JP7104356B2 - Semiconductor laser device - Google Patents

Description

The present disclosure relates to a semiconductor laser device.

Conventionally, in a device requiring a high-luminance light source, a light source device including a light emitting diode, a semiconductor laser element, or the like has been developed in place of the discharge lamp.
For example, a light source device including a plurality of semiconductor laser elements has been proposed for projector applications or in-vehicle headlight applications (Patent Documents 1, 2, etc.).

Japanese Unexamined Patent Publication No. 2015-22955 Japanese Unexamined Patent Publication No. 2005-30954

In order to obtain light of a desired wavelength corresponding to the above-mentioned application, a method of condensing the emitted light of the semiconductor laser element and irradiating the phosphor with excitation may be adopted, but the condensing spot of the semiconductor laser element may be adopted. Since the intensity distribution of the laser is a single peak type, when a plurality of spots are overlapped at the same position, the light density at the center of the spot becomes high and the excitation efficiency of the phosphor may decrease.
Under such circumstances, there is an eager desire to develop a light source device that can obtain satisfactory performance according to the application even when a plurality of semiconductor laser elements are used.
The present disclosure has been made in view of the above problems, and in particular, when a plurality of high-power semiconductor laser elements are mounted, a semiconductor laser device capable of alleviating the difference in light intensity in the light intensity distribution of the focused spot is provided. The purpose is to provide.

The present disclosure includes the following inventions.
(1) With the substrate
A pair of semiconductor laser devices mounted on the upper surface of the substrate, one of which emits light in the first direction and the other of which emits light in the direction opposite to the first direction.
A pair of reflective members mounted on the upper surface of the substrate and reflecting light from the pair of semiconductor laser elements upward.
By irradiating the pair of light reflected by the pair of reflecting members from below, a pair of spots shorter in the direction perpendicular to the second direction than in the second direction are formed on the lower surface thereof. A semiconductor laser device including a member
When viewed from above, the optical waveguide region of the pair of semiconductor laser elements is displaced, the pair of spots formed on the lower surface of the wavelength conversion member partially overlap, and the entire pair of spots is the second. A semiconductor laser device characterized in that the direction perpendicular to the second direction is shorter than the direction.
The present disclosure also includes the following semiconductor laser device.
(2) With the substrate
A plurality of semiconductor laser devices including a pair of semiconductor laser devices placed on the upper surface of the substrate and arranged so as to face each other.
A plurality of optical components mounted on the upper surface of the substrate and including a pair of optical components that convert light emitted from the pair of semiconductor laser elements into parallel light, and a plurality of optical components.
A plurality of reflective members mounted on the upper surface of the substrate and including a pair of reflective members that upwardly reflect light from the pair of optical components.
A semiconductor laser device including a wavelength conversion member in which a pair of spots having a major axis and a minor axis are formed on the lower surface thereof by irradiating a pair of light reflected by the pair of reflective members from below. ,
When viewed from above, the optical waveguide regions of the pair of semiconductor laser devices are displaced so that the pair of spots formed on the lower surface of the wavelength conversion member partially overlap and their long axes are parallel to each other. A semiconductor laser device characterized by this.
(3) With the substrate
A plurality of semiconductor laser devices including a pair of semiconductor laser devices placed on the upper surface of the substrate and arranged so as to face each other.
A plurality of optical components mounted on the upper surface of the substrate and including a pair of optical components that convert light emitted from the pair of semiconductor laser elements into parallel light, and a plurality of optical components.
A plurality of reflective members mounted on the upper surface of the substrate and including a pair of reflective members that upwardly reflect light from the pair of optical components.
A semiconductor laser device including a wavelength conversion member in which a pair of spots having a major axis and a minor axis are formed on the lower surface thereof by irradiating a pair of light reflected by the pair of reflective members from below. ,
Since both the pair of semiconductor laser elements and the pair of reflective members are tilted with respect to the main region of the upper surface of the substrate, a pair of spots formed on the lower surface of the wavelength conversion member when viewed from above A semiconductor laser device characterized in that it partially overlaps and its long axes are parallel to each other.

According to the present disclosure, it is possible to provide a semiconductor laser device capable of relaxing the intensity distribution of focused spots when a plurality of high-power semiconductor laser elements are mounted.

It is a schematic perspective view which shows the structure of the semiconductor laser apparatus of one Embodiment of this invention. It is a partially enlarged perspective view of the semiconductor laser apparatus of FIG. 1A. It is a partially enlarged plan view of the semiconductor laser apparatus of FIG. 1A. It is a side view of a pair of semiconductor laser elements and the like in the semiconductor laser apparatus of FIG. 1A. It is a schematic diagram which shows the spot of the lower surface of the wavelength conversion member in the semiconductor laser apparatus of FIG. 1A. It is a schematic partial enlarged plan view which shows the structure of the semiconductor laser apparatus of another embodiment of this invention. It is a schematic partial enlarged view of the semiconductor laser element seen from the direction facing the light emitting end face of the semiconductor laser element in the semiconductor laser apparatus of FIG. 2A. It is a figure which shows the shape of the condensing spot which is incident on the lower surface of the wavelength conversion member of the semiconductor laser apparatus of this invention. It is a graph which shows the light intensity of the plane perpendicular to the X-axis and Y-axis of the semiconductor laser apparatus of one Example of this invention and the comparative example, respectively.

The semiconductor laser device described below is for embodying the technical idea of the present invention, and the present invention is not limited to the following. In addition, the size and positional relationship of the members shown in the drawings may be exaggerated in order to clarify the explanation.
In the present application, the surface side from which light is extracted from the semiconductor laser device is referred to as an upper side.

Embodiment 1
As shown in FIGS. 1A to 1D, the semiconductor laser device 10 of the first embodiment includes a substrate 11, a plurality of semiconductor laser elements 12 having an optical waveguide region, a plurality of optical components 13, and a plurality of reflecting members 14. And a wavelength conversion member 15.
In the semiconductor laser device 10, at least a pair of semiconductor laser elements are arranged so that their optical waveguide regions are offset from each other when viewed from above, and a pair of spots formed on the lower surface of the wavelength conversion member partially overlap. And the long axes of the light forming the spot are parallel to each other.
With such a configuration, the intensity distribution of the spots focused on the lower surface of the wavelength conversion member can be relaxed, and the excitation efficiency of light in the wavelength conversion member can be improved.

(Hypokeimenon 11)
The substrate 11 mounts the semiconductor laser element 12. Further, the semiconductor laser element 12 may be used to electrically connect the semiconductor laser element 12 to the wiring or the like. Therefore, the material and shape on which the semiconductor laser device can be mounted are selected. For example, the substrate 11 can be formed of metal, glass, ceramics, or the like. In particular, in consideration of the corrosion resistance and heat dissipation of the substrate 11, a metal containing copper, a copper alloy, iron or an iron alloy or the like, or a ceramic containing aluminum nitride or aluminum oxide can be mentioned. Of these, aluminum nitride is preferable because it has excellent corrosion resistance and heat dissipation. Examples of the planar shape of the substrate 11 include various shapes such as a substantially circular shape, a substantially elliptical shape, and a substantially polygonal shape, and a substantially rectangular shape is preferable. The planar shape refers to the outer shape of the substrate 11 when viewed from above.

The substrate 11 may have a flat plate shape, but as shown in FIG. 1A, it preferably has the shape of a housing that opens upward. A lid body provided with a wavelength conversion member 15 is fixed to the upper surface of the housing. It is preferable that the upper surface 11A of the substrate within the opening is flat because the semiconductor laser element 12, the optical component 13, the reflecting member 14, and the like are arranged. The housing constituting the substrate 11 may not only have a flat surface but also have one or more steps, irregularities, etc. for arranging the wiring layer. It is preferable that the upper surface 11A of the substrate 11 and the lower surface facing the substrate 11 are flat and parallel to each other. As a result, when the semiconductor laser element is arranged on the substrate 11, it is possible to facilitate alignment with other members described later, and it is possible to extract light upward with high accuracy.

The substrate 11 preferably has a wiring layer, external electrodes, and the like on its surface, inside, and the like. The wiring layer can be formed of, for example, a single layer or a plurality of layers consisting of one or more of copper, gold, silver, aluminum, titanium, platinum, nickel, palladium or an alloy thereof. The external electrode can be formed of, for example, a single layer or a plurality of layers consisting of one or more of copper, gold, silver, aluminum, titanium, platinum, nickel, palladium or an alloy thereof. If the external electrode is made of the same material as the wiring layer, it can be formed in the same process.

(Semiconductor laser element 12)
The semiconductor laser element 12 includes a pair of semiconductor laser elements, for example, semiconductor laser elements 12A and 12B, which are placed on the upper surface of the substrate 11 and arranged at least facing each other when viewed from above. It is preferable that a plurality of semiconductor laser elements 12 are included so as to form a plurality of pairs. For example, the number of semiconductor laser elements 12 is preferably two, four, six, eight, etc. in one semiconductor laser device.
When a plurality of semiconductor laser elements 12 are placed on the upper surface of the substrate 11, their arrangement is preferably arranged radially and evenly at an arbitrary point, for example. Specifically, it is preferable that the semiconductor laser elements are arranged at the vertices of a square, a regular hexagon, and a regular octagon centered on an arbitrary point. With such an arrangement, the semiconductor laser elements can be arranged apart from each other at an equal distance from any point and even between adjacent semiconductor laser elements.

When four pairs of semiconductor laser element 12 are arranged, as shown in FIG. 1C, eight semiconductor laser elements 12A to 12H are opposed to each other at each apex of a regular octagon centered on an arbitrary point. That is, the semiconductor laser elements 12A and 12B, the semiconductor laser elements 12C and 12D, the semiconductor laser elements 12E and 12F, and the semiconductor laser elements 12G and 12H can be arranged so as to face each other. Then, in each of these pairs of semiconductor laser devices, their optical waveguide regions face each other in a state of being displaced from each other.
By arranging in this way, thermal interference with adjacent semiconductor laser elements can be reduced, and good heat dissipation can be ensured. As a result, a high-luminance output can be obtained.

When two pairs of semiconductor laser elements 12A and 12B and semiconductor laser elements 12C and 12D are arranged, the semiconductor laser elements of each pair are optical of the opposing semiconductor laser elements in the vicinity of two diagonal lines intersecting at 90 degrees. It is preferable that the waveguide regions are arranged at equal distances from the center in a state of being offset from each other.
When three pairs of semiconductor laser elements 12A and 12B, semiconductor laser elements 12C and 12D, and semiconductor laser elements 12E and 12F are arranged, the respective pairs of semiconductor laser elements face each other in the vicinity of three diagonal lines intersecting at 60 degrees. It is preferable that the optical waveguide regions of the semiconductor laser element are arranged at equal distances from the center in a state of being offset from each other.
When four pairs of semiconductor laser elements 12A and 12B, semiconductor laser elements 12C and 12D, semiconductor laser elements 12E and 12F, and semiconductor laser elements 12G and 12H are arranged, the semiconductor laser elements of each pair intersect at 45 degrees 2 It is preferable that the optical waveguide regions of the semiconductor laser elements facing each other are arranged at equal distances from the center in the vicinity of the two diagonal lines in a state of being offset from each other.
By arranging in this way, it is possible to easily realize a configuration in which the light that hits the phosphor is shifted.

Conventionally, when a plurality of semiconductor laser elements are used to obtain a high-luminance light source, the semiconductor laser elements have to be densely arranged, for example, in a matrix. Therefore, the temperature of the semiconductor laser element and the substrate became high, and various heat dissipation measures were taken, but sufficient heat dissipation measures could not be taken. On the other hand, the arrangement described above can improve the heat dissipation, and as a result, sufficient brightness can be realized by the plurality of semiconductor laser elements.

The semiconductor laser device 12 includes, for example, a semiconductor layer such as a nitride semiconductor (mainly represented by the general formula In _x Aly Ga _{1-xy N} , 0 ≦ x, 0 ≦ y, x + y ≦ 1), and has light. An optical waveguide region, which is a region for resonating the above, is provided inside. For example, known forms such as those having a ridge on the surface of the semiconductor layer and those having a current blocking region are included. By adjusting the composition of the nitride semiconductor, the oscillation wavelength of the semiconductor laser device 12 can be adjusted. For example, a semiconductor laser device having an oscillation wavelength in the range of 400 to 530 nm can be used. For example, when combined with a YAG-based phosphor, the semiconductor laser device 12 having an oscillation wavelength in the range of 420 to 490 nm is preferable. The plurality of semiconductor laser elements 12 may have some or all different oscillation wavelengths, but it is preferable that all the semiconductor laser elements have the same oscillation wavelength.
The semiconductor laser device 12 may emit either single-mode or multi-mode light, and the spot of light emitted from the light emitting end face may have a major axis and a minor axis. ..

It is preferable that the semiconductor laser element 12 is arranged so that the oscillation surface of the laser light, in other words, the light emitting end surface is perpendicular to the upper surface of the substrate 11. The vertical here means that an inclination of about ± 10 degrees is allowed. Then, at least a pair of semiconductor laser elements 12 are arranged so as to face each other with their optical waveguide regions displaced when viewed from above. Further, when a pair or more of semiconductor laser elements 12 are arranged, the semiconductor laser elements 12 of each pair are also arranged so as to face each other in a state where their optical waveguide regions are displaced when viewed from above. It is preferable to have.

Here, the fact that the optical waveguide regions of the pair of semiconductor laser elements are arranged so as to be offset means that, for example, in the semiconductor laser element 12A and the semiconductor laser element 12B, the light emitting end faces are opposed to each other and arranged in parallel with each other. As shown in FIG. 1C, when viewed from above, it means that all the extension regions extending the optical waveguide region in each pair do not overlap. In other words, it is an extension region extending the optical waveguide region of the pair of semiconductor laser elements, and is described as a line passing through the central portion in the extension direction when viewed from above (hereinafter, simply referred to as "extension line of the optical waveguide region"). However, it means that the semiconductor laser elements are arranged so as not to overlap and to be parallel.

The degree of deviation of the optical waveguide region of the pair of semiconductor laser elements can be appropriately set depending on the characteristics of the semiconductor laser element used, the characteristics of the optical component and / or the reflecting member described later, their positions, and the like. For example, the degree of deviation of the optical waveguide region is such that the shortest distance between the extension lines of the optical waveguide region of a pair of semiconductor laser elements is 1.5 to 3 times the width of the semiconductor laser element when viewed from above. Can be done. Specifically, 0.2 to 4 mm can be mentioned.
Alternatively, the degree of deviation is set so that the pair of spots formed on the lower surface of the wavelength conversion member described later partially overlap and the long axes of the light forming the spots are parallel to each other. Is preferable.

The semiconductor laser element 12 may be arranged directly on the upper surface of the substrate 11, but it is preferably arranged on the upper surface via the submount 16. As a result, the light emitting end face of the semiconductor laser element 12 can be separated from the substrate 11, and the light from the semiconductor laser element 12 can be prevented from hitting the substrate 11. As the submount 16, for example, silicon carbide, aluminum nitride, or the like can be used. Even when the submount 16 is arranged, it is preferable that the semiconductor laser element 12 is mounted so that the emitted light travels in a direction substantially parallel to the upper surface of the substrate 11.
The shape of the submount can be appropriately set, and may be a lump shape such as a rectangular cuboid or a cube, or a shape in which a plurality of fins are arranged at arbitrary portions.

(Optical component 13)
The optical component 13 is a component that is placed on the upper surface of the substrate 11 and makes the light emitted from the semiconductor laser element 12 parallel light. Examples of the optical component 13 include a Galilean lens formed by combining a concave lens and a convex lens, a collimated lens such as a Keplerian lens formed by combining convex lenses, and the like.
The optical components 13 are preferably arranged on a one-to-one basis according to the number of semiconductor laser elements 12, but may be less than the number of semiconductor laser elements depending on the arrangement form of the semiconductor laser elements 12. The optical component 13 is preferably arranged on the upper surface of the substrate 11 at a position where light from the semiconductor laser element 12 can pass through.
As long as the optical component 13 is arranged between the semiconductor laser element 12 and the reflecting member 14, the distance from the semiconductor laser element 12 may be different in a part or all of the optical component 13, but the optical component 13 may be different. It is preferable that all of the above are arranged at the same distance from the semiconductor laser element 12.

For example, when such an optical component is not used, that is, when the light emitted from the semiconductor laser element 12 is not converted to parallel light, or when an optical component which is converted to parallel light is arranged outside the substrate 11, wavelength conversion is performed. There is a problem that the size of the spot that collects light on the member becomes large, which causes the optical system in the subsequent stage to become large and reduces the efficiency of light utilization.
On the other hand, since the optical component 13 for parallel light is arranged on the substrate 11 in the vicinity of the semiconductor laser element 12, the focused spot can have a small diameter. Therefore, a spot having a small diameter can be formed on the wavelength conversion member described later, and the phosphor in the wavelength conversion member can be efficiently excited. As a result, the emission point having the highest intensity of the luminous flux after wavelength conversion can be set to a small diameter. As a result, the efficiency of light utilization can be improved. For example, when used for projector applications, the etendum can be reduced, and the optical system used in the subsequent stage of the semiconductor laser device can be reduced in size. In addition, when used for in-vehicle headlights, the diameter of the light emitting point can be reduced to reduce the size of optical components such as lenses and reflectors, enabling compact, lightweight, and thin headlights, improving the degree of freedom in design. Can be done.

(Reflective member 14)
The reflective member 14 is placed on the upper surface of the substrate 11 and is a member that upwardly reflects the light that has passed through the optical component 13, and is arranged at a position that can reflect the light that has passed through the optical component 13. The reflective member 14 has a reflective surface that is inclined with respect to the upper surface of the substrate 11, and the reflective surface is arranged so as to reflect light that has passed through the optical component 13 upward.
It is preferable that the reflecting member 14 is arranged so that its reflecting surface is located below the wavelength conversion member 15 described later. In particular, when viewed from above, it is preferable that the light reflected by the reflecting member 14 is arranged at a position where it can be incident on the lower surface of the wavelength conversion member 15 as the strongest reflected light. In other words, when viewed from above, the laser light is reflected on the reflecting surface of the reflecting member 14 on the extension line of the optical waveguide region, and substantially all of the reflected light is arranged so as to be incident on the wavelength conversion member 15. Is preferable. As described above, in the pair of semiconductor laser elements 12, the optical waveguide regions are arranged so as to be offset from each other, but the reflecting members corresponding to the pair of semiconductor laser elements 12 are semiconductors as long as the above-mentioned reflection is realized. Like the laser element, it may or may not be displaced when viewed from above.

As the reflective member 14, for example, a member provided with a reflective film on the slope of optical glass having a shape such as a triangular prism or a quadrangular pyramid can be used. The angle between the upper surface of the substrate 11 and the slope of the reflective member 14 is, for example, 60 degrees or less, preferably 50 degrees or less, and more preferably 45 degrees or less. Further, 20 degrees or more is mentioned, 30 degrees or more is preferable, and 35 degrees or more is more preferable. Here, the angle between the upper surface of the substrate 11 and the slope of the reflective member 14 refers to the angle formed by the region of the upper surface of the substrate 11 facing the lower surface of the reflective member 14 and the slope of the reflective member 14. For example, this angle refers to the angle β formed by the reflecting surface 14a of the reflecting member 14 shown in FIG. 1D and the upper surface 11A of the substrate 11.

The reflecting members 14 are preferably arranged on a one-to-one basis according to the number of semiconductor laser elements 12. In that case, it is preferable that the reflecting members 14 are arranged so as to face each of the semiconductor laser elements. However, it may be less than the number of semiconductor laser elements depending on the arrangement form of the semiconductor laser elements 12.

(Wavelength conversion member 15)
The wavelength conversion member 15 is a member that converts the wavelength of the laser light emitted from the semiconductor laser element 12, and the long axis and the short axis are generated by irradiating the pair of light reflected by the pair of reflecting members 14 from below. A pair of spots having shafts are arranged at positions formed on the lower surface thereof.

The wavelength conversion member 15 preferably contains a phosphor, and can be, for example, a sintered body obtained by sintering the phosphor itself, or a sintered body obtained by adding a sintering aid to the phosphor. ..
As the phosphor, it is preferable to select a material that can obtain white light in combination with the semiconductor laser device 12. For example, when blue light is emitted from the semiconductor laser element 12, a phosphor that emits yellow light using the emitted light of the semiconductor laser element 12 as excitation light can be used. Examples of the fluorescent substance that emits yellow light include a YAG-based fluorescent substance. Further, when light having a shorter wave than blue light (for example, ultraviolet light) is emitted from the semiconductor laser element 12, a phosphor that emits each of blue, green, and red colors can be used.

It is preferable that the wavelength conversion member 15 is arranged at an appropriate position as described above by the holding member. The holding member may function as, for example, a lid for the housing-shaped substrate 11. In FIG. 1A, the substrate 11 having the shape of a housing opened upward and the lid body provided with the wavelength conversion member 15 are separated from each other, but this is a diagram for explaining the inside of the housing and is an actual semiconductor. The laser device has a lid bonded to the upper surface of the housing. By using such a holding member, the wavelength conversion member 15 can be fixed in place with respect to the substrate 11, the semiconductor laser element 12, and the like. Further, the heat generated by the wavelength conversion member 15 can be efficiently dissipated through the holding member.

The wavelength conversion member 15 can take various shapes such as a substantially circular shape, a substantially elliptical shape, and a substantially polygonal shape when viewed from above. The size can be appropriately adjusted depending on the spot diameter irradiated to the wavelength conversion member 15. For example, one time or more, 1.5 times or more the maximum length of the spot diameter, and the like can be mentioned. The wavelength conversion member 15 preferably has a thickness such that all of the irradiated light is irradiated to the phosphor and can appropriately perform wavelength conversion, and examples thereof include 0.2 to 1 mm.

As described above, the spots of light emitted from the semiconductor laser device 12 are elliptical and have a major axis and a minor axis, respectively. Even if such light passes through the optical component or is further reflected by the reflecting member, the spot shape of the light having the long axis and the short axis is still maintained. Therefore, the spot formed on the lower surface of the wavelength conversion member of the light reflected by the reflection member and incident on the wavelength conversion member has a major axis and a minor axis. Since each spot having such a long axis and a short axis actually has a single peak type with a substantially Gaussian distribution in one spot, the light emitted from the plurality of semiconductor laser elements 12 can be emitted. Even when the light is focused, the intensity of the light is not uniform in the focused spot. Therefore, when such light is wavelength-converted by the wavelength conversion member, the excitation of the phosphor irradiated with the light becomes non-uniform, and the excitation efficiency of the phosphor may be reduced.

On the other hand, in the semiconductor laser apparatus of the present embodiment, in the wavelength conversion member 15, for example, as shown in FIG. 1E, the long axes LA and LB of the pair of spots 17A and 17B formed on the lower surface thereof are respectively. , They are not overlapped with each other, are parallel to each other, and the pair of spots 17A and 17B are offset so as to partially overlap each other. As a result, the intensity distribution of the light intensity can be relaxed in the focused spot, so that the excitation efficiency of the phosphor can be improved.
Further, the pair of spots 17A and 17B preferably have substantially the same shape and the same size on the lower surface of the wavelength conversion member 15, and all the spots have substantially the same shape and the same size. Is more preferable.
Further, the pair of spots 17A and 17B are preferably formed on the lower surface of the wavelength conversion member 15 so as to be translated in the direction of the minor axis S, and all of the spots are formed in the direction of the minor axis S, respectively. It is more preferable that they are formed as if they were translated.
Such a deviation may be caused as long as the pair of spots 17A and 17B do not completely overlap in the short axis S direction. For example, the distance D between the long axis LA and the long axis LB (distance between the long axis LA and LB) D) is 1/10 or more of the length of the minor axis S, preferably 1/4 or more, and more preferably 1/2 or more. Further, the pair of spots 17A and 17B may overlap in the minor axis S direction, but the distance D between the major axis LA and the major axis LB (distance D between the major axis LA and LB) is the length of the minor axis S. 9/10 or less, preferably 7/4/5, and more preferably 3/4 or less.
Specifically, the degree of deviation is 1/2 to 3/4 of the width of the spot in the minor axis direction, and depends on the NA of the condenser lens, but the width of the spot in the minor axis direction is, for example, 0. When it is 5 mm, the degree of deviation is exemplified by about 0.2 to 0.4 mm.
In the pair of spots 17A and 17B, the minor axes S are preferably parallel to each other, and it is more preferable that the pair of spots 17A and 17B are formed at the same position in the major axis direction. That is, it is more preferable that the minor axes S coincide with each other.
In the semiconductor laser apparatus having such a structure, the intensity distribution of the spots focused on the lower surface of the wavelength conversion member can be relaxed, and the excitation efficiency of light in the wavelength conversion member can be improved.

For example, when a pair of semiconductor laser elements 12A and 12B are used, light incident on the lower surface of the wavelength conversion member 15, and when two pairs of semiconductor laser elements 12A and 12B and semiconductor laser elements 12C and 12D are used, Light incident on the lower surface of the wavelength conversion member 14, when three pairs of semiconductor laser elements 12A and 12B, semiconductor laser elements 12C and 12D, and semiconductor laser elements 12E and 12F are used, the light is incident on the lower surface of the wavelength conversion member 14. Light, four pairs of semiconductor laser elements 12A, 12B, semiconductor laser elements 12C, 12D, semiconductor laser elements 12E, 12F, semiconductor laser elements 12G, 12H, light incident on the lower surface of the wavelength conversion member 14. Each has a spot shape shown in FIG.

Further, as an example, when a pair of semiconductor laser elements 12A and 12B are used, the direction parallel to the long axis of the focused spot is the X axis, and the direction perpendicular to the long axis (the direction parallel to the short axis) is Y. The light intensities of the planes perpendicular to the X-axis and the Y-axis as the axes are shown in FIGS. 4A and 4B, respectively.
As a comparative example with respect to this, the light intensities of the planes perpendicular to the X-axis and the Y-axis in the semiconductor laser apparatus in which the spots of the pair of semiconductor laser elements are overlapped at the same position are shown in FIGS. 4C and 4D, respectively.
In FIG. 4, the horizontal axis is the beam width, and the center is located at 0 degrees. The vertical axis is the light intensity, and the unit is arbitrary intensity. In FIG. 4, the dotted line is the intensity of one semiconductor laser element, and the solid line is the intensity when two semiconductor laser elements are used.
As can be seen from this result, in the example, the intensity of the light at the center of the focused spot is relaxed and the half width is widened in the direction perpendicular to the long axis (Y axis) as compared with the comparative example. The distribution can be relaxed. As a result, the excitation efficiency of light in the wavelength conversion member can be improved.

Embodiment 2
As shown in FIG. 2A, the semiconductor laser device 20 of the second embodiment has a substrate 21 and an optical waveguide region, and is mounted on the submount 26, similarly to the semiconductor laser device 10. It includes semiconductor laser elements 22A to 22H, a plurality of optical components 23, a plurality of reflecting members 24, and a wavelength conversion member arranged above the reflecting members 24. The relationship between the arrangement of one semiconductor laser element 22, the optical component 23 for passing the light emitted from the semiconductor laser element 22, and the reflecting member 24 for reflecting the light is the same as their arrangement in the first embodiment. It is substantially the same.
On the other hand, both the pair of semiconductor laser elements 22A and 22B and the pair of reflecting members 24 are arranged so as to be inclined with respect to the main region 21A on the upper surface of the substrate 21. Further, similarly to the semiconductor laser device 10, the pair of spots formed on the lower surface of the wavelength conversion member partially overlap each other, and the long axes of the light forming the spots are parallel to each other.
Here, the main region 21A on the upper surface of the substrate 21 is not an inclined surface 21C for arranging the semiconductor laser element 22 and the reflecting member 24 in an inclined manner, but a plurality of semiconductor laser elements 22A to 22H, an optical component 23, and the like. It means the original main surface of the base 21 for integrally holding the reflective member 24 and the like, and can be rephrased as, for example, a region parallel to the lower surface 21B of the base 21.

That is, the pair of semiconductor laser elements 22A and 22B are tilted to the same side when the semiconductor laser elements 22A and 22B are viewed from the direction facing the light emitting end faces 22a of the semiconductor laser elements 22A and 22B. Therefore, the reflecting member 24 is also tilted in the same manner as the semiconductor laser elements 22A and 22B.
In other words, when the extension lines of the respective optical waveguide regions of the pair of semiconductor laser elements 22 are used as axes, the axes of the pair of semiconductor laser elements 22 are arranged parallel to each other, but when the axes are matched. , The inclinations of the pair of semiconductor laser elements 22A and 22B are opposite to each other.

In other words, the semiconductor laser element 22 and the reflecting member 24 that reflects the light emitted from the semiconductor laser element 22 are formed on the substrate 11 so as to rotate around the extension line of the optical waveguide region of the semiconductor laser element 22. It is inclined with respect to the main region 21A on the upper surface of the.

As described above, the degree of inclination can realize a state in which a pair of spots formed on the lower surface of the wavelength conversion member partially overlap each other and the long axes of the light forming the spots are parallel to each other. As long as it can be done.
As shown in FIG. 2B, for example, when the semiconductor laser element 22 is viewed from the direction facing the light emitting end surface 22a of the semiconductor laser element 22, the inclination angle α of the semiconductor laser element 22 or the like is based on the main region 21A of the substrate 21. 10 degrees to 40 degrees, preferably 20 degrees to 30 degrees. When the main region 21A of the substrate 21 is a region parallel to the lower surface 21B, the lower surface 21B may be used as a reference, or the plane including the optical waveguide region of the semiconductor laser element 22 may be used as a reference. The degree of inclination is preferably the same for the pair of semiconductor laser elements 22A and 22B, and more preferably the same for all the semiconductor laser elements 22A to 22H.

Except for the above, it has substantially the same configuration as that of the first embodiment.
Even with such a configuration, the same effect as that of the first embodiment can be exhibited.

10, 20 Semiconductor laser device 11, 21 Base 11A Upper surface 21B Lower surface 12, 12A, 12B, 12C, 12D, 12E, 12F, 12G, 12H, 22, 22A, 22B, 22C, 22D, 22E, 22F, 22G, 22H Semiconductor Laser element 13, 23 Optical component 14, 24 Reflective member 15 Wavelength conversion member 16, 26 Submount 17A, 17B Spot 21A Main area 21C Inclined surface 22a Light emission end surface L Long axis S Short axis α Inclined angle

Claims (8)

With the base
A pair of semiconductor laser devices mounted on the upper surface of the substrate, one of which emits light in the first direction and the other of which emits light in the direction opposite to the first direction.
A pair of reflective members mounted on the upper surface of the substrate and reflecting light from the pair of semiconductor laser elements upward.
By irradiating the pair of light reflected by the pair of reflecting members from below, a pair of spots shorter in the direction perpendicular to the second direction than in the second direction are formed on the lower surface thereof. A semiconductor laser device including a member
When viewed from above, the optical waveguide regions of the pair of semiconductor laser devices are displaced, the pair of spots formed on the lower surface of the wavelength conversion member partially overlap, and the entire pair of spots is the second. The shape is shorter in the direction perpendicular to the second direction than in the direction .
The spot of light emitted from each of the pair of semiconductor laser devices is an ellipse having a major axis and a minor axis.
The second direction is a direction parallel to a straight line connecting the points where the light passing through both ends of the long axis of the elliptical light spot emitted from the semiconductor laser element irradiates the lower surface of the wavelength conversion member. A semiconductor laser device characterized by being. The semiconductor laser device according to claim 1, wherein the substrate has a wiring layer on its surface and is made of ceramic. The semiconductor laser device according to claim 1 or 2, wherein the substrate has a housing shape that opens upward. The semiconductor laser device according to any one of claims 1 to 3, wherein the wavelength conversion member is a sintered body containing a phosphor containing YAG. The semiconductor laser device according to any one of claims 1 to 4, wherein the pair of spots has substantially the same shape and the same size on the lower surface of the wavelength conversion member. Corresponding to each of the pair of semiconductor laser elements, the light emitted from the semiconductor laser element is arranged between the semiconductor laser element and the reflecting member that reflects the light emitted from the semiconductor laser element. The semiconductor laser apparatus according to any one of claims 1 to 5, further comprising a pair of optical components through which the laser passes. The invention according to any one of claims 1 to 6, wherein each of the pair of spots has an elliptical shape with the second direction as the major axis and the direction perpendicular to the second direction as the minor axis. Semiconductor laser device. The semiconductor laser apparatus according to any one of claims 1 to 7 , further comprising a plurality of semiconductor laser elements including the pair of semiconductor laser elements.

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