Laser module

Abstract

This laser module is provided with: a first laser element having a first exit port from which a first laser beam is emitted; and a second laser element having a second exit port for emitting a second laser beam, the first laser element and the second laser element being disposed such that the first laser beam and the second laser beam overlap each other.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of priority based on Japanese Patent Application No. 2023-134530 filed with the Japan Patent Office on August 22, 2023, the contents of which are incorporated herein by reference in their entirety. Technical Field

[0003] The present disclosure relates to laser modules. Background Art

[0004] A laser module is known that combines laser beams output from a plurality of laser diodes and outputs the combined laser beams. For example, Japanese Patent Application Publication No. 2016-133746 describes a laser module that includes a red laser diode, a green laser diode, a blue laser diode, and a dichroic mirror corresponding to each laser diode. Summary of the invention

[0005] In the laser module described in Japanese Patent Application Laid-Open No. 2016-133746, a plurality of dichroic mirrors are provided to combine the laser beams output from the respective laser diodes. Therefore, there is a possibility that the laser module may be enlarged.

[0006] The present disclosure describes a laser module that can be miniaturized.

[0007] A laser module according to one aspect of the present disclosure includes: a first laser element having a first emission port for emitting a first laser beam; and a second laser element having a second emission port for emitting a second laser beam. The first laser element and the second laser element are arranged so that the first laser beam and the second laser beam overlap each other.

[0008] In this laser module, the first laser element and the second laser element are arranged so that the first laser and the second laser overlap each other. Therefore, the first laser and the second laser can be combined without using optical components such as a dichroic mirror. As a result, the laser module can be miniaturized.

[0009] The above-mentioned laser module may also include: a substrate having a mounting surface on which the first laser element is mounted. The distance from the mounting surface to the first emission port may also be different from the distance from the mounting surface to the second emission port. In this case, even if the first emission port and the second emission port are brought close to each other, the possibility that the laser emitted from one laser element is blocked by another laser element is reduced. Therefore, the angle between the emission direction of the first laser and the emission direction of the second laser can be reduced. Thus, the degree of divergence of the first laser and the second laser can be suppressed at a position downstream of the emission direction more toward the position where the first laser and the second laser overlap.

[0010] The laser module may also include: a carrier on which the second laser element is mounted. The carrier may also be mounted on the mounting surface. In this case, the distance between the second emission port and the mounting surface varies according to the thickness of the carrier. Therefore, the distance between the second emission port and the mounting surface can be changed by only changing the thickness of the carrier, so that the distance between the second emission port and the mounting surface can be easily adjusted.

[0011] The first exit port may also be closer to the position where the first laser and the second laser overlap each other than the second exit port. The second exit port may also be arranged at a position closer to the first laser element than the center of the carrier in the arrangement direction of the first laser element and the second laser element. In this case, since the second exit port is close to the first exit port, the angle between the exit direction of the first laser and the exit direction of the second laser can be reduced. Thus, the degree of divergence of the first laser and the second laser can be suppressed downstream of the exit direction than the position where the first laser and the second laser overlap.

[0012] The laser module may also include a metal body that joins the second laser element and the carrier. The metal body may also include a metal ball having rigidity. In this case, the metal ball has rigidity, so the distance between the second emission port and the carrier is determined by the metal ball. Therefore, the distance between the second emission port and the carrier can be easily adjusted.

[0013] The second laser element may also be configured so that the emission direction of the second laser is inclined relative to the mounting surface. The distance from the mounting surface to the first emission port is different from the distance from the mounting surface to the second emission port. Therefore, by inclining the emission direction of the second laser relative to the mounting surface, the overlapped portion of the first laser and the second laser can be expanded.

[0014] The beam divergence angle of the first laser element may also be greater than the beam divergence angle of the second laser element. The first exit port may also be closer to the position where the first laser and the second laser overlap with each other than the second exit port. In this case, the first laser is easier to expand than the second laser. Therefore, by bringing the first exit port closer to the position where the first laser and the second laser overlap with each other than the second exit port, the degree of divergence of the laser at the above position can be suppressed.

[0015] The laser module may further include an extraction member having a through hole through which the first laser and the second laser overlap. In this case, the first laser and the second laser not included in the overlapped portion are shielded. Thus, stray light can be removed.

[0016] The above-mentioned laser module may also further include: a first photodetector for monitoring the light intensity of the first laser; and a second photodetector for monitoring the light intensity of the second laser. Each of the first laser element and the second laser element may also be an end-emitting laser element. The first photodetector may also be arranged on the opposite side of the emission direction of the first laser relative to the first laser element. The second photodetector may also be arranged on the opposite side of the emission direction of the second laser relative to the second laser element. In this case, since the first laser element and the second laser element are end-emitting laser elements, lasers are emitted from the front and rear end surfaces. The ratio of the light intensity of the laser emitted from the front end surface to the light intensity of the laser emitted from the rear end surface is preset. Therefore, the light intensity of the laser can be monitored without using an optical component for branching the laser. As a result, the laser module can be further miniaturized.

[0017] The laser module may further include: a third laser element having a third emission port for emitting a third laser. The first laser may be red light, the second laser may be green light, and the third laser may be blue light. In this case, a full-color laser module can be realized.

[0018] According to the aspects and embodiments of the present disclosure, it is possible to miniaturize the laser module. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a diagram schematically showing the structure of a laser module according to one embodiment.

[0020] Figure 2 It is a diagram showing the relationship between the overlapping portion of laser light and a pin hole.

[0021] Figure 3 yes Figure 1 A three-dimensional view of the light source unit and the pin hole plate shown.

[0022] Figure 4 yes Figure 3 A top view of the light source unit is shown.

[0023] Figure 5 yes Figure 3 The front view of the light source unit is shown.

[0024] Figure 6 It is used to illustrate Figure 3 A diagram showing a method for manufacturing a light source unit.

[0025] Figure 7 It is used to illustrate Figure 3 A diagram showing a method for manufacturing a light source unit.

[0026] Figure 8 It is used to illustrate Figure 3 A diagram showing a method for manufacturing a light source unit.

[0027] Fig. 9 It is used to illustrate Figure 3 A diagram showing a method for manufacturing a light source unit.

[0028] Fig.10 This is a diagram showing an example of bonding between a laser element and a carrier. DETAILED DESCRIPTION

[0029] Hereinafter, the embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. In addition, the same reference numerals are used for the same elements in the description of the accompanying drawings, and repeated descriptions are omitted. In each figure, an XYZ coordinate system is sometimes shown. The Y-axis direction is a direction that intersects (e.g., is orthogonal to) the X-axis direction and the Z-axis direction. The Z-axis direction is a direction that intersects (e.g., is orthogonal to) the X-axis direction and the Y-axis direction. As an example, the X-axis direction is the front-to-back direction, the Y-axis direction is the left-to-right direction, and the Z-axis direction is the up-down direction.

[0030] Reference Figure 1 and Figure 2 , a laser module according to one embodiment is described. Figure 1 This is a diagram schematically showing the structure of a laser module according to one embodiment. Figure 2 It is a diagram showing the relationship between the overlapping portion of laser light and a pin hole.

[0031] Figure 1 The laser module 1 shown is a module for emitting laser light Lc. The laser module 1 is used, for example, in a retinal projection device mounted on a near-eye wearable device. Examples of near-eye wearable devices include smart glasses such as AR (Augmented Reality) glasses, VR (Virtual Reality) glasses, and MR (Mixed Reality) glasses. The laser module 1 includes: a light source unit 2, a photodetector 3 (a first photodetector), a photodetector 4 (a second photodetector), a photodetector 5, and a pinhole plate 6 (an extraction member).

[0032] The light source unit 2 includes a laser element 21 (first laser element), a laser element 22 (second laser element), and a laser element 23 (third laser element). Each of the laser elements 21, 22, and 23 is a bare chip. Each of the laser elements 21, 22, and 23 is, for example, an end-emitting laser element, and emits laser light from both the front and rear end surfaces. In each laser element, the ratio of the light intensity of the laser light emitted from the front end surface to the light intensity of the laser light emitted from the rear end surface is preset.

[0033] The laser element 21 emits a laser beam having a red wavelength, that is, red light Lr (first laser beam) from the front end face. The laser element 22 emits a laser beam having a green wavelength, that is, green light Lg (second laser beam) from the front end face. The laser element 23 emits a laser beam having a blue wavelength, that is, blue light Lb (third laser beam) from the front end face. The laser element 21, the laser element 22, and the laser element 23 are arranged so that the red light Lr, the green light Lg, and the blue light Lb overlap with each other. The details of the light source unit 2 will be described later.

[0034] The photodetector 3 is an element for monitoring the light intensity of the red light Lr. The photodetector 3 is disposed on the opposite side of the emission direction of the red light Lr of the laser element 21. In other words, the photodetector 3 is opposite to the rear end face of the laser element 21. The photodetector 3 detects the light intensity of the laser light emitted from the rear end face of the laser element 21.

[0035] The photodetector 4 is an element for monitoring the light intensity of the green light Lg. The photodetector 4 is provided on the opposite side of the emission direction of the green light Lg of the laser element 22. In other words, the photodetector 4 is opposite to the rear end face of the laser element 22. The photodetector 4 detects the light intensity of the laser light emitted from the rear end face of the laser element 22.

[0036] The photodetector 5 is an element for monitoring the light intensity of the blue light Lb. The photodetector 5 is disposed on the opposite side of the emission direction of the blue light Lb of the laser element 23. In other words, the photodetector 5 is opposite to the rear end face of the laser element 23. The photodetector 5 detects the light intensity of the laser light emitted from the rear end face of the laser element 23.

[0037] The pin hole plate 6 is an optical component for extracting the overlapped portion Lw of the red light Lr, the green light Lg, and the blue light Lb. The pin hole plate 6 has a plate-like shape. The pin hole plate 6 is provided with a pin hole 6a (through hole) penetrating the pin hole plate 6. The portion Lw passes through the pin hole 6a, thereby obtaining the laser light Lc. Figure 2 As shown, portion Lw is larger than pin hole 6a.

[0038] Next, refer to Figure 3 to Figure 5 , the light source unit 2 is described in detail. Figure 3 yes Figure 1 A three-dimensional view of the light source unit and the pin hole plate shown. Figure 4 yes Figure 3 A top view of the light source unit is shown. Figure 5 yes Figure 3The front view of the light source unit is shown. In the laser module 1, the direction in which the pinhole plate 6 is provided with respect to the light source unit 2 is referred to as "front" or "front", and the direction in which the laser elements 21 to 23 are provided with respect to the substrate 24 described later is referred to as "above" or "upper", etc. These directions determine "rear", "lower", "left", and "right".

[0039] like Figure 3 to Figure 5 As shown, the laser element 21 includes: a laser body 21a, an electrode 21b, and a metal layer 21c. The laser body 21a has a rectangular parallelepiped shape extending in the front-to-back direction. The laser body 21a has an exit port 21d (first exit port) for emitting red light Lr. The exit port 21d is provided at the front end surface of the laser element 21. The exit port 21d is located near the center of the laser body 21a in the left-right direction and near the lower end of the laser body 21a.

[0040] An electrode 21b is provided on the upper surface of the laser body 21a. The electrode 21b covers the upper surface of the laser body 21a. The electrode 21b is the upper electrode of the laser element 21. As an example of a constituent material of the electrode 21b, a gold-tin alloy (AuSn) can be cited. In the present embodiment, the electrode 21b functions as a negative electrode. A metal layer 21c is provided on the lower surface of the laser body 21a. The metal layer 21c covers the lower surface of the laser body 21a. The metal layer 21c is a solder layer for mounting the laser element 21. As an example of a constituent material of the metal layer 21c, SAC (SnAgCu) can be cited.

[0041] The laser element 22 includes a laser body 22a, an electrode 22b, and a metal layer 22c. The laser body 22a has a rectangular parallelepiped shape extending in the front-back direction. The laser body 22a has an emission port 22d (second emission port) for emitting green light Lg. The emission port 22d is provided at the front end surface of the laser element 22. The emission port 22d is located near the right end of the laser body 22a in the left-right direction and near the lower end of the laser body 22a.

[0042] An electrode 22b is provided on the upper surface of the laser body 22a. The electrode 22b covers the upper surface of the laser body 22a. The electrode 22b is the upper electrode of the laser element 22. As an example of a constituent material of the electrode 22b, a gold-tin alloy (AuSn) can be cited. In the present embodiment, the electrode 22b functions as a negative electrode. A metal layer 22c is provided on the lower surface of the laser body 22a. The metal layer 22c covers the lower surface of the laser body 22a. The metal layer 22c is a solder layer for mounting the laser element 22. As an example of a constituent material of the metal layer 22c, SAC (SnAgCu) can be cited.

[0043] The laser element 23 includes: a laser body 23a, an electrode 23b, and a metal layer 23c. The laser body 23a has a rectangular parallelepiped shape extending in the front-back direction. The laser body 23a has an exit port 23d (third exit port) for emitting blue light Lb. The exit port 23d is provided at the front end surface of the laser element 23. The exit port 23d is located near the left end of the laser body 23a in the left-right direction, and is located near the lower end of the laser body 23a.

[0044] An electrode 23b is provided on the upper surface of the laser body 23a. The electrode 23b covers the upper surface of the laser body 23a. The electrode 23b is the upper electrode of the laser element 23. As an example of a constituent material of the electrode 23b, a gold-tin alloy (AuSn) can be cited. In the present embodiment, the electrode 23b functions as a negative electrode. A metal layer 23c is provided on the lower surface of the laser body 23a. The metal layer 23c covers the lower surface of the laser body 23a. The metal layer 23c is a solder layer for mounting the laser element 23. As an example of a constituent material of the metal layer 23c, SAC (SnAgCu) can be cited.

[0045] The light source unit 2 further includes a substrate 24, a carrier 25, and a carrier 26. The substrate 24 is a base for mounting the laser element 21. In the present embodiment, not only the laser element 21 but also the laser element 22 and the laser element 23 are mounted on the substrate 24. The substrate 24 functions as a carrier of the laser element 21. The substrate 24 includes a base material 41, a pad 42, a pad 43, and a pad 44.

[0046] The substrate 41 is a member having a rectangular plate shape. Examples of the constituent material of the substrate 41 include silicon and aluminum nitride. The substrate 41 has a mounting surface 41a and a back surface 41b. The mounting surface 41a is a surface on which the laser element 21 is mounted. The back surface 41b is a surface on the opposite side to the mounting surface 41a in the thickness direction (up and down direction) of the substrate 41.

[0047] The pad 42, the pad 43 and the pad 44 are provided on the mounting surface 41a. The pad 42 is a plate-shaped metal member for mounting the laser element 21. As an example of the constituent material of the pad 42, a gold-tin alloy (AuSn) can be cited. The outer shape of the pad 42 is larger than the outer shape of the laser element 21 when viewed from above. In the present embodiment, the pad 42 has a rectangular plate-like shape extending in the front-to-back direction. The pad 42 is provided near the center of the mounting surface 41a in the left-right direction, extending from the front end of the substrate 41 to near the rear end. The pad 42 also functions as the lower electrode of the laser element 21. In the present embodiment, the pad 42 functions as a positive electrode.

[0048] The pad 43 is a plate-shaped metal member for mounting the laser element 22. In the present embodiment, the carrier 25 on which the laser element 22 is mounted is mounted on the pad 43. As an example of the constituent material of the pad 43, gold (Au) can be cited. The outer shape of the pad 43 is larger than the outer shape of the carrier 25 when viewed from above. In the present embodiment, the pad 43 has a rectangular plate shape. The pad 43 is provided on the left side of the pad 42, extending from near the center in the front-rear direction of the substrate 41 to near the rear end.

[0049] The pad 44 is a plate-shaped metal member for mounting the laser element 23. In the present embodiment, the carrier 26 on which the laser element 23 is mounted is mounted on the pad 44. As an example of the constituent material of the pad 44, gold (Au) can be cited. The outer shape of the pad 44 is larger than the outer shape of the carrier 26 when viewed from above. In the present embodiment, the pad 44 has a rectangular plate shape. The pad 44 is provided on the right side of the pad 42, extending from a position behind the front end of the substrate 41 to a position ahead of the rear end.

[0050] The carrier 25 is a pedestal for mounting the laser element 22. The carrier 25 is mounted on the mounting surface 41a. Specifically, the carrier 25 is mounted on the pad 43. The carrier 25 includes: a substrate 25a, a pad 25b, and a metal layer 25c. The substrate 25a is a member having a rectangular plate shape. Examples of the constituent material of the substrate 25a include silicon and aluminum nitride. The outer shape of the substrate 25a (carrier 25) is larger than the outer shape of the laser element 22 when viewed from above.

[0051] A pad 25b is provided on the upper surface of the substrate 25a. The pad 25b covers the upper surface of the substrate 25a. The pad 25b is a plate-shaped metal member for mounting the laser element 22. As an example of a constituent material of the pad 25b, a gold-tin alloy (AuSn) can be cited. The pad 25b also functions as a lower electrode of the laser element 22. In the present embodiment, the pad 25b functions as a positive electrode.

[0052] A metal layer 25c is provided on the lower surface of the base material 25a. The metal layer 25c covers the lower surface of the base material 25a. The metal layer 25c is a solder layer for mounting the carrier 25. An example of a constituent material of the metal layer 25c is SAC (SnAgCu).

[0053] The carrier 26 is a pedestal for mounting the laser element 23. The carrier 26 is mounted on the mounting surface 41a. Specifically, the carrier 26 is mounted on the pad 44. The carrier 26 includes: a substrate 26a, a pad 26b, and a metal layer 26c. The substrate 26a is a member having a rectangular plate shape. Examples of the constituent material of the substrate 26a include silicon and aluminum nitride. The outer shape of the substrate 26a (carrier 26) is larger than the outer shape of the laser element 23 when viewed from above.

[0054] A pad 26b is provided on the upper surface of the substrate 26a. The pad 26b covers the upper surface of the substrate 26a. The pad 26b is a plate-shaped metal member for mounting the laser element 23. As an example of a constituent material of the pad 26b, a gold-tin alloy (AuSn) can be cited. The pad 26b also functions as a lower electrode of the laser element 23. In the present embodiment, the pad 26b functions as a positive electrode.

[0055] A metal layer 26c is provided on the lower surface of the base material 26a. The metal layer 26c covers the lower surface of the base material 26a. The metal layer 26c is a solder layer for mounting the carrier 26. An example of a constituent material of the metal layer 26c is SAC (SnAgCu).

[0056] The light source unit 2 further includes: wires Wr1, Wr2, Wg1, Wg2, Wb1, and Wb2. The wires Wr1 and Wr2 are components for passing a driving current to the laser element 21. One end of the wire Wr1 is connected to the electrode 21b. One end of the wire Wr2 is connected to the pad 42.

[0057] The wire Wg1 and the wire Wg2 are components for allowing the drive current to flow to the laser element 22. One end of the wire Wg1 is connected to the electrode 22b. One end of the wire Wg2 is connected to the pad 25b. The wire Wb1 and the wire Wb2 are components for allowing the drive current to flow to the laser element 23. One end of the wire Wb1 is connected to the electrode 23b. One end of the wire Wb2 is connected to the pad 26b.

[0058] Next, refer to Figure 3 to Figure 5 , the configuration of the laser element 21, the laser element 22, and the laser element 23 is described in detail. In the present embodiment, the laser element 21, the laser element 22, and the laser element 23 have different radiation characteristics (beam divergence angle θh in the horizontal direction and beam divergence angle θv in the vertical direction). For example, the laser element 21 has a beam divergence angle θh of 10° and a beam divergence angle θv of 32° under the condition of a light intensity of 5 mW. For example, the laser element 22 has a beam divergence angle θh of 7° and a beam divergence angle θv of 22° under the condition of a light intensity of 7 mW. For example, the laser element 23 has a beam divergence angle θh of 8° and a beam divergence angle θv of 23° under the condition of a light intensity of 7 mW.

[0059] The beam divergence angle θh of the laser element 21 is larger than any of the beam divergence angle θh of the laser element 22 and the beam divergence angle θh of the laser element 23. The beam divergence angle θv of the laser element 21 is larger than any of the beam divergence angle θv of the laser element 22 and the beam divergence angle θv of the laser element 23. The larger the beam divergence angle of the laser element, the easier it is for the laser light emitted from the laser element to diverge. Therefore, the laser element 21 is arranged so that the distance between the emission port 21d and the pin hole 6a becomes the shortest.

[0060] Specifically, the laser element 21 is arranged in front of any of the laser element 22 and the laser element 23. In other words, the emission port 21d is closer to the position (pin hole 6a) where the red light Lr, the green light Lg and the blue light Lb overlap each other than any of the emission port 22d and the emission port 23d. The length of the substrate 24 (base material 41) in the vertical direction is set so that the emission port 21d and the center of the pin hole 6a are substantially the same height. In the following description, the length in the vertical direction is sometimes referred to as "thickness". The laser element 21 is arranged substantially parallel to the mounting surface 41a, and emits the red light Lr in parallel with the mounting surface 41a. Therefore, the emission port 21d is located in front of the pin hole 6a, and the central axis of the red light Lr (the emission direction of the red light Lr) coincides with the central axis of the pin hole 6a.

[0061] The beam divergence angle θh of the laser element 23 is slightly larger than the beam divergence angle θh of the laser element 22. The beam divergence angle θv of the laser element 23 is slightly larger than the beam divergence angle θv of the laser element 22. Therefore, the laser element 23 is arranged so that the distance between the emission port 23d and the pin hole 6a is shorter than the distance between the emission port 22d and the pin hole 6a.

[0062] Specifically, the laser element 23 is arranged behind the laser element 21 and in front of the laser element 22. In other words, the emission port 23d is closer to the position (pin hole 6a) where the red light Lr, the green light Lg, and the blue light Lb overlap each other than the emission port 22d. The laser element 23 is mounted on the mounting surface 41a via the carrier 26. Therefore, the emission port 23d is located above the emission port 21d by the thickness of the carrier 26. In other words, the distance Db from the mounting surface 41a to the emission port 23d is greater than the distance Dr from the mounting surface 41a to the emission port 21d.

[0063] The laser element 23 is arranged on the right side of the laser element 21. The laser element 23 is provided on the carrier 26 at a position closer to the laser element 21 than the center of the carrier 26 in the left-right direction. The emission port 23d is located near the left end of the laser body 23a. In other words, the emission port 23d is provided at a position closer to the laser element 21 than the center of the carrier 26 in the left-right direction.

[0064] The direction of the laser element 23 (exit port 23d) is set so that the blue light Lb emitted from the exit port 23d passes through the pin hole 6a. Specifically, the laser element 23 is tilted in the left-right direction so that the front end face of the laser element 23 is closer to the laser element 21 than the rear end face of the laser element 23. Therefore, the central axis of the blue light Lb (the emission direction of the blue light Lb) is tilted so as to approach the central axis of the red light Lr as it approaches the pin hole 6a.

[0065] exist Figure 3 In the example shown, the laser element 23 is arranged substantially parallel to the mounting surface 41a and emits blue light Lb parallel to the mounting surface 41a. The laser element 23 may be tilted in the vertical direction so that the front end surface of the laser element 23 is closer to the mounting surface 41a than the rear end surface of the laser element 23.

[0066] The laser element 22 is arranged further back than either the laser element 21 or the laser element 23. In other words, the emission port 22d is further away from the position (pin hole 6a) where the red light Lr, the green light Lg, and the blue light Lb overlap each other than either the emission port 21d or the emission port 23d. The laser element 22 is mounted on the mounting surface 41a via the carrier 25. Therefore, the emission port 22d is located above the emission port 21d by the thickness of the carrier 25. Since the thickness of the carrier 25 is thicker than the thickness of the carrier 26, the emission port 22d is located above the emission port 23d. In other words, the distance Dg from the mounting surface 41a to the emission port 22d is greater than either the distance Dr or the distance Db.

[0067] The laser element 22 is arranged on the left side of the laser element 21. The laser element 22 is provided on the carrier 25 at a position closer to the laser element 21 than the center of the carrier 25 in the left-right direction. The emission port 22d is located near the right end of the laser body 22a. In other words, the emission port 22d is provided at a position closer to the laser element 21 than the center of the carrier 25 in the left-right direction.

[0068] The orientation of the laser element 22 (exit port 22d) is set so that the green light Lg emitted from the exit port 22d passes through the pin hole 6a. Specifically, the laser element 22 is tilted in the left-right direction so that the front end surface of the laser element 22 is closer to the laser element 21 than the rear end surface of the laser element 22. Therefore, the central axis of the green light Lg (the emission direction of the green light Lg) is tilted so as to approach the central axis of the red light Lr as it approaches the pin hole 6a.

[0069] exist Figure 3In the example shown, the laser element 22 is arranged substantially parallel to the mounting surface 41a, and emits green light Lg parallel to the mounting surface 41a. The laser element 22 may be tilted in the vertical direction so that the front end surface of the laser element 22 is closer to the mounting surface 41a than the rear end surface of the laser element 22.

[0070] Next, refer to Figure 6 to Figure 9 , a method for manufacturing the light source unit 2 is described. Figure 6 to Figure 9 It is used to illustrate Figure 3 A diagram showing a method for manufacturing a light source unit.

[0071] First, the laser elements 21 to 23, the substrate 24, and the carriers 25 and 26 are prepared. Then, the laser element 22 is mounted on the carrier 25, and the laser element 22 and the carrier 25 are unitized to produce a unit 27 (see Figure 7 Specifically, the laser element 22 is placed on the carrier 25 in such a manner that the metal layer 22c is in contact with the pad 25b. Then, the metal layer 22c is heated to melt the metal layer 22c, and then the metal layer 22c is solidified, thereby bonding the laser element 22 to the carrier 25.

[0072] Similarly, the laser element 23 is mounted on the carrier 26, and the laser element 23 and the carrier 26 are unitized to produce a unit 28 (see Figure 8 Specifically, the laser element 23 is placed on the carrier 26 in such a manner that the metal layer 23c is in contact with the pad 26b. Then, the metal layer 23c is heated to melt the metal layer 23c, and then the metal layer 23c is solidified to bond the laser element 23 to the carrier 26.

[0073] Then, if Figure 6 As shown, the laser element 21 is mounted on the substrate 24. Specifically, the laser element 21 is placed on the substrate 24 in such a manner that the metal layer 21c is in contact with the pad 42. Then, the metal layer 21c is heated to melt the metal layer 21c, and then the metal layer 21c is solidified, thereby bonding the laser element 21 to the substrate 24.

[0074] Then, if Figure 7 As shown, the laser element 22 is mounted on the substrate 24. Specifically, the unit 27 is placed on the substrate 24 in such a manner that the metal layer 25c is in contact with the pad 43. At this time, the unit 27 is placed in a state where the laser element 21 emits red light Lr and the laser element 22 emits green light Lg. Then, by active alignment, the direction and inclination of the unit 27 are adjusted in such a manner that the red light Lr and the green light Lg overlap each other. Then, the metal layer 25c is heated to melt the metal layer 25c, and then the metal layer 25c is solidified to bond the unit 27 to the substrate 24.

[0075] Then, if Figure 8 As shown, the laser element 23 is mounted on the substrate 24. Specifically, the unit 28 is placed on the substrate 24 in such a manner that the metal layer 26c is in contact with the pad 44. At this time, the unit 28 is placed in a state where the laser element 21 emits red light Lr, the laser element 22 emits green light Lg, and the laser element 23 emits blue light Lb. Then, by active alignment, the direction and inclination of the unit 28 are adjusted in such a manner that the red light Lr, the green light Lg, and the blue light Lb overlap each other. Then, the metal layer 26c is heated to melt the metal layer 26c, and then the metal layer 26c is solidified to bond the unit 28 to the substrate 24.

[0076] Then, if Fig. 9 As shown, wire bonding is performed. Specifically, one end of the wire Wr1 is connected to the electrode 21b, and one end of the wire Wr2 is connected to the pad 42. Similarly, one end of the wire Wg1 is connected to the electrode 22b, and one end of the wire Wg2 is connected to the pad 25b. Similarly, one end of the wire Wb1 is connected to the electrode 23b, and one end of the wire Wb2 is connected to the pad 26b.

[0077] As described above, the light source unit 2 is manufactured. In addition, the laser element 23 may be mounted on the substrate 24 before the laser element 22. The laser element 21 located at the front of the laser elements 21 to 23 is mounted first, and the laser elements 22 and 23 are mounted in such a manner that the green light Lg and the blue light Lb overlap with the red light Lr. That is, with the red light Lr emitted along the central axis of the pin hole 6a as a reference, the directions and inclinations of the laser elements 22 and 23 are adjusted in such a manner that the red light Lr, the green light Lg, and the blue light Lb overlap with each other. The laser elements 22 and 23 are arranged behind the laser element 21, so the possibility that the laser light (here, the red light Lr) serving as the reference is blocked by other laser elements or the like is reduced. Therefore, the mounting efficiency of the laser elements 22 and 23 can be improved.

[0078] In the laser module 1 described above, the laser element 21, the laser element 22, and the laser element 23 are arranged so that the red light Lr, the green light Lg, and the blue light Lb overlap each other. Therefore, the red light Lr, the green light Lg, and the blue light Lb can be combined without using an optical component such as a dichroic mirror. As a result, a full-color laser module 1 can be realized, and the laser module 1 can be miniaturized.

[0079] Since the laser element 21, the laser element 22, and the laser element 23 are arranged three-dimensionally, the distance Dr, the distance Dg, and the distance Db are different from each other. Specifically, the distance Db is greater than the distance Dr, and the distance Dg is greater than the distance Db. Therefore, even if the exit port 22d is brought close to the exit port 21d, the possibility that the green light Lg is blocked by the laser element 21 is reduced. Therefore, compared with the case where the distance Dr and the distance Dg are the same, the exit port 22d can be brought close to the exit port 21d. Similarly, even if the exit port 23d is brought close to the exit port 21d, the possibility that the blue light Lb is blocked by the laser element 21 is reduced. Therefore, compared with the case where the distance Dr and the distance Db are the same, the exit port 23d can be brought close to the exit port 21d.

[0080] Thus, the emission directions of the red light Lr, the green light Lg, and the blue light Lb can be brought closer to each other. In other words, the angle between any two of the emission directions of the red light Lr, the green light Lg, and the blue light Lb can be reduced. Thus, the degree of divergence of the red light Lr, the green light Lg, and the blue light Lb can be suppressed downstream of the emission direction where the red light Lr, the green light Lg, and the blue light Lb overlap.

[0081] The laser element 22 is mounted on the carrier 25, and the laser element 23 is mounted on the carrier 26. The carrier 25 and the carrier 26 are mounted on the mounting surface 41a. Therefore, the distance Dg changes according to the thickness of the carrier 25, and the distance Db changes according to the thickness of the carrier 26. That is, the distance Dg can be changed by only changing the thickness of the carrier 25, and the distance Db can be changed by only changing the thickness of the carrier 26. Therefore, the distance Dg and the distance Db can be easily adjusted.

[0082] Since the distance Dr, the distance Dg, and the distance Db are different from each other, when the red light Lr, the green light Lg, and the blue light Lb are emitted in parallel with respect to the mounting surface 41a, the portion Lw may be narrowed. In contrast, when the laser element 22 is arranged in a manner such that the emission direction of the green light Lg is inclined with respect to the mounting surface 41a, the portion where the red light Lr and the green light Lg overlap with each other can be expanded, and the portion Lw can be expanded. Similarly, when the laser element 23 is arranged in a manner such that the emission direction of the blue light Lb is inclined with respect to the mounting surface 41a, the portion where the red light Lr and the blue light Lb overlap with each other can be expanded, and the portion Lw can be expanded.

[0083] The beam divergence angle θh of the laser element 21 is larger than any of the beam divergence angle θh of the laser element 22 and the beam divergence angle θh of the laser element 23. The beam divergence angle θv of the laser element 21 is larger than any of the beam divergence angle θv of the laser element 22 and the beam divergence angle θv of the laser element 23. The larger the beam divergence angle of the laser element, the easier it is for the laser light emitted from the laser element to spread. Therefore, the red light Lr spreads more easily than the green light Lg and the blue light Lb. Therefore, the exit port 21d is closer to the position (pin hole 6a) where the red light Lr, the green light Lg and the blue light Lb overlap each other than the exit port 22d and the exit port 23d, so that the degree of divergence of the laser light as a whole at the above position can be suppressed.

[0084] The exit port 22d is disposed at a position closer to the laser element 21 than the center in the left-right direction of the carrier 25. Therefore, the exit port 22d is close to the exit port 21d, so that the angle between the exit direction of the red light Lr and the exit direction of the green light Lg can be reduced. Similarly, the exit port 23d is disposed at a position closer to the laser element 21 than the center in the left-right direction of the carrier 26. Therefore, the exit port 23d is close to the exit port 21d, so that the angle between the exit direction of the red light Lr and the exit direction of the blue light Lb can be reduced. As described above, the degree of divergence of the red light Lr, the green light Lg, and the blue light Lb can be suppressed at a position downstream of the exit direction than the position where the red light Lr, the green light Lg, and the blue light Lb overlap each other.

[0085] The portion Lw passes through the pin hole 6a to obtain the laser light Lc, and the red light Lr, the green light Lg, and the blue light Lb not included in the portion Lw are blocked by the pin hole plate 6. Thus, stray light can be removed.

[0086] Since each of the laser elements 21 to 23 is an end-emitting laser element, each laser element emits laser light from both the front and rear end surfaces. The photodetector 3 is arranged on the opposite side of the emission direction of the red light Lr relative to the laser element 21, and receives the laser light emitted from the rear end surface of the laser element 21. In the laser element 21, the ratio of the light intensity of the red light Lr emitted from the front end surface and the light intensity of the laser light emitted from the rear end surface is preset. Therefore, the light intensity of the red light Lr can be monitored without using an optical component for branching the red light Lr.

[0087] Similarly, the photodetector 4 is arranged on the opposite side of the emission direction of the green light Lg relative to the laser element 22, and receives the laser light emitted from the rear end face of the laser element 22. In the laser element 22, the ratio of the light intensity of the green light Lg emitted from the front end face and the light intensity of the laser light emitted from the rear end face is preset. Therefore, the light intensity of the green light Lg can be monitored without using an optical component for branching the green light Lg.

[0088] Similarly, the photodetector 5 is arranged on the opposite side of the emission direction of the blue light Lb relative to the laser element 23, and receives the laser light emitted from the rear end face of the laser element 23. In the laser element 23, the ratio of the light intensity of the blue light Lb emitted from the front end face and the light intensity of the laser light emitted from the rear end face is preset. Therefore, the light intensity of the blue light Lb can be monitored without using an optical component for branching the blue light Lb. As a result, the laser module 1 can be further miniaturized.

[0089] In addition, the laser module of the present disclosure is not limited to the above-mentioned embodiment.

[0090] For example, the laser module 1 is not limited to a structure combining red light Lr, green light Lg, and blue light Lb, but may be a structure combining at least two laser beams. In this case, laser elements emitting the respective laser beams are arranged so that at least two laser beams overlap each other.

[0091] The light source unit 2 may further include a carrier on which the laser element 21 is mounted. The carrier may also be mounted on the mounting surface 41a. The light source unit 2 may not include at least one of the carrier 25 and the carrier 26. The emission port 21d, the emission port 22d, and the emission port 23d may also be located on the same plane parallel to the mounting surface 41a. That is, the distance Dr, the distance Dg, and the distance Db may also be the same as each other.

[0092] The carrier 25 may not be placed on the placement surface 41a. The carrier 26 may not be placed on the placement surface 41a. That is, the laser element 21, the laser element 22, and the laser element 23 may not be provided on the same substrate 24, but may be provided on separate carriers.

[0093] Alternatively, the exit port 22d may be located in front of the pin hole 6a instead of the exit port 21d, and the central axis of the green light Lg (the exit direction of the green light Lg) may coincide with the central axis of the pin hole 6a. In this case, the laser element 21, the laser element 22, and the laser element 23 may be arranged in sequence in the left-right direction. Alternatively, the exit port 23d may be located in front of the pin hole 6a, and the central axis of the blue light Lb (the exit direction of the blue light Lb) may coincide with the central axis of the pin hole 6a. In this case, the laser element 21, the laser element 23, and the laser element 22 may be arranged in sequence in the left-right direction.

[0094] The laser module 1 may further include a collimator lens for converting the laser light Lc into parallel light.

[0095] The laser element 21 may be arranged so that the emission direction of the red light Lr is inclined relative to the mounting surface 41a. The laser element 22 may be arranged so that the emission direction of the green light Lg is inclined relative to the mounting surface 41a. The laser element 23 may be arranged so that the emission direction of the blue light Lb is inclined relative to the mounting surface 41a.

[0096] like Fig.10 As shown, the laser module 1 may also include a metal body 50. Fig.10 In the example shown, the metal body 50 is used to bond the laser element 22 and the carrier 25 (pad 25b). The metal body 50 includes a metal ball 51 and a plating layer 52. The metal ball 51 has rigidity. An example of a constituent material of the metal ball 51 is copper. The plating layer 52 is provided on the surface of the metal ball 51. The plating layer 52 covers the entire surface of the metal ball 51. The metal body 50 is heated to melt the plating layer 52, and then the plating layer 52 is solidified, thereby bonding the laser element 22 to the carrier 25 via the metal body 50.

[0097] The metal body 50 may be a GGI (Gold to Gold Interconnect). In this case, the metal body 50 includes a metal ball 51 having rigidity. An example of a constituent material of the metal ball 51 is gold (Au). The metal body 50 is bonded by friction generated by ultrasonic vibration.

[0098] The metal ball 51 is not easily deformed due to its rigidity. Therefore, the inclination and distance Dg of the laser element 22 are determined by the metal ball 51. Therefore, the inclination and distance Dg of the laser element 22 can be easily adjusted. Instead of adjusting the inclination by the metal body 50, the carrier 25 itself can be tilted.

[0099] The metal body 50 can also be used for bonding the laser element 21 to the mounting surface 41a (pad 42), and can also be used for bonding the laser element 23 to the carrier 26 (pad 26b). The metal body 50 can also be used for bonding the carrier 25 to the mounting surface 41a (pad 43), and can also be used for bonding the carrier 26 to the mounting surface 41a (pad 44).

[0100] (Note)

[0101] [Project 1]

[0102] A laser module, wherein:

[0103] have:

[0104] A first laser element having a first emission port for emitting a first laser beam; and

[0105] a second laser element having a second emission port for emitting a second laser beam,

[0106] The first laser element and the second laser element are arranged so that the first laser light and the second laser light overlap with each other.

[0107] [Project 2]

[0108] The laser module according to item 1, wherein:

[0109] The device further comprises: a substrate having a mounting surface on which the first laser element is mounted;

[0110] A distance from the placement surface to the first emission port is different from a distance from the placement surface to the second emission port.

[0111] [Item 3]

[0112] The laser module according to item 2, wherein:

[0113] It also includes: a carrier on which the second laser element is mounted,

[0114] The carrier is placed on the placement surface.

[0115] [Item 4]

[0116] The laser module according to item 3, wherein:

[0117] The first emission port is closer to the position where the first laser and the second laser overlap each other than the second emission port.

[0118] The second emission port is provided at a position closer to the first laser element than to the center of the carrier in the arrangement direction of the first laser element and the second laser element.

[0119] [Item 5]

[0120] The laser module according to item 3 or 4, wherein:

[0121] It also includes: a metal body that bonds the second laser element and the carrier.

[0122] The metal body includes a rigid metal ball.

[0123] [Item 6]

[0124] The laser module according to any one of items 2 to 5, wherein:

[0125] The second laser element is arranged so that the emission direction of the second laser beam is inclined with respect to the mounting surface.

[0126] [Item 7]

[0127] The laser module according to any one of items 1 to 6, wherein:

[0128] The beam divergence angle of the first laser element is greater than the beam divergence angle of the second laser element,

[0129] The first emission port is closer to a position where the first laser beam and the second laser beam overlap each other than the second emission port.

[0130] [Item 8]

[0131] The laser module according to any one of items 1 to 7, wherein:

[0132] The invention further includes an extraction member having a through hole through which a portion where the first laser beam and the second laser beam overlap each other passes.

[0133] [Item 9]

[0134] The laser module according to any one of items 1 to 8, wherein:

[0135] Also available:

[0136] a first photodetector for monitoring the light intensity of the first laser; and

[0137] a second photodetector for monitoring the light intensity of the second laser,

[0138] Each of the first laser element and the second laser element is an end-emitting laser element,

[0139] The first photodetector is arranged on the opposite side of the emission direction of the first laser light relative to the first laser element.

[0140] The second photodetector is arranged on the opposite side of the second laser element to the emission direction of the second laser beam.

[0141] [Item 10]

[0142] The laser module according to any one of items 1 to 9, wherein:

[0143] The device further comprises: a third laser element having a third emission port for emitting a third laser beam;

[0144] The first laser is red light,

[0145] The second laser is green light,

[0146] The third laser is blue light.

Claims

1. A laser module, wherein: have: A first laser element having a first emission port for emitting a first laser beam; and a second laser element having a second emission port for emitting a second laser beam, The first laser element and the second laser element are arranged so that the first laser light and the second laser light overlap with each other.

2. The laser module according to claim 1, wherein: The device further comprises: a substrate having a mounting surface on which the first laser element is mounted; A distance from the placement surface to the first emission port is different from a distance from the placement surface to the second emission port.

3. The laser module according to claim 2, wherein: It also includes: a carrier on which the second laser element is mounted, The carrier is placed on the placement surface.

4. The laser module according to claim 3, wherein: The first emission port is closer to the position where the first laser and the second laser overlap each other than the second emission port. The second emission port is provided at a position closer to the first laser element than to the center of the carrier in the arrangement direction of the first laser element and the second laser element.

5. The laser module according to claim 3 or 4, wherein: It also includes: a metal body that bonds the second laser element and the carrier. The metal body includes a rigid metal ball.

6. The laser module according to any one of claims 2 to 5, wherein: The second laser element is arranged so that the emission direction of the second laser beam is inclined with respect to the mounting surface.

7. The laser module according to any one of claims 1 to 6, wherein: The beam divergence angle of the first laser element is greater than the beam divergence angle of the second laser element, The first emission port is closer to a position where the first laser beam and the second laser beam overlap each other than the second emission port.

8. The laser module according to any one of claims 1 to 7, wherein: The invention further includes an extraction member having a through hole through which a portion where the first laser beam and the second laser beam overlap each other passes.

9. The laser module according to any one of claims 1 to 8, wherein: Also available: a first photodetector for monitoring the light intensity of the first laser; and a second photodetector for monitoring the light intensity of the second laser, Each of the first laser element and the second laser element is an end-emitting laser element, The first photodetector is arranged on the opposite side of the emission direction of the first laser light relative to the first laser element. The second photodetector is arranged on the opposite side of the second laser element to the emission direction of the second laser beam.

10. The laser module according to any one of claims 1 to 9, wherein: The device further comprises: a third laser element having a third emission port for emitting a third laser beam; The first laser is red light, The second laser is green light, The third laser is blue light.

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