel 10G is provided with a front panel 10G on which various operation switches for setting the state of the output laser light, a display panel for displaying the operation state, a connector for taking out the output laser light, and the like are arranged. It has been.
Further, a second exhaust port 10C is provided on the upper surface 10U of the housing.

Next, the configuration of the output laser generator (accommodated in the housing) will be described with reference to FIG.
The laser oscillation apparatus 10 described in the present embodiment uses laser light emitted from the semiconductor laser array 31 (hereinafter referred to as excitation laser light) as excitation light, and uses the excitation laser light as an optical fiber 70 for fiber laser. Then, laser light (hereinafter referred to as output laser light) excited in the fiber laser optical fiber 70 is extracted as an output laser.
As shown in FIG. 1A, the semiconductor laser array 31 has a plurality of light emitting portions (31a to 31h) (arranged in a line), and excitation laser light is output from each light emitting portion. In the laser oscillation device 10 described in the present embodiment, a plurality of semiconductor laser arrays 31 are used in order to increase the output laser light.

The excitation laser light emitted from each semiconductor laser array 31 is condensed by the excitation laser condensing block 60 and is incident on one end surface (incident surface) of the fiber laser optical fiber 70.
In the example shown in FIG. 3, the excitation laser condensing block 60 condenses the condensing block 61 (detailed description) that further condenses the excitation laser light beams emitted from the plurality of light emitting units of the semiconductor laser array 31. The first lens 62 that converts the excitation light beam Lin emitted from the light collection block 61 into substantially parallel light, and the excitation light beam Lin converted into parallel light is collected on the incident surface of the optical fiber 70 for fiber laser. And the second lens 64. The dichroic mirror 63 transmits light having the wavelength of the excitation light beam Lin and reflects light having the wavelength of the output laser light Lout.
The output laser light Lout emitted from the fiber laser optical fiber 70 is condensed by the output laser condensing block 80 and is incident on one end face (incident surface) of the transmission optical fiber 90.
The optical fiber for a fiber laser 70 is an optical fiber having a core 72 containing a laser active substance, and the periphery of the core 72 is covered with a clad member 73. The incident excitation laser light is confined inside, and the excitation laser light is When hitting the core 72, the output laser light is excited inside the core 72, and the output laser light is transmitted in the core 72. The fiber laser optical fiber 70 is provided with an FBG (fiber Bragg grating) 71 that reflects the excitation laser light and the output laser light on the end surface opposite to the end surface on which the excitation laser light is incident. The output laser light is extracted from the incident surface side of the excitation laser light.

The output laser light Lout generated by being excited in the core 72 of the fiber laser optical fiber 70 is output from the incident surface of the excitation light beam Lin, is converted into substantially parallel light by the second lens 64, and is converted by the dichroic mirror 63. You can change the direction of travel. The dichroic mirror 63 transmits light having the wavelength of the excitation light beam Lin and reflects light having the wavelength of the output laser light Lout. Then, the output laser light Lout whose traveling direction is changed is condensed by the third lens 81 and is incident on the incident surface of the transmission optical fiber 90. The outgoing surface of the transmission optical fiber 90 is connected to, for example, a connector for taking out output laser light provided on the front panel 10G.
In the example illustrated in FIG. 3, the output laser focusing block 80 includes a second lens 64, a dichroic mirror 63, and a third lens 81.
Here, the semiconductor laser array 31 and the optical fiber for fiber laser 70 generate a large amount of heat to generate laser light, and unless they are cooled properly, the progress of deterioration and the coefficient of thermal expansion of various components are reduced. There is a possibility that the output laser light will be lowered due to an increase in position error due to the difference.
The laser oscillation device 10 described in the present embodiment is housed in a housing by combining the output laser generator described in FIG. 3 with a cooling mechanism. This accommodation state is as shown in FIG. 5, and the outline appearance and the like of each component are as shown in FIG.
In the present embodiment, an air-cooled cooling mechanism is employed in order to reduce the size of the apparatus and improve maintainability by using a simple cooling mechanism.

As shown in FIG. 4, the semiconductor laser heat radiating member 30 includes a base heat radiating plate 32 to which the semiconductor laser array 31 is fixed, and semiconductor laser radiating fins 33 formed of a plurality of heat radiating plates that promote heat dissipation. Yes. The material is copper, aluminum, or the like having a relatively high thermal conductivity. Silicon grease or the like having thermal conductivity may be used for the contact portion between the base heat radiation plate 32 and the semiconductor laser radiation fin 33.
The fiber laser heat radiating member 50 includes a base heat radiating plate 51 to which the fiber laser optical fiber 70 is fixed, and a fiber laser radiating fin 52 formed of a plurality of heat radiating plates for promoting heat radiation. The material is copper, aluminum, or the like having a relatively high thermal conductivity. Silicon grease or the like having thermal conductivity may be used for the contact portion between the base heat radiation plate 51 and the fiber laser radiation fins 52.
Further, the base heat radiating plate 51 includes a semiconductor laser radiating member 30, an excitation laser condensing block 60 (in this case, a condensing block 61, a first lens 62, and a second lens 64), an optical fiber for fiber laser 70, and an output laser. The condensing block 80 (in this case, the second lens 64, the dichroic mirror 63, the third lens 81), the transmission optical fiber 90, and the like are positioned and fixed.

Furthermore, the semiconductor laser heat radiating member 30 and the fiber laser heat radiating member 50 are provided with a cooling fan 20 for blowing cooling air, and guide members 40 (41, 42) for guiding the cooling air. The guide members 40 (41, 42) are ducts provided in a funnel shape for promoting the flow of cooling air.
With the above configuration, the cooling air blown from the cooling fan 20 is first applied to the semiconductor laser heat radiating member 30, and at least part of the cooling air after hitting the semiconductor laser heat radiating member 30 is guided to the guide member 40 (41, 42). In this structure, the cooling air blown to the guide member 40 (41, 42) is blown to the fiber laser radiation member 50. Thereby, both the semiconductor laser array 31 and the fiber laser optical fiber 70 can be cooled by the cooling fan 20.
As indicated by the one-dot chain line circle in FIG. 4, heat dissipation that promotes heat dissipation on any surface of the semiconductor laser array 31 (excluding the surface that emits the excitation laser light and the surface that is fixed to the base heat dissipation plate 32). A plate 34 may be further provided.

In order to increase the output laser light Lout of the laser oscillation device 10, it is necessary to make more pumping laser light incident on the fiber laser optical fiber 70, and pumping from more semiconductor laser arrays 31. The luminous flux of the laser beam must be collected.
The laser condensing device 68 of the present invention includes a plurality of semiconductor laser arrays 31 and a condensing block 61 (configured by a plurality of condensing ducts 65), and appropriately applies excitation laser light from more semiconductor laser arrays 31. Can be condensed.

●● [First embodiment (FIGS. 6 and 7)]
Next, a first embodiment of the laser focusing device 68 of the present invention will be described with reference to FIGS. The laser condensing device 68 shown in FIG. 7 is configured by collecting a plurality of condensing units 67 composed of the semiconductor laser array 31 shown in FIG. 6, the long-axis direction collimating lens 35, and the condensing duct 65.
● [Configuration of light condensing unit 67 (FIG. 6)]
As shown in FIG. 1D, the laser unit 36 includes a plurality of light emitting units (in this case, 31a to 31h) that emit excitation laser light L1 that travels while spreading in a short axis direction and a long axis direction orthogonal to each other. A semiconductor laser array 31 arranged in a line in the short axis direction and a long axis collimating lens 35 provided at a position facing the light emitting portion and converting the excitation laser light L1 into parallel light with respect to the long axis direction. Has been.
As shown in the schematic diagram of FIG. 1D, the light beam Lk emitted from the laser unit 36 is converted into parallel light in the major axis direction and has a spread angle θs in the minor axis direction. Yes. When the light beam Lk is transmitted in space, the spread in the short axis direction increases as the distance becomes longer. Therefore, the light flux Lk is totally reflected in the light collecting duct 65 using the light collecting duct 65 (see FIG. 6A). Propagating without spreading while spreading. The light beam Lk is composed of a plurality of excitation laser beams L1, but is schematically illustrated as a box shape in FIG.

As shown in FIG. 6A, the condensing duct 65 has a duct width Wg corresponding to the length in the minor axis direction of the light beam Lk emitted from the laser unit 36 and a length in the major axis direction of the light beam Lk. The corresponding duct thicknesses Tg are formed to be constant. The length Lg in the duct longitudinal direction perpendicular to the duct width direction and the duct thickness direction is set to an arbitrary length.
Then, the surface including the duct width direction and the duct longitudinal direction is defined as the duct upper surface MU (the opposite surface is the same), and the surface including the duct thickness direction and the duct longitudinal direction is defined as the duct side surface MS (the opposite surface is also the same). One end surface in the longitudinal direction is defined as an end surface MM, and the other end surface in the longitudinal direction is defined as an end surface MR.
One end surface MM is a reflecting surface provided at a predetermined angle θ with respect to the duct upper surface MU and orthogonal to the duct side surface MS, and can reflect the light beam Lk (hereinafter, one end surface MM). Is described as a reflective surface MM).

The condensing unit 67 includes a laser unit 36 and a condensing duct 65 (see FIG. 6B).
Next, the positions of the laser unit 36 and the light collecting duct 65 in the light collecting unit 67 will be described. As shown in FIG. 6B, the light emitting portion of the laser unit 36 and the duct upper surface MU of the light collecting duct 65 are arranged so that the duct width direction of the light collecting duct 65 coincides with the minor axis direction of the laser unit 36. Face each other. Further, the light beam Lk emitted from the laser unit 36 is applied to the reflection surface MM from the inside of the light collection duct 65, and the light beam Lk reflected by the reflection surface MM is guided in the light collection duct 65 in the longitudinal direction of the duct. Thus, the laser unit 36 is arranged with respect to the light collecting duct 65.
In the present embodiment, since the predetermined angle θ is set to 45 degrees, the duct upper surface MU is perpendicular to the traveling direction of the light beam Lk emitted from the laser unit 36.
The material of the light collecting duct 65 is quartz glass or the like.

Then, as shown in FIG. 6C, a plurality of light collecting units are prepared (in the example of FIG. 6C, two sets of light collecting units are used), and the light collecting duct 65 of each light collecting unit is provided. In addition, the ducts are overlapped in the duct thickness direction so that the longitudinal directions of the ducts coincide with each other, and the exit surface to be the other end face MR of each condensing duct 65 (hereinafter, the other end face MR is referred to as the exit face MR) is the same plane. The laser condensing device 68 is configured so as to be positioned above.
The distance Dk between the central axes of the light beams Lk emitted from the emission surface MR of the laser condensing device 68 is very small (the same applies to the distance Dk between the central axes of the light beams Lk shown in FIG. 8D). The distance between the semiconductor laser stacks stacked in the long axis direction can be made smaller than the interval in the long axis direction, and the density of the light beam can be made extremely high.
Further, since the light flux is confined and transmitted in the condensing duct 65, it is possible to prevent the light flux from spreading in the minor axis direction even if it is transmitted over a long distance. Therefore, the interval Da (light flux Lk) of the semiconductor laser array 31 is prevented. Can be set to any distance (the same applies to the distance Da between the central axes of the light beams Lk shown in FIG. 8D). For this reason, since it can be set as the space | interval suitable for heat radiation, without concentrating the semiconductor laser array 31, it can fully cool with an air-cooling cooling mechanism.

● [Example of output laser generator using laser condensing device 68 (FIG. 7)]
The output laser generator shown in FIG. 7 shows the output laser generator shown in FIG. 3 in more detail, and includes a cooling fan 20 that cools the semiconductor laser array 31, a semiconductor laser radiation fin 33, a base heat radiation plate 32, and a heat radiation plate. The cooling mechanism comprised by 34 is also shown, and the same code | symbol is provided to the same thing in FIG. 3 and FIG.
In the example of FIG. 7, the laser condensing device 68 is configured by four sets of condensing units 67, and the excitation light beam Lin condensed using the two sets of the laser condensing devices 68 is applied to the optical fiber 70 for the fiber laser. Incident. A path conversion prism 66 is provided on the exit surface of each laser condensing device 68. The path conversion prism 66 is configured so that the traveling direction of the emitted light beam is the same and the interval between the light beams is further reduced. 66 is arranged, and the interval between the light beam from one laser condensing device 68 and the light beam from the other laser condensing device 68 is reduced to increase the density of the excitation light beam Lin. The length of the path conversion prism 66 in the Y-axis direction is the same as the length of the condensing duct 65 in the duct width direction (the length of the condensing duct 65 in the Y-axis direction in FIG. 7).

The excitation light beam Lin is parallel light in the major axis direction (in the case of FIG. 7, when it is emitted from the semiconductor laser array 31 and when it enters the first lens 62), it is parallel light, but in the minor axis direction (FIG. In the case of 7, since it spreads at the time of emission from the semiconductor laser array 31 and at the time of incidence on the first lens 62, it passes through the short-axis direction collimating lens 62 (first lens) and is short. The axial direction is converted into parallel light, and the light is converted into parallel light in both the long axis direction and the short axis direction. Then, the parallel excitation light beam Lin passes through the long-axis direction condensing lens 64a and stops (condenses) in the long-axis direction, and passes through the short-axis direction condensing lens 64b and stops (collects) in the short-axis direction. Light) and enters the incident surface of the optical fiber 70 for fiber laser.
The output laser light emitted from the core 72 of the fiber laser optical fiber 70 is reflected by the dichroic mirror 63 and is focused (condensed) in the major axis direction and the minor axis direction (a third lens). ) And is incident on the incident surface of the transmission optical fiber 90.

The length of each condensing duct 65 in the longitudinal direction (X-axis direction in the case of FIG. 7) can be set to an arbitrary length, and each semiconductor laser array 31 is separated from the base heat sink at intervals corresponding to the amount of heat generated. 32 can be fixed. In the example of FIG. 7, a heat radiating plate 34 is further added to each semiconductor laser array 31. Then, a semiconductor laser radiation fin 33 is provided on the base radiation plate 32, a cooling fan 20 is provided opposite to the semiconductor laser radiation fin 33, and a cooling mechanism capable of sufficiently cooling each semiconductor laser array 31 is realized by air cooling. Therefore, downsizing and cost reduction of the device are realized.
The shape of the light collecting duct overlapped in the duct thickness direction described above is the shape shown in (a) of FIG. 7, but the same shape as shown in (b) of FIG. 7 may be formed integrally with each other, or as shown in FIG. 7 (c), divided into the longitudinal direction of the duct so as to have the same shape (in this case, divided into 61a to 61d). May be.

●● [Second Embodiment (FIGS. 8 and 9)]
Next, a second embodiment of the laser focusing device 68 of the present invention will be described with reference to FIGS. The laser condensing device 68 shown in FIG. 9 is configured by collecting a plurality of condensing units 67 (see FIG. 8B) composed of the semiconductor laser array 31, the long-axis collimating lens 35, and the condensing duct 65. ing.
In the second embodiment, the position of the semiconductor laser array 31 with respect to the light collecting duct 65 is changed with the change in the shape of the light collecting duct 65 and the shape of the light collecting duct 65 with respect to the first embodiment. has been edited. Hereinafter, differences from the first embodiment will be described.

● [Configuration of light condensing unit 67 (FIG. 6)]
As shown in FIG. 8A, one end surface MM of the light collecting duct 65 is a reflecting surface that is provided so as to have a predetermined angle θ with respect to the duct side surface MS and to be orthogonal to the duct upper surface MU. The light beam Lk can be reflected (hereinafter, one end surface MM is referred to as a reflective surface MM).
Next, the positions of the laser unit 36 and the light collecting duct 65 in the light collecting unit 67 will be described. As shown in FIG. 8B, the light emitting portion of the laser unit 36 and the duct side surface MS of the light collecting duct 65 are arranged so that the longitudinal direction of the light collecting duct 65 coincides with the short axis direction of the laser unit 36. Face each other. Further, the light beam Lk emitted from the laser unit 36 is applied to the reflecting surface MM from the inside of the light collecting duct 65, and the light beam Lk reflected by the reflecting surface MM is guided in the light collecting duct 65 in the longitudinal direction of the duct. Thus, the laser unit 36 is arranged with respect to the light collecting duct 65.
In the present embodiment, since the predetermined angle θ is set to 45 degrees, the duct side surface MS is perpendicular to the traveling direction of the light beam Lk emitted from the laser unit 36.

  8C and 8D, a plurality of light collecting units are prepared (two sets in the example of FIG. 8C and four sets in the example of FIG. 8D). The light collecting ducts 65 of the respective light collecting units are overlapped in the duct thickness direction so that the longitudinal direction of the ducts coincide with each other, and the light exit surface (the other end surface MR of each light collecting duct 65 is used). Hereinafter, the laser focusing device 68 is configured such that the other end face MR is described as an exit face MR) so as to be positioned on the same plane.

● [Example of output laser generator using laser focusing device 68 (FIG. 9)]
In the example of FIG. 9, the laser condensing device 68 is configured by eight sets of condensing units 67, and the condensed excitation light beam Lin is incident on the optical fiber 70 for fiber laser. In the example of FIG. 9, the arrangement and schematic shape of the fiber laser optical fiber 70, the dichroic mirror 63, the condenser lens 81, and the transmission optical fiber 90 are the same as those in FIG. Is omitted.
The excitation light beam Lin is parallel light in the long axis direction (in the case of FIG. 9, when it is emitted from the semiconductor laser array 31 and when it enters the first lens 62), it is parallel light, but in the short axis direction (FIG. In the case of 9, since it spreads in the Z-axis direction when it is emitted from the semiconductor laser array 31 and in the X-axis direction when it enters the first lens 62), it passes through the short-axis collimating lens 62 (first lens). Thus, the light is converted into parallel light in the short axis direction, and is converted into parallel light in both the long axis direction and the short axis direction. Then, the parallel excitation light beam Lin passes through the long-axis direction condensing lens 64a and stops (condenses) in the long-axis direction, and passes through the short-axis direction condensing lens 64b and stops (collects) in the short-axis direction. Light) and enters the incident surface of the optical fiber 70 for fiber laser.

The length of each condensing duct 65 in the longitudinal direction (in the Z-axis direction in the case of FIG. 9) can be set to an arbitrary length, and each semiconductor laser array 31 is separated from the base heat sink at an interval corresponding to the amount of heat generated. 32 can be fixed. Then, a semiconductor laser radiation fin 33 is provided on the base radiation plate 32, a cooling fan 20 is provided opposite to the semiconductor laser radiation fin 33, and a cooling mechanism capable of sufficiently cooling each semiconductor laser array 31 is realized by air cooling. Therefore, downsizing and cost reduction of the device are realized.
The shape of the condensing duct overlapped in the duct thickness direction described above may be integrally formed as in (b) and (c) in FIG. It may be divided and configured.

The laser condensing device 68 of the present invention is not limited to the appearance and configuration described in the present embodiment, and various modifications, additions and deletions can be made without changing the gist of the present invention.
Further, the number of the light collecting units 67 constituting the laser light collecting device 68 may be any number.
In FIG. 7, the emission surfaces MR of the two sets of laser condensing devices 68 may be arranged adjacent to each other without using the path conversion prism 66.
The numerical values used in the description of the present embodiment are examples, and are not limited to these numerical values.
In the description of the present embodiment, an example of an air cooling type is described as the cooling mechanism, but other cooling mechanisms (for example, a Peltier (electronic cooling device) or a water cooling type cooling device) may be used.

It is a figure explaining the semiconductor laser array 31 and the laser unit 36. FIG. 1 is a schematic external view for explaining an embodiment of a laser oscillation device 10 using a laser condensing device 68 of the present invention. It is a figure explaining the structural example of an output laser generator. FIG. 2 is an exploded perspective view showing the appearance and the like of each component in the laser oscillation device 10. 3 is a perspective view for explaining a passage of cooling air in the laser oscillation device 10. FIG. It is a figure explaining the example of the condensing duct 65, the condensing unit 67, and the laser condensing apparatus 68 in 1st Embodiment. It is a figure explaining the example of the output laser generator using the laser condensing apparatus 68 in 1st Embodiment. It is a figure explaining the example of the condensing duct 65, the condensing unit 67, and the laser condensing apparatus 68 in 2nd Embodiment. It is a figure explaining the example of the output laser generator using the laser condensing apparatus 68 in 2nd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Laser oscillation apparatus 10E Exhaust port 10C 2nd exhaust port 10G Front panel 10N Inlet port 20 Cooling fan 31 Semiconductor laser array 31a-31h Light emission part 32 Base heat sink 33 Semiconductor laser radiation fin 35 Long-axis direction collimating lens 36 Laser unit 65 Collection Optical duct 67 Condensing unit 68 Laser condensing device Wg Duct width Tg Duct thickness MU Duct upper surface MS Duct side MM Reflecting surface MR Emitting surface 70 Optical fiber for fiber laser 90 Optical fiber for transmission

Claims (4)

A semiconductor laser array in which a plurality of light emitting portions emitting laser light traveling while spreading in a short axis direction and a long axis direction perpendicular to each other are arranged in a line in the short axis direction, and provided at a position facing the light emitting portions. A long-axis direction collimating lens that converts the laser light emitted from the plurality of light emitting units into parallel light with respect to the long-axis direction, and a laser unit,
The incident laser beam can be transmitted, and corresponds to the duct width corresponding to the length in the minor axis direction of the light beam by the plurality of laser beams emitted from the laser unit and the length in the major axis direction of the light beam. The duct thickness is formed to be constant, and the length in the duct longitudinal direction perpendicular to the duct width direction and the duct thickness direction is formed to an arbitrary length. A condensing duct having an end surface formed on a reflecting surface having a predetermined angle with respect to the upper surface of the duct including the duct width direction and the duct longitudinal direction and orthogonal to the duct side surface including the duct thickness direction and the duct longitudinal direction; With
The light emitting portion of the laser unit and the upper surface of the duct of the condensing duct face each other so that the duct width direction of the condensing duct coincides with the minor axis direction of the laser unit, and the light is emitted from the laser unit. The luminous flux is applied to the reflecting surface from the inside of the condensing duct, and the luminous flux reflected by the reflecting surface is guided in the longitudinal direction of the duct through the condensing duct with respect to the condensing duct. A laser unit is arranged, and a condensing unit is constituted by the laser unit and the condensing duct,
A plurality of the condensing units are provided, and the condensing ducts of the respective condensing units are overlapped in the duct thickness direction so that the longitudinal directions of the ducts coincide with each other, and the exit surface serving as the other end face of each condensing duct is the same plane It has a superposed structure so as to be located on the top,
A laser condensing device. A semiconductor laser array in which a plurality of light emitting portions emitting laser light traveling while spreading in a short axis direction and a long axis direction perpendicular to each other are arranged in a line in the short axis direction, and provided at a position facing the light emitting portions. A long-axis direction collimating lens that converts the laser light emitted from the plurality of light emitting units into parallel light with respect to the long-axis direction, and a laser unit,
The incident laser beam can be transmitted, and corresponds to the duct width corresponding to the length in the minor axis direction of the light beam by the plurality of laser beams emitted from the laser unit and the length in the major axis direction of the light beam. The duct thickness is formed to be constant, and the length in the duct longitudinal direction perpendicular to the duct width direction and the duct thickness direction is formed to an arbitrary length. A condensing duct having an end surface formed on a reflection surface having a predetermined angle with respect to a duct side surface including the duct thickness direction and the duct longitudinal direction and orthogonal to the duct upper surface including the duct width direction and the duct longitudinal direction; With
The light emitting part of the laser unit and the duct side surface of the condensing duct are opposed to each other so that the longitudinal direction of the condensing duct coincides with the short axis direction of the laser unit, and the light is emitted from the laser unit. The luminous flux is applied to the reflecting surface from the inside of the condensing duct, and the luminous flux reflected by the reflecting surface is guided in the longitudinal direction of the duct through the condensing duct with respect to the condensing duct. A laser unit is arranged, and a condensing unit is constituted by the laser unit and the condensing duct,
A plurality of the condensing units are provided, and the condensing ducts of the respective condensing units are overlapped in the duct thickness direction so that the longitudinal directions of the ducts coincide with each other, and the exit surface serving as the other end face of each condensing duct is the same plane It has a superposed structure so as to be located on the top,
A laser condensing device. The laser condensing device according to claim 1 or 2,
The condensing duct is integrally formed so as to have the same shape as the condensing duct overlapped in the thickness direction according to claim 1 or claim 2.
Alternatively, the condensing duct is divided and molded in the longitudinal direction so as to have the same shape as the condensing duct superimposed in the thickness direction according to claim 1 or claim 2,
A laser condensing device. The laser condensing device according to any one of claims 1 to 3,
By making the length in the longitudinal direction of the condensing duct of each condensing unit an arbitrary length, a plurality of the semiconductor laser arrays are arranged at intervals according to the heat generation amount, and fixed to the heat sink,
The heat radiating plate is provided with heat radiating fins, and a cooling fan is provided to face the heat radiating fins.
A laser condensing device.