JP6567256B2 - Optical device - Google Patents

Description

  The present invention relates to an optical device including a light source and a light guide member that are optically coupled to each other.

  When an optical fiber having a core with a rectangular cross section is used, the spot of the beam emitted from the optical fiber becomes rectangular. Such a square beam can be suitably used for applications such as laser processing machines, laser scribing, laser peening, laser repair, and medical laser equipment.

  Patent Document 1 describes a technique in which laser light emitted from a plurality of light emitting points of a semiconductor laser bar is collected in an optical circuit and a plurality of optical fibers that receive the emitted light from a plurality of optical circuits are bundled. .

JP 2004-361655 A (published on December 24, 2004)

  In order to increase the light intensity of the laser light emitted from the optical fiber, it is conceivable to bundle a plurality of optical fibers and / or to enter a plurality of laser lights into the optical fiber. If a plurality of laser beams are incident on a single optical fiber, the light density of the emitted laser beams can be increased, and the size and cost of the apparatus can be reduced.

  In the configuration of Patent Document 1, an optical circuit is required separately from the optical fiber. Light emitted from a plurality of light emitting points on the semiconductor laser bar is incident on a plurality of optical waveguides of the optical circuit, respectively. In such a configuration, laser beams from a plurality of individually packaged semiconductor laser elements cannot be efficiently introduced into a single optical fiber having a small core cross section.

  An object of the present invention is to efficiently introduce laser beams emitted from a plurality of semiconductor laser elements into an optical fiber having a rectangular core.

In order to solve the above-described problem, an optical device according to one embodiment of the present invention includes a plurality of semiconductor laser elements that emit laser light, a light guide member that includes a light guide portion that guides the laser light, and the plurality of semiconductor devices. An image forming unit that forms an image of the laser beam of the semiconductor laser element on the incident end surface of the single light guide unit, and an outer shape of the incident end surface defines a first side that defines a width of the light guide unit and The long axes of the plurality of spots formed on the incident end surface corresponding to the plurality of semiconductor laser elements have a second side that defines the height of the light guide unit, and are aligned with each other. The first side is longer than the second side, and the direction of the major axis of the plurality of spots is aligned with the first side of the incident end face.

  According to one embodiment of the present invention, loss of laser light incident on a light guide portion can be reduced.

It is a top view which shows the structure of the optical apparatus which concerns on one Embodiment of this invention. It is a front view of the light emission part seen from the AA cross section of FIG. It is a figure which shows the mode of the incident end surface of the optical fiber seen from the BB cross section of FIG. It is a figure for comparing arrangement of a plurality of light spots to a core. It is a figure which shows the modification of arrangement | positioning of the several light spot in one Embodiment of this invention. (A) is a figure which shows the mode of the incident end surface of the optical fiber in other embodiment of this invention, (b) is a figure which expands and shows the core of (a). (A) is a figure which shows the mode of the incident end surface seen from the incident direction of the optical fiber in other embodiment of this invention, (b) is the emission direction of the optical fiber in other embodiment of this invention. It is a figure which shows the mode (cross section) of the seen emission end surface, (c) is a figure which shows the fluorescent member irradiated with the laser beam from the optical fiber. It is a figure which shows the comparison with a step index type optical fiber and a graded index type optical fiber. (A) is a figure which shows the mode of the incident end surface seen from the incident direction of the optical fiber in further another embodiment of this invention, (b) is an emission of the optical fiber in other embodiment of this invention. It is a figure which shows the mode (cross section) of the output end surface which looked at the direction, (c) is a figure which shows the fluorescent member irradiated with the laser beam from the optical fiber. It is sectional drawing which compares the optical fiber which has a rectangular core, and the optical fiber which has a circular core. (A) is a figure which shows the mode of the incident end surface seen from the incident direction of the optical fiber in other embodiment of this invention, (b) is incident of the optical fiber in other embodiment of this invention. It is a figure which shows the mode of the incident end surface seen from the direction, (c) is a figure which shows the fluorescent member irradiated with the laser beam from the said optical fiber of (a), (d) is a figure of (b) It is a figure which shows the fluorescent member irradiated with the laser beam from the optical fiber.

Embodiment 1
FIG. 1 is a top view illustrating a configuration of an optical device 1 according to the present embodiment. The optical device 1 includes a light emitting unit 10, an imaging unit 20, and an optical fiber 30 (light guide member).

  The light emitting unit 10 includes a plurality of semiconductor laser elements 11 as a light source, a plurality of stems 12, and a support member 13 (support unit). Each semiconductor laser element 11 is mounted on a corresponding stem 12. The stem 12 has pins (not shown) for electrically connecting the semiconductor laser element 11 to a power source or the like. The stem 12 supports the corresponding semiconductor laser element 11 and fixes the semiconductor laser element 11 to the support member 13. The semiconductor laser element 11 may be mounted on the stem 12 via a submount made of silicon carbide, aluminum nitride, or the like. The support member 13 supports the plurality of semiconductor laser elements 11 via the stem 12 and fixes the plurality of semiconductor laser elements 11 in a predetermined positional relationship (position and angle). Further, the stem 12 and the support member 13 may be made of a material such as a metal having high thermal conductivity, and the stem 12 and the support member 13 may also serve as a radiator. Alternatively, another heat radiator may be provided on the support member 13. The radiator may include a heat sink, a fan, a Peltier, and the like.

  The semiconductor laser element 11 is an edge emitting laser here. In the edge-emitting laser, the region (light emitting region) for emitting light on the end surface (cleavage surface) of the semiconductor laser element (chip) has an elliptical shape. In the edge-emitting laser, the direction in which the cladding layer and the active layer are laminated coincides with the direction in which the semiconductor crystal grows during the manufacture of the edge-emitting laser. Since a part of the thin active layer becomes a light emitting region, the light emitting region becomes longer in the direction along the active layer. The minor axis of the light emitting region of the edge emitting laser coincides with the direction in which the cladding layer and the active layer are laminated. The near-field image of the edge-emitting laser also has an elliptical shape like the light emitting region, and the short axis of the near-field image coincides with the direction in which the clad layer and the active layer are laminated.

  The semiconductor laser element 11 is sealed with a cap (not shown). Here, the semiconductor laser element 11 has a wavelength of 405 nm or 445 nm. However, the wavelength is not limited to this, and an arbitrary wavelength can be used. The end faces (end faces having the light emission regions) of the respective semiconductor laser elements 11 are arranged so as to be parallel to each other, and are also parallel to the surface of the support member 13 (the face in contact with the stem 12).

  The imaging unit 20 is an imaging optical unit that focuses (condenses) the laser light emitted from the plurality of semiconductor laser elements 11 on the end face of the optical fiber 30. The imaging unit 20 includes a plurality of collimating lenses 21 and a condenser lens 22. The collimating lens 21 converts the laser light emitted from the corresponding semiconductor laser element 11 into parallel light. The condensing lens 22 condenses the laser light from the plurality of collimating lenses 21 on the end face of the optical fiber 30 to form an image. Here, the collimating lens 21 and the condenser lens 22 are used as the imaging unit 20, but the imaging unit 20 is not limited to this, and the imaging unit 20 transmits the laser beams of the plurality of semiconductor laser elements 11 to the end face of the optical fiber 30. In order to form an image, a plurality of condensing lenses may be used, or any other optical member can be used.

  The optical fiber 30 has a core 31 (light guide portion) having a rectangular cross-sectional shape. The periphery of the core 31 is covered with a clad 32. Laser light is guided through the core 31 from the incident end to the emission end. The size of the core 31 is assumed to be, for example, a height (z direction) of 200 μm and a width (y direction) of 800 μm. The outer shape of the optical fiber 30 itself may be circular or rectangular. Here, the optical fiber 30 is a multimode and step index type optical fiber. Instead of the optical fiber 30, a light guide member that does not have a clad and includes a core can also be used.

  FIG. 2 is a front view of the light emitting portion 10 as viewed from the AA cross section of FIG. The AA cross section passes through the end face of the semiconductor laser element 11. Here, the illustration of the stem is omitted. Four semiconductor laser elements 11 are arranged on the support member 13. The end face of the semiconductor laser element 11 is a rectangle that is long in the y direction. The light emission area EA of the semiconductor laser element 11 has an elliptical shape. The major axes of the light emitting areas EA of the plurality of semiconductor laser elements 11 are aligned in the y direction. The direction in which the clad layer and the active layer in the plurality of semiconductor laser elements 11 are stacked is the z direction.

  FIG. 3 is a view showing a state of the incident end face of the optical fiber 30 as seen from the BB cross section of FIG. The BB cross section passes through the incident end face of the optical fiber 30. The incident end surface of the core 31 is a rectangle that is long in the y direction, and the outer shape of the clad 32 that covers the periphery of the core 31 is a circle. The lower side or upper side of the outer shape of the incident end face of the core 31 defines the width (length in the y direction) of the core 31, and the right side or left side of the outer shape of the incident end face is the height of the core 31 (length in the z direction). Is specified.

  The laser beams emitted from the plurality of semiconductor laser elements 11 are respectively imaged on the incident end face of the single core 31 by the imaging unit 20. That is, the laser beams of the plurality of semiconductor laser elements 11 are introduced into one core 31. Usually, the near-field image and the far-field image of the edge-emitting laser differ in the direction of the major axis by 90 °. However, since the laser beam of the semiconductor laser element 11 is imaged on the incident end face of the core 31 by the imaging unit 20 (condensing lens 22), the light spot SP (imaged) formed on the incident end face is formed. The image) has the same elliptical shape as the light emitting area EA of the semiconductor laser element 11. The major axis direction of the light spot SP is aligned with the major axis direction of the light emitting area EA. A plurality of light spots SP by the plurality of semiconductor laser elements 11 are arranged in the incident end face of the single core 31. The directions of the major axes of the plurality of light spots SP by the plurality of semiconductor laser elements 11 are aligned with each other, and here are aligned in the y direction (parallel). The major axis directions of the plurality of light spots SP are aligned (parallel) with the lower and upper sides (sides extending in the longitudinal direction) of the outer shape of the incident end face of the core 31. In addition, the direction (z direction) in which the cladding layers and the active layers of the plurality of semiconductor laser elements 11 are stacked is aligned with the right side and the left side (sides extending in the short direction) of the outer shape of the incident end face of the core 31 (parallel). Is).

  The plurality of laser beams introduced into the rectangular core 31 are guided to the emission end of the optical fiber 30 and emitted from the optical fiber 30. A rectangular light beam is emitted from the entire rectangular emission end face (core) of the optical fiber 30.

(Comparison of light spot arrangement)
FIG. 4 is a diagram for comparing the arrangement of a plurality of light spots with respect to the core. 4A to 4C are reference examples, and FIG. 4D is an example corresponding to the present embodiment. In the example shown in FIG. 4A, four light spots SP whose major axis directions are not aligned are arranged in a circular core 31. In the example shown in FIG. 4B, four light spots SP whose major axes are aligned are arranged in a circular core 31. Here, although the light spot SP is represented by a rectangle, the light spot SP may be oval or rectangular. Moreover, the point in the light spot SP in the figure represents the position of the center of the light spot SP. When the core 31 is circular, the coupling efficiency (incidence efficiency to the optical fiber) between the laser light source and the optical fiber is not changed regardless of the direction of the major axis of the light spot SP. That is, as in the example shown in FIG. 4A, even if the directions of the long axes of the plurality of light spots SP are not aligned, the plurality of light spots SP as in the example shown in FIG. Even if the major axis directions are aligned, the incident efficiency to the optical fiber is the same.

  On the other hand, when the core 31 is rectangular, the result is different. In the example shown in FIG. 4C, four light spots SP whose major axis directions are not aligned are arranged in a rectangular core 31. In the example shown in FIG. 4D, four light spots SP whose major axis directions are aligned are arranged in a rectangular core 31, and the major axis direction of the light spot SP is the core 31. Aligned with one side. As shown in FIG. 4C, when the directions of the long axes of the plurality of light spots SP are not aligned, the light spot SP easily protrudes from the rectangular core 31, and the amount of the light beam SP protruding from the core 31 is the loss of laser light. become. Further, even if the specification (design) is such that all the light spots SP are accommodated in the core 31, the position of the light spot SP may change due to an error in manufacturing. In the example shown in FIG. 4C, even if the plurality of light spots SP are shifted upward or downward, the portion protruding from the core 31 is increased and the incidence efficiency is decreased.

  On the other hand, as shown in FIG. 4D, when the major axis direction of the plurality of light spots SP is aligned with one side of the rectangular core 31, even if an error in manufacturing occurs, Compared with the example shown in c), the light spot SP is less likely to protrude from the core 31, and the loss of incident laser light is also likely to be suppressed. Therefore, optical adjustment of the imaging unit 20 can be facilitated. Further, even when the position of the light spot SP changes due to vibration generated in the optical device 1, the incident efficiency can be kept high.

  Therefore, in the optical device 1 of the present embodiment, a highly efficient and high output rectangular beam can be emitted from the emission end of the optical fiber 30. In addition, by arranging the light spot SP in this way, the size of the core 31 can be reduced while maintaining high incidence efficiency. Therefore, a rectangular beam having a higher light density can be obtained from the emission end of the optical fiber 30. According to the present embodiment, not only the number of optical fibers can be reduced, but also the optical alignment work of the optical device 1 can be facilitated, so that the manufacturing cost can be reduced and the productivity can be improved. In addition, since the allowable range of the optical alignment can be increased, the reliability is high even in the use where the optical device 1 in which the optical alignment is shifted causes vibration.

  In addition, for example, the optical device 1 and the phosphor may be combined to irradiate the fluorescent member including the phosphor with the beam emitted from the optical fiber 30. An illumination device that emits white light (or light of any color) can be obtained by converting the wavelength of part of the light with the fluorescent member. If the optical device 1 is used, the light emitting region in the fluorescent member can be reduced, so that an illumination device with high brightness and high efficiency can be obtained. A light distribution pattern (light distribution) can be controlled by further providing an optical component (such as a mirror or a lens) in the illumination device. At this time, since the light emitting region in the fluorescent member is rectangular, a specific light distribution pattern can be easily obtained, and the light utilization efficiency can be increased. Such an illuminating device can be suitably used for, for example, a headlight, a searchlight, a projector, and the like of a vehicle (such as an automobile).

(Modification)
(A)-(c) of FIG. 5 is a figure which shows the modification of arrangement | positioning of the several light spot of this embodiment. As shown in FIG. 5A, the major axis directions of a plurality (six in this case) of light spots SP are aligned with each other, and the major axis directions of the plurality of light spots SP are rectangular cores. You may align to the short side (left side and right side) of 31. In this case, the direction in which the clad layer and the active layer in the plurality of semiconductor laser elements 11 are laminated is aligned with the long side (upper side and lower side) of the core 31. As shown in FIG. 5B, some of the plurality of light spots SP may overlap each other. As shown in (c) of FIG. 5, the shape of the core 31 may be a square. In any case of (a) to (c) in FIG. 5, the major axes of the plurality of light spots SP are aligned with each other and aligned with one side of the core 31. By making the light spot SP in such an arrangement, the incident efficiency to the optical fiber 30 can be increased.

  Note that the image (light spot SP) formed on the end face of the core 31 of the optical fiber 30 may be slightly blurred, and only needs to be condensed to be within the range of the core 31.

[Embodiment 2]
Another embodiment of the present invention will be described. For convenience of explanation, members having the same functions as those described in the above embodiment are denoted by the same reference numerals and description thereof is omitted. In the present embodiment, a case will be described in which a plurality of light spots of a plurality of semiconductor laser elements overlap. In the present embodiment, an optical fiber 30a is used instead of the optical fiber 30 of the first embodiment.

  FIG. 6A is a diagram showing a state of the incident end face of the optical fiber 30a in the present embodiment. In the present embodiment, the size (cross-sectional area) of the core 31a in the optical fiber 30a is smaller than that in the first embodiment. In the present embodiment, the size of the core 31a is, for example, 50 μm in height (z direction) and 200 μm in width (y direction). The size of the light spot SP is approximately the same as that of the first embodiment. Therefore, in order to introduce the laser beams from the plurality of semiconductor laser elements 11 into the core 31a, a plurality (for example, four) of the light spots SP are arranged so as to substantially overlap one. In other words, the imaging unit images the laser beams emitted from the plurality of semiconductor laser elements 11 so as to overlap each other on the incident end face of the core 31a of the optical fiber 30a.

  FIG. 6B is an enlarged view showing the core 31a of FIG. Vs indicates the height of the overlapping light spot SP (length of the short axis), and Hs indicates the width of the light spot SP (length of the long axis). Vc represents the height of the core 31a, and Hc represents the width of the core 31a. Vm1 and Vm2 indicate margins (margin distances) between the edge of the light spot SP and the side of the core 31a in the minor axis direction. Hm1 and Hm2 indicate margins between the edge of the light spot SP and the side of the core 31a in the major axis direction.

  When the position of the light spot SP is shifted, the influence of the light spot SP protruding from the core 31a in the minor axis direction is larger than the influence of the light spot SP protruding in the major axis direction. This is because the amount of light protruding from the core is larger in the short axis direction even if the length of the light spot SP protruding is the same. Therefore, the margins Vm1 and Vm2 in the minor axis direction are preferably larger than the margins Hm1 and Hm2 in the major axis direction. In other words, it is preferable that min (Vm1, Vm2)> max (Hm1, Hm2).

  When the size of the core 31a is reduced, the efficiency of incidence on the optical fiber 30a is likely to decrease. In the present embodiment, the loss of incident laser light can be reduced by overlapping a plurality of light spots SP corresponding to the plurality of semiconductor laser elements 11 into one. Therefore, a rectangular beam with a higher light density can be obtained. Further, if the optical device of the present embodiment is used, a higher-luminance illumination device can be realized.

  In addition, when the plurality of light spots SP partially overlap each other and when they do not overlap at all (see FIG. 3), each light spot SP (individual light spot) has a smaller margin in the minor axis direction ( The value of the margin closer to the upper side / lower side is preferably larger than the value of the smaller margin in the major axis direction (margin closer to the left side / right side). Each distance to the closest core side of the plurality of light spots SP in the short axis direction is preferably larger than each distance to the closest core side of the plurality of light spots SP in the long axis direction.

[Embodiment 3]
Still another embodiment of the present invention will be described. For convenience of explanation, members having the same functions as those described in the above embodiment are denoted by the same reference numerals and description thereof is omitted. In this embodiment, the case where the shape of the core is a rectangle with a part missing will be described. In the present embodiment, an optical fiber 30b is used instead of the optical fiber 30 of the first embodiment.

  (A) of FIG. 7 is a figure which shows the mode of the incident end surface seen from the incident direction of the optical fiber 30b in this embodiment. In the present embodiment, the outer shape of the core 31b of the optical fiber 30b is substantially rectangular, but has a shape in which a part of the rectangle is missing. The lower side 33 (first side) of the outer shape of the core 31b defines the width (length in the y direction) of the core 31b, and the left side 34 (second side) of the outer shape of the core 31b is the height (z The length of the direction). The plurality of light spots SP corresponding to the plurality of semiconductor laser elements 11 are arranged in the core 31b so that the direction of the long axis is aligned with the lower side of the core 31b.

  FIG. 7B is a view showing a state (cross section) of the emission end face when viewing the emission direction of the optical fiber 30b in the present embodiment. The laser light introduced into the core 31b is repeatedly reflected inside the optical fiber 30b and emitted from the entire core 31b at the emission end. Therefore, the beam shape of the laser light emitted from the optical fiber 30b is the same as that of the core 31b.

  (C) of FIG. 7 is a figure which shows the fluorescent member 40 irradiated with the laser beam from the optical fiber. The fluorescent member 40 is a plate-like substrate including a phosphor, and is disposed, for example, in front of the emission end of the optical fiber 30b of the optical device. The laser light emitted from the optical fiber 30b is applied to the region 41 of the fluorescent member 40. The region 41 of the fluorescent member 40 is excited by laser light and emits white light. Since the shape of the beam emitted from the optical fiber 30b is the same as the shape of the core 31b, the region 41 emitting light in the fluorescent member 40 is also the same as the shape of the core 31b.

  Therefore, by reflecting light from the fluorescent member 40 located at the focal point by a mirror having a paraboloid, etc., light is projected with an irradiation pattern 42 having the same shape as the core 31b as shown in FIG. An illumination device that performs (irradiation) can be easily realized. For example, in an automobile headlight (passing headlight (low beam)), it is necessary to irradiate forward with an irradiation pattern 42 (light distribution distribution) as shown in FIG. There is. Therefore, the illuminating device using the optical device of the present embodiment can be suitably applied to an automobile illuminating device. As described above, according to this embodiment, a beam having the same specific shape as the core 31b can be obtained. Therefore, a simple optical member that reflects and refracts light from the fluorescent member 40 can be used to obtain a desired shape. The irradiation pattern 42 can be obtained. Note that the core is not limited to the example shown in FIG.

[Embodiment 4]
Still another embodiment of the present invention will be described. For convenience of explanation, members having the same functions as those described in the above embodiment are denoted by the same reference numerals and description thereof is omitted. In the above-described embodiment, the optical fiber is a step index type, but may be a graded index type.

  (A) of FIG. 8 is a figure which shows the comparison of the refractive index distribution of a step index type optical fiber and a graded index type optical fiber. The vertical axis represents the refractive index, and the horizontal axis represents the position in the cross section of the optical fiber. The range indicated by the arrow is the range corresponding to the core. In the step index type, the refractive index changes stepwise between the clad and the core. On the other hand, in the graded index type, the refractive index of the core changes continuously and the refractive index at the center of the core is high.

  FIG. 8B is a diagram showing a comparison of light intensity distributions between the step index type optical fiber and the graded index type optical fiber. The vertical axis represents the light intensity distribution at the exit end face of the optical fiber, and the horizontal axis represents the position in the cross section of the optical fiber, as in FIG. In the step index type, the light intensity distribution is uniform on the exit end face of the core. On the other hand, the graded index type reflects the refractive index distribution, and the light intensity distribution at the center of the core is increased.

  By employing a graded index optical fiber, the light intensity at the center of the rectangular beam emitted from the optical fiber can be further increased.

[Embodiment 5]
Still another embodiment of the present invention will be described. For convenience of explanation, members having the same functions as those described in the above embodiment are denoted by the same reference numerals and description thereof is omitted. In the present embodiment, a multi-core optical fiber 30c is used instead of the optical fiber 30 of the first embodiment.

  (A) of FIG. 9 is a figure which shows the mode of the incident end surface seen from the incident direction of the optical fiber 30c in this embodiment. In the present embodiment, the optical fiber 30c has a plurality (two) of rectangular cores 31c and 31d. The longitudinal direction of the core 31c and the longitudinal direction of the core 31d are aligned. Among the plurality of light spots SP corresponding to the plurality of semiconductor laser elements 11, some of the light spots SP are disposed in the core 31c, and the other light spots SP are disposed in the core 31d. In at least one core 31d, a plurality of light spots SP are arranged, and the long axes of the plurality of light spots SP are aligned with one side (longitudinal direction) of the core 31d, respectively. Further, the major axis direction of the light spot SP arranged in the core 31d is aligned with the major axis direction of the light spot SP arranged in the core 31c. Similar to the above-described embodiment, the loss of the incident laser light can be reduced by arranging the light spot SP in this way.

  FIG. 9B is a diagram showing a state (cross section) of the emission end face when viewing the emission direction of the optical fiber 30c in the present embodiment. The laser beams introduced into the cores 31c and 31d are respectively emitted from the entire cores 31c and 31d at the emission end. Therefore, the beam shape of the laser light emitted from the optical fiber 30c is the same shape as the core 31c and the core 31d.

  FIG. 9C is a view showing the fluorescent member 40 irradiated with laser light from the optical fiber. The laser beams emitted from the core 31c and the core 31d of the optical fiber 30c are applied to the region 41c and the region 41d of the fluorescent member 40, respectively. The regions 41c and 41d of the fluorescent member 40 are excited by the laser light and emit white light. Since the shape of the beam emitted from the optical fiber 30c is the same as the shape of the cores 31c and 31d, the regions 41c and 41d that emit light in the fluorescent member 40 are also the same as the shapes of the cores 31c and 31d.

  According to this embodiment, it is possible to emit light having different characteristics (for example, light intensity) from the core 31c and the core 31d at the emission end of the optical fiber. Thereby, it is possible to emit light with different light intensity for each of the regions 41 c and 41 d of the single fluorescent member 40. That is, a plurality of phosphor excitation light sources can be obtained while using a single fluorescent member 40. By using such a plurality of light sources, the degree of freedom of design for obtaining a desired irradiation pattern in the lighting device is dramatically increased. For example, the light emitting regions 41c and 41d of the fluorescent member 40 can be used separately as a low beam and a high beam of an automobile headlight, respectively. Further, in order to dynamically control the light distribution direction of the low beam (or high beam), the plurality of light emitting regions 41c and 41d can be used by turning them on / off.

  Further, by using different semiconductor laser elements 11 corresponding to the plurality of cores 31c and 31d, it is possible to emit light of different colors for each core. Thereby, it is possible to emit light of different colors for each of the regions 41 c and 41 d of the single fluorescent member 40.

  FIG. 10 is a cross-sectional view comparing an optical fiber having a rectangular core and an optical fiber having a circular core. When a multi-core type optical fiber is used as in this embodiment, the optical fiber 35 having a plurality of rectangular cores 31c to 31e like the optical fiber 30e is more than the optical fiber 35 having a plurality of circular cores 36a and 36b. Also, the core can be densely arranged. As compared with the circular core, the rectangular core can arrange more cores in the optical fiber, or the area of the core can be widened even if the number of cores is the same. Thereby, condensing efficiency can be improved.

[Embodiment 6]
Still another embodiment of the present invention will be described. For convenience of explanation, members having the same functions as those described in the above embodiment are denoted by the same reference numerals and description thereof is omitted. In the present embodiment, a multi-core optical fiber 30f or an optical fiber 30g is used instead of the optical fiber 30 of the first embodiment.

  (A) of FIG. 11 is a figure which shows the mode of the incident end surface seen from the incident direction of the optical fiber 30f in this embodiment. The optical fiber 30f has a rectangular core 31f and a circular core 31h. Among the plurality of light spots SP corresponding to the plurality of semiconductor laser elements 11, some of the light spots SP are arranged in the core 31f, and the other light spots SP are arranged in the core 31h. In the rectangular core 31f, the plurality of light spots SP are arranged so as to overlap each other, and the long axes of the plurality of light spots SP are aligned with one side (longitudinal direction) of the core 31f, respectively. Thus, a part of the plurality of cores of the optical fiber 30f may be circular.

  FIG. 11C is a diagram showing the fluorescent member 40 irradiated with laser light from the optical fiber 30f. The laser beams emitted from the core 31f and the core 31h of the optical fiber 30f are applied to the region 41f and the region 41h of the fluorescent member 40, respectively. The regions 41f and 41h of the fluorescent member 40 are excited by the laser light and emit white light. Since the shape of the beam emitted from the optical fiber 30f is the same as the shape of the cores 31f and 31h, the regions 41f and 41h that emit light in the fluorescent member 40 are also the same as the shapes of the cores 31f and 31h.

  (B) of FIG. 11 is a figure which shows the mode of the incident end surface seen from the incident direction of the optical fiber 30g in this embodiment. The optical fiber 30g includes a rectangular core 31g that is partially cut off, such as the core 31b of the third embodiment, and a circular core 31h. Among the plurality of light spots SP corresponding to the plurality of semiconductor laser elements 11, some of the light spots SP are disposed in the core 31g, and the other light spots SP are disposed in the core 31h. In the core 31g, the plurality of light spots SP are arranged so as to overlap each other, and the long axes of the plurality of light spots SP are aligned with one side (longitudinal direction) of the core 31g, respectively.

  FIG. 11D shows the fluorescent member 40 irradiated with laser light from the optical fiber 30g. Laser light emitted from the core 31g and the core 31h of the optical fiber 30g is applied to the region 41g and the region 41h of the fluorescent member 40, respectively. The regions 41g and 41h of the fluorescent member 40 are excited by laser light and emit white light. Since the shape of the beam emitted from the optical fiber 30g is the same as the shape of the cores 31g and 31h, the regions 41g and 41h that emit light in the fluorescent member 40 are also the same as the shapes of the cores 31g and 31h.

  In this manner, by combining the rectangular cores 31f and 31g and the circular core 31h having different shapes, light emitting regions 41f, 41g, and 41h having different shapes are generated on the single fluorescent member 40. Can do. Similar to the above-described embodiment, by arranging the light spot SP on the rectangular core in this way, it is possible to reduce the loss of the incident laser light. Note that the number of the semiconductor laser elements 11 that enter the laser beam into the core may be changed for each core. According to this embodiment, it is possible to more easily control light distribution for obtaining a desired irradiation pattern, and the degree of freedom of the shape of the irradiation pattern is increased.

  In the above embodiments, the edge-emitting laser has been described as an example of the light source, but a surface-emitting semiconductor laser or a light-emitting diode may be used as the light source. When a surface emitting semiconductor laser or LED is used, if the light emission region has a shape having a long axis (rectangular or elliptical), the light spot imaged on the incident end face of the optical fiber is also rectangular or elliptical. It becomes the shape. Then, by arranging the long axes (longitudinal directions) of a plurality of rectangular or elliptical light spots so as to be aligned with one side of the rectangular core of the optical fiber, the incident laser light is incident as in the above-described embodiment. Loss can be reduced.

[Summary]
An optical device (1) according to an aspect 1 of the present invention includes a light guide member (11) having a plurality of semiconductor laser elements that emit laser light and a light guide unit (cores 31 to 31g) that guides the laser light. An optical fiber 30 to 30 g), and an imaging unit (20) that forms an image of the laser beams of the plurality of semiconductor laser elements on the incident end surface of the single light guide unit, and the outer shape of the incident end surface is A plurality of images formed on the incident end surface, the first side defining the width of the light guide section and the second side defining the height of the light guide section, corresponding to the plurality of semiconductor laser elements. The major axis directions of the spots (light spots SP) are aligned with each other, and the major axis directions of the plurality of spots are aligned with the first side or the second side of the incident end face.

  According to said structure, since the direction of the major axis of a some spot is aligned with the 1st edge | side or 2nd edge | side which prescribes | regulates the width | variety or height of the incident end surface of a light guide part, it injects into a light guide part. Loss of laser light can be reduced. Moreover, even when vibration occurs in the optical device, the incident efficiency can be kept high. By arranging the spots in this way, it is possible to reduce the size of the light guide section while maintaining high incidence efficiency. Therefore, a beam with a higher light density can be obtained from the exit end of the light guide.

  In the optical device according to aspect 2 of the present invention, in the aspect 1, the first side is longer than the second side, and the direction of the major axis of the plurality of spots is aligned with the first side. There may be.

  According to said structure, since the direction of the long axis of a spot is aligned with the 1st edge | side along the longitudinal direction of a light guide part, incident efficiency can be made still higher.

  In the optical device according to aspect 3 of the present invention, in the aspect 1, the direction in which the cladding layer and the active layer of each semiconductor laser element are stacked is aligned with respect to either the first side or the second side. It may be a configuration.

  In a normal semiconductor laser element, the light emission region is short in the direction in which the cladding layer and the active layer are stacked and long in the direction perpendicular thereto. Then, the spot imaged on the incident end face of the light guide portion has a shape corresponding to the light emission region. Therefore, according to the above configuration, the major axis direction of the plurality of spots is aligned with the first side or the second side of the light guide unit, so that loss of laser light incident on the light guide unit can be reduced. it can.

  In the optical device according to Aspect 4 of the present invention, in Aspect 2, the direction in which the cladding layer and the active layer of each semiconductor laser element are stacked may be aligned with the second side.

  According to said structure, the direction of the short axis of a some spot will align with the 2nd side which is the transversal direction of a light guide part. Therefore, the incident efficiency can be further increased.

  The optical device according to aspect 5 of the present invention is the support for fixing the plurality of semiconductor laser elements in the above aspects 1 to 4, so that the directions in which the cladding layers and the active layers of the plurality of semiconductor laser elements are stacked are aligned with each other. The structure provided with a part may be sufficient.

  According to said structure, the direction of the long axis of the several spot imaged on the incident end surface can be arrange | positioned easily mutually.

  In the optical device according to aspect 6 of the present invention, in the above aspect 2 or 4, the distance between the spot in the minor axis direction of each spot and the closest side of the light guide unit is the distance between the spot in the major axis direction and the above-described distance. The structure may be larger than the distance from the nearest side of the light guide.

  According to said structure, even if a vibration arises in an optical apparatus, the loss of the laser beam which injects into a light guide part can be suppressed.

  The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope shown in the claims, and embodiments obtained by appropriately combining technical means disclosed in different embodiments. Is also included in the technical scope of the present invention. Furthermore, a new technical feature can be formed by combining the technical means disclosed in each embodiment.

  The present invention can be used for an optical device, a lighting device, and the like.

DESCRIPTION OF SYMBOLS 1 Optical apparatus 10 Light-emitting part 11 Semiconductor laser element 12 Stem 13 Support member (support part)
20 Imaging part 21 Collimating lens 22 Condensing lens 30-30g Optical fiber (light guide member)
31-31h Core (light guide part)
32 clad 40 fluorescent member

Claims (3)

A plurality of semiconductor laser elements emitting laser light;
A light guide member having a light guide portion for guiding the laser light;
An image forming unit that forms an image of the laser beams of the plurality of semiconductor laser elements on an incident end face of the single light guide unit;
The outer shape of the incident end surface has a first side that defines the width of the light guide unit and a second side that defines the height of the light guide unit,
The directions of the major axes of the plurality of spots imaged on the incident end face corresponding to the plurality of semiconductor laser elements are aligned with each other,
The first side is longer than the second side, and the direction of the major axis of the plurality of spots is aligned with the first side of the incident end surface,
The optical device according to claim 1, wherein the plurality of spots on the incident end face are separated from each other. The optical apparatus according to claim 1 , wherein a direction in which a cladding layer and an active layer of each semiconductor laser element are stacked is aligned with the second side. As the direction in which the cladding layer and the active layer of the plurality of semiconductor laser elements are stacked are aligned with each other, the optical device according to claim 1 or 2, characterized in that it comprises a supporting portion for fixing said plurality of semiconductor laser elements .

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