Light source module

Abstract

A light source module (10) is provided with a plurality of optical units (1-6), each of the plurality of optical units (1-6) having a semiconductor laser element (200) that emits laser light, a fast axis cylindrical lens (FACL) (110), a first fast axis adjustment lens (first lens) (120), and a slow axis collimator lens (SACL) (170), and the effective focal length of the FACL (110) is set as F1, the effective focal length of the first lens (120) is set as F2, and the effective focal length of the second lens (120) is set as F2. When the distance between the principal point of the FACL (110) and the principal point of the first lens (120) is d, alpha satisfies formula 1, alpha = F2 / F1 (formula 1), beta satisfies formula 2, beta = d / F2 (formula 2), and F2 > 0, alpha and beta satisfy formula 3, formula 4, formula 5, and formula 6, alpha > 1 (formula 3), alpha beta > 1 (formula 4), beta < (1 / alpha) + (1 / 3) (formula 5), and beta < 1 (formula 6).

Description

Technical Field

[0001] The present invention relates to a light source module. Background Art

[0002] Patent Document 1 discloses a semiconductor laser device (light source module) including a semiconductor laser element, a fast-axis collimator lens for collimating laser light emitted from the semiconductor laser element in the fast-axis direction, and an adhesive member for fixing the position of the fast-axis collimator lens.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 2014-170888 Summary of the Invention

[0006] Problems to be solved by the invention

[0007] A fast-axis collimator lens with a short focal length is sometimes used in the light source module disclosed in Patent Document 1. In this light source module, the fast-axis collimator lens is fixed near the light emitting portion of the semiconductor laser element to spatially combine the laser beams emitted from the semiconductor laser element in the fast-axis direction.

[0008] However, when the fast-axis collimator lens is fixed in position during manufacturing, its short focal length can sometimes cause it to deviate from its optimal position within the optical system of the light source module by micrometers or submicrometers. This deviation of the fast-axis collimator lens from its optimal position means that the optical axis of the laser light in the fast-axis direction deviates from its optimal position. This deviation of the optical axis from its optimal position can lead to problems such as reduced coupling efficiency between an object, such as an optical fiber, and the laser light in the light source module disclosed in Patent Document 1.

[0009] Therefore, an object of the present disclosure is to provide a light source module with high coupling efficiency.

[0010] Means for solving problems

[0011] In order to achieve the above-mentioned purpose, the light source module involved in one embodiment of the present invention comprises: a base, which is provided with a plurality of workbenches in a stepped shape; and a plurality of optical units, wherein each optical unit is configured on each workbench among the plurality of workbenches, and each of the plurality of optical units comprises: a semiconductor laser element, which emits laser light; a fast-axis cylindrical lens, which is incident on the laser light emitted from the semiconductor laser element and converges the laser light in the fast-axis direction of the laser light; a first fast-axis adjustment lens, which is incident on the laser light emitted from the fast-axis cylindrical lens and adjusts the optical axis of the laser light in the fast-axis direction; and a slow-axis collimating lens, which is incident on the laser light emitted from the first fast-axis adjustment lens and collimates the laser light in the slow-axis direction of the laser light, and then adjusts the fast-axis adjustment lens to the fast-axis collimating lens. When the effective focal length is F1, the effective focal length of the first fast-axis adjustment lens is F2, and the distance between the principal point of the fast-axis cylindrical lens and the principal point of the first fast-axis adjustment lens is d, α satisfies Formula 1, α=F2 / F1···(Formula 1), β satisfies Formula 2, β=d / F2···(Formula 2), and when F2>0, the α and β satisfy Formulas 3, 4, 5, and 6, α>1···(Formula 3), αβ>1···(Formula 4), β<(1 / α)+(1 / 3)···(Formula 5), ​​β<1···(Formula 6), and when F2<0, the α and β satisfy Formulas 7, 8, 9, and 10, α<-1...(Formula 7), αβ<1...(Formula 8), β>(1 / α)-(1 / 3)...(Formula 9), β>-1...(Formula 10).

[0012] Effects of the Invention

[0013] According to the present disclosure, a light source module with high coupling efficiency can be realized. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a perspective view showing the overall structure of the light source module according to the first embodiment.

[0015] Figure 2 It is a perspective view showing the structure of the optical unit according to the first embodiment.

[0016] Figure 3 This is a side view showing the structure of the optical unit according to the first embodiment.

[0017] Figure 4A This is a front view showing the first lens and the supporting member according to the first embodiment.

[0018] Figure 4B This is a front view showing a first lens and a supporting member according to another example of the first embodiment.

[0019] Figure 5 This is a side view of the optical unit according to Embodiment 1.

[0020] Figure 6A This is a diagram showing beam spots of a plurality of laser beams on the incident surface of the condenser lens according to the first embodiment.

[0021] Figure 6B This is a diagram showing a beam spot of laser light on the end face of the core of an optical fiber, which is an object according to the first embodiment.

[0022] Figure 7 This is a side view of the optical unit showing an example of adjusting the position of the first lens of the optical unit in the fast axis direction in the method of manufacturing the light source module according to the first embodiment.

[0023] Figure 8 This is a side view of the optical unit showing another example of adjusting the position of the first lens of the optical unit in the fast axis direction in the method of manufacturing the light source module according to the first embodiment.

[0024] Figure 9 This is a side view showing the light source module of Comparative Example 1.

[0025] Figure 10 It is a side view showing a light source module of Comparative Example 2.

[0026] Figure 11 This is a side view showing the light source module according to the first embodiment.

[0027] Figure 12 This is a graph showing the results of simulation calculations of changes in coupling efficiency under various conditions of a plurality of optical systems for the light source module of Comparative Example 1.

[0028] Figure 13 It means explanation Figure 12 A diagram showing a table of conditions for multiple optical systems.

[0029] Figure 14 This is a diagram showing a reflecting mirror into which laser light is incident according to the first embodiment.

[0030] Figure 15 This is a diagram showing the ranges of α and β in the first embodiment.

[0031] Figure 16 This is a diagram showing the relationship between β and F / F1 in the first embodiment.

[0032] Figure 17 This is a diagram showing a table illustrating a plurality of conditions of an optical system for calculating changes in coupling efficiency for the light source module according to the first embodiment.

[0033] Figure 18 Yes means Figure 17 FIG. 1 is a diagram showing a table of α, β, and F / F1 under a plurality of conditions shown.

[0034] Figure 19 It means in Figure 17 A graph showing the results of calculating coupling efficiency under some of the multiple conditions shown.

[0035] Figure 20 It means in Figure 17 A graph showing the results of calculating coupling efficiency under some of the multiple conditions shown.

[0036] Figure 21 It means in Figure 17 A graph showing the results of calculating coupling efficiency under some of the multiple conditions shown.

[0037] Figure 22 It means in Figure 17 A graph showing the results of calculating coupling efficiency under some of the multiple conditions shown.

[0038] Figure 23A It means in Figure 17 A graph showing the results of calculating coupling efficiency under some of the multiple conditions shown.

[0039] Figure 23B It means in Figure 17 A graph showing the results of calculating coupling efficiency under some of the multiple conditions shown.

[0040] Figure 23C It means in Figure 17 A graph showing the results of calculating coupling efficiency under some of the multiple conditions shown.

[0041] Figure 23D It means in Figure 17 A graph showing the results of calculating coupling efficiency under some of the multiple conditions shown.

[0042] Figure 23E It means in Figure 17 A graph showing the results of calculating coupling efficiency under some of the multiple conditions shown.

[0043] Figure 23F It means in Figure 17 A graph showing the results of calculating coupling efficiency under some of the multiple conditions shown.

[0044] Figure 23G It means in Figure 17 A graph showing the results of calculating coupling efficiency under some of the multiple conditions shown.

[0045] Figure 24 This is a side view showing the structure of an optical unit according to Modification 1 of Embodiment 1.

[0046] Figure 25This is a side view showing an example in which the position of the first lens in Modification 1 of Embodiment 1 is adjusted in the fast axis direction.

[0047] Figure 26 This is a side view showing another example in which the position of the first lens in Modification 1 of Embodiment 1 is adjusted in the fast axis direction.

[0048] Figure 27 This is a diagram showing the ranges of α and β in Modification 1 of Embodiment 1.

[0049] Figure 28 This is a diagram showing the relationship between β and F / F1 in Modification 1 of Embodiment 1.

[0050] Figure 29 This is a diagram showing a table for explaining conditions for calculating the coupling efficiency of the light source module according to the first modification of the first embodiment.

[0051] Figure 30 Yes means Figure 29 Graph showing a table of α, β, and F / F1 under the conditions shown.

[0052] Figure 31 It means in Figure 29 A graph showing the calculated results of the change in coupling efficiency when the positions of the six FACLs are shifted from the optimal position under the conditions shown.

[0053] Figure 32 It means in Figure 29 A graph showing the calculated results of the change in coupling efficiency when the positions of the six FACLs are shifted from the optimal position under the conditions shown.

[0054] Figure 33 This is a side view showing the structure of an optical unit according to a second modification of the first embodiment.

[0055] Figure 34 It is a cross-sectional view showing a method for manufacturing an optical unit according to Modification 3 of Embodiment 1.

[0056] Figure 35 It is a perspective view showing the structure of a light source module according to Embodiment 2.

[0057] Figure 36 Yes Figure 35 A cross-sectional view of a cut surface of the optical unit taken along line XXXVI-XXXVI.

[0058] Figure 37 It is a perspective view showing the structure of the optical unit according to the second embodiment.

[0059] Figure 38 This is a front view for explaining the inclination of the busbar in the second embodiment.

[0060] Figure 39A This is a front view of the case where the first lens of Embodiment 2 is disposed in the first stage.

[0061] Figure 39B This is another front view when the first lens according to Embodiment 2 is provided in the first stage.

[0062] Figure 40 This is a front view showing a method for manufacturing the first lens according to the second embodiment.

[0063] Figure 41A This figure shows the results of simulation calculation of the light intensity distribution of laser light on the incident surface of the condenser lens when the angle is -15° in accordance with the second embodiment based on the prescribed conditions of the first embodiment.

[0064] Figure 41B It means in Figure 41A A graph showing the results of calculating the coupling efficiency under the specified conditions.

[0065] Figure 42 This is a diagram showing the results of simulation calculation of the maximum value of the coupling efficiency when the first lens with a variable angle is used in Embodiment 2.

[0066] Figure 43 This is a perspective view showing a portion of a light source module according to a third embodiment.

[0067] Figure 44 This is a perspective view showing a portion of a light source module according to a fourth embodiment.

[0068] Figure 45 This is a front view for explaining the inclination of the busbar in the fourth embodiment.

[0069] Figure 46 This is a front view showing a portion of a light source module according to a fifth embodiment.

[0070] Figure 47 It is a schematic diagram showing the steps of a method for manufacturing an optical unit.

[0071] Figure 48 It is a cross-sectional view showing a method for manufacturing an optical unit according to the sixth embodiment.

[0072] Figure 49 It is a perspective view showing the overall structure of a light source device including a light source module according to Embodiment 7, a condenser lens, and a wavelength conversion member.

[0073] Figure 50 It is a plan view showing the overall structure of the light-emitting device of embodiment 8.

[0074] Figure 51It is a perspective view showing another example of bonding between the first lens and the supporting member. DETAILED DESCRIPTION

[0075] The light source module of the embodiment of the present disclosure is described in detail below using the accompanying drawings. Furthermore, each embodiment described below represents a specific example of the present disclosure. Therefore, the values, shapes, materials, components, configurations of components, connection methods, steps, and the order of steps shown in the following embodiments are examples and are not intended to limit the present disclosure.

[0076] In addition, each figure is a schematic diagram and is not necessarily a strict illustration. Therefore, for example, the scales in each figure are not necessarily the same. In addition, in each figure, substantially the same structure is marked with the same reference numerals, and repeated descriptions are omitted or simplified.

[0077] In addition, in this specification, terms such as "equal" that indicate the relationship between elements, terms such as "flat shape" or "rectangular shape" that indicate the shape of an element, and numerical ranges are not expressions that express only strict meanings, but also mean that they also include substantially equivalent ranges, such as expressions of differences of about several percent.

[0078] In this specification, the terms "above" and "below" do not refer to the upper direction (vertically above) and the lower direction (vertically below) in absolute spatial recognition, but are used as terms that define relative positional relationships based on the stacking order in a stacked structure. Furthermore, the terms "above" and "below" apply not only to situations where two components are spaced apart from each other with another component between them, but also to situations where two components are closely spaced and in contact with each other.

[0079] The x-axis, y-axis, and z-axis represent the three axes of a three-dimensional orthogonal coordinate system related to the semiconductor laser element. The positive z-axis direction is sometimes referred to as "up," and the negative z-axis direction is sometimes referred to as "down." Furthermore, the upper surface is sometimes referred to as the "upper surface," and the lower surface is sometimes referred to as the "lower surface."

[0080] In each embodiment and each modification, the direction of travel along the optical axis of the laser light just emitted from the semiconductor laser element is set as the negative direction of the y-axis, the direction parallel to the fast axis of the laser light just emitted from the semiconductor laser element is set as the z-axis direction, and the direction parallel to the slow axis is set as the x-axis direction.

[0081] In the embodiments described below, a "plan view" refers to viewing the light source module from the positive side of the z-axis. A "front view" refers to viewing the light source module from the negative side of the y-axis, and this view is referred to as a front view. A "side view" refers to viewing the light source module from the positive or negative side of the x-axis, and this view is referred to as a side view.

[0082] (Implementation 1)

[0083] [structure]

[0084] First, use Figure 1 The structure of the light source module 10 according to the first embodiment will be described.

[0085] Figure 1 It is a perspective view showing the overall structure of the light source module 10 according to the present embodiment.

[0086] like Figure 1 As shown, the light source module 10 includes a housing 501, a base 510, a plurality of optical units (here, optical units 1, 2, 3, 4, 5, and 6), a plurality of reflectors 700, a condenser lens 800, an optical fiber 550, and a pair of terminals 552. The light source module 10 also includes a protective cover 551.

[0087] The light source module 10 is a module that can combine the laser beams emitted from multiple optical units in space through an optical system and then emit the combined beams. In addition, the light source module 10 can also be a module that can combine the laser beams emitted from multiple optical units in wavelength using an optical system and then emit the combined beams. Figure 1 Below this point, when the laser light intensity becomes 1 / (e 2 ) is recorded with a dotted line, showing the spread of the laser.

[0088] The housing 501 includes a base 502 , side walls 503 , and a cover (not shown).

[0089] The side wall 503 is arranged perpendicularly to the base 502 of the housing 501. In addition, the side wall 503 is arranged in a manner of surrounding a plurality of optical units, etc. In addition, a pair of terminals 552 are inserted through the side wall 503, and the outside and the inside of the housing 501 are electrically connected through the pair of terminals 552. The side wall 503 has a frame shape and a rectangular shape in a plan view, and is composed of, for example, Fe, Fe alloy, Fe-Ni-Co alloy, Cu, Cu alloy or Al. In addition, the base 502 is composed of, for example, Cu, Cu alloy, Al, ceramics with high thermal conductivity (such as AlN or BeO), etc. The cover is a component that covers the top of the housing 501, and is composed of, for example, an inorganic material such as a metal or ceramic material. The shape of the cover in a plan view is rectangular, covering the entire upper surface of the side wall 503.

[0090] The housing 501 has a space for accommodating the optical units 1 to 6. The space for accommodating the optical units 1 to 6 is hermetically sealed.

[0091] A base 510 is provided in the housing 501, and is provided with a plurality of worktables arranged in a stepped manner. The plurality of worktables are composed of a first worktable 511, a second worktable 512, a third worktable 513, a fourth worktable 514, a fifth worktable 515, and a sixth worktable 516. The first to sixth worktables 511 to 516 each have a first section and a second section. For example, the first worktable 511 has a first section 511a and a second section 511b. In each of the first to sixth worktables 511 to 516, the second section is located on the positive side of the z-axis relative to the first section, that is, located above. In addition, in the order of the first worktable 511, the second worktable 512, the third worktable 513, the fourth worktable 514, the fifth worktable 515, and the sixth worktable 516, they are arranged so that the z-axis position of each first section is on the positive side and the z-axis position of each second section is on the positive side. Each of the plurality of first segments and each of the plurality of second segments is a plane parallel to the xy plane and is an upper surface of a workbench.

[0092] In this embodiment, multiple optical units are each arranged on multiple workstations. Each of the multiple optical units is electrically connected to a pair of terminals 552, converts the power input to the pair of terminals 552, and emits laser light. In this embodiment, six optical units are provided. For identification purposes, the six optical units are sometimes described as optical unit 1, optical unit 2, optical unit 3, optical unit 4, optical unit 5, and optical unit 6. The multiple optical units are each arranged in the x-axis direction. The multiple optical units each have the same structure, but optical unit 1 will be described here.

[0093] Figure 2 It is a perspective view showing the structure of the optical units 1 and 2 according to the present embodiment. Figure 3 1 is a side view showing the structure of the optical unit 1 of this embodiment. Figure 3 Hereinafter, the optical axis LA1 of the laser beam L1 may be indicated by a dashed line. In this specification, the optical axis LA1 refers to a virtual light beam serving as the center of the laser beam L1.

[0094] The optical unit 1 includes a semiconductor laser element 200, a first submount 230, a fast-axis cylindrical lens 110, a first fast-axis adjustment lens 120, a support member 150, and a slow-axis collimating lens 170. The optical unit 1 is installed on a first stage 511. Components of the optical unit 1 will be described below.

[0095] The first sub-mount 230 is a flat-plate mounting base on which the semiconductor laser element 200 is mounted. The first sub-mount 230 has a first upper surface 231, which serves as the upper surface of the flat plate. In this embodiment, the first upper surface 231 is parallel to the xy plane. The semiconductor laser element 200 is mounted above the first upper surface 231.

[0096] The first submount 230 is disposed above the second section 511b. More specifically, the first submount 230 is disposed above the third bonding material 240 disposed above the second section 511b. The third bonding material 240 is made of an inorganic material such as a solder material such as AuSn or SnAgCu.

[0097] The first submount 230 is composed of, for example, a substrate made of a crystalline material such as AlN or SiC, or an insulating material such as ceramic, and a metal layer on the surface. The first submount 230 may include a first electrode and a second electrode on the first upper surface 231. On the first upper surface 231, the patterned first and second electrodes are arranged insulated from each other. The first and second electrodes are composed of, for example, one or more metal films such as Ni, Cu, Pt, and Au. The semiconductor laser element is arranged on the first electrode and electrically connected to the second electrode via a metal wire. The first and second electrodes are respectively connected to the second electrode, the first electrode, or the terminal 552 of the adjacent submount to supply power to the semiconductor laser element 200.

[0098] The semiconductor laser device 200 is a laser device including a semiconductor multilayer film and an optical waveguide formed on a semiconductor substrate. The semiconductor multilayer film includes an active layer, that is, the semiconductor laser device 200 includes an active layer.

[0099] The optical waveguide of semiconductor laser element 200 is disposed on the side of first submount 230. That is, semiconductor laser element 200 is fixed by so-called junction-down mounting. Furthermore, the semiconductor laser element is a transverse multimode laser that emits high-output laser light.

[0100] Semiconductor laser element 200 emits laser light L1 with a predetermined spread angle. More specifically, semiconductor laser element 200 converts external power input to an optical waveguide into stimulated emission light, such as laser light L1, and emits it from one end of the optical waveguide. The fast axis of laser light L1 is the axis along the stacking direction of the semiconductor stacked films of semiconductor laser element 200. The slow axis, orthogonal to the fast axis, is parallel to the stacking plane of the semiconductor stacked films.

[0101] In this embodiment, the active layer of the semiconductor laser element 200 extends in a direction parallel to the xy plane. The fast axis of the laser light L1 immediately after being emitted from the semiconductor laser element 200 is in the z-axis direction, and the slow axis of the laser light L1 is parallel to the x-axis direction.

[0102] The semiconductor laser element 200 can change the wavelength of the emitted laser light L1 by varying the semiconductor material it is composed of. For example, by using a nitride-based semiconductor laser element primarily composed of nitrides of Al, Ga, and In, the semiconductor laser element 200 can emit laser light L1 having a peak wavelength between 350 nm and 550 nm. Alternatively, by using a semiconductor primarily composed of Al, Ga, In, As, and P, the semiconductor laser element 200 can emit laser light L1 having a peak wavelength between 600 nm and 1600 nm. Furthermore, the semiconductor laser element 200 is not limited to being composed of the aforementioned semiconductor materials, and the wavelength of the laser light L1 emitted by the semiconductor laser element 200 is not limited to the aforementioned wavelengths. Furthermore, the semiconductor laser element 200 can select the spread angle of the laser light L1 emitted by the semiconductor stack structure and optical waveguide structure it comprises. The laser light L1 is emitted from the semiconductor laser element 200 while being spread out, and can be emitted at a speed of, for example, 1 / (e 2 ), the expansion angle is selected across the entire width of the substrate, the fast axis direction is selected between 20° and 70°, and the slow axis direction is selected between 5° and 30°.

[0103] The semiconductor laser element 200 has a rectangular shape that is long in the waveguide direction of the optical waveguide. The width of the optical waveguide is, for example, 5 μm to 300 μm inclusive, and the length is, for example, 500 μm to 5 mm inclusive.

[0104] The fast-axis cylindrical lens 110 (hereinafter referred to as FACL110 ) is a cylindrical lens into which the laser light L1 emitted from the semiconductor laser element 200 is incident and which converges the laser light L1 in the fast-axis direction of the laser light L1 .

[0105] In this embodiment, laser light L1 emitted from semiconductor laser element 200 directly enters FACL 110. FACL 110 narrows the divergence angle of laser light L1 along the fast axis, converting the incident laser light L1 into nearly parallel laser light L1 with a small divergence angle along the fast axis before emitting the laser light. In other words, the lens virtually collimates laser light L1 along the fast axis.

[0106] The FACL 110 is an optical component whose power (refractive power) in the fast axis direction is greater than that in the slow axis direction. The FACL 110 is a cylindrical lens having a power axis and a non-power axis. The power axis and the non-power axis are perpendicular to each other. The FACL 110 has a convex cylindrical surface, such as a convexly curved cylindrical surface, on the power axis.

[0107] Furthermore, FACL 110 is a convex cylindrical lens having an incident surface for laser light L1 and an exit surface for laser light L1. In other words, FACL 110 is a convex lens. In this embodiment, FACL 110 is a plano-convex cylindrical lens having a convex shape, with the incident surface being a flat surface parallel to the zx plane and the exit surface being a curved surface represented by an aspheric function.

[0108] In this embodiment, a plano-convex cylindrical lens is used as the FACL 110 . Alternatively, a biconvex cylindrical lens or a convex meniscus cylindrical lens having a convex surface on one side and a concave surface on the other side may be used.

[0109] The FACL 110 is a member made of an inorganic transparent material such as glass, and has anti-reflection coatings that match the wavelength of the laser light L1 formed on its incident and emitting surfaces.

[0110] Furthermore, the FACL 110 is fixed to the first sub-mount 230, for example, by an adhesive member (not shown). This adhesive member joins the FACL 110 to the first sub-mount 230. For example, this adhesive member may be composed of a UV-curable adhesive containing a UV-curable resin. Alternatively, this adhesive member may be composed of an inorganic adhesive formed by kneading an inorganic filler composed of an inorganic material such as alumina into a UV-curable resin. Alternatively, this adhesive member may be composed of an inorganic adhesive member composed of an inorganic material such as a solder material or a sintered metal.

[0111] The first fast-axis adjustment lens 120 (hereinafter, referred to as the first lens 120 ) is a lens into which the laser light L1 emitted from the FACL 110 is incident and which adjusts the optical axis LA1 of the laser light L1 in the fast-axis direction.

[0112] The first lens 120 is an optical component in which the power in the fast axis direction is greater than the power in the slow axis direction. In this embodiment, the first lens 120 is a cylindrical lens having a power axis and a non-power axis. Furthermore, the power axis and the non-power axis are arranged perpendicularly. The first lens 120 has a convex cylindrical surface, such as a cylindrical surface with a curved surface convex toward the power axis. The first lens 120 is a convex cylindrical lens. In other words, the first lens 120 is a convex lens.

[0113] Furthermore, the first lens 120 is a convex cylindrical lens having an incident surface for the laser light L1 and an exit surface for the laser light L1. Furthermore, the power of the first lens 120 is sufficiently smaller than that of the FACL 110. Furthermore, the curvature of the surface of the first lens 120 is sufficiently large relative to the beam spot of the transmitted laser light L1. The laser light L1 incident on the first lens 120 experiences a change in the amount of refraction depending on the position of incidence, and the direction of the optical axis LA1 changes accordingly as the laser light is emitted. This first lens 120 collimates the incident light that is slightly widened in the fast axis. In other words, the laser light L1, or virtually collimated light incident on the first lens 120, is emitted as laser light L1 collimated in the fast axis direction. Furthermore, the laser light L1 is emitted as laser light L1 with the direction of the optical axis LA1 changing depending on the position of incidence on the first lens 120.

[0114] In this embodiment, the first lens 120 is a plano-convex cylindrical lens with a flat incident surface and a convex exit surface. Furthermore, the incident surface is parallel to the zx plane, and the exit surface is a curved surface represented by a spherical function with a large radius of curvature.

[0115] In this embodiment, a plano-convex cylindrical lens is used as the first lens 120 . Alternatively, a biconvex cylindrical lens or a convex meniscus cylindrical lens with one convex surface and the other concave surface may be used.

[0116] The first lens 120 is made of an inorganic transparent material such as glass, and has anti-reflection coatings that match the wavelength of the laser light L1 formed on its incident surface and exit surface.

[0117] Furthermore, use Figure 4A and Figure 4B The first lens 120 and the supporting member 150 will be described.

[0118] Figure 4A It is a front view showing the first lens 120 and the supporting member 150 according to this embodiment.

[0119] The first lens 120 has a generatrix 125 , a first side surface 121 , a second side surface 122 , a third side surface 123 , and a fourth side surface 124 .

[0120] The busbar 125 is illustrated by a single-dot dashed line. The busbar 125 is a straight line that runs along the convex vertex portion of the surface of the convex cylinder that serves as the exit surface of the laser light L1. The first lens 120 of this embodiment is a component consisting solely of a lens body, and the thickness of the lens body of the first lens 120 is the thickest among the busbars 125. Furthermore, the straight lines at various positions when a cylindrical surface is formed by the movement of straight lines are busbars, and the busbar 125 is one of countless busbars. All busbars of the first lens 120 of this embodiment, including the busbar 125, are parallel to the xy plane.

[0121] The third side surface 123 is a side surface perpendicular to the busbar 125. The fourth side surface 124 is a side surface opposite to the third side surface 123 and perpendicular to the busbar 125. In this embodiment, the fourth side surface 124 of the first lens 120 is bonded to the support component 150. That is, the first lens 120 is bonded and supported by the support component 150 in the yz plane. Therefore, the first lens 120 can be oriented in the z-axis direction ( Figure 4A The position of the busbar 125 can be adjusted and fixed in the direction of the arrow in the y-axis direction and the y-axis direction. That is, the position of the busbar 125 can be adjusted and fixed in the direction of the fast axis of the laser light L1 or the optical axis LA1.

[0122] The support member 150 is fixed to the base 510 and supports the first lens 120. The support member 150 can have any shape as long as it can support the first lens 120. Here, as an example, it is a rectangular parallelepiped. The support member 150 has a first support side surface 151 parallel to the yz plane, a second support side surface 152 opposite to the first support side surface 151, an upper surface 153 parallel to the xy plane, and a lower surface 154 opposite to the upper surface 153.

[0123] The support member 150 is made of, for example, the same glass material as the first lens 120. Alternatively, it may be made of ceramics such as Al2O3, ZrO2, or SiN, or metal such as Fe or an Fe alloy.

[0124] Support member 150 is bonded to base 510. Lower surface 154 of support member 150 is bonded to first section 511a via second bonding material 162. Second bonding material 162 is an inorganic material such as solder or a metal sinter. In this case, support member 150 is made of glass or Al2O3 ceramic, and a base film made of a metal material such as Au that has good wettability with second bonding material 162 is formed on the surface of first support side surface 151 and lower surface 154. Second bonding material 162 is an inorganic adhesive made of a high-melting-point inorganic material such as AuSn solder or an Ag sinter.

[0125] The first lens 120 is bonded to the support member 150. The fourth side surface 124 of the first lens 120 is bonded to the first support side surface 151 of the support member 150 via the first bonding material 161. The first support side surface 151 is the mounting surface of the first lens 120. The first bonding material 161 is an inorganic adhesive component made of an inorganic material such as a solder material. In this case, a base film made of a metal material with good wettability with the solder material is also formed on the fourth side surface 124 of the first lens 120. The first bonding material 161 is made of a material with a lower melting point than the second bonding material 162, such as SnAgCu solder or AuSn solder.

[0126] Thus, in this embodiment, the first lens 120 is adjusted by moving its position in the fast axis direction, and the supporting component 150 is bonded to the first lens 120 by a surface (the first supporting side surface 151) and a surface (the fourth side surface 124). Therefore, compared with the case of bonding at points, for example, the thickness of the first bonding material 161 can be made thinner over a larger range. As a result, the stress inside the bonding material generated when the first bonding material 161 solidifies can be reduced, thereby suppressing a decrease in bonding strength. In addition, the melting point of the first bonding material 161 is lower than that of the second bonding material 162, so when the first lens 120 is fixed, the positional deviation of the supporting component 150 can be suppressed.

[0127] As described above, the first lens 120 is a lens for incident laser light L1 and adjusts the optical axis of the laser light L1 in the fast axis direction. More specifically, during the manufacture of the optical unit 1, the position of the first lens 120 is moved, i.e., adjusted, to increase the coupling efficiency between the emitted laser light L1 and the optical fiber 550.

[0128] When manufacturing the optical unit 1, the support member 150 is first fixed by the second bonding material 162. Then, to improve the coupling efficiency between the emitted laser light L1 and the optical fiber 550, the first lens 120 is moved and fixed by heating and cooling the first bonding material 161.

[0129] When the position of the first lens 120 is fixed, the first bonding material 161 may shrink upon curing. Even if this shrinkage occurs, the first lens 120 is supported in the yz plane, thereby preventing the generatrix 125 from shifting in the z-axis direction, i.e., the fast-axis direction.

[0130] Figure 4B This is a front view showing the first lens 120 and the supporting member 150 according to another example of the present embodiment.

[0131] The supporting member 150 is pre-formed on the base 510. For example, when the base 510 made of copper is formed, the supporting member 150 is formed by processing at the same time. In addition, when the base 502 and the side wall 503 are joined to manufacture the housing 501, similarly, a structure in which the supporting member 150 made of Fe alloy is joined and fixed to the base 502 using silver solder can also be adopted. According to another example, the first lens 120 includes a lens body 1201 made of glass and a lens frame 1202 made of Fe alloy. The lens frame 1202 is a flange. The lens body 1201 and the lens frame 1202 are pre-joined by low-melting-point glass or the like. In addition, Figure 4B The lens body 1201 of the other example shown is equivalent to Figure 4A The first lens 120 of this embodiment is shown.

[0132] In another example, the support member 150 similarly has a first support side surface 151. Furthermore, the first lens 120 has a fourth side surface 124. Similarly, in this other example, the first lens 120 is moved while the first support side surface 151 is brought into close contact with the fourth side surface 124, and is fixed to the support member 150 by the first bonding material 161. In this other example, a laser is irradiated onto a portion of the lens frame 1202 and the support member 150 that is close to each other, causing the lens frame 1202 and a portion of the support member 150 to melt and weld. That is, the first lens 120 and the support member 150 are bonded using the first bonding material 161, which is a welding portion made of an inorganic material. This allows the first lens 120 to be securely fixed.

[0133] Therefore, the first lens 120 of another example can be in the z-axis direction ( Figure 4B The position of the busbar 125 can be adjusted and fixed in the direction of the arrow in the y-axis direction and the y-axis direction. That is, the position of the busbar 125 can be adjusted and fixed in the direction of the fast axis of the laser L1 or the optical axis LA1.

[0134] The laser light L1 emitted from the first lens 120 of this embodiment and another example of this embodiment is collimated in the fast axis direction and travels while expanding in the slow axis direction. The laser light L1 emitted from the first lens 120 enters the slow axis collimating lens 170 (hereinafter referred to as SACL170). Return Figure 2 as well as Figure 3 , describe SACL170.

[0135] The SACL170 lens receives laser light L1 emitted from the first lens 120 and collimates the laser light L1 along its slow axis. The SACL170 lens has power along its slow axis. It also has a non-power axis perpendicular to its power axis. The SACL170 lens has a power axis that includes a convexly curved cylindrical surface, i.e., a convex cylindrical surface. In this embodiment, the SACL170 is a plano-convex cylindrical lens with a flat surface for laser light L1 and a convex surface for laser light L1. As an example, the SACL170 is made of glass with an anti-reflection coating formed on its surface.

[0136] Furthermore, the SACL 170 may be a biconvex cylindrical lens or a meniscus cylindrical lens with one surface being convex and the other being concave.

[0137] The plurality of SACLs 170 collimate the slow axis direction component of the incident laser beam and are provided in the first section 511 a .

[0138] According to the above configuration, the laser light L1 that has passed through the SACL 170 becomes collimated light in both the fast and slow axes and travels to the reflector 700. Furthermore, the beam width of the laser light L1 in the fast axis direction that reaches the reflector 700 is width W1, which is the same as the beam width W1 in the fast axis direction of the laser light L1 emitted from the first lens 120.

[0139] Use again Figure 1 The reflecting mirror 700 will be described.

[0140] like Figure 1 As shown, optical unit 1 emits laser light L1. Similarly, optical units 2 to 6 emit laser light L2, L3, L4, L5, and L6, respectively. The laser lights (ie, laser lights L1 to L6) emitted from the optical units enter the reflection mirrors 700.

[0141] The multiple reflectors 700 are optical components each having an incident surface (reflecting surface) for the laser beams that have passed through the multiple SACLs 170. The multiple reflectors 700 reflect the laser beams collimated by the multiple first lenses 120 and the multiple SACLs 170, deflecting the laser beams by 90°. The reflective surfaces of the multiple reflectors 700 are inclined 45° relative to the zx plane in plan view. Here, the multiple laser beams L1 to L6 travel parallel to the y-axis in the negative y-axis direction and enter the multiple reflectors 700. The multiple laser beams L1 to L6, reflected by the multiple reflectors 700, travel parallel to the x-axis in the positive x-axis direction.

[0142] The plurality of reflecting mirrors 700 are respectively disposed at the first section of each of the plurality of work stages. For example, the reflecting mirror 700 on which the laser light L1 is incident is disposed at the first section 511 a.

[0143] The plurality of laser beams L1 to L6 reflected by the reflecting mirror 700 are spatially multiplexed so that their fast axes coincide with the same optical axis, and then reach the condensing lens 800 fixed to the base 502 .

[0144] The condenser lens 800 is an optical component having an incident surface for the laser beams that have passed through the multiple SACLs 170. Furthermore, the condenser lens 800 is also an optical component for the multiple laser beams L1 to L6 that have passed through the reflector 700. In this embodiment, the condenser lens 800 is a lens that focuses the multiple laser beams L1 to L6 that have arrived. The multiple laser beams L1 to L6, whose fast axes are aligned with the same optical axis after passing through the reflector 700, are incident on the condenser lens 800. Furthermore, the multiple laser beams L1 to L6 focused by the condenser lens 800 are incident on the end face, or incident surface, of the core of the optical fiber 550, which is an example of the object 550a. By providing such a condenser lens 800, the multiple laser beams L1 to L6 can be efficiently focused on the object 550a.

[0145] Optical fiber 550 is provided so as to penetrate sidewall 503. Laser light from each of the multiple optical units, focused by reflector 700, is coupled to optical fiber 550. Furthermore, protective cover 551 is a component used to cover and protect the periphery of optical fiber 550. The multiple laser light coupled to optical fiber 550 propagates within the core of optical fiber 550 and is emitted from the end of optical fiber 550 outside housing 501 as output laser light L100.

[0146] Furthermore, all of the plurality of reflecting mirrors 700 corresponding to the plurality of optical units can have the same shape.

[0147] In addition, if Figure 1 As shown, each of the plurality of workbenches of the base 510 is provided with an optical unit and a reflecting mirror 700 .

[0148] Here, further use Figure 5 The parameters of the optical unit 1 will be described in more detail.

[0149] In addition, use Figure 6A The beam spots of the plurality of laser beams L1 to L6 on the incident surface of the condenser lens 800 will be described. Figure 6B The beam spots of the laser light L1 and the laser light L2 at the end face of the core of the optical fiber 550 will be described.

[0150] Figure 5 This is a side view of the optical unit 1 according to the present embodiment. That is, it shows the structure of the optical system of the optical unit 1 in the fast axis direction.

[0151] The semiconductor laser element 200 emits laser light L1 having a predetermined spread angle from one end of the optical waveguide, namely, a light emitting point 201. The width of the region emitting laser light L1 in the active layer of the semiconductor laser element 200 in the optical unit 1 in the slow axis direction (x-axis direction) is sometimes referred to as the light emitting region width.

[0152] As described above, the optical unit 1 includes the FACL 110 and the first lens 120. Therefore, the optical system of the optical unit 1 in the fast axis direction can be handled using a composite lens composed of the FACL 110 and the first lens 120. Each lens has a principal point and an effective focal length, determined by factors such as surface curvature and thickness. The principal point of the FACL 110 is principal point P1, and the effective focal length is effective focal length F1. The principal point of the first lens 120 is principal point P2, and the effective focal length is effective focal length F2. Furthermore, the composite lens has principal point P0, which is the principal point, and effective focal length F, which is the effective focal length. The distance between the FACL 110 and the first lens 120 is the distance between the principal points P1 and P2, i.e., the lens distance d.

[0153] First lens 120 is a convex cylindrical lens, so F2 > 0. Furthermore, principal point P0 is determined by principal point P1, principal point P2, effective focal length F1, effective focal length F2, and lens distance d. The distance between principal point P0 and principal point P1 is δ. Effective focal length F is determined by effective focal length F1, effective focal length F2, and lens distance d.

[0154] In the optical unit 1, a light-emitting point 201 is arranged near the focal position of the composite lens. Therefore, the distance between the principal point P0 of the composite lens and the light-emitting point 201 corresponds to the effective focal length F of the composite lens.

[0155] The beam width of laser light L1 emitted from the first lens 120 of the optical unit 1 in the fast axis direction is defined as width W1. In a light source module 10 equipped with multiple optical units, when combining multiple laser beams in the fast axis direction, width W1 is preferably as small as possible. In this case, width W1 is proportional to the effective focal length F of the combining lens, so the smaller the effective focal length F, the better.

[0156] Figure 6A 1 is a diagram showing beam spots of a plurality of laser beams L1 to L6 on the incident surface of the condenser lens 800 according to the present embodiment.

[0157] exist Figure 6A In FIG, the beam points of the plurality of lasers L1 to L6 are indicated by dotted lines. The beam points indicate the range where the beam intensity of the lasers L1 to L6 is high, and the beam intensity becomes 1 / (e 2 ) is indicated by a dotted line. Furthermore, the beam spot of laser light L1 is indicated by beam spot LO1, the beam spot of laser light L2 is indicated by beam spot LO2, the beam spot of laser light L3 is indicated by beam spot LO3, the beam spot of laser light L4 is indicated by beam spot LO4, the beam spot of laser light L5 is indicated by beam spot LO5, and the beam spot of laser light L6 is indicated by beam spot LO6.

[0158] The width of the beam spot LO1 in the fast axis (z axis) direction is W1. Figure 3 As described in the above, the width W1 is the same as the beam width in the fast axis direction of the laser light L1 reaching the reflector 700. Figure 5 As described in , this is the same as the width W1 , which is the beam width in the fast axis direction of the laser light L1 emitted from the first lens 120 .

[0159] That is, in this embodiment, the beam width of laser light L1 in the fast axis direction, i.e., width W1, is constant from the time laser light L1 is emitted from first lens 120 to the time it is incident on condenser lens 800. The width of beam spot LO2 in the fast axis direction is width W2, the width of beam spot LO3 in the fast axis direction is width W3, the width of beam spot LO4 in the fast axis direction is width W4, the width of beam spot LO5 in the fast axis direction is width W5, and the width of beam spot LO6 in the fast axis direction is width W6.

[0160] As with laser L1, laser L2 has a constant beam width W2 in the fast axis direction from the time it exits first lens 120 to the time it enters condenser lens 800. This constant beam width in the fast axis direction also applies to lasers L3 to L6.

[0161] In addition, the width in the fast axis direction between beam spot LO1 and beam spot LO2 is width D1, the width in the fast axis direction between beam spot LO2 and beam spot LO3 is width D2, the width in the fast axis direction between beam spot LO3 and beam spot LO4 is width D3, the width in the fast axis direction between beam spot LO4 and beam spot LO5 is width D4, and the width in the fast axis direction between beam spot LO5 and beam spot LO6 is width D5.

[0162] Furthermore, the width of the combined laser light in the fast axis direction after spatially combining laser light L1 to L6 is width Wt1. Width Wt1 is the sum of width W1, width D1, width W2, width D2, width W3, width D3, width W4, width D4, width W5, width D5, and width W6. When the outer diameter of condenser lens 800 is fixed, in order for all laser light L1 to L6 to be incident on condenser lens 800, width Wt1 must be less than or equal to the outer diameter of condenser lens 800. More preferably, width Wt1 is less than or equal to 1 / √2 of the outer diameter of condenser lens 800. Therefore, widths W1, D1, W2, D2, W3, D3, W4, D4, W5, D5, and W6 are preferably less than or equal to a certain value. While this embodiment illustrates the case where six laser light L1 to L6 are incident, it is preferable to make widths W1 and D1 smaller when more laser light is incident.

[0163] Figure 6B 1 and 2 are diagrams showing beam spots of the laser light L1 and the laser light L2 on the end face of the core of the optical fiber 550 , which is the object 550 a of the present embodiment.

[0164] The laser light emitted from the condenser lens 800 is incident on the object 550 a . Figure 6B FIG. 5 shows an example of the beam spots of the laser light L1 and the laser light L2 on the end face of the core of the optical fiber 550 as the object 550a. Figure 6B, a core having a size DS in the y-axis direction and a size DF in the z-axis direction, and a beam spot of laser light L1 having a size WS1 in the y-axis direction and a size WF1 in the z-axis direction are shown. The size WF1 of laser light L1 in the z-axis direction is the sum of the size of the light emitting point 201 of the semiconductor laser element 200 in the z-axis direction and the optical magnification of the optical system consisting of the FACL 110, the first lens 120, and the focusing lens 800. The beam spot of laser light L2 is also shown. In object 550a, laser light L1 and laser light L2 are arranged in an overlapping state within the core. Laser light L3 to L6 (not shown) are similarly arranged in an overlapping state with laser light L1 and L2 within the core. Therefore, multiple laser light L1 to L6 can be incident on the same core in overlapping fashion. This allows the multiple laser light L1 to L6 to be combined, increasing the intensity of the laser light within the core and achieving a light source module 10 with high brightness for emitting laser light L100. In this embodiment, an example is shown in which six laser beams L1 to L6 are made incident on the core in a superimposed manner. However, by making more laser beams incident on the core, a light source module 10 with higher brightness of the emitted laser beam L100 can be realized.

[0165] As described above, the beam width W1 of laser light L1 in the fast-axis direction is relatively small. Similarly, the beam widths W2 to W6 of laser light L2 to L6 in the fast-axis direction are also relatively small. Therefore, in this embodiment, the width Wt1 of the combined laser light in the fast-axis direction after spatially combining laser light L1 to L6 is smaller than the width of the incident surface of condenser lens 800, which has a predetermined size.

[0166] By reducing the width W1 in this manner, it is possible to increase the number of laser beams incident on the incident surface of the condenser lens 800 of a predetermined size. This can increase the radiation brightness of the laser beams emitted from the condenser lens 800.

[0167] exist Figure 6B , laser light L1 and laser light L2 are slightly offset from each other. However, before entering condenser lens 800, if laser light L1 and laser light L2 are completely parallel, laser light L1 and laser light L2 are aligned. Furthermore, before entering condenser lens 800, for example, if the traveling direction of laser light L1 is tilted relative to imaginary line IL, the beam spot of laser light L1 is located outside object 550a, thereby reducing coupling efficiency.

[0168] Therefore, by increasing the number of laser beams L1 to L6 to be combined at the incident surface of condenser lens 800 and aligning each laser beam L1 to L6 with imaginary line IL, the amount of laser beams L1 to L6 incident on optical fiber 550 from the end face of the core of optical fiber 550 can be increased. Furthermore, the amount and radiant brightness of the laser beams emitted from optical fiber 550 of light source module 10 can be increased.

[0169] In the optical unit 1, the effective focal length F1 of the FACL 110 is small, while the effective focal length F2 of the first lens 120 is sufficiently greater than the effective focal length F1 of the FACL 110. In this case, the effective focal length F of the synthesizing lens approaches the effective focal length F1. Therefore, to minimize the beam width W1 of the laser light L1 in the fast axis direction, as described above, the effective focal length F1 can be reduced, while increasing the ratio of the effective focal length F2 to the effective focal length F1. This increases the amount and radiant brightness of the laser light emitted from the optical fiber 550 of the light source module 10.

[0170] Here, width W1, representing the beam width, is preferably small. However, if it is too small, lenses such as FACL 110 become too small and difficult to handle. In this embodiment, width W1 is, for example, not less than 0.17 mm and not more than 0.5 mm. Furthermore, in this embodiment, the effective focal length F1 of FACL 110 is, for example, not less than 0.15 mm and not more than 0.65 mm.

[0171] And, use Figure 7 and Figure 8 The effect of adjusting the first lens 120 will be described. Here, the effect is described using the laser light L1 emitted from the optical unit 1, but the same effect can be expected for the optical units 2 to 6.

[0172] Figure 7 This is a side view of the optical unit 1 showing an example of adjusting the position of the first lens 120 of the optical unit 1 in the fast axis direction in the method of manufacturing the light source module 10 according to the present embodiment. Figure 8 This is a side view of the optical unit 1 showing another example of adjusting the position of the first lens 120 of the optical unit 1 in the fast axis direction in the method of manufacturing the light source module 10 according to the present embodiment.

[0173] use Figure 1The manufacturing method of the light source module 10 is described. First, the semiconductor laser element 200 is placed on the base 510 of the housing 501 via the first submount 230. Next, the optical fiber 550, the reflector 700, and the focusing lens 800 are fixed to the housing 501 at a predetermined position using bonding material (not shown). Next, the FACL 110, the first lens 120, and the SACL 170 are arranged at predetermined positions. Here, the FACL 110, the first lens 120, and the SACL 170 are initially arranged at the design center of the optical system. However, in reality, because the positions of the semiconductor laser element 200 and the subsequent optical system are slightly offset from the design positions, the positions of the FACL 110 and the SACL 170 need to be fine-tuned to improve the coupling efficiency between the laser lights L1 to L6 and the optical fiber 550. As this method, the semiconductor laser element 200 emits light while monitoring the amount of light emitted from the optical fiber 550 , and the FACL 110 and SACL 170 are moved to optimal positions and fixed by so-called active alignment to perform position adjustment and fixation.

[0174] However, even if these position adjustments and fixations are performed, the coupling efficiency between the laser beams L1 to L6 and the optical fiber 550 may not be sufficiently improved. Figure 7 This shows an example in which the coupling efficiency is improved by adjusting the position of the first lens 120 after the FACL 110 is fixed. Figure 7 (a) is a side view before adjusting the first lens 120. Figure 7 For ease of explanation, the imaginary line IL, the optimal optical axis of the optical unit 1, is shown. Specifically, the coupling efficiency is highest when the laser light L1 is incident on the reflector 700 aligned with or parallel to the imaginary line IL. In this embodiment, the imaginary line IL is parallel to the y-axis, and the position of the imaginary line IL in the z-axis direction is the same as the position of the light-emitting point 201 in the z-axis direction. As described above, the FACL 110 is positioned using active alignment and secured with an adhesive (not shown). However, during the securing of the adhesive, the position of the FACL 110 may deviate by several sub-micrometers to several micrometers from the specified position due to curing shrinkage and other factors. In particular, when the FACL 110 deviates toward the fast axis, the focal length is shortened, significantly reducing the coupling efficiency.

[0175] Figure 7 The figure shows a case where FACL 110 is offset in the positive z-axis direction (upward) (indicated by a short arrow). In this case, virtually collimated laser light L1 tilts upward from the y-axis direction by an angle of 0° or more and propagates in the negative y-axis direction. In other words, the angle formed between the optical axis LA1 of laser light L1 passing through FACL 110 and the imaginary line IL is greater than 0°.

[0176] At this time, if Figure 7As shown in (a), when the z-axis position of the generatrix 125 of the first lens 120 overlaps with the imaginary line IL, that is, when the first lens 120 is positioned as designed during the light source module manufacturing method, the laser light L1 transmitted through the first lens 120 tilts upward from the y-axis and travels in the negative y-axis direction, although the angle between the optical axis LA1 of the laser light L1 and the imaginary line IL changes due to refraction. In this case, a portion of the laser light L1 does not enter the reflector 700, or even if it does, it cannot pass through the focusing lens 800 and enter the optical fiber 550. If this state is maintained, the coupling efficiency in the light source module 10 is reduced.

[0177] However, if Figure 7 As shown in (b), in this embodiment, the position of the first lens 120 is adjusted. Figure 7 In (b), the position of the first lens 120 before the movement is indicated by a double-dashed line. Also, a generatrix 1251 of the first lens 120 before adjustment is shown. For example, Figure 7 As shown, while the FACL 110 is fixed while offset in the positive z-axis direction, the position of the first lens 120 is adjusted in the negative z-axis direction (indicated by the long arrow). Specifically, the generatrix 125 of the first lens 120 is positioned at a predetermined position farther from the imaginary line IL than the generatrix 1251 before adjustment, further to the negative z-axis. This allows the collimated laser light L1 that has passed through the first lens 120 to be refracted further than before adjustment. Although offset from the imaginary line IL, it can still travel parallel to it. At this point, similar to the FACL 110, the position of the first lens 120 is adjusted to the optimal position by monitoring the amount of light emitted from the optical fiber 550 while emitting light from the semiconductor laser element 200.

[0178] Thus, the laser light L1 is reflected by the reflecting mirror 700 and can be incident on the optical fiber 550 through the condenser lens 800. Furthermore, in the light source module 10, the coupling efficiency can be improved.

[0179] In the above example, if the FACL 110's position shifts from its specified position by several sub-μm to several μm in the z-axis direction, coupling efficiency will drop dramatically. On the other hand, even if the first lens 120 shifts from its specified position by several μm to tens of μm, coupling efficiency will not change significantly. This prevents any drop in coupling efficiency even if the first lens 120 shifts by several μm due to shrinkage of the bonding material, etc., while the first lens 120 is fixed.

[0180] Figure 8(a) illustrates an example where the optical axis LA1 of the laser light L1 transmitted through the FACL 110 is parallel to or aligned with the imaginary line IL. Specifically, this is when the FACL 110 is adjusted and fixed at the optimal position, with no deviation. In this case, the position of the first lens 120 does not need to be adjusted.

[0181] Figure 8 (b) is a diagram showing the case where the FACL 110 is fixed after being offset from a predetermined position in the negative direction of the z axis (short arrow). Figure 8 In (b), the position of the first lens 120 before movement is indicated by a dotted line, which indicates a generatrix 1251 before adjustment of the first lens 120. In this case, the virtually collimated laser light L1 that has passed through the FACL 110 is tilted downward from the y-axis direction to an angle of 0° or more relative to the imaginary line IL and travels in the negative y-axis direction.

[0182] Moreover, in Figure 8 In (b), the position of the first lens 120 is adjusted in the positive direction of the z-axis. That is, the busbar 125 of the first lens 120 is located on the positive side of the z-axis with respect to the busbar 1251. As a result, the collimated laser light L1 that has passed through the first lens 120 is refracted more greatly than the first lens 120 before the adjustment, and travels parallel to the imaginary line IL. That is, after passing through the FACL 110, the optical axis LA1 tilts downward from the y-axis direction to an angle of more than 0°, but after passing through the first lens 120, it becomes parallel to the imaginary line IL. Therefore, after being reflected by the reflector 700, the laser light L1 can be incident on the optical fiber 550, and the coupling efficiency can be improved in the light source module 10.

[0183] exist Figure 7 and Figure 8 , an example is shown in which first lens 120 moves in the z-axis direction, but the present invention is not limited to this. For example, if first lens 120 moves in the y-axis direction, the distance between the incident surface of first lens 120 and light-emitting point 201 of semiconductor laser element 200 changes. As a result, the parallelism of laser light L1 emitted from first lens 120 can be controlled.

[0184] Next, a specific example of the light source module 10 of the present embodiment will be described. Here, the light source module 10x of Comparative Example 1 and the light source module 10xx of Comparative Example 2 will also be described.

[0185] Figure 9 1 is a side view showing a light source module 10 x according to Comparative Example 1. Figure 10 1 is a side view showing a light source module 10xx of Comparative Example 2. Figure 11 FIG is a side view showing the light source module 10 of this embodiment. Figures 9 to 11 In the figure, two optical units are used for illustration for simplicity.

[0186] In addition, Figures 9 to 11 In the embodiment, laser beams L1 and L2 are emitted from two optical units. Figures 9 to 11 The beam width of the laser light L1 in the fast axis direction that reaches the reflector 700 when viewed from the side is width W1. The beam width of the laser light L2 in the fast axis direction that reaches the reflector 700 is width W2. Similarly, when viewed from the side, the width in the fast axis direction between the laser light L1 and the laser light L2 that reach the reflector 700 is width D1. And, when viewed from the side, the width in the fast axis direction that is the sum of width W1, width D1, and width W2 is width Wt2. In addition, Figure 11 The width of the fast axis between the laser L1 and the laser L2, that is, the width D1, is the same as that in Figure 6A The widths of the beam spots LO1 and LO2 described above in the fast axis direction are the same.

[0187] Comparative Example 1 ( Figure 9 ) has the same structure as the light source module 10 of the present embodiment, except that the optical units 1 to 6 are replaced with an optical unit 1x and an optical unit 2x having the same structure as the optical unit 1x, and four optical units.

[0188] The optical unit 1 x of Comparative Example 1 has the same structure as the optical unit 1 of the present embodiment, except that it does not include the first lens 120 .

[0189] In order to reduce the width Wt2 in the optical unit 1x, it is necessary to reduce the effective focal length F1x of the fast-axis collimating lens 1101 and thereby reduce the widths W1 and W2. Here, a problem that may occur when the effective focal length F1x is small will be described.

[0190] In this optical unit 1x, the position of the principal point P1 with the highest coupling efficiency is set as the optimal position of the principal point P1. When manufacturing the optical unit 1x, the position of the principal point P1 is sometimes offset from the optimal position of the principal point P1. A specific example is that after the fast-axis collimating lens 1101 is adjusted by active alignment, the volume of the bonding material changes when it is fixed, and the fast-axis collimating lens 1101 is offset. In the case where F1x, which is the effective focal length, is small, for example, when the position of the principal point P1 is offset from the optimal position of the principal point P1 in the z-axis direction, the traveling direction of the laser is tilted relative to the imaginary line IL, resulting in a problem of reduced coupling efficiency with the optical fiber. Figure 9 In FIG, the laser beams with such inclined traveling directions are represented as laser beam L11 and laser beam L21. Figure 9 In FIG. 1 , laser light obtained when the position of the principal point P1 is not deviated from the optimal position of the principal point P1 when manufacturing the optical units 1 x and 2 x is represented as laser light L1 and laser light L2 .

[0191] In addition, since the optical unit 1x does not have the first lens 120, it cannot play the role of Figure 11 Therefore, in the light source module 10x of Comparative Example 1, the coupling efficiency is likely to be lowered compared to the present embodiment.

[0192] The light source module 10xx of Comparative Example 2 has the same structure as the light source module 10 of the present embodiment, except that it includes an optical unit 1xx, an optical unit 2xx having the same structure as the optical unit 1xx, and four optical units instead of the optical units 1 to 6 .

[0193] The optical unit 1 xx of Comparative Example 2 has the same structure as the optical unit 1 of the present embodiment, except that a first lens 120 xx is provided instead of the first lens 120 .

[0194] In Comparative Example 2, the effective focal length of the composite lens formed by the FACL 110 and the first lens 120xx is set to Fxx. The distance between the principal point P0 and the principal point P1 is set to δxx. The distance between the principal point P1 of the FACL 110 and the principal point P2 of the first lens 120xx is set to dxx. The effective focal length of the first lens 120xx is set to F2xx.

[0195] In the light source module 10xx of Comparative Example 2, F2xx is insufficiently large compared to the effective focal length F1 of the FACL 110. Furthermore, in the light source module 10xx of Comparative Example 2, the values ​​of F2xx and dxx are relatively close. In this case, δxx is relatively large relative to F2xx, that is, the values ​​of F2xx and δxx are close to each other. Furthermore, in the light source module 10 of the embodiment, δ is relatively small relative to F2. More specifically, F2, δ, F2xx, and δxx satisfy the relationship (F2 / δ) > (F2xx / δxx).

[0196] In the light source module 10xx, since δxx is relatively large relative to F2xx, even if the FACL 110 having a small effective focal length F1 is used, the widths W1 and W2 become larger, and as a result, the width Wt2 becomes larger.

[0197] The width Wt2 becomes larger, resulting in the width of the fast axis direction of the combined laser after spatial combination being larger than that of the focusing lens. Figure 10 In the light source module 10x of the comparative example 2 shown in FIG. Figure 11 Compared with the present embodiment shown, the coupling efficiency is likely to decrease.

[0198] Furthermore, the following description will be given using Equations 17 and 18.

[0199] The effective focal length F of the composite lens, the effective focal length F1 of the FACL 110, the effective focal length F2 of the first lens 120, the lens distance d which is the distance between the principal points P1 and P2, and the distance δ between the principal points P0 and P1 satisfy Equations 17 and 18.

[0200] 1 / F=(1 / F1)+(1 / F2)-(d / (F1×F2))…(Equation 17)

[0201] δ=(F×d) / F2…(Equation 18)

[0202] F, which is the effective focal length of the composite lens, can be expressed by Formula 17. Furthermore, δ, which is the distance between the principal point P0 and the principal point P1, can be expressed by Formula 18.

[0203] In this embodiment, by sufficiently increasing F2, F can be brought close to F1, and δ can be reduced.

[0204] Next, for the light source module 10 x of Comparative Example 1, the calculation results of the change in coupling efficiency when the position of the fast-axis collimator lens is shifted from the optimal position will be described.

[0205] Figure 12 This figure shows the results of simulation calculation of the change in coupling efficiency under various optical system conditions (conditions A1 to A9) for the light source module 10x of Comparative Example 1. The structure of the light source module 10x is as follows: Figure 1 The light source module 10 is constructed without the first lens 120 and support member 150. Specifically, six optical units, consisting of the semiconductor laser element 200, the fast-axis collimator lens 1101, and the SACL 170, are arranged on a base. The emitted light from each optical unit is reflected by six mirrors and spatially combined in the fast-axis direction. The combined light is then focused by a condenser lens onto the end face of the optical fiber for coupling. Figure 13 It shows the description Figure 12 The table shows multiple optical system conditions (conditions A1 to A9). Specifically, the table shows the optical parameters of the semiconductor laser element 200, fast-axis collimator lens 1101, SACL 170, condenser lens 800, and optical fiber 550 under conditions A1 to A9. The fast-axis collimator lens 1101 is a plano-convex lens with a flat incident surface and a curved exit surface represented by an aspheric function.

[0206] In light source module 10x, given the divergence angle of semiconductor laser element 200 and the numerical aperture of the optical fiber, the coupling efficiency to optical fiber 550 strongly depends on the width of the light-emitting region of semiconductor laser element 200 and the core diameter of the optical fiber. Therefore, calculations were performed using nine conditions, obtained by multiplying the three optical system conditions (conditions A1 to A3, conditions A4 to A6, and conditions A7 to A9) by the three combinations of light-emitting region width and core diameter.

[0207] like Figure 13 As shown in Figure 1, under conditions A1 to A9, the peak wavelength of the semiconductor laser element 200 is all 450 nm. In addition, when semiconductor laser elements with different peak wavelengths are used, the lens materials, lens functions, surface anti-reflection coatings, and reflective designs of each lens are optimized, but the same results are obtained. The spread angle of the semiconductor laser element 200 is 1 / (e 2 ) with a fast-axis angle of 48° and a slow-axis angle of 12°. Furthermore, similar results can be achieved by optimizing the optical system when using a semiconductor laser element with a spread angle that is also different from the peak wavelength. Furthermore, focusing lens 800 is a plano-convex lens with an incident surface represented by an aspheric function and a flat exit surface. Optical fiber 550 is a step-index multimode optical fiber having a core and a cladding, and has a numerical aperture (NA) of 0.22.

[0208] Under condition A1, the light emitting region width of the semiconductor laser element 200 is 50 μm, the effective focal length F1x of the fast axis collimating lens 1101 is 0.15 mm, the effective focal length of the SACL 170 is 6.4 mm, the effective focal length of the focusing lens 800 is 4.5 mm, and the core diameter of the optical fiber 550 is 50 μm.

[0209] Condition A2 is the same as Condition A1 except that the core diameter of the optical fiber 550 is 70 μm. Condition A3 is the same as Condition A1 except that the light emitting region width is 100 μm and the core diameter of the optical fiber 550 is 100 μm.

[0210] Condition A4 is the same as Condition A1 except that the effective focal length F1x of the fast-axis collimator lens 1101 is 0.38 mm, the effective focal length of the SACL 170 is 13.5 mm, and the effective focal length of the condenser lens 800 is 7.3 mm.

[0211] Condition A5 is the same as Condition A4 except that the core diameter of the optical fiber 550 is 70 μm. Condition A6 is the same as Condition A4 except that the light emitting region width is 100 μm and the core diameter of the optical fiber 550 is 100 μm.

[0212] Condition A7 is the same as Condition A1 except that the effective focal length F1x of the fast-axis collimator lens 1101 is 0.65 mm, the effective focal length of the SACL 170 is 15.3 mm, and the effective focal length of the condenser lens 800 is 11.3 mm.

[0213] Condition A8 is the same as Condition A7 except that the core diameter of the optical fiber 550 is 70 μm. Condition A9 is the same as Condition A7 except that the light emitting region width is 100 μm and the core diameter of the optical fiber 550 is 100 μm.

[0214] Then, follow Figure 13 A simulation was performed under the multiple conditions shown (Conditions A1 to A9). In this simulation, six laser beams emitted from the six optical units (optical unit 1x, optical unit 2x having the same structure as optical unit 1x, and four optical units) included in the light source module 10x of Comparative Example 1 were spatially combined, and the coupling efficiency when incident on the optical fiber 550 was calculated. Furthermore, this coupling efficiency was calculated as the ratio of the total light intensity of the six laser beams emitted from the six semiconductor laser elements 200 to the light intensity of the laser beams propagating through the core of the optical fiber 550. The normalized coupling efficiency is the coupling efficiency expressed as 1 when each optical element is optimally positioned in each optical system.

[0215] Figure 12 (a) Calculate the coupling efficiency using conditions A1 to A3. Figure 12 (b) Calculate the coupling efficiency using conditions A4 to A6. Figure 12 (c) Calculate the coupling efficiency using conditions A7 to A9.

[0216] Figure 12 The horizontal axis in represents the change in the z-axis position of the six fast-axis collimator lenses 1101 included in the six optical units. Note that, here, all six fast-axis collimator lenses 1101 experience the same position change.

[0217] right Figure 12 The case where the horizontal axis, i.e. the z-axis direction, is 0 is described below. Figure 12 In each of the multiple conditions, the z-axis position of each of the six fast-axis collimating lenses 1101 when the light source module 10x exhibits the highest coupling efficiency is set to 0, and the coupling efficiency at this time is set to 1 for standardization. In other words, the z-axis position of 0 means that the principal point P1 of each of the six fast-axis collimating lenses 1101 is at the optimal position of the principal point P1. Figure 12 , shows the change in coupling efficiency when all six fast-axis collimating lenses 1101 included in the six optical units are moved from the position 0 in the z-axis direction to the positive direction or the negative direction of the z-axis.

[0218] like Figure 12 As shown in (a), under conditions A1 to A3, when the positions of the six fast-axis collimating lenses 1101 are moved by only 0.5 μm in the positive or negative direction of the z-axis, the coupling efficiency begins to decrease to about 0.85 to about 0.99. Even if it is moved by only 1 μm, the coupling efficiency is reduced to about 0.2 to about 0.85.

[0219] In addition, if Figure 12 As shown in (b), under conditions A4 to A6, even if the position of each of the six fast-axis collimating lenses 1101 is slightly moved by 1.5 μm in the positive or negative direction of the z-axis, the coupling efficiency decreases to approximately 0 to 0.8.

[0220] In addition, if Figure 12 As shown in (c), under conditions A7 to A9, even if the position of each of the six fast-axis collimating lenses 1101 is slightly moved by 2 μm in the positive or negative direction of the z-axis, the coupling efficiency decreases to approximately 0 to approximately 0.86.

[0221] That is, even when the positions of the six fast-axis collimating lenses 1101 are moved in the positive or negative z-axis direction by sub-μm or μm units, the coupling efficiency drops sharply under any of the conditions A1 to A9.

[0222] Furthermore, in Comparative Example 1, the fast axis collimating lens 1101 is bonded to the first submount 230 via a bonding material, and the bonding material is relatively thick. Therefore, due to the shrinkage of the bonding material during solidification, the position of the fast axis collimating lens 1101 is offset. This position offset may be on the order of several sub-μm to several μm. Figure 12 As shown, the coupling efficiency of the light source module 10 x according to Comparative Example 1 is reduced due to the positional deviation from several sub-μm to several μm order.

[0223] Next, the light source module 10 according to the present embodiment will be described.

[0224] Figure 14 This is a diagram showing the relationship between the reflectors 701 to 703 on which the laser beams L1 to L3 are incident and the beam points LO1 to LO3 of this embodiment. Here, in order to identify the multiple reflectors 700, sometimes they are described as the reflector 701 on which the laser beam L1 is incident, the reflector 702 on which the laser beam L2 is incident, and the reflector 703 on which the laser beam L3 is incident. In addition, Figure 14 The diagram shows the reflection mirrors 701 to 703 as viewed from the positive x-axis direction. Beam spots LO1 to LO3 represent the beam shapes of the laser beams L1 to L3 on the reflection surfaces of the reflection mirrors 701 to 703.

[0225] like Figure 14As shown, the width of laser L1, that is, the width of beam spot LO1, is W1. The width of laser L2, that is, the width of beam spot LO2, is W2. The width of laser L3, that is, the width of beam spot LO3, is W3. In addition, when viewed from the positive direction of the x-axis, the width in the fast axis direction between beam spot LO1 and beam spot LO2 is width D1, and the width in the fast axis direction between beam spot LO2 and beam spot LO3 is width D2. In addition, the width in the fast axis direction between beam spot LO2 and beam spot LO3, that is, width D2, is equal to Figure 6A The widths of the beam spots LO2 and LO3 described above in the fast axis direction are the same.

[0226] In addition, the reflector 701 has an upper surface 701a, and the reflector 702 has an upper surface 702a. The distance from the beam point LO1 to the upper surface 701a is the distance MU1, and the distance from the beam point LO2 to the upper surface 701a is the distance ML1. The distance from the beam point LO2 to the upper surface 702a is the distance MU2, and the distance from the beam point LO3 to the upper surface 702a is the distance ML2. The width D1 is the sum of the distance MU1 and the distance ML1, and the width D2 is the sum of the distance MU2 and the distance ML2.

[0227] Here, the width between two beam spots, such as the width D1 and the width D2, is approximately the same as the width of one beam spot, such as the width W1, the width W2, and the width W3.

[0228] The width W2 of the present embodiment is proportional to the effective focal length F of the optical unit 2. Furthermore, assuming that the optical unit 2 of the present embodiment does not include the first lens 120, the width W2 is proportional to the effective focal length F1 of the FACL 110. Therefore, the width W2 of the present embodiment is larger than that of the optical unit 2 of the present embodiment without the first lens 120, at a ratio of F / F1.

[0229] Therefore, when F / F1 is too large, the upper end of the laser L2 (the end on the positive side of the z axis) is located closer to the positive side of the z axis than the upper surface 702a of the reflector 702, resulting in problems such as the upper end of the laser L2 not being reflected by the reflector 702.

[0230] Furthermore, if F / F1 is too large, the lower end (the end on the negative side of the z-axis) of the laser light L2 is located further to the negative side of the z-axis than the upper surface 701a of the reflector 701. This also causes problems such as the lower end of the laser light L2 reflected by the reflector 702 being blocked by the reflector 701. Thus, if F / F1 is too large, the coupling efficiency in the light source module 10 may be reduced.

[0231] As described above, if the width between two lasers (width D1 and width D2, etc.) is of the same value as the width of one laser (width W1, width W2, width W3, etc.), then in an ideal optical system, even if F / F1 increases to about 2, the coupling efficiency is unlikely to decrease.

[0232] However, in real optical systems, slight shifts in the optical axes of the laser beams can cause the beam spot position to shift in the fast axis direction, or the size of the reflector 700 can shift. Consequently, the distance between the beam spot and the reflector can vary slightly. Consequently, when F / F1 is greater than 1, the width of a single laser beam (such as width W1, width W2, and width W3) increases, potentially leading to the same problems as those described above when F / F1 is excessively large.

[0233] Therefore, in this embodiment, F / F1 is less than 1.5. Thus, the above-mentioned problem is suppressed. Figures 9-11 As described in , in order to reduce δ, F can be made close to F1 by sufficiently increasing F2, for example, F / F1 is greater than 1.

[0234] Therefore, in this embodiment, F and F1 satisfy 1<F / F1<1.5.

[0235] Here, α and β in this embodiment are described. α satisfies Equation 1, and β satisfies Equation 2.

[0236] α=F2 / F1…(Formula 1)

[0237] β=d / F2…(Formula 2)

[0238] Therefore, according to the above-mentioned equations 17, 1, and 2, F, F1, α, and β satisfy equation 19.

[0239] [Formula 1]

[0240]

[0241] Here, F2, which is the effective focal length of the first lens 120, satisfies F2>0 and is larger than F1, which is the effective focal length of the FACL 110. Therefore, α satisfies Expression 3.

[0242] α>1…(Formula 3)

[0243] In addition, since F and F1 satisfy 1<F / F1<1.5, according to Formula 19, α and β satisfy Formula 4 and Formula 5.

[0244] αβ>1…(Formula 4)

[0245] β<(1 / α)+(1 / 3)…(Formula 5)

[0246] Since the distance d between the principal point P1 of the FACL 110 and the principal point P2 of the first lens 120 is shorter than the effective focal length F2 of the first lens 120 , β satisfies Equation 6.

[0247] β<1…(Equation 6)

[0248] Figure 15 It is a diagram showing the ranges of α and β in this embodiment.

[0249] exist Figure 15 In the figure, the ranges of α and β that satisfy the above-mentioned equations 3, 4, 5, and 6 are shaded.

[0250] Furthermore, F2 of the first lens 120 is preferably larger than F1 of the FACL 110. This is because when the value of F2 approaches the value of F1, the adjustment range of the first lens 120 becomes approximately the same as that of the FACL 110. Therefore, it is sufficient to satisfy Equation 11.

[0251] α≧9.3…(Equation 11)

[0252] If α is too large, the effective focal length F2 of the first lens 120 becomes longer, that is, the power becomes too small. As a result, the function of adjusting the tilt of the optical axis becomes too small. Therefore, α only needs to satisfy Equation 13.

[0253] α≦633…(Equation 13)

[0254] Furthermore, α more preferably satisfies Formula 20.

[0255] α ≤ 250…(Equation 20)

[0256] When α and β are large, the optical distance from the FACL 110 to the first lens 120 becomes longer. As a result, the distance from the light-emitting point 201 to the reflector 700 becomes longer, and the size of the light source module 10 becomes larger.

[0257] Therefore, α satisfies 9.3≦α≦633, and β satisfies Formula 15.

[0258] 0<β≦0.33…(Equation 15)

[0259] Furthermore, it is more preferable that α satisfies 9.3≦α≦250, and β satisfies Formula 21.

[0260] 0.02 ≦ β ≦ 0.33 (Equation 21)

[0261] Figure 16 β and F / F1 in this embodiment. Figure 16The relationship between β and F / F1 is shown for multiple conditions where α is 5, 10, 50, 100, 600, and 1000. As described above, F / F1 is preferably less than 1.5. In this case, for example, when α is small, such as α = 5, β is selected within the range of 0.2 ≤ β ≤ 0.33. For example, when α is large, such as α = 10, β is selected within the range of 0.1 ≤ β ≤ 0.33. Furthermore, for example, when α is large, such as α = 50 to 1000, β is selected within the range of 0 < β ≤ 0.33.

[0262] Next, regarding the light source module 10 of the present embodiment, calculation results of changes in coupling efficiency with respect to changes in the positions of the FACL 110 and the first lens 120 are described through simulation.

[0263] Figure 17 : is a diagram showing a table of a plurality of conditions (conditions B1 to B15) of the optical system for calculating the change in coupling efficiency of the light source module 10 of this embodiment. Figure 18 It shows that Figure 17 Graph showing a table of α, β, and F / F1 under various conditions shown.

[0264] In this simulation, six lasers L1 to L6 are emitted from the six optical units 1 to 6 of the light source module 10 and spatially combined by the reflector 700. Furthermore, the coupling efficiency of the spatially combined lasers L1 to L6 when coupled to the optical fiber 550 through the focusing lens 800 is calculated by simulation. At this time, the optical parameters of FACL110 and the first lens 120 are changed for comparison. In addition, according to the values ​​of the optical parameters of FACL110 and the first lens 120, the optical parameters of SACL170 and the focusing lens 800 are changed. The peak wavelengths of the semiconductor laser elements 200 are all 450 nm. In addition, when semiconductor laser elements with different peak wavelengths are used, the lens materials, lens functions, surface anti-reflection films, and reflection designs of each lens are optimized, but the same results are obtained. The expansion angle of the semiconductor laser element 200 is 1 / (e 2 ) has an entire width, with the fast axis being 48° and the slow axis being 12°. Furthermore, when using a semiconductor laser element having an expansion angle that is also different from the peak wavelength, the same result can be obtained by optimizing the optical system. Furthermore, in this embodiment, the FACL 110 is a plano-convex lens having a flat incident surface and a curved surface represented by an aspheric function on the exit surface. The first lens 120 is a plano-convex lens having a flat incident surface and a curved surface represented by a spherical function on the exit surface. The focusing lens 800 is a plano-convex lens having a curved surface represented by an aspheric function on the incident surface and a flat exit surface. The optical fiber 550 is a step-index multimode optical fiber having a core and a cladding, and has a numerical aperture NA of 0.22.

[0265] In this simulation, the combination of the width of the light emitting region of the semiconductor laser element 200 and the core diameter of the optical fiber 550 was changed to confirm the change in coupling efficiency. Figure 17 Summarized in.

[0266] First, if Figure 17 As shown, under condition B1, the width of the light-emitting area of ​​the semiconductor laser element 200 is 50 μm, the effective focal length F1 of the FACL 110 is 0.15 mm, the effective focal length F2 of the first lens 120 is 38 mm, the lens distance d is 4.6 mm, the effective focal length of the SACL 170 is 6.4 mm, the effective focal length of the focusing lens 800 is 4.5 mm, and the core diameter of the optical fiber 550 is 50 μm.

[0267] Condition B2 is the same as Condition B1 except that the core diameter of the optical fiber 550 is 70 μm. Condition B3 is the same as Condition B1 except that the light emitting region width is 100 μm and the core diameter of the optical fiber 550 is 100 μm.

[0268] Condition B4 is the same as condition B1 except that the effective focal length F1 of the FACL 110 is 0.38 mm, the lens distance d is 6.3 mm, the effective focal length of the SACL 170 is 13.5 mm, and the effective focal length of the condenser lens 800 is 7.3 mm.

[0269] Condition B5 is the same as Condition B4 except that the core diameter of the optical fiber 550 is 70 μm. Condition B6 is the same as Condition B4 except that the light emitting region width is 100 μm and the core diameter of the optical fiber 550 is 100 μm.

[0270] Condition B7 is the same as condition B1 except that the effective focal length F1 of the FACL 110 is 0.65 mm, the lens distance d is 4.7 mm, the effective focal length of the SACL 170 is 15.3 mm, and the effective focal length of the condenser lens 800 is 11.6 mm.

[0271] Condition B8 is the same as Condition B7 except that the core diameter of the optical fiber 550 is 70 μm. Condition B9 is the same as Condition B7 except that the light emitting region width is 100 μm and the core diameter of the optical fiber 550 is 100 μm.

[0272] Condition B10 is the same as Condition B7 except that the effective focal length F2 of the first lens 120 is 6.5 mm and the lens distance d is 2.0 mm.

[0273] Condition B11 is the same as Condition B1 except that the lens distance d is 11.5 mm, the effective focal length of the SACL 170 is 9.7 mm, and the effective focal length of the condenser lens 800 is 4.5 mm.

[0274] Condition B12 is the same as Condition B4 except that the effective focal length F2 of the first lens 120 is 95 mm and the lens distance d is 1.5 mm.

[0275] Condition B13 is the same as Condition B12 except that the lens distance d is 31 mm.

[0276] Condition B14 is the same as Condition B1 except that the effective focal length F2 of the first lens 120 is 95 mm and the lens distance d is 2.0 mm.

[0277] Condition B15 is the same as Condition B14 except that the lens distance d is 31 mm.

[0278] In addition, if Figure 18 As shown, α, β, and F / F1 satisfy Expressions 3, 4, 5, and 6 under any of a plurality of conditions (conditions B1 to B15). Figure 15 The values ​​of α and β corresponding to a plurality of conditions (conditions B1 to B15) are shown.

[0279] Figures 19 to 23G It means in Figure 17 A graph showing the results of calculating coupling efficiency under some of the multiple conditions shown.

[0280] In addition, it is shown that Figure 19 Conditions B1, B4 and B7, Figure 20 Condition B1, in Figure 21 Condition B4, in Figure 22 Condition B7, in Figure 23A Conditions B4, B5, and B6, Figure 23B Condition B10, in Figure 23C Condition B11, in Figure 23D Condition B12, in Figure 23E Condition B13, in Figure 23F Condition B14, in Figure 23G The results of calculating the coupling efficiency under condition B15.

[0281] Figure 19 The horizontal axis in represents the change in the z-axis position of the six FACLs 110 included in the six optical units 1 to 6. Note that, here, all six FACLs 110 experience the same position change.

[0282] right Figure 19 The case where the horizontal axis, i.e. the z-axis direction, is 0 is described below. Figure 19In the figure, under conditions B1, B4, and B7, the z-axis position of each of the six FACLs 110 when the light source module 10 exhibits the highest coupling efficiency is set to 0, and the coupling efficiency at that time is set to 1 for normalization. In other words, the z-axis position of 0 means that the principal point P1 of each of the six FACLs 110 is at the optimal position of the principal point P1.

[0283] exist Figure 19 In FIG. 1 , the change in coupling efficiency when all six FACLs 110 are moved from the z-axis position of 0 to the z-axis positive direction or the z-axis negative direction is shown. Figure 19 In the six optical units 1 to 6, all six first lenses 120 are Figure 7 The position shown in (a), that is, the position of the z-axis direction of the generatrix 125 of each of the six first lenses 120 is the same as the position of the z-axis direction of the imaginary line IL.

[0284] like Figure 19 As shown, under condition B1, even if the positions of the six FACLs 110 are slightly shifted by 1 μm in the positive or negative z-axis direction, the coupling efficiency decreases to approximately 0.4. Furthermore, under conditions B4 and B7, even if the positions of the six FACLs 110 are slightly shifted by only 1.5 μm in the positive or negative z-axis direction, the coupling efficiency decreases to approximately 0.5. In other words, even if the positions of the six FACLs 110 shift in the z-axis direction by the order of μm, the coupling efficiency decreases.

[0285] And, yes Figure 17 Conditions B1, B4, B5, B6, B7, and B10 to B15 shown will be described.

[0286] exist Figure 20 , the coupling efficiency in the light source module 10 is shown when the principal points P1 of the six FACLs 110 are shifted from the optimal position along the z-axis direction under condition B1. Figure 21 In condition B4, Figure 22 In condition B7, Figure 23A In the conditions B4, B5 and B6, Figure 23B In the condition B10, Figure 23C In condition B11, Figure 23D In condition B12, Figure 23E In condition B13, Figure 23F In condition B14, Figure 23G , under condition B15, shows the coupling efficiency in the light source module 10 when the principal point P1 of each of the six FACLs 110 is shifted from the above-mentioned optimal position in the z-axis direction.

[0287] In addition, Figure 20 , the coupling efficiency when the positional deviation in the z-axis direction is +1.5 μm, ±0 μm, −0.5 μm, −1.0 μm, and −1.5 μm is shown.

[0288] In addition, Figure 21 , the coupling efficiency when the positional deviation in the z-axis direction is +2.0 μm, ±0 μm, −1.0 μm, −1.5 μm, and −2.0 μm is shown.

[0289] In addition, Figure 22 , the coupling efficiency when the positional deviation in the z-axis direction is +1.5 μm, ±0 μm, and −2.0 μm is shown.

[0290] In addition, Figure 23A , the coupling efficiency when the position offset in the z-axis direction is -2.0 μm under condition B4, the coupling efficiency when the position offset in the z-axis direction is -3.0 μm under condition B5, and the coupling efficiency when the position offset in the z-axis direction is -4.0 μm and -2.0 μm under condition B6 are shown.

[0291] In addition, Figure 23B , the coupling efficiency when the positional offset in the z-axis direction is -2.0 μm is shown.

[0292] In addition, Figure 23C , the coupling efficiency when the positional offset in the z-axis direction is -2.0 μm is shown.

[0293] In addition, Figure 23D , the coupling efficiency when the positional offset in the z-axis direction is -2.0 μm is shown.

[0294] In addition, Figure 23E , the coupling efficiency when the position shift in the z-axis direction is -1.5 μm is shown.

[0295] In addition, Figure 23F , the coupling efficiency when the positional offset in the z-axis direction is -2.0 μm is shown.

[0296] In addition, Figure 23G , the coupling efficiency when the position shift in the z-axis direction is -0.5 μm is shown.

[0297] in addition, Figure 20 The horizontal axis represents the adjustment amount of the position of each of the six first lenses 120 in the z-axis direction. Figure 20 The case where the horizontal axis of is zero means that the position of the generatrix 125 of each of the six first lenses 120 in the z-axis direction is the same as the position of the imaginary line IL in the z-axis direction.

[0298] Right now, Figure 20 The horizontal axis represents the position of the z-axis direction of the generatrix 125 of each of the six first lenses 120 based on the imaginary line IL. Figure 20 , the coupling efficiency under the condition that the six FACLs 110 and the first lens 120 are in the optimal position is normalized to 1. Figures 21 to 23G Same here.

[0299] It is known that Figure 20 Under any of the multiple position shift conditions shown in FIG, by adjusting the position of each of the six first lenses 120 in the z-axis direction, the coupling efficiency can be improved. Figure 19 As shown, even if the coupling efficiency decreases due to the positional deviation of the six FACLs 110 in the z-axis direction, adjusting the positions of the six first lenses 120 can improve the coupling efficiency in the light source module 10. In this case, even if the positions of the six FACLs 110 deviate in either the positive or negative z-axis direction, adjusting the positions of the six first lenses 120 can improve the coupling efficiency in the light source module 10. Furthermore, if the positions of the six FACLs 110 are not deviated in the z-axis direction, and if the generatrixes of the six first lenses 120 are positioned near the position overlapping the imaginary line IL, high optical efficiency can be maintained even without adjusting the positions of the six FACLs 110. In other words, when the six FACLs 110 are fixed after active alignment, even if the positions of the six FACLs 110 vary by sub-μm or μm levels, causing a decrease in optical efficiency, the first lenses 120 can still improve optical efficiency.

[0300] And, as Figure 20As shown, the z-axis position adjustment range for each of the six first lenses 120 is on the order of hundreds of μm, facilitating, for example, adjustment of the optical axis LA1 in the optical unit 1. Furthermore, even if the position of the first lens 120, adjusted to match the position of the FACL 110 and maximize optical efficiency, deviates by approximately ±50 μm from its optimal position, the reduction in coupling efficiency is within 5%. In other words, when the adjusted first lenses 120 are secured using a first bonding material 161 composed of an inorganic material such as SnAgCu solder, even a deviation of several μm, similar to the FACL 110, can suppress a reduction in optical efficiency. In other words, the allowable range for positional deviation of the first lens 120 is significantly greater than that of Comparative Examples 1 and 2. More specifically, the allowable range for positional deviation of the first lens 120 is significantly greater than that of the fast-axis collimator lens 1101 in Comparative Example 1 and the first lens 120xx in Comparative Example 2. As described above, in this embodiment, in order to improve the coupling efficiency, precise position adjustment and fixation, for example, at the sub-μm level, is unnecessary, thereby making it possible to easily realize the light source module 10 with high coupling efficiency.

[0301] exist Figures 21 to 23G The same effect can be achieved in Figure 21 Under condition B4, even if the position of the first lens 120, which is adjusted to match the position of the FACL 110 and maximize the optical efficiency, deviates from its optimal position by about ±75 μm, the reduction in coupling efficiency is within 5%. Figure 22 Under condition B7, the position of the first lens 120 adjusted to match the position of the FACL 110 and maximize optical efficiency is within 5% even if it deviates by about ±75 μm from its optimal position.

[0302] in addition, Figure 23A Conditions B4, B5, and B6 are examples in which the combination of the width of the light emitting region of the semiconductor laser element 200 and the core diameter of the optical fiber 550 is changed, but the same effect is obtained.

[0303] In addition, Figures 23B to 23G The same effect was obtained under conditions B10 to B15. Figure 15 Under the conditions within the ranges of the formulas 4, 5, and 6 shown, the light source module 10 with high coupling efficiency can be easily realized.

[0304] In addition, Figures 23C to 23GUnder conditions B11 to B15, even if the position of the first lens 120 adjusted to match the position of the FACL 110 and maximize optical efficiency is shifted from the optimal position by approximately ±10 μm to ±100 μm, the reduction in coupling efficiency is within 5%.

[0305] In contrast, in Figure 23B Under condition B10, the position range of first lens 120 within which the coupling efficiency decreases by less than 5% from the maximum value is approximately ±10 μm. In other words, even if the position of first lens 120 deviates, the acceptable range is several tens of μm. These values ​​are sufficient for adjusting the position of first lens 120, but are smaller than those under the other conditions. This is because as α decreases, the adjustment range of first lens 120 approaches FACL 110. Therefore, α only needs to satisfy Equation 11.

[0306] α≧9.3…(Equation 11)

[0307] In addition, in conditions B13 and B15, β is relatively large, i.e., 0.33, and the first lens 120 is arranged at a position away from the FACL 110. Under these conditions, the SACL 170 is arranged between the FACL 110 and the first lens 120. Under these conditions, Figure 23E as well as Figure 23G As shown, by adjusting the position of first lens 120 to account for the positional deviation of FACL 110, coupling efficiency can also be improved. In other words, it is possible to suppress a decrease in coupling efficiency. However, since first lens 120 is positioned away from FACL 110, some of laser light L1 to L6 does not enter the reflector, reducing the effect of suppressing a decrease in coupling efficiency compared to other conditions. Therefore, β is preferably smaller than this value, specifically, preferably 0.33 or less.

[0308] In addition, in conditions B14 and B15, α is relatively large, which is 633. Under this condition, Figure 23F as well as Figure 23G As shown, adjusting the position of the first lens 120 relative to the FACL 110 can improve coupling efficiency. In other words, it is possible to minimize degradation in coupling efficiency. However, this increases the effective focal length F2 of the first lens 120, which in turn reduces power. The adjustment range is limited to millimeters. This adjustment range is approximately the same as the size of optical components such as the first lens 120, so α is preferably smaller than this.

[0309] That is, according to conditions B14 and B15, α only needs to satisfy equation 13.

[0310] α≦633…(Equation 13)

[0311] In addition, according to condition B15, α only needs to satisfy formula 15.

[0312] 0<β≦0.33…(Equation 15)

[0313] In addition, in conditions B12 and B14, β is relatively small, i.e., 0.02, and the first lens 120 is arranged at a position close to the FACL 110. Under these conditions, Figure 23D as well as Figure 23F As shown, by adjusting the position of the first lens 120 in response to the positional deviation of the FACL 110, the coupling efficiency can also be improved. In other words, the reduction in coupling efficiency can be suppressed. Therefore, β is preferably larger than this value, specifically, preferably greater than 0.02.

[0314] That is, according to condition B14, β only needs to satisfy equation 21.

[0315] 0.02 ≦ β ≦ 0.33 (Equation 21)

[0316] In addition, in conditions B12 and B13, α is 250. Under this condition, Figure 23D as well as Figure 23E As shown, the coupling efficiency can be improved by adjusting the position of the first lens 120 relative to the position offset of the FACL 110. Furthermore, when comparing condition B13 (α=250) and condition B15 (α=633), the maximum value of the coupling efficiency is greater under condition B13.

[0317] That is, according to conditions B12 and B13, α only needs to satisfy equation 20.

[0318] α ≤ 250…(Equation 20)

[0319] Therefore, α satisfies 9.3≦α≦633, and β satisfies Formula 15.

[0320] Furthermore, it is more preferable that α satisfies 9.3≦α≦250, and β satisfies Formula 21.

[0321] Furthermore, as an example where α satisfies 9.3≦α≦250 and β satisfies equation 21, condition B11 is shown. Under condition B11, α is 100 and β is 0.04. Under this condition, Figure 23C As shown, by adjusting the position of the first lens 120 relative to the position of the FACL 110, the coupling efficiency can be improved to approximately 1. Furthermore, even if the position of the first lens 120, which is adjusted to match the position of the FACL 110 and maximize the optical efficiency, deviates from the optimal position by approximately ± several tens of μm, the reduction in coupling efficiency is within 5%. The permissible range for this deviation is similar to Figure 12 The allowable range of the displacement amount when the fast-axis collimator lens 1101 of the comparative example shown is sufficiently larger than that.

[0322] In the above description, the effective focal length, that is, F1, of the FACL 110 in conditions B1 to B15 is 0.15 mm or more and 0.65 mm or less, and is more effective with respect to F1 in this range.

[0323] Furthermore, in the above embodiment, an inorganic adhesive can be used as the adhesive member for securing FACL 110. A portion of the laser light emitted from light-emitting point 201 irradiates the adhesive member positioned near light-emitting point 201. Therefore, by using an inorganic adhesive as the adhesive member, degradation of the adhesive member by the laser light can be suppressed. Similarly, by using an inorganic adhesive as first bonding material 161 and second bonding material 162, degradation of the adhesive member by the laser light can be suppressed.

[0324] In addition, in the above embodiment, the first bonding material 161 and the second bonding material 162 are each an inorganic adhesive component, but are not limited thereto. The first bonding material 161 and the second bonding material 162 may each be composed of an adhesive component such as an ultraviolet-curing adhesive containing an ultraviolet-curing resin. Alternatively, the first bonding material 161 and the second bonding material 162 may each be composed of an inorganic adhesive component such as an adhesive formed by mixing an inorganic filler composed of an inorganic material such as alumina with an ultraviolet-curing resin.

[0325] Furthermore, in the above embodiment, a concave reflective cylindrical lens can be used as the FACL 110. Furthermore, a concave reflective cylindrical lens can be used as the first lens 120. Furthermore, the SACL 170 can also be a concave reflective cylindrical lens. Furthermore, the SACL 170 and the reflector 700 are integrated optical components and can also be a concave reflective cylindrical lens.

[0326] Hereinafter, modifications 1 to 3 of Embodiment 1 will be described. Hereinafter, the description will focus on the differences from Embodiment 1, and the description of the common points will be omitted or simplified.

[0327] [Variation 1 of Embodiment 1]

[0328] Figure 24 This is a side view showing the structure of an optical unit 1 a according to Modification 1 of Embodiment 1.

[0329] The light source module 10a of this modification has the same structure as the light source module 10 of Embodiment 1, except that it includes the optical unit 1a and five optical units having the same structure as the optical unit 1a instead of the optical units 1 to 6. That is, the light source module 10a of this modification includes six optical units.

[0330] The optical unit 1 a of this modification has the same structure as the optical unit 1 of the first embodiment, except that a first fast axis adjustment lens 120 a (hereinafter referred to as the first lens 120 a ) is provided instead of the first lens 120 .

[0331] The first lens 120 a is a lens for receiving the laser light L1 emitted from the FACL 110 and adjusting the optical axis LA1 of the laser light L1 in the fast axis direction.

[0332] The first lens 120a is an optical component in which the power in the fast axis direction is greater than the power in the slow axis direction. The first lens 120a involved in this modified example is a cylindrical lens having a power axis and a non-power axis. In addition, the power axis and the non-power axis are arranged perpendicular to each other. The first lens 120a has a concave cylindrical surface, such as a cylindrical surface with a curved surface that is concave on the power axis. The first lens 120a is a concave cylindrical lens. In other words, the first lens 120a is a concave lens.

[0333] Furthermore, the first lens 120a is a concave cylindrical lens having an incident surface for laser light L1 and an exit surface for laser light L1. Furthermore, the absolute value of the power of the first lens 120a is sufficiently smaller than the absolute value of the power of the FACL 110. In this modified example, the first lens 120a is a plano-concave lens with a flat incident surface and a concave exit surface. Furthermore, the incident surface is parallel to the zx plane. The exit surface is a curved surface represented by a spherical function with a large radius of curvature. This first lens 120a collimates the incident light while slightly converging along the fast axis.

[0334] The first lens 120 a is made of an inorganic transparent material such as glass, and has anti-reflection coatings that match the wavelength of the laser light L1 formed on its incident surface and exit surface.

[0335] The first lens 120a has a generating line 125a.

[0336] Generator line 125a is a straight line along the valley bottom portion of the concave cylindrical surface serving as the exit surface of laser light L1. First lens 120a is thinner along generator line 125a. Generator line 125a of first lens 120a in this modified example is parallel to the xy plane.

[0337] As described above, the optical unit 1 a includes the FACL 110 and the first lens 120 a .

[0338] As in Embodiment 1, the principal point of the FACL 110 is the principal point P1, and the principal point of the first lens 120a is the principal point P2. Furthermore, the optical unit 1a has a principal point P0, which is the principal point of the combined lens of the FACL 110 and the first lens 120a.

[0339] In this variation, principal point P0 is located closer to light-emitting point 201 than principal point P1. The effective focal length of the composite lens is F, and the distance between principal point P0 and principal point P1 is δ. Light-emitting point 201 is located at an effective focal length F from principal point P0.

[0340] The effective focal length of FACL 110 is F1, and the effective focal length of first lens 120a is F2. Since first lens 120a is a plano-concave cylindrical lens, F2 < 0. Furthermore, the distance between the principal point P1 of FACL 110 and the principal point P2 of first lens 120a is the lens distance d.

[0341] In this modification, the effective focal length F of the composite lens, the effective focal length F1 of the FACL 110 , the effective focal length F2 of the first lens 120 a , the lens distance d, and the distance δ between the principal points P0 and P1 also satisfy Equations 17 and 18.

[0342] 1 / F=(1 / F1)+(1 / F2)-(d / (F1×F2))…(Equation 17)

[0343] δ=(F×d) / F2…(Equation 18)

[0344] However, in this modification, since F2<0, δ is a negative value, and the principal point P0 is located on the positive side of the y-axis with respect to the principal point P1.

[0345] Laser light L1 emitted from light-emitting point 201 enters FACL 110, becomes virtually collimated light, and then exits. In this variation, FACL 110 converts the incident laser light L1 into nearly parallel light, slightly converged along the fast axis, and then emits the laser light L1. Laser light L1 emitted from FACL 110 is collimated along the fast axis by first lens 120a and then exits from first lens 120a. At this time, the beam width of laser light L1 emitted from first lens 120a along the fast axis is defined as width W1a. In this variation, δ is a negative value, so the effective focal length F is smaller than the effective focal length F1, making width W1a easily reducible. On the other hand, if width W1a is too small, the light density increases, potentially degrading the surface of reflector 700, where laser light L1 enters. Therefore, in this variation, F / F1 is set to be greater than 0.75. This prevents width W1a from becoming too small, which could cause the aforementioned problem.

[0346] As described above, the first lens 120a is a lens for incident laser light L1 and adjusts the optical axis LA1 of the laser light L1 in the fast axis direction. Figure 24Although not shown, the first lens 120a is supported and fixed by the support member 150. During the manufacture of the optical unit 1a, the position of the first lens 120a is moved, i.e., adjusted, to increase the coupling efficiency between the emitted laser light L1 and the optical fiber 550. During the manufacture of the optical unit 1a, the support member 150 is first fixed to a predetermined position on the base 510 using the second bonding material 162. The position of the first lens 120a is then moved to increase the coupling efficiency between the emitted laser light L1 and the optical fiber 550, and then fixed using the first bonding material 161.

[0347] Furthermore, use Figure 25 and Figure 26 The effect of adjusting the first lens 120a will be described below. Here, the effect is described using the laser light L1 emitted from the optical unit 1a, but similar effects can be expected for the other five optical units included in the light source module 10a of this modification.

[0348] Figure 25 This is a side view showing an example in which the position of the first lens 120 a according to this modification is adjusted in the fast axis direction. Figure 26 This is a side view showing another example in which the position of the first lens 120 a of this modification is adjusted in the fast axis direction.

[0349] Figure 25 1 shows an example of adjusting the position of the first lens 120a after the FACL 110 is fixed. More specifically, Figure 25 (a) is a side view of the first lens 120a before adjustment. Figure 25 (b) is a side view of the first lens 120a after adjustment. Figure 25 , for convenience of explanation, an imaginary line IL is shown. The imaginary line IL is parallel to the y-axis, and the position of the imaginary line IL in the z-axis direction is the same as the position of the light-emitting point 201 in the z-axis direction.

[0350] exist Figure 25In the example, first, the first lens 120a is positioned near the position where the z-axis position of the generatrix 125a overlaps the imaginary line IL. Furthermore, the FACL 110 is also positioned near the position where the z-axis position of the generatrix of the FACL 110 overlaps the imaginary line IL. Subsequently, active alignment is performed to precisely adjust the position of the FACL 110. Subsequently, the FACL 110 is fixed relative to the light-emitting point 201 using a bonding material. However, suppose that due to volumetric changes in the bonding material, the position of the generatrix of the FACL 110 shifts slightly upward from the imaginary line IL, that is, in the positive z-axis direction. In this case, the laser light L1 emitted from the light-emitting point 201 and transmitted through the FACL 110 propagates at an angle upward from the imaginary line IL. Specifically, the laser light L1 is slightly tilted in the positive z-axis direction and travels in the negative y-axis direction. In other words, the angle formed between the optical axis LA1 of the laser light L1 transmitted through the FACL 110 and the imaginary line IL is greater than 0°.

[0351] Furthermore, if Figure 25 As shown in (a), if the z-axis position of the busbar 125a of the first lens 120a is the same as the z-axis position of the imaginary line IL, the laser light L1 transmitted through the first lens 120a further tilts toward the positive z-axis direction and travels toward the negative y-axis direction. Consequently, the laser light L1 cannot enter the reflector 700 or the subsequent optical fiber 550. If this state persists, the coupling efficiency in the light source module 10a decreases.

[0352] However, if Figure 25 As shown in (b), in this modification, the position of the first lens 120a is adjusted. Figure 25 In (b), the position of the first lens 120a before the movement is indicated by a dotted line. Figure 25 In (b), 1251a represents the position of the generatrix of the first lens 120a before the movement. Figure 25 As shown, when the laser light L1 transmitted through the FACL 110 is tilted in the positive direction of the z-axis and moves in the negative direction of the y-axis, the position of the first lens 120a is adjusted to the positive direction of the z-axis (the adjusted first lens 120a is in the positive direction of the z-axis). Figure 25 (indicated by a solid line in (b)). Specifically, busbar 125a of first lens 120a is positioned at a predetermined position on the positive side of the z-axis relative to imaginary line IL and busbar 1251a. Consequently, collimated laser light L1 passing through first lens 120a travels parallel to imaginary line IL. Consequently, laser light L1 is incident on reflector 700, improving coupling efficiency within light source module 10a.

[0353] Figure 26(a) shows the configuration of the generatrix of first lens 120a, fixed to imaginary line IL. In this case, the optical axis LA1 of laser light L1 emitted from light-emitting point 201 and transmitted through FACL 110 is parallel to imaginary line IL. In this case, the position of first lens 120a does not require adjustment of generatrix 125a.

[0354] Figure 26 Figure (b) shows the case where FACL 110 is fixed and offset downward from imaginary line IL. In this case, virtually collimated laser light L1 emitted from light-emitting point 201 and transmitted through FACL 110 tilts downward from imaginary line IL, that is, in the negative z-axis direction, and propagates in the negative y-axis direction. Specifically, in laser light L1 transmitted through FACL 110, the angle formed between its optical axis LA1 and imaginary line IL is greater than 0° in the negative z-axis direction.

[0355] Moreover, in Figure 26 In (b), the position of the first lens 120a is adjusted. Figure 26 In (b), the position of the first lens 120a before the movement is indicated by a dotted line. Figure 26 As shown in (b), when laser light L1 passing through FACL 110 is tilted in the negative z-axis direction and travels in the negative y-axis direction, the position of first lens 120a is adjusted downward, i.e., in the negative z-axis direction. Specifically, generatrix 125a of first lens 120a is positioned further to the negative z-axis side than imaginary line IL and generatrix 1251a before adjustment. Consequently, the collimated laser light L1 passing through first lens 120a travels parallel to the y-axis direction. This allows laser light L1 to be incident on reflector 700, improving coupling efficiency within light source module 10a.

[0356] Here, α and β in this modification are described. In this modification, as in the first embodiment, α satisfies Equation 1 and β satisfies Equation 2.

[0357] α=F2 / F1…(Formula 1)

[0358] β=d / F2…(Formula 2)

[0359] Therefore, according to the above-mentioned equations 17, 1, and 2, F, F1, α, and β satisfy equation 19.

[0360] [Formula 2]

[0361]

[0362] Here, the absolute value of F2, which is the effective focal length of the first lens 120 a , is larger than F1, which is the effective focal length of the FACL 110 . Therefore, α satisfies Expression 7.

[0363] α<-1…(Formula 7)

[0364] In addition, in this modification, since F and F1 satisfy 0.75<F / F1<1, according to Formula 19, α and β satisfy Formula 8 and Formula 9.

[0365] αβ<1…(Equation 8)

[0366] β>(1 / α)-(1 / 3)…(Equation 9)

[0367] Since the distance d between the principal point P1 of the FACL 110 and the principal point P2 of the first lens 120 a is shorter than the effective focal length F2 of the first lens 120 a , β satisfies Equation 10.

[0368] β>-1…(Equation 10)

[0369] Figure 27 Graph showing the ranges of α and β in this modification.

[0370] exist Figure 27 In , points are marked on the ranges of α and β that satisfy the above-mentioned equations 7, 8, 9, and 10.

[0371] The absolute value of the effective focal length F2 of the first lens 120 a is preferably greater than the effective focal length F1 of the FACL 110 , and therefore, Formula 12 is preferably satisfied.

[0372] α ≤ -9.3…(Equation 12)

[0373] If α is too small, that is, the absolute value of α is too large, the effective focal length F2 of the first lens 120a becomes longer and the power becomes smaller. As a result, the ability to adjust the tilt of the optical axis LA1 becomes too small. Therefore, α only needs to satisfy Equation 14.

[0374] α≧-633…(Equation 14)

[0375] Furthermore, α more preferably satisfies Formula 22.

[0376] α≧-250…(Equation 22)

[0377] When the absolute value of α is large and β is large, the optical distance from the FACL 110 to the first lens 120a becomes longer. As a result, the distance from the light-emitting point 201 to the reflector 700 becomes longer, and the light source module 10a becomes larger.

[0378] Therefore, α satisfies -9.3≧α≧-633, and β satisfies Formula 16.

[0379] -0.33≦β<0…(Equation 16)

[0380] Furthermore, it is more preferable that α satisfies -9.3≧α≧-250, and β satisfies Formula 23.

[0381] -0.3 ≤ β ≤ -0.02… (Equation 23)

[0382] Figure 28 β and F / F1 in this modification are shown in FIG.

[0383] exist Figure 28 Figure 2 shows the relationship between β and F / F1 under multiple conditions, with α values ​​of -5, -10, -50, -100, -600, and -1000. As described above, F / F1 is preferably greater than 0.75 and less than 1. In this case, for example, when α is large, such as α = -5, β is selected within the range of -0.33 ≤ β ≤ -0.2. For example, when α is large, such as α = 10, β is selected within the range of -0.33 ≤ β ≤ -0.1. Furthermore, for example, when α is small, such as α = -50 to -1000, β is selected within the range of -0.33 ≤ β < 0.

[0384] Next, the calculation results of the change in coupling efficiency of the light source module 10 a according to this modification will be described.

[0385] Figure 29 : is a diagram showing a table for explaining the condition C1 for calculating the coupling efficiency of the light source module 10a of this modification. Figure 30 It shows that Figure 29 FIG. 1 is a table showing α, β, and F / F1 under condition C1.

[0386] like Figure 29 As shown, under condition C1, the peak wavelength of semiconductor laser element 200 is set to 450 nm, similar to Embodiment 1. When using semiconductor laser elements with different peak wavelengths, the lens materials, lens functions, surface antireflection coatings, and reflective designs of each lens are optimized, but similar results are achieved. Furthermore, the light-emitting region width of semiconductor laser element 200 is 50 μm, the effective focal length F1 of FACL 110 is 0.38 mm, the effective focal length F2 of first lens 120a is -38 mm, the lens distance d is 5.0 mm, the effective focal length of SACL 170 is 13.5 mm, the effective focal length of condenser lens 800 is 7.3 mm, and the core diameter and numerical aperture NA of optical fiber 550 are 50 μm and 0.22, respectively.

[0387] In addition, if Figure 30 As shown in FIG, α, β and F / F1 satisfy equations 7, 8, 9 and 10 under condition C1. In addition, the values ​​of α and β corresponding to condition C1 are shown in FIG. Figure 27 .

[0388] Figure 31 as well as Figure 32: is a graph showing the calculation results of the change in coupling efficiency when the positions of the six FACLs 110 are shifted from the optimal position under condition C1. More specifically, Figure 31 and Figure 32 The results of simulation calculations of the coupling efficiency when six laser beams emitted from six optical units included in the light source module 10 a are spatially multiplexed under condition C1 are shown. The coupling efficiency refers to the coupling efficiency of the six laser beams with the optical fiber 550 .

[0389] Figure 31 The horizontal axis in represents the change in the z-axis position of the six FACLs 110 included in the six optical units of this modification. Note that, here, all six FACLs 110 experience the same position change.

[0390] right Figure 31 The case where the horizontal axis, i.e. the z-axis direction, is 0 is described below. Figure 31 In the example, under condition C1, the z-axis position of each of the six FACLs 110 when the light source module 10a exhibits the highest coupling efficiency is set to 0, and the coupling efficiency at this time is set to 1 for normalization. In other words, the z-axis position of 0 means that the principal point P1 of each of the six FACLs 110 is at the optimal position of the principal point P1.

[0391] exist Figure 31 In FIG. 1 , the change in coupling efficiency when all six FACLs 110 are moved from the z-axis position of 0 to the z-axis positive direction or the z-axis negative direction is shown. Figure 31 In the six optical units according to this modification, all of the six first lenses 120a are Figure 25 The position shown in (a), that is, the position of the generatrix 125a of each of the six first lenses 120a in the z-axis direction is the same as the position of the imaginary line IL in the z-axis direction.

[0392] like Figure 31 As shown in Figure 1, under condition C1, even if the positions of the six FACLs 110 are slightly shifted by 1 μm in the positive or negative z-axis direction, the coupling efficiency decreases to approximately 0.5. In other words, even if the positions of the six FACLs 110 are shifted by μm in the z-axis direction, the coupling efficiency decreases.

[0393] Furthermore, Figure 29 Condition C1 shown will be described.

[0394] exist Figure 32 , the coupling efficiency of the light source module 10 a is shown when the principal points P1 of the six FACLs 110 are shifted from the above-mentioned optimal positions in the z-axis direction under the condition C1 .

[0395] In addition, Figure 32 , the coupling efficiency when the positional deviation in the z-axis direction is +2.0 μm, ±0 μm, −1.0 μm, −1.5 μm, and −2.0 μm is shown.

[0396] Figure 32 The horizontal axis represents the adjustment amount of the position of each of the six first lenses 120 a in the z-axis direction. Figure 32 The case where the horizontal axis is 0 means that the position of the z-axis direction of the generatrix 125a of each of the six first lenses 120a is the same as the position of the z-axis direction of the imaginary line IL. That is, Figure 32 The horizontal axis represents the position of the z-axis direction of the generatrix 125a of each of the six first lenses 120a based on the imaginary line IL. Figure 32 In FIG, the coupling efficiency when the FACL 110 and the first lens 120 a are arranged at the optimal position, that is, on the imaginary line IL, is normalized to 1.

[0397] Obviously, in Figure 32 Under any of the multiple position shift conditions shown in FIG. 1 , by adjusting the position of each of the six first lenses 120a in the z-axis direction, the coupling efficiency can be increased to approximately 1. Figure 30 As shown, even if the six FACLs 110 are arranged such that the coupling efficiency is reduced due to displacement in the positive or negative z-axis direction, the coupling efficiency in the light source module 10a can be improved by adjusting the positions of the six first lenses 120a. Furthermore, even if the six FACLs 110 are not displaced in the z-axis direction, the coupling efficiency of the light source module 10a can be maintained at a high level by fixing the first lenses 120a at predetermined positions.

[0398] And, as Figure 32 As shown, the z-axis position of each of the six first lenses 120a can be adjusted by an amount on the order of hundreds of microns, facilitating, for example, adjustment of the optical axis LA1 in the optical unit 1a. Furthermore, even if the position of the first lenses 120a, adjusted to match the position of the FACL 110 and maximize optical efficiency, deviates by approximately ±50 μm from their optimal position, the reduction in coupling efficiency is within 5%. In other words, when the adjusted first lenses 120a are secured using a UV-curable adhesive, for example, similar to securing the FACL 110, even a deviation of a few μm can suppress a reduction in optical efficiency. Thus, in this modified example, precise sub-μm positional adjustment and fixation are no longer necessary to improve coupling efficiency. Consequently, a light source module 10a with high coupling efficiency can be easily realized.

[0399] [Variation 2 of Embodiment 1]

[0400] Figure 33 This is a side view showing the structure of an optical unit 1b according to a second modification of the first embodiment.

[0401] The light source module of this modification has the same structure as the light source module 10 of Embodiment 1, except that it includes an optical unit 1b and five optical units each having the same structure as the optical unit 1b instead of the optical units 1 to 6. That is, the light source module of this modification has six optical units.

[0402] The optical unit 1 b of this modification has the same structure as the optical unit 1 of the first embodiment, except that it further includes a second sub-mount 250 and an adhesive member 280 .

[0403] Second sub-mount 250 in this modified example is a flat-plate mounting platform for mounting first sub-mount 230 of semiconductor laser element 200 and fast-axis cylindrical lens 110 (FACL 110). Second sub-mount 250 is made of a material with high thermal conductivity and low thermal expansion coefficient. For example, second sub-mount 250 may be made of a crystalline material such as AlN or SiC, or an insulating material such as ceramic.

[0404] The second sub-mount 250 has a second upper surface 251, which serves as the upper surface of the flat plate. In this modified example, the second upper surface 251 is parallel to the xy plane. The second sub-mount 250 protrudes relative to the first sub-mount 230 in the direction of travel of the laser beam L1. Furthermore, the first sub-mount 230 and the FACL 110 are disposed above the second upper surface 251 of the protruding portion of the second sub-mount 250.

[0405] The adhesive member 280 is a member for fixing the FACL 110. That is, the FACL 110 and the second submount 250 are bonded together by the adhesive member 280. The adhesive member 280 may be formed of an inorganic adhesive member such as a solder material or a metal sintered body.

[0406] During the manufacture of the light source module of this variation, when the FACL 110 is positioned above the second upper surface 251, the FACL 110 is supported and secured by the second upper surface 251, which is parallel to the xy plane. This facilitates adjustment of the FACL 110's position in the y-axis direction, i.e., the focal direction. Furthermore, an adhesive member 280 is disposed and bonded between the second upper surface 251 and the lower surface of the FACL 110. Specifically, the FACL 110 is secured by the adhesive member 280 disposed on the second upper surface 251. Consequently, the FACL 110 and the second submount 250 are bonded surface-to-surface, enabling the FACL 110 to be securely secured to the semiconductor laser element 200.

[0407] On the other hand, the adhesive member 280 has a thickness for adjusting and securing the FACL 110 in the z-axis direction. Therefore, when the FACL 110 is adjusted and secured in the z-axis direction, the volume of the adhesive member 280 may cause the FACL 110 to shift from its optimal position. However, in this modified example, the optical unit 1b includes a first lens 120 for adjusting the optical axis LA1 of the laser light L1 in the z-axis direction. This allows for secure securing of the FACL 110 and facilitates adjustment of the optical axis LA1 of the laser light L1.

[0408] In addition, if Figure 33 As shown, the second submount 250 is disposed above the second section 511b of the first workbench 511 of the base 510. The second submount 250 and the second section 511b are bonded together by a fourth bonding material 290. The fourth bonding material 290 may also be formed of an inorganic bonding member such as a solder material or a metal sintered body.

[0409] [Variation 3 of Embodiment 1]

[0410] Figure 34 : is a cross-sectional view showing a method of manufacturing an optical unit 1c according to a third modification of the first embodiment. Figure 34 In the figure, the setting direction and the like are described by dotted arrows.

[0411] The light source module of this variation has the same structure as the light source module 10 of Embodiment 1, except that it includes an optical unit 1c and five optical units each having the same structure as optical unit 1c, instead of optical units 1 to 6. In other words, the light source module of this variation includes six optical units. Each of the six optical units has the same structure, but optical unit 1c will be described here.

[0412] The optical unit 1 c of this modification has the same structure as the optical unit 1 of the first embodiment, except that it mainly includes a package 400 .

[0413] The optical unit 1c includes a package 400 that hermetically seals and houses the semiconductor laser element 200 and the FACL 110. More specifically, the package 400 also hermetically seals and houses the first submount 230.

[0414] The package body 400 is a component including a light-transmitting window 420 , a bottom plate 410 , side plates 430 , and a top plate 440 .

[0415] The light transmission window 420 is an optical component that transmits the laser light L1 emitted from the FACL 110. The light transmission window 420 is, for example, a rectangular inorganic glass plate, and has anti-reflection coatings formed on its incident and emitting surfaces for the laser light L1.

[0416] The base plate 410 is a plate-shaped member made of an inorganic material with high thermal conductivity. The base plate 410 may be made of metal such as Cu or a Cu alloy, or ceramics such as AlN, SiC, or diamond, or polycrystalline.

[0417] The side plates 430 are plate components positioned on the positive y-axis side, the positive x-axis side, and the negative x-axis side of the semiconductor laser element 200. The light-transmitting window 420 and the base plate 410 form a rectangular frame in plan view. Specifically, the semiconductor laser element 200, the FACL 110, and the first submount 230 are positioned within the opening of this rectangular frame. The side plates 430 are made of an inorganic material such as metal, ceramic, or glass, and are provided with terminals (not shown). For example, the side plates 430 are primarily made of an inorganic insulating material such as alumina ceramic or AlN ceramic, and the terminals are provided.

[0418] The top plate 440 is a plate-shaped member made of an inorganic material such as metal or ceramics, and covers the rectangular frame-shaped opening formed by the light-transmitting window 420 and the bottom plate 410 .

[0419] The light-transmitting window 420 is joined to the side panels 430 . In addition, the bottom panel 410 is joined to the light-transmitting window 420 and the side panels 430 , and the top panel 440 is joined to the light-transmitting window 420 and the side panels 430 .

[0420] Package 400, consisting of a light-transmitting window 420, a bottom plate 410, side plates 430, and a top plate 440, has a sealed interior space within which semiconductor laser element 200, FACL 110, and first submount 230 are disposed. Furthermore, semiconductor laser element 200 disposed within package 400 is electrically connected to the exterior of package 400 via terminals.

[0421] That is, the semiconductor laser element 200 and the FACL 110 are hermetically sealed by the package 400 .

[0422] This protects the semiconductor laser element 200 from impurities such as organic matter from outside the package 400. Therefore, during operation of the semiconductor laser element 200, it is possible to suppress degradation of the semiconductor laser element 200 due to impurities such as organic matter adhering to the semiconductor laser element 200.

[0423] Furthermore, the optical unit 1c includes a second sub-mount 250c.

[0424] The second sub-mount 250c is a component that is bonded to the first sub-mount 230 and supports the FACL 110. The second sub-mount 250c can have any shape as long as it can support the FACL 110. Here, as an example, it is a flat plate. The second sub-mount 250c has an upper surface parallel to the xy plane and is fixed to the first sub-mount 230 so as to protrude in the direction of travel of the laser light L1. An adhesive member 280c is then placed on this upper surface of the second sub-mount 250c to secure the FACL 110. Specifically, the adhesive member 280c is placed between the lower surface of the FACL 110 and the upper surface of the second sub-mount 250c, bonding the FACL 110. Furthermore, the second sub-mount 250c and the first sub-mount 230 are bonded by a bonding material (not shown). In this modified example, the side surface of the second sub-mount 250c parallel to the xz plane is bonded to the side surface of the first sub-mount 230 parallel to the xz plane. The adhesive member 280c is composed of an inorganic adhesive member such as a solder material or a metal sintered body. Figure 34 As shown, the second submount 250 c is also hermetically sealed by the package body 400 .

[0425] Next, the base 510c of this modified example will be described. The base 510c is provided with multiple stepped worktables. The multiple worktables comprise a first worktable 511c, a second worktable, a third worktable, a fourth worktable, a fifth worktable, and a sixth worktable. The optical unit 1c is provided on the first worktable 511c.

[0426] Furthermore, unlike first worktable 511 in Embodiment 1, first worktable 511c is a single-segment worktable, i.e., it does not have multiple segments such as first segment 511a and second segment 511b. Similarly, the second through sixth worktables in this variation are each comprised of a single worktable. First worktable 511c and the second through sixth worktables are each planes parallel to the xy plane.

[0427] In this modification, the sixth bonding material 320 bonds the bottom plate 410 of the package 400 to the first stage 511c. The sixth bonding material 320 is made of, for example, an inorganic bonding member such as a solder material or a metal sintered body.

[0428] It should be noted that if Figure 34 As shown, the semiconductor laser element 200 , FACL 110 , first submount 230 , adhesive member 280 c , second submount 250 c , and package 400 among the plurality of components included in the optical unit 1 c may be collectively described as a package unit 600 .

[0429] Here, a method for manufacturing the light source module of this modification will be described. More specifically, a method for manufacturing the optical unit 1 c will be described.

[0430] Figure 34 (a) is a cross-sectional view illustrating the placement of the package 400 on the first workbench 511c. First, a package unit 600 is fabricated within the package 400, with the semiconductor laser element 200, first submount 230, second submount 250c, and FACL 110 fixed in predetermined positions. At this point, the FACL 110 is positioned on the upper surface of the second submount 250c and secured with adhesive 280c. Next, the sixth bonding material 320 is applied to the first workbench 511c, and the package unit 600 is placed on the sixth bonding material 320.

[0431] Figure 34 (b) is a cross-sectional view before the first lens 120 of this variation is installed. First, the package unit 600, which is placed on the sixth bonding material 320 on the first workbench 511c, is heated and cooled while being pressed toward the first workbench 511c. At this point, the package unit 600 is bonded to the first workbench 511c via the sixth bonding material 320. Next, a predetermined power is applied to the package unit 600, causing laser light L1 to be emitted from the light emitting point 201 of the semiconductor laser element 200. Figure 34 (c) is a cross-sectional view of the first lens 120 of this modification example after position adjustment and installation.

[0432] exist Figure 34 In (b) and (c), an imaginary line IL is shown for illustration. The imaginary line IL is parallel to the y-axis, and the position of the imaginary line IL in the z-axis direction is the same as the position of the light-emitting point 201 in the z-axis direction.

[0433] when Figure 34 When the package unit 600 shown in (b) is fixed to the first workbench 511c, the package unit 600 may be fixed at an angle relative to the first workbench 511c, or the film thickness of the adhesive member 280c in the package unit 600 may be changed. In this case, since the FACL 110 is offset from the optimal position in the fast axis direction, that is, the z-axis direction, the optical axis LA1 of the laser light L1 may be tilted relative to the imaginary line IL. Figure 34 (b) shows an example where laser light L1 travels diagonally upward relative to imaginary line IL. Specifically, the angle formed between optical axis LA1 of laser light L1 transmitted through light-transmitting window 420 and imaginary line IL is greater than 0°. Laser light L1 transmitted through light-transmitting window 420 is located closer to the positive z-axis than imaginary line IL and is not parallel to the y-axis. Instead, it travels in both the negative y-axis direction and the positive z-axis direction.

[0434] Moreover, if Figure 34 As shown in (c), in this modified example, the first lens 120 is provided and the position of the first lens 120 is adjusted. Figure 34As shown, when laser light L1 passes through light-transmitting window 420 and travels in the negative y-axis direction and the positive z-axis direction, generatrix 125 of first lens 120 is positioned closer to the positive z-axis side than imaginary line IL. Consequently, laser light L1 passing through first lens 120 is refracted and travels parallel to the y-axis. This allows laser light L1 to be incident on reflector 700, improving coupling efficiency in the light source module according to this variation.

[0435] [Effects, etc.]

[0436] The light source module 10 according to the first embodiment includes a base 510 having a plurality of stepped stages (first to sixth stages 511 to 516 ), and a plurality of optical units (optical units 1 to 6 ) disposed on the stages. Each of the optical units 1 to 6 includes a semiconductor laser element 200 for emitting laser light, a fast-axis cylindrical lens (FACL 110 ) for receiving the laser light emitted from the semiconductor laser element 200 and converging the laser light in the direction of the laser light's fast axis, a first fast-axis adjustment lens (first lens 120 ) for receiving the laser light emitted from the FACL 110 and adjusting the optical axis LA1 of the laser light in the fast-axis direction, and a slow-axis collimating lens 170 (SACL 170 ) for receiving the laser light emitted from the first lens 120 and collimating the laser light in the direction of the laser light's slow axis.

[0437] The effective focal length of the FACL 110 is F1, the effective focal length of the first lens 120 is F2, and the distance between the principal point P1 of the FACL 110 and the principal point P2 of the first lens 120, that is, the lens distance d, is denoted as d.

[0438] α=F2 / F1…(Formula 1)

[0439] β satisfies Equation 2.

[0440] β=d / F2…(Formula 2)

[0441] When F2>0, α and β satisfy Equations 3, 4, 5, and 6.

[0442] α>1…(Formula 3)

[0443] αβ>1…(Formula 4)

[0444] β<(1 / α)+(1 / 3)…(Formula 5)

[0445] β<1…(Equation 6)

[0446] When F2<0, α and β satisfy Equations 7, 8, 9, and 10.

[0447] α<-1…(Formula 7)

[0448] αβ<1…(Equation 8)

[0449] β>(1 / α)-(1 / 3)…(Equation 9)

[0450] β>-1…(Equation 10)

[0451] For example, in the first embodiment, F2>0. In this case, it can be obtained Figures 19 to 23G That is, even if the positions of the principal points P1 of the plurality of FACLs 110 (six FACLs 110 in this example) deviate from the optimal positions in the z-axis direction, the coupling efficiency in the light source module 10 can be improved by adjusting the positions of the plurality of first lenses 120 (six first lenses 120 in this example).

[0452] In addition, for example, in the first modification of the first embodiment, F2<0. In this case, it is possible to obtain Figure 31 and Figure 32 That is, even if the position of the principal point P1 of each of the plurality of FACLs 110 (six FACLs 110 in this example) deviates from the optimal position in the z-axis direction, the coupling efficiency in the light source module 10a can be improved by adjusting the positions of the plurality of first lenses 120a (six first lenses 120a in this example).

[0453] In this way, in either case of F2>0 or F2<0, by adjusting the positions of the six first lenses 120 and 120 a , it is possible to implement the light source modules 10 and 10 a with high coupling efficiency.

[0454] For example, when F2>0 (as an example, embodiment 1), α satisfies Expression 11.

[0455] 9.3≦α…(Equation 11)

[0456] Furthermore, for example, when F2<0 (as an example, Modification 1 of Embodiment 1), α satisfies Expression 12.

[0457] -9.3≧α…(Equation 12)

[0458] Therefore, in the above Figure 23B Under the condition B10, the position range of the first lens 120 that can reduce the coupling efficiency by less than 5% is about ±10 μm, that is, the position range can be made sufficiently larger than that of Comparative Examples 1 and 2. Figure 32 Under the condition C1, the position of the first lens 120a can be set within a range of approximately ±50 μm so that the reduction in coupling efficiency is within 5%.

[0459] For example, when F2>0 (as an example, embodiment 1), α satisfies Expression 13.

[0460] α≦633…(Equation 13)

[0461] Furthermore, for example, when F2<0 (as an example, Modification 1 of Embodiment 1), α satisfies Expression 14.

[0462] α≧-633…(Equation 14)

[0463] Therefore, as mentioned above Figure 23F Condition B14 and Figure 23G As shown in condition B15, the position deviation of FACL110 can be suppressed by adjusting the position of the first lens 120 to suppress the reduction of coupling efficiency. Figure 32 As shown in the condition C1, the positional deviation of the FACL 110 can be suppressed by adjusting the position of the first lens 120 a to suppress a decrease in coupling efficiency.

[0464] For example, the fast axis cylindrical lens (FACL110) includes an incident surface on which laser light is incident and an exit surface from which laser light is exited, and the incident surface is arranged to face the light emitting point 201 of the semiconductor laser element 200 .

[0465] This allows the fast-axis cylindrical lens (FACL 110 ) to be disposed near the light-emitting point 201 of the semiconductor laser element 200 , thereby reducing the beam width in the fast-axis direction of the laser beam focused in the fast-axis direction.

[0466] In Embodiment 1, each of the plurality of first lenses 120 is a cylindrical lens and a convex lens.

[0467] As shown in Embodiment 1, when the plurality of first lenses 120 are each a convex lens, F2>0 is satisfied. Therefore, even if the position of the fast-axis cylindrical lens (FACL 110) is shifted from the optimal position, as described above, the coupling efficiency in the light source module 10 can be improved. Furthermore, since the plurality of first lenses 120 are each a cylindrical lens, the light source module 10 can be easily configured.

[0468] In the first embodiment, β satisfies Expression 15.

[0469] 0<β≦0.33…(Equation 15)

[0470] As described above, by setting β within the range of Expression 15, F / F1 can be made smaller than 1.5 together with the condition of F2>0, thereby suppressing a decrease in the coupling efficiency of the light source module 10 .

[0471] In the first modification of the first embodiment, each of the plurality of first lenses 120 a is a cylindrical lens and a concave lens.

[0472] As shown in Modification 1 of Embodiment 1, when the plurality of first lenses 120a are each concave lenses, F2 < 0 is satisfied. Therefore, as described above, even if the position of the fast-axis cylindrical lens (FACL 110) is shifted from the optimal position, the coupling efficiency in the light source module 10a can be improved. Furthermore, since the plurality of first lenses 120a are each cylindrical lenses, the light source module 10a can be easily constructed.

[0473] In the first modification of the first embodiment, β satisfies Expression 16.

[0474] -0.33≦β<0…(Equation 16)

[0475] As described above, by setting β within the range of Expression 16, F / F1 can be made larger than 0.75 together with the condition of F2<0. Therefore, in the light source module 10 a , degradation of the surface of the reflecting mirror 700 can be suppressed.

[0476] In the first embodiment, F1 is equal to or greater than 0.15 mm and equal to or less than 0.65 mm.

[0477] The optical units 1 to 6 of the first embodiment include the FACL 110 whose effective focal length F1 satisfies the above-mentioned conditions. In the light source module 10 including such optical units 1 to 6, the coupling efficiency can be improved.

[0478] In Embodiment 1, each of optical units 1 to 6 includes a support member 150 mounted on a base 510. In each of optical units 1 to 6, support member 150 has a mounting surface (first supporting side surface 151) on which first lens 120 is mounted. First lens 120 has a side surface (fourth side surface 124) perpendicular to busbar 125. Semiconductor laser element 200 includes an active layer. The side surface (fourth side surface 124) is fixed to the mounting surface (first supporting side surface 151) perpendicular to the active layer.

[0479] Thus, for example Figure 4A As shown, the position of the busbar 125 can be adjusted and fixed in the fast axis direction of the laser light L1 or the optical axis LA1 direction.

[0480] In the first embodiment, each of the plurality of optical units includes an adhesive member for fixing the FACL 110 .

[0481] Therefore, in the first embodiment, even if the position of the FACL 110 shifts in the fast axis direction due to the volume change of the adhesive member, the coupling efficiency can be improved by adjusting the position of the first lens 120 .

[0482] In addition, the adhesive member may include an inorganic adhesive member.

[0483] Thus, in the first embodiment, the adhesive shrinks less during curing than, for example, when a resin material is used to secure the FACL 110. Consequently, the z-axis positional deviation of the FACL 110 is reduced, making it easier to adjust the position of the first lens 120 to improve coupling efficiency.

[0484] In addition, in the second modification of the first embodiment, the adhesive member 280 corresponds to the adhesive member.

[0485] In the first embodiment, the adhesive member is composed of an inorganic adhesive member.

[0486] This can suppress degradation of the adhesive member fixing the FACL 110 due to laser light and reduction in adhesive strength.

[0487] In the second modification of the first embodiment, each of the plurality of optical units includes a first sub-mount 230 on which the semiconductor laser element 200 is mounted, and a second sub-mount 250 bonded to the first sub-mount 230 and the FACL 110 .

[0488] Thus, in Variation 2 of Embodiment 1, when FACL 110 is placed above second submount 250 (more specifically, second upper surface 251), FACL 110 is supported and fixed by second upper surface 251, which is parallel to the xy plane. This makes it easy to adjust the distance between light-emitting point 201 and FACL 110, that is, the position of FACL 110 in the focal direction.

[0489] Furthermore, the first sub-mount 230 and the second sub-mount 250 may be integrally formed of the same material.

[0490] In the second modification of the first embodiment, the adhesive member 280 is disposed between the lower surface of the FACL 110 and the upper surface (second upper surface 251 ) of the second sub-mount 250 .

[0491] Thus, in the second modification of the first embodiment, the lower surface of the FACL 110 and the second upper surface 251 are bonded to each other in a surface-to-surface manner, and the FACL 110 can be firmly fixed.

[0492] In the third modification of the first embodiment, each of the plurality of optical units includes a package 400 that accommodates the semiconductor laser element 200 and the FACL 110 and hermetically seals the package.

[0493] Thus, in the third variation of the first embodiment, the semiconductor laser element 200, the FACL 110, and the package 400 constitute a package unit 600, which protects the semiconductor laser element 200 from impurities such as organic matter from outside the package 400. Therefore, during the operation of the semiconductor laser element 200, it is possible to suppress degradation of the semiconductor laser element 200 due to impurities such as organic matter adhering to the light-emitting point 201 of the semiconductor laser element 200.

[0494] In the package unit 600, the adhesive member 280c that secures the FACL 110 may be an inorganic adhesive member. This can prevent the semiconductor laser element 200 from being degraded by floating foreign matter such as siloxane generated from the adhesive member 280c within the package 400 and adhering to the light emitting point 201 of the semiconductor laser element 200.

[0495] (Implementation Method 2)

[0496] Hereinafter, Embodiment 2 will be described. Hereinafter, the description will focus on the differences from Embodiment 1, and the description of the common points will be omitted or simplified.

[0497] [structure]

[0498] First, use Figure 35 The structure of the light source module 10d according to the second embodiment will be described.

[0499] Figure 35 It is a perspective view showing the structure of a light source module 10d according to the second embodiment.

[0500] A light source module 10 d of the present embodiment has the same structure as the light source module 10 of the first embodiment, except that it includes optical units 1 d to 6 d instead of the optical units 1 to 6 .

[0501] Figure 36 Yes Figure 35 2 is a cross-sectional view of a cut surface of the optical unit 1d taken along line XXXVI-XXXVI. Figure 37 1d and 2d are perspective views showing the structures of the optical units 1d and 2d according to this embodiment. The optical units 1d to 6d have the same structure, but the optical unit 1d will be mainly described here.

[0502] The optical unit 1 d of this embodiment has the same structure as the optical unit 1 of the first embodiment, except that a first fast axis adjustment lens 120 d (hereinafter referred to as the first lens 120 d ) is provided instead of the first lens 120 and the support member 150 is not provided.

[0503] The optical unit 1d of this embodiment moves the first lens 120d in the x-axis direction to move the generatrix 125d in the z-axis direction. The first lens 120d has the same structure as the first lens 120 of the first embodiment except that the generatrix 125d is replaced by the generatrix 125.

[0504] In the first embodiment, busbars 125 are parallel to the xy plane. Furthermore, in the first embodiment, the active layer of semiconductor laser element 200 is parallel to the xy plane, so busbars 125 are parallel to the active layer. Furthermore, busbars 125 are parallel to the busbars of FACL 110. Furthermore, busbars 125 are parallel to the top surfaces of first through sixth workstations 511 through 516.

[0505] The busbar 125d of this embodiment is inclined relative to the active layer of the semiconductor laser element 200. That is, the busbar 125d is inclined relative to the upper surface of the first to sixth workstations 511 to 516. That is, the busbar 125d is inclined relative to the busbar of the FACL 110. Figure 38 The inclination of the busbar 125d will be described.

[0506] Figure 38 125d is a front view for explaining the inclination of the busbar 125d of this embodiment. Figure 38 1 and 2 mainly show the first lens 120d.

[0507] The busbar 125d is tilted relative to the active layer, the first workbench 511 (more specifically, the first section 511a) and the xy plane. Here, the angle formed by the busbar 125d and the active layer is set to angle θ1. In addition, when tilted from the positive direction of the x-axis to the positive direction of the z-axis, θ1 takes a positive value, and when tilted from the positive direction of the x-axis to the negative direction of the z-axis, θ1 takes a negative value. Since the busbar 125d is tilted relative to the active layer, 0°<|θ1| is satisfied. In addition, 0°<|θ1|<45° is sufficient, 0.5°<|θ1|<23° is sufficient, and 1°<|θ1|<5° is sufficient. In addition, the first lens 120d is formed by Figure 38 The position of the busbar 125d is adjusted by moving in the x-axis direction indicated by the arrow.

[0508] Apart from Figure 38 In addition, we also use Figure 36 and Figure 37Description. The first lens 120d has a bottom surface 1211. In addition, the busbar 125d is inclined relative to the bottom surface 1211. The first lens 120d is different from the first lens 120 in embodiment 1 and is not supported by the supporting component 150. The bottom surface 1211 of the first lens 120d is bonded to the first segment 511a by the first bonding material 161, whereby the first lens 120d is fixed to the base 510. The first segment 511a is the mounting surface of the first lens 120d. That is, in embodiment 1, the first bonding material 161 is arranged on the side surface (the fourth side surface 124) of the first lens 120, but in the present embodiment, it is arranged on the bottom surface 1211 of the first lens 120d. In addition, the bottom surface 1211 is directly connected to a part or all of the first segment 511a, or a thin layer of the first bonding material 161, for example, less than 5 μm, is formed between the bottom surface 1211 and the first segment 511a or in a part or all of the space between the bottom surface 1211 and the first segment 511a.

[0509] In this embodiment, the first lens 120d is positioned above the first segment 511a of the first workbench 511. Furthermore, the first segment 511a on which the first lens 120d is positioned corresponds to the target plane. Furthermore, the bottom surface 1211 is parallel to the target plane (the first segment 511a). Since the first segment 511a is parallel to the xy plane, the busbar 125d can be said to be inclined relative to the target plane (the first segment 511a), the active layer, and the xy plane.

[0510] exist Figure 36 In the embodiment, the angle formed between the optical axis LA1 of the laser light L1 after it is emitted from the FACL 110 and the imaginary line IL is greater than 0°, and is tilted upward. Furthermore, the generatrix 125d of the first lens 120d is located below the imaginary line IL in the z-axis direction of the optical axis LA1. Thus, similar to the first embodiment, the optical axis LA1 of the laser light L1 emitted from the first lens 120d is refracted and adjusted so that it is parallel to the imaginary line IL.

[0511] exist Figure 37 In the figure, the dotted line indicates beam spot LO1d of laser light L1 incident on first lens 120d of optical unit 1d. Similarly, the dotted line indicates beam spot LO2d of laser light L2 incident on first lens 120d of optical unit 2d. Beam spots LO1d and LO2d are rectangular with rounded corners, elongated in the x-axis direction, when viewed from the front.

[0512] Here, in the manufacture of the light source module 10d, a front view of the first lens 120d included in the optical unit 1d when it is installed in the first segment 511a is used for description.

[0513] Figure 39AThis is a front view of the first lens 120d according to this embodiment when the position of the first lens 120d is adjusted and fixed on the first segment 511a in the method of manufacturing the optical unit 1d.

[0514] exist Figure 39A 1 shows a collet 1100 for moving the first lens 120d and a syringe 1200 for ejecting the first bonding material 161. Figure 39A , an example is shown in which the first bonding material 161 is an ultraviolet curing adhesive containing an ultraviolet curing resin. Figure 39A , an example is shown in which the angle θ1 of the first lens 120 d is negative.

[0515] Figure 39A This figure shows a situation where, after the FACL 110 is adjusted and fixed in the optical unit 1d, it is slightly displaced upward from its predetermined position, i.e., in the positive z-axis direction. The first lens 120d is then moved to adjust the direction of the optical axis LA1 of the laser light L1. At this time, the semiconductor laser element 200 is activated to emit the laser light L1. Figure 39A (a) is a main view before the first lens 120d moves. Figure 39A (b) is the main view after the first lens 120d moves. Figure 39A The first lens 120d shown in (a) is Figure 39A The first lens 120d shown in (b) is moved to the negative side of the x-axis. In this case, the first lens 120d is moved so that the bottom surface 1211 is along the installation plane (the first segment 511a).

[0516] exist Figure 39A In (a), when viewed from the front, beam spot LO1d of laser light L1 is positioned above busbar 125d, that is, in the positive z-axis direction. At this point, the distance d11 between the center of beam spot LO1d and busbar 125d in the z-axis direction is the distance d11, and the center of beam spot LO1d and busbar 125d do not overlap. That is, on reference line XXXIX-XXXIX, the center of beam spot LO1d is a distance d11 away from busbar 125d. In other words, in the front view, the z-axis position of the center of beam spot LO1d is offset from the z-axis position of busbar 125d.

[0517] exist Figure 39A In (b), when viewed from the front, the busbar 125d moves in the negative x-axis direction, so on the reference line XXXIX-XXXIX, the busbar 125d moves in the negative z-axis direction. The center of the light beam point LO1d is a distance d111 from the busbar 125d.

[0518] In this case, the cross-sectional view of the optical unit 1d at the reference line XXXIX-XXXIX is equivalent to Figure 36 Figure 1 shows the bonding material removed. Furthermore, the optical axis LA1 of laser light L1, emitted obliquely upward relative to imaginary line IL, is adjusted by adjusting the position of generatrix 125d of first lens 120d to adjust the amount of refraction parallel to imaginary line IL. Furthermore, laser light L1 is efficiently coupled to optical fiber 550.

[0519] exist Figure 39A In (c), the first bonding material 161 is applied from the syringe 1200 to the portion where the first lens 120d arranged at a predetermined position is connected to the first segment 511a. Thereafter, the first bonding material 161 is cured by irradiation with ultraviolet light, and the first lens 120d is fixed to the base 510.

[0520] Figure 39B This is another front view of the first lens 120d of this embodiment when it is provided in the first segment 511a. Figure 39B and Figure 39A Similarly, in the optical unit 1 d , when the FACL 110 is position-adjusted and fixed, the FACL 110 is slightly deviated from the predetermined position downward, that is, in the negative z-axis direction.

[0521] exist Figure 39B In (a), when viewed from the front, the beam spot LO1d of the laser L1 is located below the generatrix 125d, i.e., in the negative z-axis direction. The distance between the center of the beam spot LO1d and the generatrix 125d in the z-axis direction is distance d11.

[0522] exist Figure 39B In (b), when viewed from the front, the busbar 125d moves in the positive x-axis direction, so on the reference line XXXIX-XXXIX, the busbar 125d moves in the positive z-axis direction. The center of the light beam point LO1d is a distance d111 from the busbar 125d.

[0523] The FACL 110 adjusts the position of the generating line 125d of the first lens 120d so that the optical axis LA1 of the laser light L1 emitted obliquely downward relative to the imaginary line IL is parallel to the imaginary line IL. The laser light L1 is efficiently coupled to the optical fiber 550.

[0524] exist Figure 39B In (c), Figure 39A (c) Similarly, the first lens 120 d is fixed to the base 510 via the first bonding material 161 .

[0525] Thus, in this embodiment, even if FACL 110 is displaced from its predetermined position in the positive or negative z-axis directions when fixed, adjusting the position of first lens 120d in the x-axis direction allows the inclination of optical axis LA1 of laser light L1 relative to imaginary line IL to be adjusted. Specifically, adjusting the position of first lens 120d along first segment 511a allows the inclination of optical axis LA1 to be adjusted. Furthermore, laser light L1 is efficiently coupled to optical fiber 550.

[0526] Since the busbar 125d is tilted relative to the active layer and the xy plane, Figure 39A As shown in (a) and (b), when the first lens 120d moves along the x-axis direction, the distance between the center of the beam spot LO1d and the busbar 125d in the z-axis direction changes. Moreover, when the angle θ1 is 0°<|θ1|<45°, the change in the distance between the center of the beam spot LO1d and the busbar 125d in the z-axis direction is smaller than the movement of the first lens 120d in the x-axis direction. When the position of the first lens 120d in the x-axis direction is adjusted by the manufacturing equipment, the position in the x-axis direction is adjusted with the same accuracy as the manufacturing equipment. As described above, the change in the distance between the center of the beam spot LO1d and the busbar 125d in the z-axis direction is smaller than the movement of the first lens 120d in the x-axis direction, so the position of the first lens 120d in the z-axis direction can be adjusted with a higher accuracy than the manufacturing equipment.

[0527] For example, when the angle θ1 is 6°, the change in the distance between the center of the beam point LO1d and the busbar 125d in the z-axis direction relative to the movement of the first lens 120d in the x-axis direction is about 1 / 10, so the position in the z-axis direction can be adjusted with an accuracy of 1 / 10 of the manufacturing equipment accuracy.

[0528] In this optical unit 1d, the position of the first lens 120d can be easily adjusted to increase the coupling efficiency between the laser light L1 emitted from the semiconductor laser element 200 and the optical fiber 550. This is also true for the other optical units 2d to 6d. In other words, a light source module 10d with high coupling efficiency is achieved.

[0529] and, Figure 39A (c) is a front view of the first lens 120d after the movement when the first bonding material 161 is emitted. In this way, the first bonding material 161 is provided at the end portion on the negative side of the x-axis and the end portion on the positive side of the x-axis of the first lens 120d, bonding the first lens 120d.

[0530] Next, a method for manufacturing the first lens 120d will be described. Figure 40 This is a front view showing a method for manufacturing the first lens 120d according to this embodiment.

[0531] More specifically, Figure 40 (a) is a front view showing the prepared cylindrical lens 900, Figure 40 (b) is a front view showing a plurality of segment lenses 901 after being cut. Figure 40 (c) is a front view for explaining the grinding of the plurality of segment lenses 901. Figure 40 (d) is a front view showing a plurality of manufactured first lenses 120d.

[0532] First, if Figure 40 As shown in (a), a cylindrical lens 900 having a busbar 915 is prepared. Figure 40 The cylindrical lens 900 is cut along the plurality of cutting lines 902 shown by the dotted lines in (a). Here, the plurality of cutting lines 902 are parallel to each other, and the cylindrical lens 900 is cut so that the angle γ formed by each of the plurality of cutting lines 902 and the generatrix 915 satisfies 0°<γ<90°.

[0533] By cutting the cylindrical lens 900, a plurality of segment lenses 901 are obtained. Figure 40 As shown in (b) , the plurality of segment lenses 901 are fixed by a jig and a temporary fixing resin (not shown) so that the cut surfaces thereof are in contact with each other.

[0534] Next, the plurality of segment lenses 901 fixed to a jig or the like are ground together. Figure 40 As shown in (c), the plurality of segment lenses 901 are ground together to two parallel grinding lines 903 shown by the dotted lines. Figure 40 As shown in (d), a plurality of first lenses 120d are obtained in which the end surfaces are inclined with respect to the generatrix 125.

[0535] Then, by removing the jig and the temporary fixing resin, a plurality of first lenses 120d are manufactured.

[0536] Next, use Figures 41A to 42 The effects of the optical unit 1d of this embodiment will be described.

[0537] First, the influence of the inclination of the busbar 125d with respect to the active layer and the xy plane on the optical characteristics of the optical unit 1d was examined.

[0538] The inclination of the generatrix 125d causes aberration, and therefore, it is expected that the light intensity distributions of the laser beams L1 to L6 on the incident surface of the condenser lens 800 and the light intensity distributions of the laser beams L1 to L6 on the incident surface of the optical fiber 550 will be distorted.

[0539] Figure 41AThis is a diagram showing the results of simulation calculation of the light intensity distribution of the laser beams L1 to L6 on the incident surface of the condenser lens 800 when the angle θ1 is -15° in this embodiment in addition to the condition B6 of the first embodiment. Figure 41A , the beam spots of the laser beams L1 to L6 are shown, and the darker the color, the higher the light intensity.

[0540] exist Figure 41A The light intensity distribution was calculated under the following conditions. Specifically, the peak wavelength and light emission area width of the semiconductor laser element 200 were 450 nm and 100 μm, respectively. The effective focal length F1 of the FACL 110 was 0.38 mm, the effective focal length F2 of the first lens 120 d was 38 mm, the lens distance d was 6.3 mm, the effective focal length of the SACL 170 was 13.5 mm, the effective focal length of the condenser lens 800 was 7.3 mm, and the core diameter and numerical aperture NA of the optical fiber 550 were 100 μm and 0.22, respectively.

[0541] Since the angle θ1 is -15°, Figure 41A As shown in FIG. 1 , the beam points of lasers L1 to L6 increase in value on the vertical axis as the value on the horizontal axis increases. Figure 42 In FIG, each beam spot of laser light L1 to L6 has a shape with a rising right shoulder.

[0542] Here, in this embodiment, using Figure 41B , the result of calculating the change in the coupling efficiency of the optical fiber 550 with respect to the x-axis direction of the first lens 120 d in the optical system of the light source module 10 d will be described. Figure 41B It means in Figure 41A The results of calculating the coupling efficiency under the conditions of . That is, Figure 41B The data shown by the black dots and solid line are Figure 41A Similarly, the calculation results for this embodiment, excluding condition B6 of embodiment 1, are shown when angle θ1 is -15°. In this case, FACL 110 is offset by 2 μm (-2 μm) in the negative Z-axis direction. In this case, the optical efficiency is below 80% at the reference position. However, by moving first lens 120d in the positive x-axis direction, the coupling efficiency increases. By adjusting the position by approximately 0.8 mm, the coupling efficiency can be restored to approximately 100%.

[0543] In addition, use Figure 42 The influence of a change in the angle θ1 will be described.

[0544] Figure 42 This is a diagram showing the results of simulation calculation of the maximum value of the coupling efficiency when the first lens 120 d having a variable angle θ1 according to this embodiment is used.

[0545] exist Figure 42 In the middle, the white quadrilateral and the solid line are in the Figure 41A Under the same conditions, the coupling efficiency was calculated by varying θ1. Furthermore, the coupling efficiency when θ1 = 0° was normalized by setting it to 1.

[0546] like Figure 42 As shown in Figure 1, even when the absolute value of angle θ1 increases from 0° to 15°, the coupling efficiency remains approximately 1. Furthermore, if the absolute value of angle θ1 exceeds 15°, the coupling efficiency begins to gradually decrease, and if it exceeds 23°, the coupling efficiency falls below 0.95. Therefore, under these conditions, the absolute value of angle θ1 is preferably 23° or less.

[0547] Under the above conditions, for example, it is possible to compare Figure 23A The case where the first lens 120d is adjusted in the x-axis direction under condition B6 and the case where Figure 23A FIG. 5 shows a change in coupling efficiency when the first lens 120 is adjusted in the z-axis direction under condition B6. Figure 23A as well as Figure 41A The black circles and solid line represent the change in coupling efficiency when FACL110 is offset by 2.0 μm in the negative z-axis direction. Figure 23A This is the case where the generatrix of the first lens 120 is not tilted. Figure 41A The range where the coupling efficiency exceeds 95% is approximately 300 μm when the busbar 125 d is not tilted, and approximately 650 μm when θ1 is -15°, which more than doubles the adjustment range.

[0548] Furthermore, in Figure 41B Figure 2 shows the change in coupling efficiency when the first lens 120d is moved in the x-axis direction under condition B10, with the angle θ1 of the generatrix of the first lens 120d varying between -1°, 2.5°, and 5°. In this case, FACL 110 is similarly offset by 2.0 μm in the negative z-axis direction. At any angle θ1, adjusting the first lens 120d in the x-axis direction improves coupling efficiency. Specifically, when the angle θ1 is between 1° and 5°, coupling efficiency improves. Furthermore, it can be seen that reducing the angle θ1 further expands the adjustment range.

[0549] In addition, Figure 42 In addition to condition B6, conditions B10 and B4 also show the results of calculating the maximum coupling efficiency when using the first lens 120d of this embodiment with a variable angle θ1. Compared to condition B6, conditions B10 and B4 narrow the range of angle θ1 within which the maximum coupling efficiency does not decrease. Therefore, angle θ1 can be appropriately selected depending on the optical unit.

[0550] As in Figure 39A as well as Figure 39B As described in

[15] and

[16] , by satisfying the angle θ1 of 0°<θ1<45°, when the FACL 110 is offset, the coupling efficiency can be improved by adjusting the position of the first lens 120d in the x-axis direction.

[0551] [Effects, etc.]

[0552] In Embodiment 2, in each of the plurality of optical units (optical units 1d to 6d), the first fast axis adjustment lens (first lens 120d) is a cylindrical lens having a generatrix 125d. The plurality of semiconductor laser elements 200 each have an active layer. The generatrix 125d is inclined relative to the active layer.

[0553] In embodiment 2, as Figure 39A As shown in (a) and (b), if the first lens 120d moves in the x-axis direction, the distance between the center of the beam spot LO1d and the generatrix 125d in the z-axis direction changes. Furthermore, when the angle θ1 satisfies 0°<θ1<45°, the change in the distance between the center of the beam spot LO1d and the generatrix 125d in the z-axis direction is smaller than the movement of the first lens 120d in the x-axis direction. If the x-axis position of the first lens 120d is adjusted using manufacturing equipment, the x-axis position can be adjusted with an accuracy equal to that of the manufacturing equipment, while the z-axis position can be adjusted with an accuracy higher than that of the manufacturing equipment.

[0554] In this optical unit 1d, the position of the first lens 120d can be easily adjusted to increase the coupling efficiency between the laser light L1 emitted from the semiconductor laser element 200 and the optical fiber 550. This is also true for the other optical units 2d to 6d. In other words, a light source module 10d with high coupling efficiency is achieved.

[0555] In the second embodiment, in each of the optical units 1 d to 6 d , the first lens 120 d has a bottom surface 1211 that is inclined with respect to the generatrix 125 d , and the bottom surface 1211 is directly or indirectly fixed to the base 510 .

[0556] Thus, the first lens 120 d can be fixed to the base 510 .

[0557] In embodiment 2, in each of optical units 1d to 6d, the semiconductor laser element 200 has an active layer, the base 510 has a mounting surface (first section 511a) parallel to the active layer and on which the first lens 120d is mounted, and the bottom surface 1211 is fixed to the mounting surface (first section 511a).

[0558] As a result, the generatrix 125d of the first lens 120d is tilted toward the active layer. Therefore, as described above, if the x-axis position of the first lens 120d is adjusted using manufacturing equipment, the x-axis position can be adjusted with the same accuracy as the manufacturing equipment, and the z-axis position can be adjusted with a higher accuracy than the manufacturing equipment.

[0559] In Embodiment 2, in each of optical units 1d to 6d, first lens 120d is positioned above a mounting plane (first segment 511a) of the stage. The first fast-axis adjustment lens (first lens 120d) has a bottom surface 1211 parallel to the mounting plane, and a plurality of generatrixes 125d are inclined relative to bottom surface 1211.

[0560] As a result, when the first lens 120d is moved so that its bottom surface 1211 is aligned with the plane on which it is installed (first segment 511a), as described above, the change in the distance between the center of the beam spot LO1d and the generatrix 125d in the z-axis direction becomes smaller than the change in the x-axis direction of the first lens 120d. Therefore, in this optical unit 1d, it is easy to adjust the position of the first lens 120d to improve the coupling efficiency between the laser light L1 emitted from the semiconductor laser element 200 and the optical fiber 550. The same applies to the other optical units 2d to 6d. In other words, a light source module 10d with high coupling efficiency is achieved. Furthermore, a high-brightness laser light L100d can be emitted from the end face of the optical fiber 550 of the light source module 10d.

[0561] (Implementation 3)

[0562] Hereinafter, a description will be given of Embodiment 3. The following description will focus on the differences from Embodiment 2, and the description of the common points will be omitted or simplified.

[0563] Figure 43 It is a perspective view showing a part of a light source module 10f according to the third embodiment.

[0564] The light source module 10f of this embodiment has the same structure as the light source module 10d of the second embodiment, except that it includes an optical unit 1f, an optical unit 2f having the same structure as the optical unit 1f, and four optical units instead of the optical units 1d to 6d. In other words, the light source module 10f of this embodiment includes six optical units. Each of the six optical units has the same structure, but the description here focuses on the optical unit 1f.

[0565] The optical unit 1 f of the present embodiment has the same structure as the optical unit 1 d of the second embodiment, except that it mainly includes a package 400 .

[0566] Specifically, the optical unit 1 f of this embodiment includes a package unit 600 (semiconductor laser element 200 , FACL 110 , first sub-mount 230 , adhesive member 280 c , second sub-mount 250 c , and package 400 ), a first lens 120 d , and a SACL 170 .

[0567] The package unit 600 includes the semiconductor laser element 200 , the FACL 110 , the first submount 230 , the adhesive member 280 c , the second submount 250 c , and the package 400 .

[0568] The package 400 includes a bottom plate 410, a side plate 430 surrounding the periphery, and a light-transmitting window 420. The light-transmitting window 420 is configured to cover a front opening 630 formed in a portion of the side plate 430. Figure 43 The top plate 440 of the package 400 is not shown. The bottom plate 410 and the side plate 430 are integrally formed package components from a material with high heat dissipation properties, such as ceramic. Furthermore, the side plate 430 is formed with a first internal electrode 611, a second internal electrode 612, a first external electrode 621, and a second external electrode 622. The first external electrode 621 is electrically connected to the first internal electrode 611, forming a terminal. The second external electrode 622 is electrically connected to the second internal electrode 612, forming a terminal. The first internal electrode 611 and the second internal electrode 612 are connected to the semiconductor laser element 200, and by inputting power to the first external electrode 621 and the second external electrode 622, a predetermined power is input to the semiconductor laser element 200.

[0569] Furthermore, the light source module 10 f of this embodiment is similar to the third modification of the first embodiment and includes a base 510 c .

[0570] In this embodiment, the semiconductor laser element 200 and the FACL 110 are hermetically sealed by the package 400. At this time, the FACL 110 is fixed at a predetermined position in the package 400 by an adhesive member 280c.

[0571] This protects the semiconductor laser element 200 from impurities such as organic matter from outside the package 400. Therefore, during operation of the semiconductor laser element 200, it is possible to suppress degradation of the semiconductor laser element 200 due to impurities such as organic matter adhering to the semiconductor laser element 200.

[0572] Furthermore, the busbar 125d of the first lens 120d is inclined relative to the active layer and the xy plane. The angle θ1 formed by the busbar 125d and the active layer satisfies 0° < |θ1| < 45°. Therefore, similar to Embodiment 2, in the optical unit 1f, the position of the first lens 120d can be easily adjusted to improve the coupling efficiency between the laser light L1 emitted from the semiconductor laser element 200 and the optical fiber 550. That is, when the package unit 600 is fixed to the optical unit 1f, even if the FACL 110 is fixed at a position offset from the specified position, the coupling efficiency can be improved by adjusting the position of the first lens 120d on the upper surface of the base 510c, i.e., the xy plane. This is also true for the optical unit 2f and the other four optical units. Thus, a light source module 10f with high coupling efficiency is achieved.

[0573] (Implementation 4)

[0574] Hereinafter, a description will be given of Embodiment 4. The following description will focus on the differences from Embodiment 3, and the description of the common points will be omitted or simplified.

[0575] [structure]

[0576] First, use Figure 44 The structure of a light source module 10g according to the fourth embodiment will be described.

[0577] Figure 44 It is a perspective view showing a part of a light source module 10g according to a fourth embodiment.

[0578] The light source module 10g of this embodiment has the same structure as the light source module 10f of Embodiment 3, except that it includes an optical unit 1g, an optical unit 2g having the same structure as the optical unit 1g, and four optical units instead of the six optical units of Embodiment 3. In other words, the light source module 10g of this embodiment includes six optical units. Each of the six optical units has the same structure, but the description here focuses on the optical unit 1g.

[0579] The optical unit 1 g of the present embodiment has the same structure as the optical unit 1 f of the third embodiment, except that it mainly includes a second fast axis adjustment lens 130 .

[0580] The second fast-axis adjustment lens 130 (hereinafter, referred to as the second lens 130 ) is a lens into which the laser light L1 emitted from the first lens 120 d is incident and which adjusts the optical axis of the laser light L1 in the fast-axis direction.

[0581] The second lens 130 is an optical component whose power in the fast axis direction is greater than its power in the slow axis direction. In this embodiment, the second lens 130 is a cylindrical lens having a power axis and a non-power axis. Furthermore, the power axis and the non-power axis are arranged perpendicularly. The second lens 130 has a cylindrical surface that is convex toward the power axis, i.e., a convex cylindrical surface. In this embodiment, the second lens 130 is a plano-convex lens with a flat incident surface for laser light L1 and a convex curved exit surface.

[0582] The incident surface of the second lens 130 is parallel to the zx plane. The curvature radius of the curved surface of the exit surface of the second lens 130 is sufficiently larger than that of the FACL 110 .

[0583] The second lens 130 is made of an inorganic transparent material such as glass, and has anti-reflection coatings that match the wavelength of the laser light L1 formed on its incident surface and exit surface.

[0584] Before adjusting and fixing the first lens 120 d , the second lens 130 is fixed in advance using the seventh bonding material 330 .

[0585] Furthermore, the second lens 130 has a busbar 135. In addition, the second lens 130 can be said to have the same structure as the first lens 120d except that it has a busbar 135 instead of the busbar 125d.

[0586] The generatrix 135 of the second lens 130 is the same as the generatrix 125d of the first lens 120d and is inclined with respect to the active layer of the semiconductor laser element 200. Figure 45 The inclination of the bus bars 125d and 135 will be described.

[0587] Figure 45 1 is a front view for explaining the inclination of the busbars 125d and 135 of this embodiment. Figure 45 (a) mainly shows the first lens 120d. Figure 45 (b) mainly shows the second lens 130.

[0588] The generatrix 125d of the first lens 120d is tilted relative to the active layer and the xy plane. Figure 45 As shown in (a), the busbar 125d is inclined in a counterclockwise direction (pseudo-clockwise) relative to the active layer and the xy plane.

[0589] The generatrix 135 of the second lens 130 is tilted relative to the active layer and the xy plane. Figure 45 As shown in (b), the busbar 135 is inclined in a clockwise direction (pseudo-clockwise) relative to the active layer and the xy plane.

[0590] Here, the angle formed by busbar 135 and the active layer is defined as angle θ2. Since busbar 135 is inclined relative to the active layer, 0° < |θ2| satisfies this. Furthermore, 0° < |θ2| < 45° is sufficient, with 0.5° < |θ2| < 30° being more preferable, and 1° < |θ2| < 10° being even more preferable.

[0591] Thus, the optical unit 1g includes a first lens 120d and a second lens 130. Generic lines 125d of the first lens 120d and 135 of the second lens 130 are inclined relative to the active layer. Furthermore, the direction in which generic lines 125d are inclined relative to the active layer is opposite to the direction in which generic lines 135 are inclined relative to the active layer.

[0592] like Figure 41A As shown, in the light source module 10d without the second lens 130, the light intensity distribution of the laser lights L1 to L6 is distorted, that is, the beam spots of the laser lights L1 to L6 rise to the right. This is because, as described above, the inclination of the generatrix 125d causes aberration.

[0593] When the laser beams L1 to L6 are arranged in the z-axis direction using the reflector 700 , a portion of the laser beams L1 to L6 with a large inclination in the set at the position of the condenser lens 800 is shielded by other reflectors and does not enter the optical fiber 550 , which may reduce the coupling efficiency.

[0594] However, in this embodiment, the second lens 130 is provided, and the direction in which the generatrix 125d is inclined relative to the active layer is opposite to the direction in which the generatrix 135 is inclined relative to the active layer. Therefore, the distortion of the light intensity distribution caused by the aberration caused by the first lens 120d is eliminated by the second lens 130 having the generatrix 135 inclined in the opposite direction. That is, Figure 41A The beam spot shown rises rightward when viewed from the front, but the beam spots of the laser beams L1 to L6 that have passed through the second lens 130 are approximately parallel to the xy plane. As a result, the coupling efficiency in the light source module 10g is improved.

[0595] [Effects, etc.]

[0596] In Embodiment 4, each of the plurality of optical units further includes a second fast-axis adjustment lens (second lens 130) for receiving the laser light emitted from the first fast-axis adjustment lens (first lens 120d) and adjusting the optical axis of the laser light in the fast-axis direction. In each of the plurality of optical units, the semiconductor laser element 200 includes an active layer, and the first lens 120d and the second lens 130 are cylindrical lenses having generatrixes 125d and 135, respectively. In each of the plurality of optical units, the generatrix 125d and the generatrix 135 are inclined relative to the active layer, with the generatrix 125d tilted in the opposite direction to the generatrix 135.

[0597] Thus, the distortion of the light intensity distribution caused by the aberration caused by the first lens 120d is eliminated by the second lens 130 having the generatrix 135 inclined in the opposite direction. Figure 41A The beam spot shown rises rightward when viewed from the front, but the beam spots of the laser beams L1 to L6 that have passed through the second lens 130 can all be aligned parallel to the xy plane. This prevents the laser beams L1 to L6 from being blocked by other reflectors 700, thereby improving the coupling efficiency in the light source module 10g.

[0598] (Implementation 5)

[0599] Hereinafter, Embodiment 5 will be described. Hereinafter, the description will focus on the differences from Embodiment 1, and the description of the common points will be omitted or simplified.

[0600] [structure]

[0601] First, use Figure 46 The structure of the light source module according to the fifth embodiment will be described.

[0602] Figure 46 1 is a front view showing a portion of a light source module according to Embodiment 5. More specifically, Figure 46 It is a front view showing a part of the optical unit 1h included in the light source module of the present embodiment.

[0603] The light source module of this embodiment has the same structure as the light source module of Embodiment 1, except that it includes an optical unit 1h and five optical units each having the same structure as optical unit 1h, instead of optical units 1 to 6. That is, the light source module 10 of this embodiment includes six optical units. Each of the six optical units has the same structure, but the description here focuses on optical unit 1h.

[0604] The optical unit 1 h has the same structure as that of the optical unit 1 , except that it includes a first lens 120 h instead of the first lens 120 and a support member 150 h instead of the support member 150 .

[0605] The first lens 120h includes a lens body 1201h and a lens frame 1202h as a flange. The first lens 120h is formed by bonding the lens body 1201h and the lens frame 1202h together with a bonding material 1203.

[0606] The lens body 1201h has the same structure as the first lens 120 in Embodiment 1. The lens holder 1202h is a component that holds the lens body 1201h. In this embodiment, the lens holder 1202h is disposed below the lens body 1201h. The lens holder 1202h is composed of, for example, an inorganic material such as glass or silicon. The lens holder 1202h can be composed of, for example, an Fe alloy such as Fe or stainless steel, a metal such as Cu or a Cu alloy, or a ceramic such as Al2O3, ZrO2, or SiN. The bonding material 1203 is composed of, for example, a material with a high melting point such as AuSn solder or a sintered Ag.

[0607] The lens holder 1202h is a component comprising an upper surface located closer to the positive z-axis side and parallel to the xy plane, and a lower surface 121h located closer to the negative z-axis side and inclined relative to the xy plane. The upper surface of the lens holder 1202h is bonded to the lower surface of the lens body 1201h. The lower surface 121h is bonded to the support member 150h. Therefore, the first lens 120h has a lower surface 121h that is inclined relative to the generatrix 125.

[0608] The support member 150h is disposed between the first lens 120h and the first segment 511a. The support member 150h is made of, for example, an inorganic material such as glass or silicon. Alternatively, it may be made of metals such as Fe, Fe alloys such as stainless steel, Cu or Cu alloys, or ceramics such as Al2O3, ZrO2, or SiN.

[0609] Support member 150h includes an upper surface 153h located closer to the positive side of the z-axis and inclined relative to the xy plane, and a lower surface 154h located closer to the negative side of the z-axis and parallel to the xy plane. Lower surface 154h and first segment 511a are bonded via second bonding material 162. Second bonding material 162 can also be made of, for example, solder or a sintered metal. Therefore, support member 150h, fixed to base 510, has an upper surface 153h inclined relative to the surface of first segment 511a.

[0610] After adjusting the position of the first lens 120h, the upper surface 153h of the support member 150h and the lower surface 121h of the first lens 120h are bonded together using a first bonding material 161, which serves as an adhesive member. The upper surface 153h serves as the mounting surface for the first lens 120h. The lower surface 121h and the upper surface 153h, which serves as an inclined surface, are parallel to each other. Furthermore, in this embodiment, the active layer of the semiconductor laser element 200 is also parallel to the xy plane. Therefore, the lower surface 121h and the upper surface 153h are inclined relative to the xy plane, that is, they are also inclined relative to the active layer.

[0611] Here, the degree of inclination of the upper surface 153h as an inclined surface will be described. Figure 46 Angle θ3 is shown in FIG. Angle θ3 is the angle between the xy plane and the upper surface 153h, which is an inclined surface. That is, angle θ3 is the angle between the first segment 511a and the upper surface 153h. In addition, angle θ3 is the angle between the active layer parallel to the xy plane and the upper surface 153h. In this embodiment, angle θ3 satisfies 0°<|θ3|<45°. In addition, in the first lens 120h, the angle between the busbar 125 and the lower surface 121h is angle θ3.

[0612] Furthermore, use Figure 47 An example of a method for manufacturing the optical unit 1h will be described. Here, the optical unit 1h will be described as an example, but the other five optical units can also be manufactured by the same method.

[0613] Figure 47 Schematic diagram showing the steps of the method for manufacturing the optical unit 1h. More specifically, Figure 47 , the process of adjusting the position of the first lens 120h and then bonding it to the support member 150h is shown. Prior to this process, the following three processes are performed: These processes include placing the semiconductor laser element 200, the first submount 230, and the FACL 110 on the second section 511b; preparing the first lens 120h by bonding the lens body 1201h to the lens holder 1202h; and bonding and fixing the support member 150h to a predetermined position on the first section 511a.

[0614] Then, if Figure 47 As shown, the first lens 120h is positionally adjusted and then bonded to the supporting member 150h.

[0615] Figure 47 (a) illustrates the process of placing the first lens 120h on the upper surface 153h of the support member 150h and emitting light from the semiconductor laser element 200. First, the collet 1100 grasps the upper surface of the lens holder 1202h of the first lens 120h and moves it onto the upper surface 153h. At this point, the collet 1100 moves so that the generatrix 125 is aligned with the imaginary line IL of the optical unit 1h. Subsequently, the semiconductor laser element 200 emits laser light L1.

[0616] At this time, Figure 47During the process of securing FACL 110 to semiconductor laser element 200, FACL 110 is offset upward, i.e., in the positive z-axis direction, relative to imaginary line IL of optical unit 1h. In this case, laser light L1 travels diagonally upward relative to imaginary line IL. At this time, beam spot LO1d of laser light L1 in first lens 120h is offset from generatrix 125 in the positive z-axis direction. The offset in the z-axis direction is denoted by distance d12. That is, on reference line XLVII-XLVII, the center of beam spot LO1d is a distance d12 from generatrix 125.

[0617] Figure 47 (b) is a diagram showing the process of moving the position of the first lens 120h, the so-called alignment process. At this time, the first lens 120h moves along the upper surface 153h inclined relative to the x-axis direction. Figure 47 The first lens 120h shown in (a) is Figure 47 The first lens 120h shown in (b) moves to the negative side of the x-axis and the negative side of the z-axis as indicated by the hollow arrow.

[0618] At this time, the generatrix 125 moves in a direction away from the position of the beam spot LO1d, and the distance between the center of the beam spot LO1d and the generatrix 125 becomes a distance d121 greater than the distance d12.

[0619] During the alignment process, the position of first lens 120h is moved, or adjusted, to improve the coupling efficiency between emitted laser light L1 and optical fiber 550. This adjustment results in the center of beam spot LO1d being spaced a distance d121 from generatrix 125 along reference line XLVII-XLVII. Consequently, laser light L1, emitted from FACL 110 and traveling diagonally upward relative to imaginary line IL, is refracted parallel to imaginary line IL upon passing through lens body 1201h of first lens 120h. This improves the coupling efficiency between laser light L1 and optical fiber 550.

[0620] Figure 47 Figure (c) illustrates the process of securing first lens 120h to support member 150h. With first lens 120h held in collet 1100 after position adjustment, first bonding material 161, such as a UV-curable adhesive, is applied using syringe 1200 to the portion where the side of lens holder 1202h meets the upper surface 153h of support member 150h. Next, ultraviolet light is irradiated to cure first bonding material 161.

[0621] Figure 47(d) is a diagram showing the process of disassembling the syringe 1200 and the collet 1100. The first lens 120h is fixed to the support member 150h by the first bonding material 161, so that the first lens 120h is fixed to a predetermined position on the base 510. Figure 47 The optical unit 1h is manufactured by the manufacturing method shown in (a) to (d).

[0622] In the light source module of Embodiment 5, when the angle θ3 satisfies 0° < |θ3| < 45°, the same effects as those of the light source module 10d of Embodiment 2 can be achieved. More preferably, it is 0.5° < |θ3| < 30°, and even more preferably, it is 1° < |θ3| < 10°. When the angle θ3 satisfies 0° < |θ3| < 45°, when the first lens 120h moves along the inclined upper surface 153h, the change in the distance between the center of the beam spot LO1d and the generatrix 125 in the z-axis direction is less than the movement of the first lens 120h in the x-axis direction. Therefore, as in Embodiment 2, in the optical unit 1h, the position of the first lens 120h can be easily adjusted to improve the coupling efficiency between the laser light L1 emitted from the semiconductor laser element 200 and the optical fiber 550. This is also true for the other five optical units. In other words, a light source module with high coupling efficiency is achieved.

[0623] [Effects, etc.]

[0624] In Embodiment 5, each of the multiple optical units further includes a support member 150h that supports the first lens 120h. In each of the multiple optical units, the semiconductor laser element 200 includes an active layer, and the first lens 120h (more specifically, the lens body 1201h) is a cylindrical lens having a generatrix 125. In each of the multiple optical units, the generatrix 125 is parallel to the active layer. The support member 150h has an inclined surface (upper surface 153h) that is inclined relative to the active layer. The first lens 120h (more specifically, the lens body 1201h) is provided on the inclined surface (upper surface 153h).

[0625] Thus, when first lens 120h is moved in the x-axis direction along the inclined surface (upper surface 153h), the change in the distance between the center of beam spot LO1d and generatrix 125 in the z-axis direction is smaller than the x-axis movement of first lens 120h. Therefore, similar to Embodiment 2, in optical unit 1h, the position of first lens 120h can be easily adjusted to improve the coupling efficiency between laser light L1 emitted from semiconductor laser element 200 and optical fiber 550. The same applies to the other five optical units. In other words, a light source module with high coupling efficiency is achieved.

[0626] In Embodiment 5, each of the plurality of optical units includes a support member 150h mounted on a base 510. In each of the plurality of optical units, the support member 150h has a mounting surface (upper surface 153h) on which the first lens 120h is mounted, and the semiconductor laser element 200 includes an active layer. The bottom surface (lower surface 121h) of the first lens 120h is fixed to the mounting surface (upper surface 153h) of the support member 150h, which is inclined relative to the active layer.

[0627] Thus, the bottom surface (lower surface 121h) of the first lens 120h is disposed on the mounting surface (upper surface 153h) that is inclined relative to the active layer. Therefore, as described above, in the optical unit 1h, the position of the first lens 120h can be easily adjusted to increase the coupling efficiency between the laser light L1 emitted from the semiconductor laser element 200 and the optical fiber 550.

[0628] In addition, in this embodiment, the lens body 1201h and the lens frame 1202h are different components, but are not limited to this. The lens body 1201h and the lens frame 1202h can also be formed integrally from the same glass material. In addition, as the first bonding material 161, it is described that an ultraviolet curing adhesive is used, but it is not limited to this. For example, an inorganic bonding component made of an inorganic material such as a solder material can also be used as the first bonding material 161, and the lens frame 1202h can be fixed to the support member 150h by heating and cooling. In addition, the lens frame 1202h and the support member 150h can also be made of an Fe alloy. In this case, the lens frame 1202h can also be fixed to the support member 150h by irradiating a laser near the first bonding material 161 to form the first bonding material 161 as a laser welding portion. By using an inorganic bonding member as the first bonding material 161 , it is possible to prevent foreign matter such as low molecular weight siloxane from being generated from the first bonding material 161 and adhering to the light emitting point 201 of the semiconductor laser element 200 during operation of the light source module, thereby preventing the characteristics of the semiconductor laser element 200 from being degraded.

[0629] (Implementation 6)

[0630] Figure 48 is a cross-sectional view showing a method for manufacturing the optical unit 1j according to Embodiment 6. Figure 48 In the figure, the setting direction and the like are indicated by thick arrows.

[0631] The light source module of this embodiment has the same structure as the light source module of Variation 3 of Embodiment 1, except that it includes an optical unit 1j and five optical units each having the same structure as optical unit 1j, instead of optical unit 1c and five optical units each having the same structure as optical unit 1c. That is, the light source module of this embodiment includes six optical units. Each of the six optical units has the same structure, but optical unit 1j will be described here.

[0632] The optical unit 1 j of the present embodiment has the same structure as the optical unit 1 c of the third modification of the first embodiment, except that it mainly includes a package 400 j instead of the package 400 .

[0633] The optical unit 1j includes a package 400j that hermetically seals and houses the semiconductor laser element 200 and the FACL 110. More specifically, the package 400j also hermetically seals and houses the first sub-mount 230 and the second sub-mount 250c. The FACL 110 is secured to the upper surface of the second sub-mount 250c via an adhesive 280c. It should be noted that the semiconductor laser element 200, FACL 110, first sub-mount 230, second sub-mount 250c, adhesive 280c, and package 400j, among the multiple components of the optical unit 1j, are sometimes collectively referred to as a package unit 600j.

[0634] The package 400j includes a frame portion 430j surrounding the semiconductor laser element 200 and the lower and side surfaces of the FACL 110, a light-transmitting window 420, and a top plate 440. The frame portion 430j corresponds to a member combining the bottom plate 410 and the side plates 430 of the package 400.

[0635] In this embodiment, the light-transmitting window 420 is provided at the front opening 420c of the frame portion 430j. Figure 48 As shown, the front opening portion 420c has layers, a plane corresponding to one layer is a first mounting surface 430a, and a plane corresponding to the other layer is a second mounting surface 430b.

[0636] Figure 48 (a) is a cross-sectional view for explaining the installation of the light-transmitting window 420 with respect to the front opening 420c. The light-transmitting window 420 is mounted on the first mounting surface 430a.

[0637] Figure 48(b) is a cross-sectional view illustrating the placement of the package unit 600j on the first workbench 511c. The package unit 600j is bonded to the first workbench 511c via the sixth bonding material 320. When the package unit 600j is bonded, the FACL 110 may be fixed offset from its optimal position, i.e., the imaginary line IL, due to variations in the thickness of the adhesive member 280c. Figure 48 (b) shows a case where the FACL 110 is fixed above the imaginary line IL. In this case, the optical axis LA1 of the laser light L1 is tilted upward relative to the imaginary line IL, and the laser light L1 travels diagonally upward. In this case, the laser light L1 is hardly coupled to the optical fiber 550 .

[0638] In this embodiment, the first lens 120 is further mounted on the second mounting surface 430b of the front opening 420c. The position of the first lens 120 is moved along the second mounting surface 430b, thereby adjusting the position of the first lens 120 in the z-axis direction.

[0639] Figure 48 (c) is a cross-sectional view after the first lens 120 is joined. As described above, the position of the first lens 120 in the z-axis direction is adjusted. Here, the position of the first lens 120 in the z-axis direction is adjusted to a position where the optical axis LA1 of the laser light L1 emitted from the first lens 120 is parallel to the imaginary line IL. When the position of the first lens 120 in the z-axis direction becomes this position, the first lens 120 is joined by the first bonding material 161. As an example, the first bonding material 161 can be made of a solder material. In addition, the first bonding material 161 can also be made of an inorganic bonding component such as a metal sintered body or a bonding component such as an ultraviolet curing adhesive containing an ultraviolet curing resin.

[0640] The optical unit 1j of this embodiment can easily adjust and bond the z-axis position of the first lens 120. Furthermore, the laser light L1 can be efficiently coupled to the optical fiber 550. Furthermore, there is no need to prepare a separate component to support the first lens 120.

[0641] The light source module of Embodiment 6 includes the same number of mounting surfaces as the number of optical units. In each of the optical units, the first lens 120 has an incident surface for the laser light emitted from the FACL 110. This incident surface has a flat portion. This flat portion is fixed to one of the mounting surfaces (the second mounting surface 430b).

[0642] Thus, the position of the first lens 120 can be easily adjusted in the fast axis direction, that is, the z-axis direction, and can be fixed after the position adjustment.

[0643] In the sixth embodiment, in each of the plurality of optical units, one mounting surface (the second mounting surface 430 b ) is provided on the package 400 j .

[0644] Thus, the first lens 120 can be fixed to the package 400 j , and therefore, there is no need to prepare a separate component for supporting the first lens 120 .

[0645] (Implementation 7)

[0646] Figure 49 1 is a perspective view showing the overall structure of a light source device 1900 including a light source module 10 k , a condenser lens 554 , and a wavelength conversion member 555 according to a seventh embodiment.

[0647] The light source module 10 k of this embodiment does not include the condenser lens 800 , the optical fiber 550 , and the protective cover 551 , and has the same structure as the light source module 10 of the first embodiment except that a light-transmitting window 553 is provided on the side wall 503 .

[0648] The light source module 10k according to this embodiment includes a housing 501, a base 510, multiple optical units (herein, optical units 1, 2, 3, 4, 5, and 6), and multiple reflectors 700. In this embodiment, a light-transmitting window 553 is provided on the sidewall 503. Laser beams L1 to L6 reflected by the multiple reflectors 700 are spatially combined before entering the light-transmitting window 553 and then pass through the window 553. The spatially combined laser beams L1 to L6 that have passed through the window 553 are referred to herein as laser beams L10. In other words, laser beam L10 is light emitted from the light source module 10k.

[0649] Lasers L1 to L6 are collimated lasers. Therefore, laser L10 is also collimated laser. Furthermore, lasers L1 to L6 are spatially combined by first lens 120 into precisely parallel collimated lasers. Laser L10, formed by spatially combining multiple collimated lasers, is a collimated laser with high optical output and optical density.

[0650] Therefore, the collimated laser light L10 having high optical output and high light density can be emitted from the light source module 10 k.

[0651] exist Figure 49 55 , a beam spot LO10 of the laser light L10 is shown. The laser light L10 that has passed through the light-transmitting window 553 is incident on the condenser lens 554 .

[0652] The condenser lens 554 is a lens that focuses the incoming laser light L10. The laser light L10 focused by the condenser lens 554 is emitted from the condenser lens 554 and enters the focusing area LO20 at a predetermined position on the wavelength conversion component 555. In this embodiment, the object 550a is the condenser lens 554. Since the laser light L10 is collimated, it is efficiently coupled to the condenser lens 554. Furthermore, when the light source module 10 includes the condenser lens 554, the object 550a is the focusing area LO20.

[0653] The wavelength conversion component 555 is a component that converts the wavelength of the laser light L10 emitted from the condenser lens 554, and is, for example, a component containing a phosphor. For example, the wavelength conversion component 555 is a rotating component, a so-called phosphor wheel. The wavelength of the laser light L10 is converted by the wavelength conversion component 555, and the wavelength-converted light is emitted from the wavelength conversion component 555. For example, if the laser light L10 emitted from the condenser lens 554 is blue light, and the wavelength conversion component 555 contains a yellow phosphor that receives the blue light and emits yellow light, the blue light of the laser light L10 and the yellow light emitted by the yellow phosphor are combined, and white light is emitted from the wavelength conversion component 555.

[0654] At this time, the laser light L10 incident on the condenser lens 554 is collimated and has high optical output and optical density. Therefore, the laser light L10 is focused by the condenser lens 554 at a high optical density onto the focusing area LO20 at a predetermined position on the wavelength conversion member 555. Consequently, wavelength conversion member 555 emits wavelength-converted light with high brightness. In other words, light source device 1900 can emit wavelength-converted light with high brightness.

[0655] In this embodiment, a phosphor wheel is used as the wavelength conversion component 555, but this is not limiting. A laser crystal can also be used as the wavelength conversion component 555. Furthermore, a resonator optical system can be provided in which the laser crystal is disposed within the resonator. This can achieve a solid-state laser with excellent luminous efficiency.

[0656] (Implementation 8)

[0657] Figure 50 It is a plan view showing the overall structure of a light-emitting device 2000 according to Embodiment 8.

[0658] The light emitting device 2000 of this embodiment includes a plurality of (three) light source modules 10m, 10n, and 10p, a reflector 1000, a first dichroic mirror 1001, and a second dichroic mirror 1002. Light source modules 10m, 10n, and 10p have the same configuration as light source module 10k according to Embodiment 7, except for the wavelength of emitted laser light.

[0659] The light source modules 10 m , 10 n , and 10 p respectively emit laser beams of different wavelengths.

[0660] The light source module 10m has the same configuration as the light source module 10k of the seventh embodiment, except that the wavelength of laser light L10m, which is light emitted from the light source module 10m, is 430 nm to 480 nm.

[0661] The light source module 10n has the same configuration as the light source module 10k according to the seventh embodiment, except that the wavelength of the laser light L10n, which is the light emitted from the light source module 10n, is 480 nm to 570 nm.

[0662] The light source module 10 p has the same structure as the light source module 10 k of the seventh embodiment, except that the wavelength of laser light L10 p , which is light emitted from the light source module 10 p , is 570 nm to 700 nm.

[0663] The reflector 1000 reflects the laser light L10p emitted from the light source module 10p. The first dichroic mirror 1001 transmits light with wavelengths in the red region (light with wavelengths between 570 nm and 700 nm) and reflects light with wavelengths in the green region (light with wavelengths between 480 nm and 570 nm). The laser light L10p reflected by the reflector 1000 and the laser light L10n emitted from the light source module 10n are incident on the first dichroic mirror 1001. The first dichroic mirror 1001 transmits the laser light L10p and reflects the laser light L10n.

[0664] The second dichroic mirror 1002 transmits light with wavelengths in the red and green regions, and reflects light with wavelengths in the blue region (light with wavelengths between 430 nm and 480 nm). Laser light L10p that has passed through the first dichroic mirror 1001, laser light L10n that has been reflected by the first dichroic mirror 1001, and laser light L10m emitted from the light source module 10m enter the second dichroic mirror 1002. The second dichroic mirror 1002 transmits laser light L10p and laser light L10n, and reflects laser light L10m.

[0665] As a result, a light emitting device 2000 can be realized that combines laser beams with wavelengths in the red, green, and blue regions with high brightness (ie, laser beams L10m to L10p) on the same optical axis. Such a light emitting device 2000 can be used in displays.

[0666] Furthermore, the wavelengths of laser light L10m to L10p are not limited to those described above. Alternatively, the wavelength of laser light L10m may be between 360 nm and 390 nm, the wavelength of laser light L10n may be between 390 nm and 410 nm, and the wavelength of laser light L10p may be between 410 nm and 440 nm. In such a light-emitting device 2000, the reflection and transmission characteristics of the first dichroic mirror 1001 and the second dichroic mirror 1002 may be aligned with the wavelengths described above. Such a light-emitting device 2000 can be used, for example, in an exposure apparatus as a replacement for a mercury lamp (i-line: 365 nm, h-line: 405 nm, g-line: 436 nm).

[0667] (Other embodiments)

[0668] The light source module of the present disclosure has been described above based on various embodiments and various variations, but the present disclosure is not limited to these embodiments and various variations. As long as it does not depart from the main purpose of the present disclosure, the embodiments obtained by implementing various variations conceived by those skilled in the art, and other methods constructed by combining some of the constituent elements of the embodiments and various variations are also included in the scope of the present disclosure.

[0669] For example, in the above-described embodiments and variations, convex cylindrical lenses are used as the fast-axis cylindrical lens, the first fast-axis adjustment lens, the second fast-axis adjustment lens, and the slow-axis collimating lens, but the present invention is not limited to this. Concave cylindrical lenses may be used instead of convex cylindrical lenses as the fast-axis cylindrical lens, the first fast-axis adjustment lens, the second fast-axis adjustment lens, and the slow-axis collimating lens.

[0670] In addition, Figure 4A , an example is shown in which the fourth side surface 124 of the first lens 120 is bonded to the first supporting side surface 151 of the supporting member 150 via the first bonding material 161 , but the present invention is not limited thereto. Figure 51 1 is a perspective view showing another example of bonding between the first lens 120 and the support member 150. For example, the first lens 120 may be bonded to two support members 150 through the first bonding material 161. Figure 51 In the embodiment, at least a portion of the light incident surface 120q of the first lens 120 is a plane, and the light incident surface 120q is bonded to the mounting surfaces of the two support members 150, i.e., the plane on the negative side of the y-axis. Such a first lens 120 and the two support members 150 can also be arranged between the FACL 110 and the reflector. With this structure, the first lens 120 and its busbar 125 can be moved and fixed in the fast axis direction, i.e., the z-axis direction, for position adjustment. In addition, as another example, at least a portion of the light exit surface of the first lens 120 can also be a plane, and the light exit surface can be bonded to the plane on the positive side of the y-axis, which is the mounting surface of the support member 150.

[0671] In addition, various changes, substitutions, additions, omissions, etc. can be made to the above-described embodiments within the scope of the claims or their equivalents.

[0672] [Industrial Applicability]

[0673] According to the present disclosure, a light source module with high coupling efficiency can be provided.

[0674] Explanation of symbols

[0675] 1, 1a, 1b, 1c, 1d, 1f, 1g, 1h, 1j, 1x, 1xx, 2, 2d, 2f, 2g, 2x, 2xx, 3, 4, 5, 6 optical units

[0676] d lens distance

[0677] d11, d12, d111, d121 distances

[0678] 10, 10a, 10d, 10f, 10g, 10k, 10m, 10n, 10p, 10x, 10xx light source modules

[0679] LA1 optical axis

[0680] D1, D2, D3, D4, D5 width

[0681] IL imaginary line

[0682] L1, L2, L3, L4, L5, L6, L10, L10m, L10n, L10p, L11, L21 laser

[0683] L100, L100d emit laser

[0684] P0, P1, P2 main points

[0685] Width of W1, W1a, W2, W3, W4, W5, W6, Wt1, Wt2

[0686] 110FACL (Fast Axis Cylindrical Lens)

[0687] 120, 120a, 120d, 120h, 120xx first lens

[0688] 120q light incident surface

[0689] 121 First side

[0690] 121h lower surface

[0691] 1211 Bottom

[0692] 122 Second side

[0693] 123 Third Side

[0694] 124 The Fourth Side

[0695] 125, 125a, 125d, 135, 915, 1251, 1251a busbars

[0696] 130 second lens

[0697] 150, 150h supporting parts

[0698] 151 First supporting side

[0699] 152 Second supporting side

[0700] 153 upper surface

[0701] 153h upper surface

[0702] 154 lower surface

[0703] 154h lower surface

[0704] 161 first bonding material

[0705] 162 second bonding material

[0706] 170 SACL

[0707] 200 semiconductor laser elements

[0708] 201 Luminous Point

[0709] 230 First Co-pilot

[0710] 231 First upper surface

[0711] 240 third bonding material

[0712] 250, 250c second seat

[0713] 251 second upper surface

[0714] 280, 280c bonding parts

[0715] 290 Fourth bonding material

[0716] 320 Sixth bonding material

[0717] 330 Seventh bonding material

[0718] 400, 400j package

[0719] 410 base plate

[0720] 420 light-transmitting window

[0721] 420c, 630 front opening

[0722] 430 side panels

[0723] 430j frame

[0724] 430a First mounting surface

[0725] 430b Second mounting surface

[0726] 440 top plate

[0727] 501 housing

[0728] 502 base

[0729] 503 sidewall

[0730] 510, 510c base

[0731] 511, 511c first workbench

[0732] 511a Paragraph 1

[0733] 511b Paragraph 2

[0734] 512 Second Workbench

[0735] 513 Third Workbench

[0736] 514 Fourth Workbench

[0737] 515 Fifth Workbench

[0738] 516 Sixth Workbench

[0739] 550 fiber

[0740] 550a Object

[0741] 551 protective cover

[0742] 552 terminal

[0743] 553 Translucent Window

[0744] 554 Condenser Lens

[0745] 555 wavelength conversion component

[0746] 600, 600j package unit

[0747] 700, 701, 702, 703, 1000 reflectors

[0748] 701a top surface

[0749] 702a upper surface

[0750] 800 condenser lens

[0751] 900 cylindrical lens

[0752] 1001 First Dichroic Mirror

[0753] 1002 Second dichroic mirror

[0754] 1100 Collet

[0755] 1101 Fast Axis Collimating Lens

[0756] 1200 Syringes

[0757] 1201, 1201h lens

[0758] 1202, 1202h lens holder

[0759] 1203 bonding materials

[0760] 1900 Light Source Device

[0761] 2000 Lighting Device

[0762] LO1, LO2, LO3, LO4, LO5, LO6, LO10, LO1d, LO2d beam points

[0763] LO20 spotlight area

[0764] ML1 distance

[0765] ML2 distance

[0766] MU1 distance

[0767] MU2 distance

Claims

1. A light source module comprising: A base having a plurality of stepped workbenches; and a plurality of optical units, wherein each optical unit is configured on each workbench of the plurality of workbenches, Each of the plurality of optical units has: Semiconductor laser element, emitting laser light; A fast-axis cylindrical lens receives the laser light emitted from the semiconductor laser element and converges the laser light in the fast-axis direction of the laser light. a first fast axis adjustment lens, which receives the laser light emitted from the fast axis cylindrical lens and adjusts the optical axis of the laser light in the fast axis direction; and a slow axis collimating lens for receiving the laser light emitted from the first fast axis adjustment lens and collimating the laser light in the slow axis direction of the laser light; When the effective focal length of the fast axis cylindrical lens is set to F1, The effective focal length of the first fast axis adjustment lens is set to F2, When the distance between the principal point of the fast axis cylindrical lens and the principal point of the first fast axis adjustment lens is set to d, α satisfies Equation 1, α=F2 / F1…(Formula 1) β satisfies Equation 2, β=d / F2…(Formula 2) When F2>0, the α and β satisfy equations 3, 4, 5, and 6. α>1…(Formula 3) αβ>1…(Formula 4) β<(1 / α)+(1 / 3)…(Formula 5) β<1…(Equation 6) When F2<0, the α and β satisfy equations 7, 8, 9, and 10. α<-1…(Formula 7) αβ<1…(Equation 8) β>(1 / α)-(1 / 3)…(Equation 9) β>-1…(Formula 10).

2. The light source module according to claim 1, wherein When F2>0, the α satisfies formula 11, 9.3≦α…(Equation 11) When F2<0, the α satisfies equation 12, -9.3≧α…(Formula 12).

3. The light source module according to claim 1, wherein: When F2>0, the α satisfies equation 13, α≦633…(Equation 13) When F2<0, the α satisfies equation 14, α≧-633…(Formula 14).

4. The light source module according to claim 1, wherein: The fast-axis cylindrical lens includes an incident surface on which the laser beam is incident and an exit surface from which the laser beam is exited, and the incident surface is arranged to face the light-emitting point of the semiconductor laser element.

5. The light source module according to any one of claims 1 to 4, wherein: Each of the plurality of first fast-axis adjustment lenses is a cylindrical lens and a convex lens. The light source module according to claim 5 , wherein: The β satisfies Equation 15, 0<β≦0.33…(Formula 15).

7. The light source module according to any one of claims 1 to 4, wherein: Each of the plurality of first fast-axis adjustment lenses is a cylindrical lens and a concave lens.

8. The light source module according to claim 7, wherein: The β satisfies Equation 16, -0.33≦β<0…(Formula 16).

9. The light source module according to any one of claims 1 to 8, wherein: The F1 is greater than or equal to 0.15 mm and less than or equal to 0.65 mm.

10. The light source module according to claim 1, wherein In each of the plurality of optical units, the first fast-axis adjustment lens has a generating line. The light source module according to claim 10 , wherein: Each of the plurality of optical units includes a support member provided on the base. In each of the plurality of optical units, The supporting member has a mounting surface for mounting the first fast axis adjustment lens. The first fast axis adjustment lens has a side surface orthogonal to the generatrix, The semiconductor laser element has an active layer. The side surface is fixed to the mounting surface that is perpendicular to the active layer.

12. The light source module according to claim 10, wherein: In each of the plurality of optical units, The first fast axis adjustment lens has a bottom surface inclined relative to the generatrix, The bottom surface is fixed to the base directly or indirectly.

13. The light source module according to claim 12, wherein: In each of the plurality of optical units, The semiconductor laser element has an active layer. The base has a mounting surface that is parallel to the active layer and on which the first fast axis adjustment lens is mounted. The bottom surface is fixed to the mounting surface.

14. The light source module according to claim 12, wherein: Each of the plurality of optical units includes a support member provided on the base. In each of the plurality of optical units, The supporting member has a mounting surface for mounting the first fast axis adjustment lens. The semiconductor laser element has an active layer. The bottom surface is fixed to a mounting surface of the support member that is inclined with respect to the active layer.

15. The light source module according to any one of claims 1 to 9, wherein: Each of the plurality of optical units includes an adhesive member for fixing the fast-axis cylindrical lens.

16. The light source module according to claim 15, wherein: The adhesive member is composed of an inorganic adhesive member.

17. The light source module according to claim 15, wherein: Each of the plurality of optical units has: a first submount on which the semiconductor laser element is mounted; and The second sub-mount is bonded to the first sub-mount and the fast-axis cylindrical lens.

18. The light source module according to claim 17, wherein: The adhesive member is arranged between a lower surface of the fast-axis cylindrical lens and an upper surface of the second sub-mount.

19. The light source module according to claim 18, Each of the plurality of optical units includes a package that accommodates the semiconductor laser element and the fast-axis cylindrical lens and hermetically seals the package.

20. The light source module according to claim 19, wherein having mounting surfaces, the number of the mounting surfaces being the same as the number of the plurality of optical units, In each of the plurality of optical units, The first fast axis adjustment lens includes an incident surface on which the laser light emitted from the fast axis cylindrical lens is incident, and the incident surface has a flat portion. The flat portion is fixed to one of the plurality of mounting surfaces.

21. The light source module according to claim 20, wherein: In each of the plurality of optical units, the one mounting surface is provided on the package body.

22. The light source module according to any one of claims 1 to 9, wherein: In each of the plurality of optical units, The first fast axis adjustment lens is a cylindrical lens having a generatrix, The semiconductor laser element has an active layer. The busbar is inclined relative to the active layer.

23. The light source module according to claim 22, wherein: In each of the plurality of optical units, The first fast axis adjustment lens is arranged above the setting plane of the workbench. The first fast axis adjustment lens has a bottom surface parallel to the set plane, The busbar is inclined relative to the bottom surface.

24. The light source module according to any one of claims 1 to 9, wherein: Each of the plurality of optical units further includes a supporting member, The supporting member supports the first fast axis adjustment lens, In each of the plurality of optical units, The semiconductor laser element has an active layer. The first fast axis adjustment lens is a cylindrical lens having a generatrix, The busbar is parallel to the active layer, The support member has an inclined surface inclined relative to the active layer. The first fast axis adjustment lens is provided on the inclined surface.

25. The light source module according to any one of claims 1 to 9, wherein: Each of the plurality of optical units further includes a second fast axis adjustment lens configured to receive the laser light emitted from the first fast axis adjustment lens and adjust the optical axis of the laser light in the fast axis direction. In each of the plurality of optical units, The semiconductor laser element has an active layer. The first fast axis adjustment lens and the second fast axis adjustment lens are cylindrical lenses having a generatrix, The generatrix of the first fast axis adjustment lens and the generatrix of the second fast axis adjustment lens are inclined relative to the active layer. The direction in which the generatrix of the first fast axis adjustment lens is inclined relative to the active layer is opposite to the direction in which the generatrix of the second fast axis adjustment lens is inclined relative to the active layer.

Images