JPWO2007111046A1 - Optical fiber array, semiconductor laser condensing device, and optical fiber array manufacturing method - Google Patents

Abstract

An object of the present invention is to provide an optical fiber array, a semiconductor laser condensing device, and a method for manufacturing the optical fiber array that can further suppress loss. For this reason, the present invention makes each light emitted from an array light emitting source (10) in which a plurality of light emitting sections (12a) emitting light traveling while spreading in an elliptical shape are arranged in the short axis direction of the ellipse enter. It is composed of a plurality of optical fibers (22a), and each optical fiber is arranged so that each incident surface of each optical fiber faces each light emitting part according to the short-axis direction interval of the light emitting part. The incident surface side of the optical fiber is fixed by a fixing member to form an integrated part (21) by the fixing member and the incident surface of the optical fiber, and is incident on the incident surface side of each optical fiber in the integrated part. The lens part that collects light is formed by grinding, cutting, polishing, or melting and pressing the mold.

Description

  The present invention relates to an optical fiber array capable of efficiently condensing laser light emitted from a semiconductor laser array, a semiconductor laser condensing apparatus, and an optical fiber array manufacturing method.

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 include semiconductor laser bars in which a plurality of emitters (light emitting portions) are arranged one-dimensionally, and semiconductor laser stacks in which semiconductor laser bars are stacked and a plurality of emitters (light emitting portions) are arranged two-dimensionally. It has been commercialized.
For example, a general semiconductor laser bar is 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 mounted on a heat sink, and about 1 μm in length in the thickness direction. About 10 light emitting portions having a pitch of about 500 μm are integrated in the direction. 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 this specification, the semiconductor laser bar and the semiconductor laser stack are collectively referred to as a semiconductor laser array.

In a general semiconductor laser array, as shown in the example of FIG. 1 (example in which the light emitting part is one-dimensionally arranged), the laser light L1 emitted from the light emitting parts (12a to 12g) is emitted 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. 2, the spread angle θf in the major axis direction is about several tens of degrees (for example, 30 to 40 degrees), and as shown in the example of FIG. 3, the spread angle θs in the minor axis direction. Is about several degrees (for example, 3 to 4 degrees). Further, as described above, the dimensions of the light emitting portions (12a to 12g) 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.
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, a single-mode fiber is fused or bonded to one end of a single-mode fiber by attaching a lens-shaped multimode fiber having a slanted cross section with a wedge shape and a tip portion having a convex curved surface. A fiber with a partial lens has been proposed. Laser light emitted from the light emitting portion of the semiconductor laser is refracted inward by a lens-like convex curved surface in the major axis direction, and further refracted so as to have a smaller diameter by an internal refractive index distribution, and in the minor axis direction. The light is refracted so as to have a smaller diameter by the refractive index distribution and guided to the single mode fiber.
In the prior art described in Patent Document 2, a semiconductor laser array and a lens array are mounted on a metal block, the metal block is laser-welded inside a window on the side wall of a package (housing), and the outside of the window. Has proposed a semiconductor laser module in which a sleeve on which an optical fiber array is mounted is positioned and laser-welded. By fixing the metal block to the side of the package (chassis) without fixing it to the side, the bottom surface is displaced and the position is shifted due to temperature rise during laser emission (the position of the semiconductor laser array, lens array, and optical fiber array is shifted). ) Is reduced.
In the prior art described in Patent Document 3, a fiber array is formed of fibers made of a material whose cladding etching rate is faster than the core etching rate. Each fiber tip is etched, and the core end surface is a spherical lens. It is processed into a shape.
JP 2000-304965 A JP-A-6-308358 JP-A-6-324234

In the prior art described in Patent Document 1, the optical fiber and the lens are integrated, and the positioning of the light emitting part of the semiconductor laser and the optical fiber is not performed without positioning the light emitting part of the semiconductor laser, the lens, and the optical fiber. What is necessary is just to position two persons. However, in the case of using a semiconductor laser array having a plurality of light emitting portions, it is necessary to align the position of one optical fiber for each light emitting portion of the semiconductor laser array. The loss due to may increase.
In the prior art described in Patent Document 2, the metal block on which the semiconductor laser array and the lens array are mounted is separate from the optical fiber array. When the output of the array is relatively large, the heat generation of the semiconductor laser array and the lens array becomes larger than that of the optical fiber array, and a positional shift occurs due to the difference between the thermal expansion amount of the metal block and the thermal expansion amount of the optical fiber array. Loss can be significant.
In the prior art described in Patent Document 3, since a fiber is formed by etching to form a lens on the end face of the core, only a substantially spherical lens shape can be processed. For example, a suitable lens that suppresses loss such as a cylindrical lens shape. It is difficult to form into a shape. In addition, since it is a method that expects to form a spherical surface by melting by etching, it is difficult to obtain desired lens characteristics such as a focal length that can further suppress loss. It is also difficult to further suppress loss by precisely matching the position of the lens formed on the core end face (position in the longitudinal direction of the core) for each fiber.
The present invention has been made in view of such a point, and an object of the present invention is to provide an optical fiber array, a semiconductor laser condensing device, and a method for manufacturing the optical fiber array that can further suppress loss. .

In order to solve the above-described problems, the present invention is an optical fiber array, a semiconductor laser condensing device, and a method for manufacturing the optical fiber array, each having a configuration as set forth in the claims.
The optical fiber array according to the first aspect of the present invention is a plurality of light incident on each light emitted from an arrayed light source in which a plurality of light emitting portions emitting light that travels in an elliptical shape are arranged in the short axis direction of the ellipse. An optical fiber array composed of fibers.
Each optical fiber is arranged so that each incident surface of each optical fiber faces each light emitting unit according to the interval in the minor axis direction of the light emitting unit.
Then, the incident surface side of each optical fiber is fixed by a fixing member to form an integral part of the fixing member and the incident surface of the optical fiber, and is incident on the incident surface side of each optical fiber in the integral part. The lens portion that collects light is formed by grinding, cutting, polishing, or melting, and pressing the mold.
According to the first invention, since the incident surfaces of the plurality of optical fibers in the integrated part are aligned in accordance with the intervals of the light emitting parts of the array light source, the individual optical fibers are adapted to the positions of the light emitting parts. Therefore, positioning is easy and positioning accuracy is high. Thereby, loss can be suppressed more.

In the optical fiber array of the second invention, the fixing member is made of a solid material that hardens the tip portions on the incident surface side of the plurality of optical fibers.
According to the second invention, the fixing member can be easily configured with a solid material.

In the optical fiber array of the third invention, the fixing member is composed of at least two fixing plates in which surfaces orthogonal to the major axis direction of the ellipse are opposed to each other, and tips on the incident surface side of the plurality of optical fibers The portion is sandwiched and fixed by a fixed plate.
According to the third aspect of the invention, the fixing member can be easily configured with at least two fixing plates that sandwich the optical fiber.

In the optical fiber array according to the fourth aspect of the invention, at least one of the fixed plates is formed with a groove for positioning the optical fiber at an interval in the minor axis direction of the light emitting portion.
According to the fourth invention, the optical fiber can be easily positioned with respect to the fixed plate.

In the optical fiber array of the fifth invention, the lens portion is integrally formed in a convex shape with respect to the major axis direction so that light incident on the integral portion is refracted in the major axis direction.
According to the fifth aspect of the invention, in the long axis direction with a large divergence angle, the lens portion reduces the divergence angle and guides it into the optical fiber, and in the short axis direction with a small divergence angle, the light is guided as it is. In addition, light can be appropriately guided into the optical fiber, and loss can be further suppressed.
In addition, since the lens portion is integrally formed in the integral portion, it is easy to create the lens portion. Moreover, since the lens part in each optical fiber becomes the same shape (a variation is very small), positioning is easy and loss can be suppressed more.

In the semiconductor laser condensing device of the sixth invention, the optical fiber array according to any one of the first to fifth inventions and the laser light that travels while spreading in an elliptical shape are emitted as the arrayed light source. A semiconductor laser condensing device comprising a semiconductor laser array in which a plurality of light emitting portions are arranged in the minor axis direction of an ellipse, wherein each of the light emitting portions and each of the incident surfaces on which the lens portions are formed face each other. The semiconductor laser array and the integrated part are positioned, and the laser light emitted from each light emitting part is incident on each optical fiber and condensed.
According to the sixth aspect of the present invention, it is possible to position the plurality of light emitting portions and the respective optical fibers together by only positioning the two of the semiconductor laser array and the integral portion. Since there is no need to position individual optical fibers according to the position of each light emitting part, positioning is easy and positioning accuracy is high. Thereby, loss can be suppressed more.

In the semiconductor laser condensing device of the seventh invention, the semiconductor laser array and the integral part are fixed on the same member.
According to the seventh invention, even if the semiconductor laser array, which is a member located on the path from the time when the laser light is emitted from the light emitting portion and condensed, and the integrated portion generate heat, the fixed members are the same. Since they are members and have the same coefficient of thermal expansion, it is possible to suppress the amount of displacement due to thermal expansion, and it is possible to further suppress loss.

According to an eighth aspect of the present invention, there is provided a method of manufacturing an optical fiber array, wherein each light emitted from an array light source in which a plurality of light emitting portions emitting light that travels in an elliptical shape is arranged in the short axis direction of the ellipse is incident. A method of manufacturing an optical fiber array composed of a plurality of optical fibers, wherein each optical fiber is aligned with a short axis direction interval of the light emitting part so that each incident surface of each optical fiber faces each light emitting part. And the incident surface side of each optical fiber is fixed by a fixing member, and an integral part is formed by the fixing member and the incident surface of the optical fiber.
Then, from the incident surface side of the optical fiber in the integral part, the machining tool having a concave shape with respect to the major axis direction is pressed to move the machining tool in the minor axis direction, and the incident light is refracted in the major axis direction. Thus, a convex lens portion is formed integrally with the incident surface of each optical fiber with respect to the long axis direction.
According to the eighth aspect of the invention, the lens portion having a convex shape with respect to the major axis direction can be easily and integrally formed in the integrated portion in which the tips of the optical fibers in the optical fiber array are integrated. .

According to a ninth aspect of the present invention, there is provided a method of manufacturing an optical fiber array, wherein each light emitted from an array-shaped light source in which a plurality of light emitting portions emitting light that travels in an elliptical shape is arranged in the minor axis direction of the ellipse is incident. A method of manufacturing an optical fiber array composed of a plurality of optical fibers, wherein each optical fiber is aligned with a short axis direction interval of the light emitting part so that each incident surface of each optical fiber faces each light emitting part. And the incident surface side of each optical fiber is fixed by a fixing member, and an integral part is formed by the fixing member and the incident surface of the optical fiber.
Then, on the incident surface side of the optical fiber in the integrated part, the integrated part is arranged in the long axis direction so that the cylindrical processing tool having a rotation axis parallel to the short axis direction is refracted in the long axis direction. In order to refract the incident light in the long axis direction, a convex lens portion with respect to the long axis direction is integrally formed on the incident surface of each optical fiber.
According to the ninth aspect, a lens portion having a convex shape with respect to the major axis direction can be integrally formed with higher accuracy in the integrated portion in which the tips of the optical fibers in the optical fiber array are integrated.

According to a tenth aspect of the present invention, there is provided a method of manufacturing an optical fiber array, in which each light emitted from an array light source in which a plurality of light emitting portions emitting light that travels in an elliptical shape is arranged in the short axis direction of the ellipse is incident. A method of manufacturing an optical fiber array composed of a plurality of optical fibers, wherein each optical fiber is aligned with a short axis direction interval of the light emitting part so that each incident surface of each optical fiber faces each light emitting part. And the incident surface side of each optical fiber is fixed by a fixing member, and an integral part is formed by the fixing member and the incident surface of the optical fiber.
Then, the optical fiber and the fixing member are made of the same material or a material having a close melting point, and the incident surface side of the optical fiber in the integral part is melted and pressed against the mold, so that the incident light is in the major axis direction. A lens portion convex in the major axis direction is integrally formed on the incident surface of each optical fiber so as to be refracted.
According to the tenth aspect of the present invention, a lens portion having a convex shape with respect to the major axis direction can be more easily integrally formed with the integrated portion in which the tips of the optical fibers in the optical fiber array are integrated.

In the optical fiber array manufacturing method according to the eleventh aspect of the present invention, each optical fiber is formed such that the tip portion protrudes from the groove array in each groove of the groove array in which a plurality of grooves are formed at intervals in the minor axis direction of the light emitting portion. And the protruding tip is fixed by a fixing member to form an integral part.
According to the eleventh aspect, it is possible to easily position the optical fibers at intervals in the minor axis direction of the light emitting portions, and an integrated portion in which the tips of the optical fibers in the optical fiber array are integrated is easily formed. be able to.

It is a figure (perspective view) explaining the structure of a general semiconductor laser array and emitted laser light. It is a figure (side view) explaining the structure of a general semiconductor laser array and emitted laser light. It is a figure (plan view) illustrating the structure of a general semiconductor laser array and emitted laser light. It is a figure explaining the structure of the optical fiber array 20 of this invention. It is a figure explaining the structure of the optical fiber array 20 of this invention, and the semiconductor laser condensing apparatus 1. FIG. 4 is a diagram for explaining the relationship between the spread angle and radius of laser light emitted from the optical fiber array 20 and the spread angle and radius of laser light incident on a transmission optical fiber 40. FIG. It is a figure explaining the structure (side view) and function of the integral part. It is a figure explaining the structure (plan view) and function of an integral part. It is a figure which shows the example of the groove | channel array. It is a figure explaining the example of the manufacturing method of the optical fiber array 20 in which the lens part was integrally formed. It is a figure explaining the application example of the semiconductor laser condensing device. It is a figure explaining the application example of the semiconductor laser condensing device. It is a figure explaining the other Example in the structure of the optical fiber array. It is a figure which shows the example of the front-end | tip part of the optical fiber array shown in FIG. It is a figure explaining the method to integrally form a lens part in the entrance plane side of the optical fiber array shown in FIG. It is a figure (perspective view) explaining the other Example in the method of integrally forming a lens part in the entrance plane side of the optical fiber array shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Semiconductor laser condensing apparatus 10 Semiconductor laser array 12a-12g Light emission part 20 Optical fiber array 21 Integrated part 22a-22g Optical fiber 23a Clad member 24a Core member 26 Groove array 29 Bundle part 30 Condensing means 31, 32 Lens 40 For transmission Optical fiber 50 Substrate 60 Heat sink 70 Fin 80 Optical fiber for fiber laser 81 Dichroic mirror 82 Lens 83 FBG

The best mode for carrying out the present invention will be described below with reference to the drawings. In all the drawings, the X-axis direction indicates the short-axis direction, the Y-axis direction indicates the long-axis direction, and the Z-axis direction indicates the emission direction of the laser light emitted from the light emitting unit.
FIGS. 4-6 has shown the example of the laser condensing apparatus containing the optical fiber array 20 of this invention, and the semiconductor laser condensing apparatus 1 of this invention.
● [Configuration of optical fiber array (Fig. 4)]
As shown in the example of FIG. 4, in the optical fiber array 20 of the present invention, each light incident surface of each optical fiber (22 a, 22 b) is placed in each light emitting unit in accordance with the interval in the minor axis direction of the light emitting unit of the semiconductor laser array 10. They are arranged so as to face each other (the center interval in the minor axis direction of the adjacent light emitting portions is the same as the center interval in the minor axis direction of the incident surface of the adjacent optical fiber).
Then, an integrated portion 21 is formed in which the periphery of the incident surface of the adjacent optical fiber is solidified with a solid material (for example, an ultraviolet curable resin, a quartz compound (polysilane, polysilazane) or an epoxy adhesive). Each optical fiber (22a, 22b,...) Constitutes an optical fiber array 20.
In addition, a lens portion for collecting incident laser light is formed on the incident surface side of the optical fiber (22a, 22b) in the integrated portion 21, and the lens portion will be described later.

● [Configuration of Semiconductor Laser Condenser 1 (FIG. 5)]
As shown in the example of FIG. 5, the semiconductor laser condensing device 1 of the present invention includes a semiconductor laser array 10 and an optical fiber array 20.
The semiconductor laser array 10 and the integrated portion 21 (optical fiber array 20) are arranged so that the respective incident surfaces of the integrated portion 21 face the light emitting portions (12a to 12g, see FIG. 1) of the semiconductor laser array 10. Positioning.
There are various forms of condensing means 30 from the exit surface of the optical fiber array 20 to condensing on the transmission optical fiber 40. In the example of FIG. 5, an NA conversion optical system using lenses 31 and 32 is used. In this example, laser light emitted from the semiconductor laser array is directly used as a processing light source. In the description of FIG. 11 and FIG. 12 to be described later, an example used directly as a processing light source and an example used as excitation light for a solid-state laser will be described.

The exit surface of the optical fiber array 20 is bundled (bundled) as shown in FIG. 6, and its radius is r1, and the spread angle of the emitted laser light is θ1. Further, assuming that the radius of the incident surface of the transmission optical fiber 40 on which the laser light condensed by the lenses 31 and 32 is incident is r2, and the incident angle of the incident laser light is θ2, r1 * θ1 = r2 *. θ2 is established.
Furthermore, when the numerical aperture of the transmission optical fiber 40 is NA, by selecting appropriate r1, r2, and NA so that sin θ2 <NA, the laser light emitted from the optical fiber array 20 is transmitted to the transmission optical fiber. 40 can be efficiently incident.

● [Structure and function of integrated unit 21 (FIGS. 7 and 8)]
Next, the structure and function of the integrated portion 21 will be described with reference to FIGS.
7 is a view of the light emitting portion 12a, the integrated portion 21, and the optical fiber 22a of the semiconductor laser array 10 in FIG. 4 as viewed from the short axis direction (X axis direction), and FIG. 8 is the long axis direction (Y axis direction). It is the figure seen from.
As shown in FIG. 7, a lens portion for condensing incident laser light L1 is formed on the incident surface side of the optical fiber 22a in the integrated portion 21, and the laser light L1 is refracted by the lens portion. It is possible to guide the light into the optical fiber 22a with a small divergence angle (refracted so as to be almost parallel light), and appropriately guide the light into the core portion 24a covered with the cladding 23a. is there. The lens portion is integrally formed in a convex shape with respect to the major axis direction in the integral portion 21 (the formation method will be described later in the description of FIGS. 9 and 10).
In the example of FIG. 8, the lens shape is not formed in the minor axis direction. However, since the divergence angle is small in the minor axis direction, the laser beam is not incident on the optical fiber 22a with a numerical aperture NA or less even if it is not condensed. It is possible to guide L1.
Of course, a lens portion may be formed on the incident surface of each optical fiber so as to be further convex in the minor axis direction, but the curved surface in the major axis direction and the curved surface in the minor axis direction have different curvatures.

[Production method of optical fiber array 20 in which lens portion is integrally formed (FIGS. 9 and 10)]
Next, an example of a method for manufacturing the optical fiber array 20 in which the lens portions are integrally formed (a method for forming the integral portion 21 and a method for integrally forming the lens portion) will be described with reference to FIGS.
First, a groove array 26 is prepared in which V grooves are formed at the center interval (interval in the minor axis direction) of the light emitting portions 12x of the semiconductor laser array 10 (FIG. 9). The number of V grooves is the same as or more than the number of light emitting portions. The shape of the groove is not limited to the V-groove, and various shapes of grooves can be used.
Then, as shown in the example of FIG. 10, the same number of optical fibers 22 n as the number of light emitting portions are arranged in the V-groove so that the tip portion protrudes from the groove array 26. Then, the projecting tip is solidified with a solid material such as an ultraviolet curable resin, a quartz compound (polysilane, polysilazane), or an adhesive such as epoxy to form an integrated unit 21. In the next step, the lens portion is integrally formed by grinding with a processing tool T (in this example, a rotating grindstone) from the tip of the integral portion 21. Therefore, when the integral portion 21 is formed (before the lens portion is formed). ), The length of projection from the groove array 26 may not be uniform even if the adhesive surface or the like covers the incident surface of the optical fiber.
Then, the inner wall Ta of the machining tool T is integrally formed by using the machining tool T (in this example, the rotating grindstone T (the rotation axis is parallel to the major axis direction)) in which the inner wall Ta has a concave shape with respect to the major axis direction. While moving to the minor axis direction (X-axis direction) while pressing against the lens 21, the shape is adjusted and the incident surface of each optical fiber is exposed to the surface. Lens part) is integrally formed. Since they are integrally formed, they can be formed easily in a short time. The processing tool T is not limited to a rotating grindstone as long as it can transfer the shape of the inner wall Ta, and may be a processing tool that reciprocally vibrates in the short axis direction, for example.
The groove array 26 may be removed after the lens portion is formed, or may be attached as it is as the condensing optical fiber portion 20.

In the integrated portion 21 in which the lens portions are formed as described above, the lens portions having the same shape are formed on the incident surfaces of the optical fibers, and the intervals between the incident surfaces of the optical fibers are the same as the intervals between the light emitting portions.
Therefore, the laser beam emitted from the plurality of light emitting portions can be appropriately incident on each of the plurality of optical fibers only by positioning the semiconductor laser array 10 and the integrated portion 21, which is very convenient, Loss due to misalignment can be suppressed.
Further, each lens part is integrally formed, and the variation in shape of each lens part is very small (since the variation in focal length is very small), it is possible to further suppress the loss due to the displacement.
Further, when it is desired to process (form) the lens portion so as to be convex in the short axis direction, the processing tool rotated 90 degrees (rotated so that the concave shape of the inner wall Ta becomes concave in the short axis direction, However, the lens portion may be processed by moving in the major axis direction (Y-axis direction) while pressing against the incident surface of each optical fiber using a concave curvature of the inner wall Ta different from that of the processing tool T). .

[Application example of the semiconductor laser focusing device 1 (FIGS. 11 and 12)]
The example shown in FIG. 11 uses six sets of the semiconductor laser array 10 and the optical fiber array 20 constituting the semiconductor laser condensing device 1 of the present invention. A collection unit configured by bundling the emission surfaces of the optical fiber arrays 20 with a bundle unit 29, and including a lens 31 (a collimating lens for converting into parallel light) and a lens 32 (a condensing lens for reducing the diameter of the parallel laser light). The light means is used to collect the laser light L1 emitted from the bundle unit 29, enter the transmission optical fiber 40, and extract the laser light from the emission surface of the transmission optical fiber 40. In this example, laser light emitted from the semiconductor laser array 10 is directly used as a processing light source.
The semiconductor laser array 10 and the integrated portion 21 of the optical fiber array 20 are fixed to the same member (a heat-dissipating substrate 50 and made of a metal having a high thermal conductivity). Even if the substrate 50 expands according to the coefficient of thermal expansion due to the heat generated by the semiconductor laser array 10 and the integrated part 21, the difference in coefficient of thermal expansion between the position where the semiconductor laser array 10 is fixed and the position where the integrated part 21 is fixed. (Because they are the same member), they are fixed in the same direction, so even if thermal expansion occurs, the same amount acts in the same direction, and it is possible to suppress displacement due to temperature change and loss. Can be further suppressed.
In FIG. 11, a heat sink 60 and a fan 70 are further provided on the substrate 50 to dissipate heat. It is also possible to make a pass hole in the substrate 50 and cool it with a fluid such as water or oil.

In the example shown in FIG. 12, six sets of the semiconductor laser array 10 and the optical fiber array 20 constituting the semiconductor laser condensing device 1 of the present invention are used as in FIG. 11 is different from the bundle unit 29 of the optical fiber array 20 in FIG.
In FIG. 12, reference numeral 80 denotes an optical fiber for a fiber laser having a core portion doped with a rare earth element (the periphery of the core portion is composed of a clad portion for confining incident excitation light), and the incident surface When pumping light (in this case, laser light emitted from the semiconductor laser array) enters, the core portion is excited and (oscillation) laser light is generated in the core portion. The (oscillation) laser light is emitted from both ends of the optical fiber 80 for fiber laser. An FBG (fiber Bragg grating) is provided on the end surface opposite to the end surface on the incident surface side of the excitation light to reflect the (oscillation) laser light. Then, the laser beam is returned to the incident surface side, and (oscillation) laser light is extracted from the incident surface side of the excitation light.

In the optical fiber 80 for fiber laser, the (oscillation) laser beam generated in the direction toward the FBG side but reflected by the FBG and the (oscillation) laser beam generated in the direction toward the incident surface side are superimposed. The light is emitted from the core portion of the incident surface. The emitted (oscillation) laser light is converted into parallel light by the lens 32, and the traveling direction is further converted by the dichroic mirror 81. The lens 32 functions as a condensing lens for reducing the diameter of the laser light (excitation light) emitted from the semiconductor laser array 10 so as to guide the laser light to the optical fiber 80 for fiber laser. The (oscillation) laser light emitted from the optical fiber 80 functions as a collimating lens that converts the (oscillation) laser light into parallel light.
The dichroic mirror 81 transmits light having a wavelength of excitation light (in this case, laser light emitted from the semiconductor laser array 10), and (oscillation) laser light (laser light emitted from the optical fiber 80 for fiber laser). ) Is reflected.
The (oscillation) laser light reflected by the dichroic mirror 81 is reduced in diameter by the condenser lens 82 and is incident on the incident surface of the transmission optical fiber 40. Then, laser light is extracted from the exit surface of the transmission optical fiber 40. In this example, laser light emitted from the semiconductor laser array 10 is used as excitation light.
The semiconductor laser array 10 and the integrated portion 21 of the optical fiber array 20 are fixed to the same member (such as the heat-dissipating substrate 50), and since the loss is the same as in FIG. .

[Other Embodiments of Optical Fiber Array Configuration and Manufacturing Method (FIGS. 13 to 16)]
Next, another embodiment in the configuration of the optical fiber array 20 will be described with reference to FIG. 13, and another embodiment in the method for manufacturing the optical fiber array 20 will be described with reference to FIGS.
As shown in FIG. 13, a fixing member is constituted by two fixing plates 21a and 21b whose surfaces orthogonal to the major axis direction (Y-axis direction) are opposed to each other, and incident surfaces of a plurality of optical fibers 22a to 22e. Are fixed by being sandwiched between the fixing plates 21a and 21b. In the example of FIG. 13, the fixing member is configured by one fixing plate 21a and one fixing plate 21b. However, the fixing plate 21a or 21b may be configured by two or more fixing plates.
In the example of FIG. 13, in order to position the optical fibers 22 a to 22 e more stably, the fixing plate 21 b that sandwiches the distal ends of the optical fibers 22 a to 22 e is slightly more than the distal ends of the optical fibers 22 a to 22 e. Although the fixing plate 27 that sandwiches the rear is provided, the fixing plate 27 may be omitted. The fixing plates 21b and 27 are fixed to the fixing plate 21a with screws 21n.

Grooves 21m (for example, V-grooves) are formed in at least one fixing plate (the fixing plate 21a in the example of FIG. 13) at intervals in the minor axis direction of the light emitting portions of the semiconductor laser array 10. The optical fibers 22a to 22e are positioned in the minor axis direction at intervals of the grooves 21m, and are positioned on the surface of the fixed plate 21a that is orthogonal to the major axis direction. Of course, you may provide the groove | channel 21m in both the fixed plates 21a and 21b.
Further, as the material of the fixing plates 21a and 21b, for example, metal or glass that is relatively resistant to heat (melting point is higher than that of the optical fiber) can be used. As a result, compared with the case where the fixing member is formed of a relatively heat-sensitive material such as an adhesive or a resin, the leakage laser light when the laser light is incident on the incident surface of the optical fiber (generally, FIG. The laser beam included in the range indicated by L1 in FIG. 3 is approximately 86%, and the remaining approximately 14% of the laser beam leaks out of the range indicated by L1). Can do. The fixed plate 21a and the fixed plate 21b may be made of different materials.

Next, a method for manufacturing the optical fiber array 20 will be described with reference to FIGS.
The manufacturing method shown in FIGS. 14 and 15 uses the same processing tool T as the manufacturing method described in FIG. 10 (the inner wall Ta has a concave shape in the long axis direction), and the inner wall Ta of the processing tool T is an integral part. Is pressed from the incident surface side of the optical fiber, and the working tool T is moved in the short axis direction (X-axis direction) to grind or cut or polish the lens portion having a convex shape with respect to the long axis direction. These are formed integrally on the incident surface of each optical fiber. The optical fiber array in this case may have the configuration shown in FIG. 10 or the configuration shown in FIG.

  In the manufacturing method shown in FIG. 16, a substantially cylindrical rotating grindstone having a rotation axis in the minor axis direction (X-axis direction) is used as the processing tool T. And by moving the said processing tool T along the shape of the lens part which forms convex shape with respect to a major axis direction, with respect to a major axis direction, incident light is refracted in a major axis direction. A convex lens portion is integrally formed on the incident surface of each optical fiber. The optical fiber array in this case may have the configuration shown in FIG. 10 or the configuration shown in FIG.

As still another manufacturing method, the optical fiber and the fixing member are made of the same material or a material having a close melting point. The optical fiber array in this case may have the configuration shown in FIG. 10 or the configuration shown in FIG.
Then, the incident surface side of the optical fiber in the integrated part is heated and melted, and a mold (mold such as metal or cemented carbide) for forming (transferring) the lens part is pressed against the major axis direction. A convex lens portion is integrally formed on the incident surface of each optical fiber (not shown).

As described above, a spherical lens (or an aspheric surface (a spherical surface with a non-constant curvature)) is integrally formed on the incident surface of each optical fiber by simultaneously processing an integrated portion integrated with the optical fiber and the fixing member. Lens), or cylindrical lens (or non-cylindrical (cylindrical cylinder) lens). Since the lens part of an arbitrary shape can be formed by processing, the incidence of each optical fiber is adjusted so that the loss can be further suppressed and the appropriate position (position aligned with each optical fiber) can be obtained. A lens portion can be formed on the surface.
Further, in the configuration of the optical fiber array shown in FIG. 13, an optical fiber array that can prevent burning can be configured by appropriately selecting the material of the fixing plates 21a and 21b.
Further, if the fixing member is made of the same or similar material as the optical fiber, the processing accuracy can be further improved, the uneven wear of the processing tool T can be suppressed, and the shape of the lens part after processing may be lost. It becomes difficult to occur.

The optical fiber array 20 and the semiconductor laser condensing device 1 of the present invention are not limited to the appearance, configuration, structure, and the like described in the present embodiment, and various modifications, additions, and the like can be made without changing the gist of the present invention. Can be deleted.
The numerical values used in the description of the present embodiment are examples, and are not limited to these numerical values.
In addition, the optical fiber array 20 described in the present embodiment is not limited to condensing laser light from the semiconductor laser array, and emits light that travels in a substantially elliptical shape in the major axis direction and the minor axis direction. It can be used for the purpose of condensing each light emitted from an arrayed light source in which a plurality of light emitting units are arranged in the short axis direction.

Claims (11)

An optical fiber array comprising a plurality of optical fibers that receive light emitted from an array-shaped light source in which a plurality of light emitting portions that emit light traveling in an elliptical shape are arranged in the short axis direction of the ellipse Because
Each optical fiber is arranged so that each incident surface of each optical fiber faces each light emitting unit according to the interval in the minor axis direction of the light emitting unit,
The incident surface side of each optical fiber is fixed by a fixing member to form an integral part of the fixing member and the incident surface of the optical fiber,
On the incident surface side of each optical fiber in the integrated part, a lens part that collects incident light is formed by grinding, cutting, polishing, or melting and pressing a mold Fiber array. The optical fiber array according to claim 1, wherein
The said fixing member is an optical fiber array comprised with the solid material which solidifies the front-end | tip part by the side of the incident surface of the said some optical fiber. The optical fiber array according to claim 1, wherein
The fixing member is composed of at least two fixing plates in which surfaces perpendicular to the major axis direction of the ellipse are opposed to each other, and tip portions on the incident surface side of the plurality of optical fibers are the fixing plates. An optical fiber array that is sandwiched and fixed. The optical fiber array according to claim 3,
An optical fiber array in which a groove for positioning the optical fiber is formed in at least one of the fixing plates at an interval in the minor axis direction of the light emitting section. The optical fiber array according to any one of claims 1 to 4,
The lens unit is an optical fiber array integrally formed in a convex shape with respect to the major axis direction so that light incident on the integral part is refracted in the major axis direction. An optical fiber array according to any one of claims 1 to 5,
A semiconductor laser condensing device comprising a semiconductor laser array as a plurality of light emitting units that emit laser light that travels while spreading in an elliptical shape as the array-shaped light source,
The semiconductor laser array and the integrated portion are positioned so that each of the light emitting portions and each of the incident surfaces on which the lens portions are formed face each other, and laser light emitted from each light emitting portion is A semiconductor laser condensing device that collects light by entering an optical fiber. The semiconductor laser condensing device according to claim 6,
A semiconductor laser condensing device in which the semiconductor laser array and the integral part are fixed on the same member. An optical fiber array comprising a plurality of optical fibers that receive light emitted from an array-shaped light source in which a plurality of light emitting portions that emit light traveling in an elliptical shape are arranged in the short axis direction of the ellipse A manufacturing method of
Each optical fiber is arranged so that each incident surface of each optical fiber faces each light emitting unit in accordance with the interval in the minor axis direction of the light emitting unit,
Fixing the incident surface side of each optical fiber with a fixing member, forming an integral part of the fixing member and the incident surface of the optical fiber;
A machining tool having a concave shape with respect to the major axis direction is pressed from the incident surface side of the optical fiber in the integrated portion to move the machining tool in the minor axis direction, and incident light is incident on the major axis. A method of manufacturing an optical fiber array, in which a lens portion convex to the major axis direction is integrally formed on an incident surface of each optical fiber so as to be refracted in a direction. An optical fiber array comprising a plurality of optical fibers that receive light emitted from an array-shaped light source in which a plurality of light emitting portions that emit light traveling in an elliptical shape are arranged in the short axis direction of the ellipse A manufacturing method of
Each optical fiber is arranged so that each incident surface of each optical fiber faces each light emitting unit in accordance with the interval in the minor axis direction of the light emitting unit,
Fixing the incident surface side of each optical fiber with a fixing member, forming an integral part of the fixing member and the incident surface of the optical fiber;
On the incident surface side of the optical fiber in the integral part, the integral part is arranged so that incident light is refracted in the major axis direction with a cylindrical processing tool having a rotation axis parallel to the minor axis direction. A lens portion having a convex shape with respect to the long axis direction is moved to the incident surface of each optical fiber so that the incident light is refracted in the long axis direction. A manufacturing method of an optical fiber array formed integrally. An optical fiber array comprising a plurality of optical fibers that receive light emitted from an array-shaped light source in which a plurality of light emitting portions that emit light traveling in an elliptical shape are arranged in the short axis direction of the ellipse A manufacturing method of
Each optical fiber is arranged so that each incident surface of each optical fiber faces each light emitting unit in accordance with the interval in the minor axis direction of the light emitting unit,
Fixing the incident surface side of each optical fiber with a fixing member, forming an integral part of the fixing member and the incident surface of the optical fiber;
The optical fiber and the fixing member are made of the same material or a material having a close melting point,
By melting the incident surface side of the optical fiber in the integrated portion and pressing the mold, a lens portion having a convex shape with respect to the major axis direction is formed so that incident light is refracted in the major axis direction. A method for manufacturing an optical fiber array, which is integrally formed on an incident surface of each optical fiber. It is a manufacturing method of the optical fiber array in any one of Claims 8-10,
In each groove of the groove array in which a plurality of grooves are formed at intervals in the minor axis direction of the light emitting portion, each optical fiber is arranged so that a tip portion protrudes from the groove array,
A method of manufacturing an optical fiber array, wherein the protruding tip portion is fixed by the fixing member to form the integrated portion.

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