Semiconductor laser device

Abstract

To provide a miniaturized semiconductor laser device.SOLUTION: A semiconductor laser device includes a light-emitting element that emits laser light, and a part of a paraboloid of revolution that reflects the laser light.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present disclosure relates to a semiconductor laser device. [Background technology]

[0002] In recent years, semiconductor laser devices have been developed, for example as disclosed in the following Patent Document 1. In general, a semiconductor laser device includes a light emitting element that emits laser light, a reflecting member that reflects the laser light, and a collimating lens that collimates the laser light. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2004-31708 A Summary of the Invention [Problem to be solved by the invention]

[0004] According to the above semiconductor laser device, two components, a reflecting member and a collimating lens, are required to form the laser light, which makes it difficult to further reduce the size of the semiconductor laser device.

[0005] The present disclosure has been made in consideration of the above-mentioned problems, and has an object to provide a miniaturized semiconductor laser device. [Means for solving the problem]

[0006] The semiconductor laser device of the present disclosure includes a light emitting element that emits laser light and a portion of a paraboloid of revolution that reflects the laser light. [Brief description of the drawings]

[0007] [Figure 1] 1 is a perspective view of a semiconductor laser device according to a first embodiment. [Diagram 2]1 is a plan view of a semiconductor laser device according to a first embodiment. [Diagram 3] FIG. 3 is a cross-sectional view taken along line III-III in FIG. [Figure 4] 2 is a bottom view of the semiconductor laser device of the first embodiment. FIG. [Diagram 5] FIG. 4 is a bottom view of a modified example of the semiconductor laser device of the first embodiment. [Figure 6] 4 is a cross-sectional view for illustrating the path of laser light emitted from a light-emitting element of the semiconductor laser device of the first embodiment and reflected by a part of a paraboloid of revolution. FIG. [Figure 7] 2 is an elevation view for explaining the path of laser light emitted from a light emitting element of the semiconductor laser device according to the first embodiment and reflected by a part of a paraboloid of revolution. FIG. [Figure 8] 4 is a cross-sectional view for illustrating a state in which a reflective film is provided on a part of the paraboloid of revolution of the semiconductor laser device according to the first embodiment. FIG. [Figure 9] FIG. 2 is a diagram for explaining a paraboloid of revolution. [Figure 10] 2 is a diagram for explaining a part of a paraboloid of revolution obtained by cutting the paraboloid of revolution along a first imaginary plane including an axis of symmetry. FIG. [Figure 11] FIG. 2 is a diagram for explaining a portion of a paraboloid of revolution in which the paraboloid of revolution is cut along a first imaginary plane that includes the axis of symmetry and is cut along a second imaginary plane that is perpendicular to the axis of symmetry. [Figure 12] 4 is a cross-sectional view of a modified example of the outer shell of the semiconductor laser device of the first embodiment. [Figure 13] 13 is a cross-sectional view of another modified example of the outer shell portion of the semiconductor laser device of the first embodiment. [Figure 14] 11 is a plan view of an outer shell portion of a semiconductor laser device according to a second embodiment. FIG. [Figure 15] 13 is a plan view of a modified outer shell portion of the semiconductor laser device according to the second embodiment. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, a semiconductor laser device according to an embodiment of the present disclosure will be described with reference to the drawings. In the drawings, the same or equivalent elements are designated by the same reference numerals, and redundant description of the same or equivalent elements will not be repeated.

[0009] (Embodiment 1) Fig. 1 is a perspective view of the semiconductor laser device 100 of the embodiment 1. Fig. 2 is a plan view of the semiconductor laser device 100 of the embodiment 1. Fig. 3 is a cross-sectional view taken along line III-III in Fig. 2. Fig. 4 is a bottom view of the semiconductor laser device 100 of the embodiment 1.

[0010] As can be seen from FIG. 1 to FIG. 4, the semiconductor laser device 100 includes a non-transparent outer shell part SH, a translucent sealing member SM, a plurality of substrates S called submounts, and a plurality of light-emitting elements LD. In this embodiment, the plurality of light-emitting elements LD are each made of a laser diode and mounted on the plurality of substrates S. This allows the positions of the light-emitting parts of the plurality of light-emitting elements LD to be adjusted. In order to improve heat dissipation, a metal pattern HS is provided on the outer shell part SH, and the substrate S is mounted on the metal pattern HS. The metal pattern HS may be a non-connected metal (for example, metal plating or AuSn vapor deposition) that is not connected to an external power source (not shown). It is not necessary to provide a metal pattern.

[0011] The substrate S is not an essential component and may not be provided. For example, the light-emitting elements LD may be directly mounted on the metal pattern HS on the outer shell part SH. The light-emitting elements LD may be provided in any manner within the space in the recess CC formed by the outer shell part SH and the transparent sealing member SM. The sealing member SM prevents dust and the like from adhering to the light-emitting elements LD and adsorbs siloxane contained in the air, thereby suppressing oscillation defects of the laser diode that constitutes the light-emitting elements LD.

[0012] In this embodiment, the number of light emitting elements LD is four, but may be one, two, three, or any number equal to or greater than five. In addition, the multiple light emitting elements LD do not need to have the same structure, and may have different structures.

[0013] The outer shell portion SH includes a bottom plate portion BP and a peripheral wall portion CW. The peripheral wall portion CW rises from the bottom plate portion BP. The bottom plate portion BP and the peripheral wall portion CW form a recess CC in the outer shell portion SH. In this embodiment, the outer shell portion SH is formed of one material. In other words, the bottom plate portion BP and the peripheral wall portion CW are integrally formed of the same material. The outer shell portion SH is preferably made of a material having high heat dissipation properties and high insulation properties, for example, a ceramic such as SiC or AlN.

[0014] However, the bottom plate portion BP and the peripheral wall portion CW may be formed of two different materials. In other words, the outer shell portion SH may be formed by combining two different materials. For example, the bottom plate portion BP may be made of ceramic such as SiC or AlN, while the peripheral wall portion CW may be made of a material with a relatively low thermal conductivity such as Al2O3. The peripheral wall portion CW may be made of a metal material with a relatively high thermal conductivity. However, in this case, it is preferable to prevent the bottom plate portion BP from cracking due to the difference in thermal expansion coefficient between the peripheral wall portion CW made of a metal material and the bottom plate portion BP made of ceramics.

[0015] The substrates S and the light-emitting elements LD are provided inside a recess CC. In a plan view, the recess CC has a circular bottom surface BS and an inner circumferential surface IC extending upward from the periphery of the bottom surface BS so as to surround the bottom surface BS. The bottom surface BS is a circular flat surface. The inner circumferential surface IC includes an upright surface RS extending away from the circular bottom surface BS, an inclined surface IS which is a part of the side surface of a cone, and a part PS of a paraboloid of revolution recessed from the inclined surface IS in a direction along the bottom surface BS.

[0016] Laser light emitted from the multiple light-emitting elements LD is reflected by the part PS of the paraboloid of revolution, passes through the transparent sealing member SM, and is emitted to the outside of the semiconductor laser device 100. The part PS of the paraboloid of revolution will be described in detail later.

[0017] The parts PS of the plurality of paraboloids of revolution may be arranged so as to be spaced at equal angles on the inner circumferential surface IC that is circular in plan view. That is, the plurality of light-emitting elements L can be arranged at intervals of 90° when the angle is obtained by dividing 360° by the number of the plurality of light-emitting elements L, for example, by 4. This is expected to have the effect of improving the symmetry of the light that passes through the light-transmitting sealing member SM and is emitted to the outside of the semiconductor laser device 100 with respect to the center line of the semiconductor laser device 100.

[0018] The bottom plate portion BP has a pair of through holes TH. The pair of through holes TH is blocked by a pair of conductive plugs P1, P2. A pair of electrodes AC is provided on the lower side surface LS of the bottom plate portion BP. The number of through holes TH is not limited to two, and three or more through holes TH may be provided in the bottom plate portion BP. If a large number of through holes TH are provided in the bottom surface portion BP, a large number of plugs can be provided. Therefore, the resistance value of the plug P to the current flowing into and flowing out of each light-emitting element LD can be reduced. A hermetic seal and a lead pin may be used instead of each of the pair of plugs P1, P2.

[0019] As can be seen from the above, the pair of electrodes AC are electrically connected to a pair of conductive plugs P1, P2, respectively. Each of the pair of plugs P1, P2 is formed of, for example, tungsten (W). The pair of electrodes AC consisting of the electrode A and the electrode C is electrically connected to the anode and the cathode of the light-emitting element LD, respectively. The electrodes A and C are fixed to the surface constituting the outer shell part SH on the opposite side to the surface on which the recess CC is provided, more specifically, to the lower surface of the outer shell part SH shown in FIG. 3. The electrodes A and C may be disposed in any manner with respect to the outer shell part SH, as long as the electrodes A and C are exposed to the external space of the outer shell part SH, i.e., the space other than the space in the recess CC.

[0020] A pair of conductive flat plates FP1 and FP2 electrically insulated from each other are provided on the inner surface of the bottom surface portion BP, i.e., on the bottom surface BS. The pair of flat plates FP1 and FP2 are electrically connected to both ends of a plurality of light-emitting elements LD connected in series by a plurality of electrical wirings W. Some of the plurality of electrical wirings W have one end connected to the light-emitting element LD and the other end connected to a wiring pattern (not shown) formed on the upper surface of the substrate S. The substrate S is made of a material such as AlN or SiC, and the wiring pattern on the substrate S is made of, for example, Ti / Pt / Au.

[0021] Each of the light-emitting elements LD may be connected in parallel to a pair of electrodes AC. In this case, it is possible to prevent a malfunction in which all of the light-emitting elements LD cannot emit light due to the disconnection of any of the electrical wirings W.

[0022] In this embodiment, the plurality of substrates S are provided on the plurality of metal patterns HS, respectively. Therefore, heat generated by the plurality of light-emitting elements LD is dissipated to the outside of the outer shell portion SH via the plurality of substrates S, the plurality of metal patterns HS, the bottom plate portion BP, and the pair of electrodes AC.

[0023] The inner peripheral surface IC includes a rising surface RS that extends away from the bottom surface BS of the recess CC. The rising surface RS is provided so as to avoid contact between the inner peripheral surface IC and the substrate S. In other words, the rising surface RS extends from the lower end of the inner peripheral surface IC that forms a conical surface almost perpendicular to the bottom surface BS. Therefore, the corners of the substrate S, which is rectangular in plan view, do not contact the lower end of the inner peripheral surface IC that forms a conical surface. Note that the tip of the part PS of the paraboloid of revolution, including the apex of the paraboloid of revolution, is cut along a virtual plane perpendicular to the axis of symmetry of the paraboloid of revolution. This will be described in detail later.

[0024] In this embodiment, the vertical surface RS is perpendicular to the bottom surface BS in a cross-sectional view and has the shape of a cylindrical peripheral surface. However, for example, when the outer shell portion SH is formed by mold molding, the diameter of the circle in the cross section may increase with increasing distance from the bottom surface BS from the viewpoint of ease of removing the mold for forming the recess CC.

[0025] The light-transmitting sealing member SM is a plate-like member, and is made of, for example, lid glass. The sealing member SM is provided with respect to the outer shell portion SH so as to contain the space inside the recess CC. The sealing member SM is fixed to the upper end of the peripheral wall portion CW. This seals the space containing the light-emitting element LD. For example, when the peripheral wall portion CW is made of ceramics, a metal pattern provided on the upper end surface of the peripheral wall portion CW and the lid glass constituting the sealing member SM are joined by soldering or eutectic. Also, for example, when the peripheral wall portion CW is made of metal, the lid glass constituting the sealing member SM is directly joined to the upper end surface of the peripheral wall portion CW.

[0026] FIG. 5 is a bottom view of a modification of the semiconductor laser device 100 according to the first embodiment.

[0027] As shown in Fig. 5, a heat sink NC that is not electrically connected to any of the light emitting elements LD may be provided between the electrodes A and C. In this way, the electrodes A and C that perform the function of electrical conduction are physically separated from the heat sink NC that performs the function of heat dissipation. This makes it possible to prevent the heat sink NC that performs the function of heat dissipation from adversely affecting the electrodes A and C that perform the function of electrical conduction. Note that, according to the structure shown in Fig. 4, the electrodes A and C also function as heat sinks that dissipate heat generated by the multiple light emitting elements LD to the outside.

[0028] Fig. 6 is a cross-sectional view for explaining the path of laser light L emitted by the light-emitting element LD of the semiconductor laser device 100 according to the first embodiment and reflected by the part PS of the paraboloid of revolution. Fig. 7 is an elevation view for explaining the path of laser light L emitted by the light-emitting element LD of the semiconductor laser device 100 according to the first embodiment and reflected by the part PS of the paraboloid of revolution.

[0029] As shown in FIG. 6 and FIG. 7, the semiconductor laser device 100 of this embodiment includes a light-emitting element LD and a part PS of a paraboloid of revolution. The light-emitting element LD emits a laser light L. In this embodiment, the laser light L emitted by each of the multiple light-emitting elements LD travels along the bottom surface BS of the recessed portion CC, is reflected by the part PS of the paraboloid of revolution, and then travels along a direction approximately perpendicular to the bottom surface BS of the recessed portion CC. Therefore, in this embodiment, the light-emitting element L and the part PS of the paraboloid of revolution are arranged so that the laser light L is directly irradiated from the light-emitting element L to the part PS of the paraboloid of revolution without being reflected by other members and without passing through other members. In addition, multiple light-emitting elements LD can be provided in the recessed portion CC, and multiple laser lights L can be emitted along the same direction. Therefore, the output of the semiconductor laser device 100 can be improved without increasing the size of the semiconductor laser device 100.

[0030] As can be seen from Figures 6 and 7, the laser light L reflected by the part PS of the paraboloid of revolution in this embodiment travels in one direction with almost the same width without becoming wider or narrower when viewed from any direction. More preferably, the laser light travels in one direction with the same width without becoming wider or narrower when viewed from any direction. This is because the light emitting part LE that emits the laser light L of the light emitting element LD is provided at a position that almost coincides with the focal point F of the paraboloid of revolution. However, as long as the requirements for the directivity of the laser light L required for the semiconductor laser device 100 are satisfied, the light emitting part LE that emits the laser light L of the light emitting element LD may be provided at a position slightly shifted from the focal point F of the paraboloid of revolution.

[0031] In this embodiment, the part P of the paraboloid of revolution functions as both a reflecting mirror and a collimator lens, which contributes to miniaturization of the semiconductor laser device 100. Also, compared to when the reflecting surface is a part of a sphere, the focal point is fixed to one, making it easier to form a parallel laser beam.

[0032] FIG. 8 is a cross-sectional view for illustrating a state in which a reflective film RF is provided on a part PS of the paraboloid of revolution of the semiconductor laser device 100 according to the first embodiment.

[0033] As shown in Fig. 8, in this embodiment, the reflective film RF is provided so as to cover the part PS of the paraboloid of revolution. The reflective film RF is provided along the surface of the part PS of the paraboloid of revolution. Therefore, the surface of the reflective film RF also has a shape that forms part of the paraboloid of revolution. Therefore, in the case of the structure shown in Fig. 8, the part PS of the paraboloid of revolution that reflects the laser light emitted by the light-emitting element LD is the surface of the reflective film RF. The reflectance of the laser light L at the reflective film RF is higher than the reflectance of the laser light L at the part PS of the paraboloid of revolution.

[0034] The reflective film RF is preferably a dielectric multilayer film, for example, a laminated film of SiO2 / TiO2. Depending on the combination of laminated layers of the dielectric multilayer film, a reflective film having a high reflectance in the wavelength range of the laser light L can be formed. In addition, the dielectric multilayer film is unlikely to undergo a change in composition due to irradiation with the laser light L, so it is unlikely to burn out. In addition, the reflective film RF may be a reflective mirror with a metal reflective film as an undercoat. Note that the reflective film RF is provided only on the part PS of the paraboloid of revolution, but it may be provided on the inner circumferential surface IC other than the part PS of the paraboloid of revolution. In addition, the reflective film PF may not be provided as long as the part PS of the paraboloid of revolution has a desired reflectance. In addition, the reflective film RF may cover the entire part PS of the paraboloid of revolution, or may cover only part of the part PS of the paraboloid of revolution.

[0035] Fig. 9 is a diagram for explaining the paraboloid of revolution RPS. Fig. 10 is a diagram for explaining a part PS of the paraboloid of revolution obtained by cutting the paraboloid of revolution RPS shown in Fig. 9 along a first imaginary plane VP1 including the symmetry axis SA. Fig. 11 is a diagram for explaining a part PS of the paraboloid of revolution obtained by cutting the paraboloid of revolution RPS along the first imaginary plane VP1 including the symmetry axis SA and along a second imaginary plane VP2 perpendicular to the symmetry axis V1.

[0036] The part PS of the paraboloid of revolution shown in Fig. 10 is one of two parts obtained by dividing the paraboloid of revolution RPS shown in Fig. 9 along a first imaginary plane VP1 including the symmetry axis SA of the paraboloid of revolution RPS. The part PS of the paraboloid of revolution shown in Fig. 11 has a shape in which a tip part including a vertex T of the paraboloid of revolution RPS of the part PS of the paraboloid of revolution shown in Fig. 10 is cut off along a second imaginary plane V2 perpendicular to the symmetry axis SA of the paraboloid of revolution RPS. Note that the part PS of the paraboloid of revolution in this embodiment is a curved surface cut off as a partial area of ​​any part inside the part PS of the paraboloid of revolution shown in Fig. 11.

[0037] In this embodiment, the multiple light-emitting elements LD and the multiple parts PS of the paraboloids of revolution are provided in a one-to-one relationship. However, it is not necessary to provide a light-emitting element that emits laser light L toward any of the multiple parts PS of the paraboloids of revolution. In other words, the number of the multiple light-emitting elements LD may be less than the number of the multiple parts PS of the paraboloids of revolution. This is to make it possible to adjust the number of light-emitting elements LD according to the intensity of the laser light L required for the semiconductor laser device 100.

[0038] Each of the portions PS of the multiple paraboloids of revolution reflects the laser light L. The paraboloid of revolution RPS is a curved surface that is traced by a path when a parabola is rotated around its central axis, the central axis being the axis of symmetry of the paraboloid. A cross section perpendicular to the central axis of the paraboloid of revolution RPS is a circle. The portions PS of the paraboloid of revolution in this embodiment are arc-shaped in any cross section perpendicular to the axis of symmetry of the paraboloid of revolution.

[0039] Each of the multiple light emitting elements LD is disposed so that the laser light L travels in a direction from the focal point F of the paraboloid of revolution RPS toward the part PS of the paraboloid of revolution. The focal point F of the paraboloid of revolution RPS is the focal point of all the parabolas constituting the paraboloid of revolution RPS, and preferably substantially coincides with the light emitting part LE where the laser light L reflected by the part PS of the paraboloid of revolution becomes substantially parallel light.

[0040] The light emitting element LD and the part PS of the paraboloid of revolution are arranged so that the laser light L reflected by the part PS of the paraboloid of revolution travels in one direction. This is because, in order for the semiconductor laser device 100 to emit highly directional laser light L, it is preferable that the light emitting element LD and the focal point F of the paraboloid of revolution RPS coincide with each other and the light reflected by the part PS of the paraboloid of revolution becomes parallel light.

[0041] However, in order for the laser light L reflected by the part PS of the paraboloid of revolution to travel in one direction, the light emitting element LD and the focal point F of the paraboloid of revolution RPS do not have to completely coincide. In other words, in order for the laser light L reflected by the part PS of the paraboloid of revolution to travel in one direction, the light emitting element LD and the focal point F of the paraboloid of revolution RPS may be slightly misaligned. In other words, the laser light L emitted by the semiconductor laser device 100 may be approximately such that the laser light L reflected by the part PS of the paraboloid of revolution can be considered to travel in one direction, depending on the performance required for the semiconductor laser device 100.

[0042] Each of the parts PS of the paraboloids of revolution is preferably arranged to reflect the laser light L along a predetermined direction. In other words, each of the parts PS of the paraboloids of revolution is preferably arranged to reflect the substantially parallel laser light L in a substantially parallel manner. However, the laser light L reflected by each of the parts PS of the paraboloids of revolution does not have to travel completely parallel as long as it has the desired performance. It is sufficient that the laser light L reflected by each of the parts PS of the paraboloids of revolution travels along a predetermined direction that is considered to be approximately the same direction. This allows the semiconductor laser device 100 to emit laser light L with high directivity.

[0043] The semiconductor laser device 100 has an outer shell portion SH having a recess CC formed by a bottom plate portion BP and a peripheral wall portion CW rising from the bottom plate portion BP. The light emitting element LD is provided in the space inside the recess CC. A part PS of the paraboloid of revolution is provided as a part of the inner peripheral surface IC of the recess CC. This eliminates the need to form the part PS of the paraboloid of revolution in a process separate from the process of forming the inner peripheral surface IC. In other words, the inner peripheral surface IC and the part PS of the paraboloid of revolution can be formed in the same process. This prevents the manufacturing process of the semiconductor laser device 100 from becoming complicated.

[0044] In addition, the bottom plate portion BP has a through hole TH, and the light emitting element LD and a pair of electrodes AC exposed to the outside of the outer shell portion SH are electrically connected via a pair of plugs P1, P2 in the through hole TH. This reduces the risk that the electrical path from the light emitting element LD to the pair of electrodes AC will impede the progress of the laser light L emitted from the light emitting element LD. This increases the degree of freedom in the installation position of the part PS of the paraboloid of revolution.

[0045] The inner peripheral surface IC includes an inclined surface IS in addition to the portion PS of the paraboloid of revolution. The inclined surface IS widens as it moves away from the base plate portion BP, i.e., the base portion BS. The inclined surface IS is a part of the surface obtained by cutting the peripheral surface of the cone along two imaginary planes perpendicular to the center line of the cone, and is the surface between the two imaginary planes excluding the portion PS of the paraboloid of revolution.

[0046] Fig. 12 is a cross-sectional view of a modified example of the outer shell portion SH of the semiconductor laser device of the first embodiment. The inner circumferential surface IC includes an inclined surface IS in addition to the part PS of the paraboloid of revolution. In Fig. 12, the angle between the inclined surface IS of the recess CC and the bottom surface BS of the recess CC (the angle of the part constituting the outer shell portion SH) is 90°.

[0047] 13 is a cross-sectional view of another modified example of the outer shell portion SH of the semiconductor laser device of the embodiment 1. The angle between the inclined surface IS of the recess CC and the bottom surface BS of the recess CC (the angle of the slit portion constituting the outer shell portion SH) is 45°.

[0048] In addition, in Figs. 12 and 13, the part PS of the paraboloid of revolution is a surface that includes the vertex T of the paraboloid of revolution RPS.

[0049] As shown in Figures 12 and 13, in the cross-sectional view of the recess CC, the angle between the inclined surface IS and the bottom surface BS is preferably 45° to 90°. If the angle between the inclined surface IS and the bottom surface BS is less than 45°, the surface on which the part PS of the paraboloid of revolution can be formed becomes narrow. On the other hand, if the angle between the inclined surface IS and the bottom surface BS is more than 90°, an overhanging structure is formed, making it impossible to remove the mold.

[0050] The outer shell portion SH may be formed by a layered structure using a 3D printer. According to these manufacturing methods, a part PS of a paraboloid of revolution consisting of a smooth curved surface can be formed. The outer shell portion SH is not limited to the manufacturing method of the present embodiment, and may be formed by any method such as die molding.

[0051] The light-emitting element LD may have two or more light emitting portions LE each emitting two or more laser beams L. A part PS of the paraboloid of revolution reflects each of the two or more laser beams L. For example, when the light-emitting element LD has two light-emitting points, one light-emitting element LD emits two laser beams L. A part PS of one paraboloid of revolution reflects two laser beams emitted from the light-emitting element LD having two light-emitting points. This makes it possible to increase the output of the semiconductor laser device 100 without increasing the number of light-emitting elements LD.

[0052] (Embodiment 2) A semiconductor laser device according to the second embodiment will be described. Note that, in the following, description of the same points as in the first embodiment will not be repeated. Semiconductor laser device 100 according to the present embodiment differs from semiconductor laser device 100 according to the first embodiment in the following points.

[0053] FIG. 14 is a plan view of the outer shell SH of the semiconductor laser device 100 of the second embodiment. As can be seen from FIG. 14, in this embodiment, the inclined surface IS is a part of the side surface of the pyramid. The inclined surface IS is a part of the surface cut along two imaginary planes perpendicular to the central axis of the pyramid, and is a surface obtained by removing a part PS of the paraboloid of revolution from the peripheral surface of the pyramid. The semiconductor laser device 100 having the inclined surface IS of the pyramid of this embodiment can also obtain an effect similar to that obtained by the semiconductor laser device 100 having the inclined surface IS of the cone of the first embodiment. In this embodiment, the bottom surface BS is square or rectangular.

[0054] Fig. 15 is a plan view of a modified example of the outer shell SH of the semiconductor laser device 100 of the second embodiment. As shown in Fig. 15, each plane constituting the inclined surface IS described above may have not only a portion PS of one paraboloid of revolution, but also a portion PS of a plurality of paraboloids of revolution. This also makes it possible to obtain an effect similar to that obtained by the semiconductor laser device 100 having the inclined surface IS of a part of a cone of the first embodiment.

[0055] In the present embodiment, similarly to the first embodiment, it is preferable that the angle between the inclined surface IS and the bottom surface BS in the cross-sectional view of the recess CC is 45° to 90°.

[0056] In this embodiment, the pyramid is a quadrangular pyramid, but may be any polygonal pyramid such as a triangular pyramid, a pentagonal pyramid, a hexagonal pyramid, an octagonal pyramid, a deca-pyramid, or a dodecagonal pyramid, etc. However, the polygonal pyramid is preferably a regular polygonal pyramid in which the sides of the base are the same length. [Explanation of symbols]

[0057] 100 Semiconductor laser device BP bottom plate part BS bottom CC recess CW peripheral wall IC inner surface IS slope L Laser light LD light emitting element LE light emitting part PS Part of a paraboloid of revolution RS standing surface SH Outer shell SM sealing material TH through hole

Claims

1. A light emitting element that emits laser light; A part of a paraboloid of revolution that reflects the laser light; An outer shell portion having a recess formed by a bottom plate portion and a peripheral wall portion rising from the bottom plate portion, The light emitting element is provided in the space inside the recess, A portion of the paraboloid of revolution is provided as a portion of an inner circumferential surface of the recess, The light emitting device further includes a substrate provided inside the recess and on which the light emitting element is mounted, the inner circumferential surface includes a rising surface extending in a direction away from a bottom surface of the recess so as to avoid contact between the inner circumferential surface and the substrate; Semiconductor laser device.

2. The light emitting element is disposed so that the laser light travels along a direction from a focus of the paraboloid of revolution to a part of the paraboloid of revolution.

2. The semiconductor laser device according to claim 1.

3. The light emitting element and the part of the paraboloid of revolution are arranged so that the laser light reflected by the part of the paraboloid of revolution travels along one direction.

3. The semiconductor laser device according to claim 1 or 2.

4. A plurality of light-emitting elements, each of which is the light-emitting element; and a plurality of portions of a paraboloid of revolution, each portion being a portion of the paraboloid of revolution.

4. The semiconductor laser device according to claim 1.

5. Each of the parts of the plurality of paraboloids of revolution is arranged to reflect the laser light along a predetermined direction.

5. The semiconductor laser device according to claim 4.

6. The bottom plate portion has a through hole, The light-emitting element and the electrode exposed on the outside of the outer shell are electrically connected via the through hole.

6. The semiconductor laser device according to claim 1.

7. the inner circumferential surface includes an inclined surface that widens as it moves away from the bottom plate portion, separate from a part of the paraboloid of revolution, The angle between the inclined surface and the bottom surface of the recess is 45° to 90°.

7. The semiconductor laser device according to claim 1.

8. The device further includes a light-transmitting sealing member fixed to an upper end of the peripheral wall portion so as to enclose the space inside the recess.

8. The semiconductor laser device according to claim 1.

9. the light-emitting element has two or more light emitting parts each emitting two or more laser beams including the laser beam, A part of the paraboloid of revolution reflects each of two or more laser beams.

9. The semiconductor laser device according to claim 1.

10. 10. A semiconductor laser device according to claim 1, wherein the portion of the paraboloid of revolution is one of two portions obtained by dividing the paraboloid of revolution along a first imaginary plane including an axis of symmetry of the paraboloid of revolution.

11. 11. The semiconductor laser device according to claim 1, wherein a portion of the paraboloid of revolution has a shape in which a tip portion including an apex of the paraboloid of revolution is cut along a second imaginary plane perpendicular to the axis of symmetry of the paraboloid of revolution.

12. The semiconductor laser device according to any one of claims 1 to 11, wherein the light-emitting element and the portion of the paraboloid of revolution are positioned such that the laser light is directly irradiated from the light-emitting element to the portion of the paraboloid of revolution without being reflected by other components and without passing through the other components.

13. A part of the paraboloid of revolution is constituted by a surface of a reflective film.

13. The semiconductor laser device according to claim 1.

Images