WO2024075594A1 - Semiconductor laser device - Google Patents

Abstract

This semiconductor laser device comprises: a semiconductor laser element (11) and a semiconductor laser element (12); a reflecting mirror (71) that reflects first laser light emitted from the semiconductor laser element (11); and a reflecting mirror (72) that reflects second laser light emitted from the semiconductor laser element (12). The semiconductor laser element (11) has a light emitting point (11e). The semiconductor laser element (12) has a light emitting point (12e). When the optical axis of the first laser light entering the reflecting mirror (71) is a first optical axis, the optical axis of the second laser light entering the reflecting mirror (72) is a second optical axis, and a direction passing through the light emitting point (11e) and perpendicular to the first optical axis is a first direction, a first distance from the light emitting point (11e) to the first optical axis in the first direction and a second distance from the light emitting point (11e) to the second optical axis in the first direction are different from each other. A third distance from the light emitting point (12e) to the second optical axis in the first direction is greater than the first distance.

Description

Semiconductor laser device

This disclosure relates to a semiconductor laser device.

Patent Document 1 describes a semiconductor laser device that includes a multi-stage base arranged on a flat bottom surface, a plurality of semiconductor laser elements and a plurality of reflecting mirrors arranged on the multi-stage base, a focusing lens, and an optical fiber. Each of the plurality of semiconductor laser elements and each of the plurality of reflecting mirrors are arranged on each stage of the multi-stage base. The plurality of laser beams from the plurality of semiconductor laser elements are respectively deflected by the plurality of reflecting mirrors and enter the focusing lens. The focusing lens focuses the incident plurality of laser beams onto the incident end face of the optical fiber.

The semiconductor laser device described in Patent Document 1 aims to realize a compact, high-output laser light source through the above-mentioned configuration.

International Publication No. 2021/230294

When the bottom surface of the semiconductor laser device described in Patent Document 1 is placed on a heat sink, the distances from the multiple semiconductor laser elements to the bottom surface are different from one another, resulting in non-uniform heat dissipation characteristics for the multiple semiconductor laser elements. Also, in the semiconductor laser device described in Patent Document 1, the multiple semiconductor laser elements need to be mounted in multiple stages that are different heights from one another, making the mounting process complicated. In the semiconductor laser device described in Patent Document 1, the positions at which the semiconductor laser elements are arranged are determined on a multi-stage base, making it difficult to solve these problems.

The present disclosure therefore aims to increase the degree of freedom in arranging multiple semiconductor laser elements in a semiconductor laser device that includes multiple semiconductor laser elements.

In order to achieve the above object, a semiconductor laser device according to one embodiment of the present disclosure includes a housing having a bottom surface, a first semiconductor laser element and a second semiconductor laser element disposed within the housing, a first reflecting mirror that reflects a first laser light emitted from the first semiconductor laser element, a second reflecting mirror that reflects a second laser light emitted from the second semiconductor laser element, a focusing lens that focuses the first laser light reflected by the first reflecting mirror and the second laser light reflected by the second reflecting mirror, a first mirror mounting surface on which the first reflecting mirror is mounted, and a second mirror mounting surface on which the second reflecting mirror is mounted, the first mirror mounting surface and the second mirror mounting surface being parallel to each other, , the second mirror installation surface is not on the same plane, the first semiconductor laser element has a first light-emitting point from which the first laser light is emitted, the second semiconductor laser element has a second light-emitting point from which the second laser light is emitted, the optical axis of the first laser light incident on the first reflecting mirror is a first optical axis, the optical axis of the second laser light incident on the second reflecting mirror is a second optical axis, and a direction passing through the first light-emitting point and perpendicular to the first optical axis is a first direction, a first distance in the first direction from the first light-emitting point to the first optical axis and a second distance in the first direction from the first light-emitting point to the second optical axis are different from each other, and a third distance in the first direction from the second light-emitting point to the second optical axis is greater than the first distance.

In order to achieve the above object, a semiconductor laser device according to another aspect of the present disclosure includes a housing having a bottom surface, a first semiconductor laser element and a second semiconductor laser element arranged within the housing, a first reflecting mirror that reflects a first laser light emitted from the first semiconductor laser element, a second reflecting mirror that reflects a second laser light emitted from the second semiconductor laser element, a focusing lens that focuses the first laser light reflected by the first reflecting mirror and the second laser light reflected by the second reflecting mirror, a first collimating element arranged between the first semiconductor laser element and the first reflecting mirror and deflecting the propagation direction of the first laser light, and a second collimating element arranged between the second semiconductor laser element and the second reflecting mirror and deflecting the propagation direction of the second laser light, the first semiconductor laser element having a first light-emitting point from which the first laser light is emitted, and the second semiconductor laser element having a second light-emitting point from which the second laser light is emitted. The optical axis of the first laser light incident on the first parallelizing element is parallel to the optical axis of the second laser light incident on the second parallelizing element, the optical axis of the first laser light incident on the first reflecting mirror is parallel to the optical axis of the second laser light incident on the second reflecting mirror, and the optical axis of the first laser light incident on the first reflecting mirror is inclined with respect to the optical axis of the first laser light incident on the first parallelizing element, and when the optical axis of the first laser light incident on the first reflecting mirror is the first optical axis, and the optical axis of the second laser light incident on the second reflecting mirror is the second optical axis, and a direction passing through the first light emitting point and perpendicular to the first optical axis is the first direction, a first distance in the first direction from the first light emitting point to the first optical axis and a second distance in the first direction from the first light emitting point to the second optical axis are different from each other, and a third distance in the first direction from the second light emitting point to the second optical axis is greater than the first distance.

According to the present disclosure, in a semiconductor laser device having multiple semiconductor laser elements, it is possible to increase the degree of freedom in the arrangement of the multiple semiconductor laser elements.

1 is a perspective view showing a configuration of a semiconductor laser device according to a first embodiment; 1 is a plan view showing a configuration of a semiconductor laser device according to a first embodiment; 1 is a side view showing a configuration of a semiconductor laser device according to a first embodiment; 2 is a schematic diagram showing the spot shape of laser light on the end face of an optical fiber. FIG. FIG. 2 is a plan view showing a configuration of a semiconductor laser device according to a first modification of the first embodiment. 1 is a side view showing a configuration of a semiconductor laser device according to a first modification of the first embodiment. FIG. FIG. 11 is a plan view showing a configuration of a semiconductor laser device according to a second modification of the first embodiment. FIG. 11 is a side view showing a configuration of a semiconductor laser device according to a second modification of the first embodiment. FIG. 11 is a perspective view showing a configuration of a semiconductor laser device according to a second embodiment. FIG. 11 is a perspective view showing a detailed configuration example of an airtight package according to a second embodiment. FIG. 11 is a perspective view showing an internal configuration of an airtight package according to a modified example of the second embodiment. FIG. 11 is a plan view showing a configuration of a semiconductor laser device according to a third embodiment. FIG. 11 is a side view showing a configuration of a semiconductor laser device according to a third embodiment. FIG. 11 is a perspective view showing a configuration of a semiconductor laser device according to a fourth embodiment. FIG. 13 is a side view showing a configuration of a semiconductor laser device according to a fourth embodiment. FIG. 13 is a perspective view showing a configuration of a semiconductor laser device according to a first modification of the fourth embodiment. FIG. 13 is a side view showing a configuration of a semiconductor laser device according to a first modification of the fourth embodiment. FIG. 13 is a side view showing a configuration of a semiconductor laser device according to a second modification of the fourth embodiment. FIG. 13 is a perspective view showing a configuration of a semiconductor laser device according to a fifth embodiment. FIG. 13 is a side view showing a configuration of a semiconductor laser device according to a fifth embodiment. FIG. 13 is a perspective view showing a configuration of a semiconductor laser device according to a modification of the fifth embodiment. FIG. 11 is a perspective view showing a configuration of a semiconductor laser device according to a third modification of the first embodiment. FIG. 11 is a perspective view showing a configuration of a semiconductor laser device according to a fourth modification of the first embodiment.

Below, a semiconductor laser device according to an embodiment of the present disclosure will be described in detail with reference to the drawings. Note that each of the embodiments described below shows a specific example of the present disclosure. Therefore, the numerical values, shapes, materials, components, arrangement and connection of the components, steps, and order of steps shown in the following embodiments are merely examples and are not intended to limit the present disclosure.

In addition, each figure is a schematic diagram and is not necessarily an exact illustration. Therefore, for example, the scales of each figure do not necessarily match. In addition, in each figure, the same reference numerals are used for substantially the same configuration, and duplicate explanations are omitted or simplified.

In addition, in this specification, terms indicating the relationship between elements, such as "equal," terms indicating the shape of elements, such as "flat," "parallel," "vertical," "plate-shaped," "curved," and numerical ranges, are not expressions that express only a strict meaning, but are expressions that include a substantially equivalent range, for example, a difference of about a few percent.

In addition, in this specification, the terms "above" and "below" do not refer to vertically above and below in an absolute spatial sense, but are used as terms defined by a relative positional relationship based on the stacking order in the stacked configuration. Furthermore, the terms "above" and "below" are applied not only to cases where two components are arranged with a gap between them and another component exists between the two components, but also to cases where two components are arranged in close contact with each other and the two components are in contact.

(Embodiment 1)
A semiconductor laser device according to a first embodiment will be described.

[1-1. Configuration]
The configuration of the semiconductor laser device according to the first embodiment will be described with reference to FIGS. 1 to 3. FIGS. 1, 2, and 3 are a perspective view, a plan view, and a side view, respectively, showing the configuration of the semiconductor laser device 1 according to the present embodiment. In FIGS. 1 to 3, in order to show the inside of the semiconductor laser device 1, the cover of the housing 2 of the semiconductor laser device 1 and a part or all of the side wall 3 are not shown. Each figure shows an X-axis, a Y-axis, and a Z-axis that are orthogonal to each other. The X-axis, the Y-axis, and the Z-axis are in a right-handed Cartesian coordinate system. Hereinafter, the relative position in the X-axis direction may be expressed as "upper" (or "up") or "lower" (or "lower"). For example, a position on the positive side of a certain position in the X-axis direction may be expressed as an upper position, and a position on the negative side of the X-axis direction may be expressed as a lower position.

As shown in FIG. 1, the semiconductor laser device 1 includes a housing 2, a plurality of semiconductor laser elements 10-15, a plurality of reflecting mirrors 70-75, a focusing lens 90, and a plurality of mirror mounting surfaces 80-85. In this embodiment, the semiconductor laser device 1 further includes submounts 20-25, FAST axis collimator lenses 30-35, a deflection element 40, parallelizing elements 51-55, SLOW axis collimator lenses 60-65, an optical fiber 4, a laser base 7, current introduction terminals 9a, 9b, and a wiring member 9c.

The semiconductor laser device 1 is a module that can spatially combine and emit the laser light emitted from each of the multiple semiconductor laser elements 10 to 15 using an optical system.

The housing 2 has a bottom 6, a side wall 3, and a lid (not shown).

The bottom 6 is a plate-like member that is placed on the bottom of the housing 2 (the lower end, i.e., the end on the negative side in the X-axis direction in each figure). The bottom 6 has a flat bottom surface 6a. The bottom surface 6a is a flat region of the main surface of the bottom 6 that is located on the inside of the housing 2. In other words, the bottom surface 6a is a surface that is in the same plane. In this embodiment, the bottom surface 6a is the entire main surface of the bottom 6. Note that the main surface of the bottom 6 that is located on the inside of the housing 2 may have a non-flat region (i.e., a region other than the bottom surface 6a).

The sidewall 3 is disposed perpendicular to the bottom 6 of the housing 2. The sidewall 3 is disposed so as to surround the multiple semiconductor laser elements 10-15. The sidewall 3 is made of, for example, Cu, a Cu alloy, an Fe-Ni-Co alloy, or Al. The bottom 6 is made of, for example, Cu, a Cu alloy, Al, or a ceramic with high thermal conductivity (for example, AlN or BeO). The lid is a member that covers the upper part of the housing 2.

The current introduction terminals 9a, 9b are terminals for introducing a current from the outside of the housing 2 to the inside of the housing 2. One end of each of the current introduction terminals 9a, 9b is disposed outside the housing 2, and the other end is disposed inside the housing 2. In this embodiment, the current introduction terminals 9a, 9b are disposed on the side wall 3 and penetrate the side wall 3. If the side wall 3 is formed of a conductive material, an insulating member is disposed between the current introduction terminals 9a, 9b and the side wall 3.

The multiple mirror installation surfaces 80 to 85 are surfaces on which multiple reflective mirrors 70 to 75 are respectively installed. That is, the reflective mirror 70 is installed on the mirror installation surface 80, the reflective mirror 71 is installed on the mirror installation surface 81, the reflective mirror 72 is installed on the mirror installation surface 82, the reflective mirror 73 is installed on the mirror installation surface 83, the reflective mirror 74 is installed on the mirror installation surface 84, and the reflective mirror 75 is installed on the mirror installation surface 85. The multiple mirror installation surfaces 80 to 85 have different heights (or average heights) from the bottom surface 6a. Specifically, the mirror installation surface 81 is higher from the bottom surface 6a than the mirror installation surface 80, the mirror installation surface 82 is higher from the bottom surface 6a than the mirror installation surface 81, the mirror installation surface 83 is higher from the bottom surface 6a than the mirror installation surface 82, the mirror installation surface 84 is higher from the bottom surface 6a than the mirror installation surface 83, and the mirror installation surface 85 is higher from the bottom surface 6a than the mirror installation surface 84. In this embodiment, the mirror installation surfaces 80 to 85 are flat surfaces parallel to the bottom surface 6a.

The multiple mirror mounting surfaces 80-85 include a first mirror mounting surface and a second mirror mounting surface. Mirror mounting surface 81 is an example of a first mirror mounting surface on which a reflecting mirror 71 (first reflecting mirror) is mounted. Mirror mounting surface 82 is an example of a second mirror mounting surface on which a reflecting mirror 72 (second reflecting mirror) is mounted.

In this embodiment, the semiconductor laser device 1 includes a multi-stage base 8 having a plurality of mirror mounting surfaces 80-85. The multi-stage base 8 has a lower surface 8ba, and is mounted on the bottom surface 6a so that the lower surface 8ba is parallel to the bottom surface 6a. The multi-stage base 8 has a plurality of stair-like steps. Each of the multiple steps of the multi-stage base 8 has a surface parallel to the lower surface 8ba, and the surfaces parallel to the lower surface 8ba correspond to each of the multiple mirror mounting surfaces 80-85. Therefore, each of the multiple mirror mounting surfaces 80-85 is parallel to the bottom surface 6a. Furthermore, each of the multiple mirror mounting surfaces 80-85 is parallel to one another and is not on the same plane.

The laser base 7 is a base on which multiple semiconductor laser elements 10 to 15 are mounted. In this embodiment, the laser base 7 is a rectangular plate-shaped member having a flat laser mounting surface 7a. Multiple semiconductor laser elements 10 to 15 are mounted on the laser mounting surface 7a. The laser base 7 is made of, for example, the same material as the bottom 6 of the housing 2.

The semiconductor laser elements 10-15 are elements that convert input power and emit laser light, and are arranged inside the housing 2. The semiconductor laser elements 10-15 are arranged in the Y-axis direction. In this embodiment, the semiconductor laser elements 10-15 are installed on the same plane. The heights of the semiconductor laser elements 10-15 from the bottom surface 6a are equal. Specifically, the semiconductor laser elements 10-15 are installed on the laser installation surface 7a of the laser base 7 via the submounts 20-25, respectively. The semiconductor laser element 11 and the semiconductor laser element 12 are examples of the first semiconductor laser element and the second semiconductor laser element included in the semiconductor laser elements 10-15, respectively.

Each of the semiconductor laser elements 10-15 is a laser element in which a semiconductor laminate film and an optical waveguide are formed on a semiconductor substrate. The semiconductor laser elements 10-15 each have light-emitting points 10e-15e that emit a plurality of laser beams L0A-L5A (see FIG. 2). The semiconductor laser elements 10-15 convert the power input from the outside to the optical waveguide into stimulated emission light such as laser beams and emit the light from the light-emitting points 10e-15e, which are one end of the optical waveguide. The semiconductor laser elements 10-15 each emit laser beams L0A-L5A (see FIG. 2). Note that in FIG. 2 and FIG. 3, the optical axes of the laser beams L0A-L5A are indicated by dashed lines. Also, in FIG. 3, the diameter (spot size) of each laser beam is indicated by a dashed line. The laser beams L1A and L2A are examples of the first laser beam and the second laser beam, respectively. The light-emitting point 11e is an example of a first light-emitting point from which the first laser light is emitted. The light-emitting point 12e is an example of a second light-emitting point from which the second laser light is emitted.

The FAST axis of the laser light L0A to L5A is the axis in the stacking direction of the semiconductor laminated film of the multiple semiconductor laser elements 10 to 15, and the SLOW axis perpendicular to the FAST axis is an axis parallel to the stacking surface of the semiconductor laminated film and is an axis parallel to the Y-axis direction in each figure. In this embodiment, the FAST axis direction of the multiple semiconductor laser elements 10 to 15 is the height direction from the bottom surface 6a (the X-axis direction in each figure). The wavelength of the laser light emitted from the semiconductor laser elements 10 to 15 changes depending on the semiconductor material that constitutes the semiconductor laminated film. For example, by making the multiple semiconductor laser elements 10 to 15 nitride-based semiconductor laser elements mainly composed of nitrides of Al, Ga, and In, the multiple semiconductor laser elements 10 to 15 can emit laser light having a peak wavelength between 350 nm and 550 nm, for example. Furthermore, for example, by making the multiple semiconductor laser elements 10-15 semiconductor laser elements whose main components are semiconductors made of Al, Ga, In, As, and P, the multiple semiconductor laser elements 10-15 can emit laser light having a peak wavelength between 600 nm and 1600 nm. Note that the multiple semiconductor laser elements 10-15 are not limited to semiconductor laser elements made of the above semiconductor materials, and the wavelength of the laser light emitted by the multiple semiconductor laser elements 10-15 is not limited to the above wavelength.

The multiple semiconductor laser elements 10 to 15 are rectangular in shape and are long in the waveguiding direction of the optical waveguide. The optical waveguide has a width of, for example, 5 μm to 300 μm and a length of, for example, 500 μm to 5 mm. The multiple semiconductor laser elements 10 to 15 are transverse multimode lasers in which the laser light is multimode in the SLOW axis.

In addition, in this embodiment, the multiple semiconductor laser elements 10 to 15 are laser elements with Fabry-Perot mirrors formed on both ends of the optical waveguide, but the configuration of the multiple semiconductor laser elements 10 to 15 is not limited to this. For example, the multiple semiconductor laser elements 10 to 15 may be so-called superluminescent diodes in which no mirror is formed on the light-emitting point side of the optical waveguide. Furthermore, the multiple semiconductor laser elements 10 to 15 may be elements for so-called external resonator type semiconductor lasers in which no mirror is formed on the light-emitting point side of the optical waveguide, but a resonator mirror is placed as a separate component from the multiple semiconductor laser elements 10 to 15 on the emission direction side of the emitted light to perform laser oscillation.

In this embodiment, a current is supplied to the semiconductor laser elements 10-15 from outside the housing 2 via the current introduction terminals 9a, 9b and the wiring member 9c. The wiring member 9c is a conductive member disposed within the housing 2, and constitutes part of the current path between the current introduction terminals 9a, 9b and the semiconductor laser elements 10-15. The wiring member 9c extends from near the current introduction terminal 9a to near the semiconductor laser element 10. The semiconductor laser elements 10-15 are connected in series using metal wires W. The current introduction terminal 9a is connected to the wiring member 9c by the metal wire W, and the wiring member 9c is connected to the semiconductor laser element 10 by the metal wire W. More specifically, one electrode of the semiconductor laser element 10 is connected to an electrode formed on the submount 20 via a conductive bonding member such as Au or AuSn, and the electrode formed on the submount 20 is connected to the wiring member 9c by the metal wire W. The other electrode of the semiconductor laser element 10 is connected to the semiconductor laser element 11 by a metal wire W. More specifically, one electrode of the semiconductor laser element 11 is connected to an electrode formed on the submount 21, and the electrode formed on the submount 21 is connected to the other electrode of the semiconductor laser element 11 by a metal wire W. The semiconductor laser elements 11 to 15 are connected in the same manner as the semiconductor laser element 10 and the semiconductor laser element 11. The semiconductor laser element 15 is connected to the current introduction terminal 9b by a metal wire W. As described above, by using the wiring member 9c that extends from near the current introduction terminal 9a to near the semiconductor laser element 10, the length of the metal wire W can be shortened and interference between the multiple metal wires W can be suppressed.

The submounts 20-25 are bases on which the semiconductor laser elements 10-15 are mounted. In this embodiment, the submounts 20-25 are mounted on the laser mounting surface 7a of the laser base 7. The submounts 20-25 are block-shaped members made of insulating materials such as crystals, such as AlN or SiC, or ceramics. Electrodes are formed on the upper surfaces of the block-shaped submounts 20-25, and are each connected to one of the electrodes of the semiconductor laser elements 10-15. The electrodes are made of one or more metal films, such as Ni, Cu, Pt, and Au.

The multiple FAST axis collimator lenses 30-35 are respectively disposed between the semiconductor laser elements 10-15 and the deflection element 40 (and the parallelization elements 51-55), and are optical elements into which the laser beams L0A-L5A are incident. The multiple FAST axis collimator lenses 30-35 collimate the FAST axis direction component of the laser beams L0A-L5A, respectively, and emit laser beams L0B-L5B with the FAST axis direction component collimated. The laser beams L1B and L2B are examples of the first laser beam and the second laser beam, respectively.

The multiple FAST axis collimator lenses 30 to 35 may be, for example, lenses having a convex cylindrical surface. More specifically, the multiple FAST axis collimator lenses 30 to 35 may be, for example, plano-convex cylindrical lenses made of glass with an anti-reflection coating formed on the surface.

The multiple FAST axis collimator lenses 30 to 35 include a first FAST axis collimator lens and a second FAST axis collimator lens. The FAST axis collimator lens 31 and the FAST axis collimator lens 32 are examples of the first FAST axis collimator lens and the second FAST axis collimator lens, respectively.

The deflection element 40 is disposed between the semiconductor laser elements 11-15 and the reflecting mirrors 71-75, and is a deflection element that gives a height component from the bottom surface 6a to the propagation direction of the laser beams L1B-L5B (i.e., deflects in the height direction). In this embodiment, the deflection element 40 is disposed between the multiple FAST axis collimator lenses 31-35 and the multiple parallelizing elements 51-55, and deflects the laser beams L1B-L5B upward (i.e., in the positive direction in the X-axis direction) and emits the deflected laser beams L1C-L5C. The laser beams L1C-L5C are deflected, for example, by 5 degrees or more and 20 degrees or less with respect to the laser beams L1B-L5B. The laser beams L1C and L2C are examples of the first laser beam and the second laser beam, respectively. The deflection element 40 deflects the laser beams L1B-L5B at the same angle. In this embodiment, the laser light L0B does not enter the deflection element 40. In other words, the deflection element 40 is not disposed on the optical path of the laser light L0B. Therefore, the laser light L0B propagates parallel to the bottom surface 6a from the light emitting point 10e to the reflecting mirror 70 (and the focusing lens 90) without being given a component in the height direction. For example, a transmissive deflection element can be used as the deflection element 40. The transmissive deflection element is, for example, a prism having an entrance surface and an exit surface, and the entrance surface and the exit surface are not parallel.

The laser beams L0A to L5A and L0B to L5B propagate parallel to the bottom surface 6a in the positive direction of the Z axis between the semiconductor laser elements 10 to 15 and the deflection element 40. In addition, the laser beams L0A to L5A and L0B to L5B propagate parallel to each other between the semiconductor laser elements 10 to 15 and the deflection element 40.

The deflection element 40 is an example of a first deflection element that is disposed between the semiconductor laser element 11 (first semiconductor laser element) and the reflecting mirror 71 (first reflecting mirror) and provides a height component from the bottom surface 6a to the propagation direction of the laser light L1B (first laser light). The deflection element 40 is also an example of a second deflection element that is disposed between the semiconductor laser element 12 (second semiconductor laser element) and the reflecting mirror 72 (second reflecting mirror) and provides a height component from the bottom surface 6a to the propagation direction of the laser light L2B (second laser light).

In this embodiment, the semiconductor laser device 1 includes a single deflection element 40, but may include multiple deflection elements. For example, the semiconductor laser device 1 may include five deflection elements that impart height components to each of the laser beams L1B to L5B. In this case, for example, the five deflection elements may be installed at the same height from the bottom surface 6a.

The parallelizing elements 51 to 55 are disposed between the deflection element 40 and the reflecting mirrors 71 to 75, respectively, and are deflection elements that deflect the propagation direction of the laser beams L1C to L5C in a direction parallel to the mirror mounting surfaces 81 to 85, and emit the laser beams L1D to L5D. The laser beams L1D and L2D are examples of the first laser beam and the second laser beam, respectively. In this embodiment, the parallelizing elements 51 to 55 are disposed on the mirror mounting surfaces 81 to 85, respectively. As a result, the heights from the bottom surface 6a at the positions where the parallelizing elements 51 to 55 are disposed are different from one another. The parallelizing elements 51, 52, 53, 54, and 55 are higher in height from the bottom surface 6a at the mounting positions in that order. Note that no parallelizing element is disposed on the optical path of the laser beam L0B. Since the laser beams L1B to L5B are deflected by the deflection element 40 at the same angle, it is necessary to make the distance from the deflection element 40 to each of the parallelization elements 51 to 55 different depending on the height of the installation position of each parallelization element. In other words, it is necessary to make the distance from the deflection element 40 longer in the order of the parallelization elements 51, 52, 53, 54, and 55. As described above, the multiple laser beams L1C to L5C between the deflection element 40 and the multiple parallelization elements 51 to 55 are parallel to each other. In addition, the laser beams L1D to L5D are deflected, for example, by 5 degrees or more and 20 degrees or less with respect to the laser beams L1C to L5C. The distances between the deflection element 40 and the multiple parallelization elements 51 to 55 are different from each other. For example, the distance between the deflection element 40 and the parallelization element 52 is longer than the distance between the deflection element 40 and the parallelization element 51. The distance in the Z-axis direction from each parallelizing element to each semiconductor laser element increases as the height from the bottom surface 6a of the installation position of each parallelizing element increases. This allows the distance from the deflection element 40 to each parallelizing element to be different depending on the height from the bottom surface 6a of the installation position of each parallelizing element. The parallelizing elements 51 to 55 are installed near the ends of the mirror installation surfaces 81 to 85 that are closer to the semiconductor laser elements 11 to 15. In other words, the distance in the Z-axis direction from the end located between each semiconductor laser element and each parallelizing element on each mirror installation surface to each parallelizing element is smaller than the distance in the Z-axis direction from the end to each semiconductor laser element. This reduces the blocking of each laser light by the multi-stage base 8.

The distance from the end of each mirror mounting surface closest to each semiconductor laser element increases as the height of each mirror mounting surface from the bottom surface 6a increases. Also, as the height of each mirror mounting surface from the bottom surface 6a increases, the length of each mirror mounting surface in the propagation direction (Z-axis direction) of the laser light L0E to L5E decreases.

The height of the area of the multistage base 8 between the multiple mirror mounting surfaces 80-85 and the multiple semiconductor laser elements 10-15 from the bottom surface 6a is lower than the height of the bottom surface 6a of each light emitting point of the semiconductor laser elements 10-15. This reduces the blocking of each laser light by the multistage base 8. In this embodiment, the position of the end of the multistage base 8 close to each semiconductor laser element coincides with the end of the multiple mirror mounting surfaces 80-85. In other words, there are no components of the multistage base 8 located between each mirror mounting surface and the laser base 7. This reduces the blocking of each laser light by the multistage base 8, and makes the multistage base 8 lighter.

Furthermore, at the end of each mirror mounting surface, an end face perpendicular to the bottom face 6a is formed on the multi-stage base 8. The distance in the Z-axis direction from the end face to each semiconductor laser element increases as the height from the bottom face 6a of each mirror mounting surface increases. This reduces the blocking of the laser light by the multi-stage base 8 between the deflection element 40 and the parallelization elements 51 to 55, as shown in FIG. 3.

For example, a transmissive deflection element can be used as the multiple parallelizing elements 51 to 55. A transmissive deflection element is, for example, a prism having an entrance surface and an exit surface, and the entrance surface and the exit surface are not parallel.

The parallelizing element 51 is an example of a first parallelizing element that is disposed between the deflection element 40 (first deflection element) and the reflection mirror 71 (first reflection mirror) and deflects the propagation direction of the laser light L1C (first laser light) in a direction parallel to the mirror mounting surface 81 (first mirror mounting surface). The parallelizing element 52 is also an example of a second parallelizing element that is disposed between the deflection element 40 (second deflection element) and the reflection mirror 72 (second reflection mirror) and deflects the propagation direction of the laser light L2C (second laser light) in a direction parallel to the mirror mounting surface 82 (second mirror mounting surface).

The multiple SLOW axis collimator lenses 60-65 are optical elements that are respectively disposed between the multiple FAST axis collimator lenses 30-35 and the reflecting mirrors 70-75, and into which the laser beams L0B, L1D-L5D are incident. In this embodiment, the multiple SLOW axis collimator lenses 60-65 are respectively mounted on the mirror mounting surfaces 80-85. As a result, the heights from the bottom surface 6a at the positions where the SLOW axis collimator lenses 60-65 are mounted are different from one another. The heights from the bottom surface 6a at the mounting positions increase in the order of the SLOW axis collimator lenses 60, 61, 62, 63, 64, 65.

The multiple SLOW-axis collimator lenses 60-65 collimate the components of the laser light L0B, L1D-L5D in the SLOW-axis direction, respectively. The multiple SLOW-axis collimator lenses 60-65 may be, for example, lenses having a convex cylindrical surface. More specifically, the multiple SLOW-axis collimator lenses 60-65 may be, for example, plano-convex cylindrical lenses made of glass with an anti-reflection coating formed on the surface.

The spot size in the SLOW axis direction of each laser light emitted from the multiple SLOW axis collimator lenses 60 to 65 increases as the optical path length from each semiconductor laser element to each SLOW axis collimator lens increases. In order to align the spot size in the SLOW axis direction of each laser light emitted from the multiple SLOW axis collimator lenses 60 to 65, the optical path length from each of the multiple SLOW axis collimator lenses 60 to 65 to each of the multiple semiconductor laser elements 10 to 15 may be aligned. Accordingly, the Z axis direction positions of each of the SLOW axis collimator lenses 60 to 65 are different. As shown in FIG. 2, the Z axis direction positions of the SLOW axis collimator lens 60 and the SLOW axis collimator lens 65 differ by ΔL. The Z axis direction distance from each SLOW axis collimator lens to each semiconductor laser element decreases as the height from the bottom surface 6a of each SLOW axis collimator lens increases. This makes it possible to align the optical path length from each SLOW axis collimator lens to each semiconductor laser element.

The multiple SLOW-axis collimator lenses 60 to 65 include a first SLOW-axis collimator lens and a second SLOW-axis collimator lens. The SLOW-axis collimator lens 61 and the SLOW-axis collimator lens 62 are examples of the first SLOW-axis collimator lens and the second SLOW-axis collimator lens, respectively.

The multiple reflecting mirrors 70-75 are optical elements that reflect the multiple laser beams L0E-L5E emitted from the multiple semiconductor laser elements 10-15, respectively, and emit multiple laser beams L0F-L5F. Laser beam L1F and laser beam L2F are examples of the first laser beam and the second laser beam, respectively. In this embodiment, the multiple reflecting mirrors 70-75 each reflect the multiple laser beams L0E-L5E, thereby deflecting them by 90 degrees. The multiple reflecting mirrors 70-75 are respectively mounted on the multiple mirror mounting surfaces 80-85. As a result, the heights from the bottom surface 6a at the positions where the reflecting mirrors 70-75 are mounted are different from one another. The heights from the bottom surface 6a at the mounting positions increase in the order of the reflecting mirrors 70, 71, 72, 73, 74, and 75.

The multiple reflecting mirrors 70 to 75 include a first reflecting mirror and a second reflecting mirror. Reflecting mirror 71 is an example of a first reflecting mirror that reflects laser light L1E (first laser light) emitted from semiconductor laser element 11 (first semiconductor laser element). Reflecting mirror 72 is an example of a second reflecting mirror that reflects laser light L2E (second laser light) emitted from semiconductor laser element 12 (second semiconductor laser element). In this specification, laser light L1E emitted from semiconductor laser element 11 refers to laser light that is laser light L1A emitted from semiconductor laser element 11 and enters reflecting mirror 71 via FAST axis collimator lens 31, deflection element 40, parallelization element 51, and SLOW axis collimator lens 61. Moreover, the laser light L2E emitted from the semiconductor laser element 12 means the laser light L2A emitted from the semiconductor laser element 12 that is incident on the reflecting mirror 72 via the FAST axis collimator lens 32, the deflection element 40, the parallelizing element 52, and the SLOW axis collimator lens 62. Moreover, the optical axis of the first laser light that is incident on the first reflecting mirror is the first optical axis, and the optical axis of the second laser light that is incident on the second reflecting mirror is the second optical axis. Hereinafter, the direction that passes through the light emitting point 11e (first light emitting point) of the semiconductor laser element 11 and is perpendicular to the first optical axis is also referred to as the first direction.

3, when the light emitting point 11e of the semiconductor laser element 11 is used as a reference, a first distance D1 in a first direction (X-axis direction in this embodiment) from the light emitting point 11e (first light emitting point) of the semiconductor laser element 11 to the optical axis (first optical axis A1) of the laser light L1E incident on the reflecting mirror 71 and a second distance D2 in the first direction from the light emitting point 11e of the semiconductor laser element 11 to the optical axis (second optical axis A2) of the laser light L2E incident on the reflecting mirror 72 are different from each other. Similarly, the distances in the first direction (X-axis direction in this embodiment) from the light emitting point 11e of the semiconductor laser element 11 to the optical axes of the laser light L1E to L5E incident on the reflecting mirrors 71 to 75, respectively, are different from each other.

The laser beams L1D to L5D and L1E to L5E propagate in the positive direction of the Z axis between the parallelizing elements 51 to 55 and the reflecting mirrors 71 to 75, respectively, parallel to the bottom surface 6a and parallel to the mirror installation surfaces 81 to 85. The laser beams L1D to L5D also propagate parallel to each other.

The laser beams L0F to L5F emitted from the multiple reflecting mirrors 70 to 75 have parallel propagation directions, do not overlap in height from the bottom surface 6a, and overlap in positions parallel to the bottom surface 6a. For example, the laser beams L1F emitted from the reflecting mirror 71 and the laser beams L2F emitted from the reflecting mirror 72 have parallel propagation directions, do not overlap in the FAST axis direction (height from the bottom surface 6a in this embodiment), and overlap in the SLOW axis direction (direction parallel to the bottom surface 6a in this embodiment). The laser beams L0F to L5F propagate in the negative Y-axis direction and parallel to the bottom surface 6a between the reflecting mirrors 70 to 75 and the focusing lens 90.

In this embodiment, as described above, the semiconductor laser elements 10-15 are disposed on the same plane, and the multiple reflective mirrors 70-75 are respectively mounted on multiple mirror mounting surfaces 80-85 having different heights from each other. Therefore, in this embodiment, the difference in height between the light emitting point 11e of the semiconductor laser element 11 from the bottom surface 6a and the height of the mirror mounting surface 81 from the bottom surface 6a is greater than the difference in height between the light emitting point 10e of the semiconductor laser element 10 from the bottom surface 6a and the height of the mirror mounting surface 80 from the bottom surface 6a. Similarly, the difference in height between the light emitting point 12e of the semiconductor laser element 12 from the bottom surface 6a and the height of the mirror mounting surface 82 from the bottom surface 6a is greater than the difference in height between the light emitting point 11e of the semiconductor laser element 11 from the bottom surface 6a and the height of the mirror mounting surface 81 from the bottom surface 6a. In other words, as shown in FIG. 3, a third distance D3 in a first direction (in this embodiment, the X-axis direction) from the light emitting point 12e (second light emitting point) of the semiconductor laser element 12 to the optical axis (second optical axis A2) of the laser light L2E incident on the reflecting mirror 72 is greater than the distance in the first direction from the light emitting point 11e (first light emitting point) of the semiconductor laser element 11 to the optical axis (first optical axis A1) of the laser light L1E incident on the reflecting mirror 71.

In this way, in this embodiment, the difference between the height of one light-emitting point and the height of the mirror installation surface corresponding to that light-emitting point differs for each combination of light-emitting point and mirror installation surface. Note that each difference here is defined as the absolute value of the value resulting from the subtraction. Each difference described below is also defined as an absolute value in the same way.

In addition, in this embodiment, for example, the difference between the height of the light emitting point 11e of the semiconductor laser element 11 from the bottom surface 6a and the height of the light emitting point 12e of the semiconductor laser element 12 from the bottom surface 6a is smaller than the difference between the height of the mirror installation surface 81 from the bottom surface 6a and the height of the mirror installation surface 82 from the bottom surface 6a. In other words, as shown in FIG. 3, the distance in the first direction from the light emitting point 11e (first light emitting point) of the semiconductor laser element 11 to the light emitting point 12e (second light emitting point) of the semiconductor laser element 12 is smaller than a fourth distance D4 in the first direction from the optical axis (first optical axis A1) of the laser light L1E incident on the reflection mirror 71 to the optical axis (second optical axis A2) of the laser light L2E incident on the reflection mirror 72. In addition, in this embodiment, the distance in the first direction from the light emitting point 11e of the semiconductor laser element 11 to the light emitting point 12e of the semiconductor laser element 12 is zero and is not shown in FIG. 3. In this way, in this embodiment, the deviation in height of the multiple semiconductor laser elements 10-15 from the bottom surface 6a can be reduced more than the deviation in height of the multiple reflecting mirrors 70-75 from the bottom surface.

The multiple reflecting mirrors 70 to 75 include a first reflecting mirror and a second reflecting mirror. Reflecting mirror 71 is an example of a first reflecting mirror that reflects laser light L1E (first laser light) emitted from semiconductor laser element 11 (first semiconductor laser element). Reflecting mirror 72 is an example of a second reflecting mirror that reflects laser light L2E (second laser light) emitted from semiconductor laser element 12 (second semiconductor laser element). In this specification, laser light L1E emitted from semiconductor laser element 11 refers to laser light that is laser light L1A emitted from semiconductor laser element 11 and enters reflecting mirror 71 via FAST axis collimator lens 31, deflection element 40, parallelization element 51, and SLOW axis collimator lens 61. In addition, the laser light L2E emitted from the semiconductor laser element 12 refers to the laser light L2A emitted from the semiconductor laser element 12 that passes through the FAST axis collimator lens 32, the deflection element 40, the parallelizing element 52, and the SLOW axis collimator lens 62 and enters the reflecting mirror 72.

The focusing lens 90 is a lens that focuses the multiple laser beams L0F to L5F reflected by the multiple reflecting mirrors 70 to 75. In this embodiment, the focusing lens 90 focuses the laser beams L0F to L5F so that most of the multiple laser beams L0F to L5F are incident on the end face of the optical fiber 4 and can propagate through the optical fiber 4. For example, a spherical lens can be used as the focusing lens 90. Here, the spot shape of the laser beams L0F to L5F on the focusing lens 90 will be described with reference to FIG. 4. FIG. 4 is a schematic diagram showing the spot shape of the laser beams L0F to L5F on the incident surface of the focusing lens 90. In FIG. 4, the outlines of the laser beams L0F to L5F are shown by dashed lines. As shown in FIG. 4, in this embodiment, the overlap of the laser beams L0F to L5F on the focusing lens 90 is reduced.

The optical fiber 4 is a member that guides the laser beams L0F to L5F from inside the housing 2 to the outside. As described above, the laser beams L0F to L5F emitted from the focusing lens 90 are incident on the end face of the optical fiber 4 that is located inside the housing 2 at the same position at different angles of incidence. As shown in FIG. 4, in this embodiment, the overlap of the laser beams L0F to L5F at the focusing lens 90 is reduced, so that deterioration and damage to the optical fiber 4 caused by the laser beams L0F to L5F concentrating on a portion of the end face of the optical fiber 4 can be suppressed.

[1-2. Effects, etc.]
The effects of the semiconductor laser device 1 according to this embodiment will be described.

As described above, the semiconductor laser device 1 according to one aspect of the present embodiment includes a housing 2 having a bottom surface 6a, a semiconductor laser element 11 and a semiconductor laser element 12 arranged in the housing 2, a reflecting mirror 71 that reflects the laser light L1E emitted from the semiconductor laser element 11, a reflecting mirror 72 that reflects the laser light L2E emitted from the semiconductor laser element 12, a focusing lens 90 that focuses the laser light L1F reflected by the reflecting mirror 71 and the laser light L2F reflected by the reflecting mirror 72, a mirror mounting surface 81 on which the reflecting mirror 71 is mounted, and a mirror mounting surface 82 on which the reflecting mirror 72 is mounted. The mirror mounting surface 81 and the mirror mounting surface 82 are parallel to each other. The mirror mounting surface 81 and the mirror mounting surface 82 are not on the same plane. The semiconductor laser element 11 has a light emitting point 11e that emits the laser light L1A, and the semiconductor laser element 12 has a light emitting point 12e that emits the laser light L2A. The optical axis of the laser light L1E incident on the reflecting mirror 71 is the first optical axis A1, and the optical axis of the laser light L2E incident on the reflecting mirror 72 is the second optical axis A2. A first distance D1 in the first direction from the light emitting point 11e of the semiconductor laser element 11 to the first optical axis A1 and a second distance D2 in the first direction from the light emitting point 11e of the semiconductor laser element 11 to the second optical axis are different from each other. A third distance D3 in the first direction from the light emitting point 12e of the semiconductor laser element 12 to the second optical axis A2 is greater than the first distance D1. In other words, the difference between the height of the light emitting point 12e of the second semiconductor laser element from the bottom surface 6a and the height of the mirror installation surface 82 from the bottom surface 6a is greater than the difference between the height of the light emitting point 11e of the first semiconductor laser element from the bottom surface 6a and the height of the mirror installation surface 81 from the bottom surface 6a.

In this way, in the semiconductor laser device 1, it is not necessary to make the difference between the height of each light emitting point from the bottom surface 6a and the height of each mirror mounting surface from the bottom surface 6a uniform. This increases the degree of freedom in arranging each semiconductor laser element. For example, it becomes possible to reduce the height of each semiconductor laser element from the bottom surface 6a. This makes it possible to improve the heat dissipation characteristics of each semiconductor laser element by connecting a heat sink to the bottom 6.

A semiconductor laser device 1 according to another aspect of this embodiment includes a housing 2 having a bottom surface 6a, a semiconductor laser element 11 and a semiconductor laser element 12 arranged in the housing 2, a reflection mirror 71 that reflects the laser light L1E emitted from the semiconductor laser element 11, a reflection mirror 72 that reflects the laser light L2E emitted from the semiconductor laser element 12, and a focusing lens 90 that focuses the laser light L1F reflected by the reflection mirror 71 and the laser light L2F reflected by the reflection mirror 72. The semiconductor laser device 1 further includes a parallelizing element 51 that is arranged between the semiconductor laser element 11 and the reflection mirror 71 and that deflects the propagation direction of the laser light L1C, and a parallelizing element 52 that is arranged between the semiconductor laser element 12 and the reflection mirror 72 and that deflects the propagation direction of the laser light L2C. The semiconductor laser element 11 has an emission point 11e that emits the laser light L1A, and the semiconductor laser element 12 has an emission point 12e that emits the laser light L2A. The FAST axis direction of the laser light L1A at the emission point 11e of the semiconductor laser element 11 is parallel to the first direction. The optical axis of the laser light L1C incident on the collimating element 51 is parallel to the optical axis of the laser light L2C incident on the collimating element 52. The optical axis of the laser light L1E incident on the reflecting mirror 71 is parallel to the optical axis of the laser light L2E incident on the reflecting mirror 72. The optical axis of the laser light L1E incident on the reflecting mirror 71 is inclined with respect to the optical axis of the laser light L1C incident on the collimating element 51. The optical axis of the laser light L1E incident on the reflecting mirror 71 is the first optical axis A1, and the optical axis of the laser light L2E incident on the reflecting mirror 72 is the second optical axis A2. A first distance D1 in the first direction from the light emitting point 11e of the semiconductor laser element 11 to the first optical axis A1 and a second distance D2 in the first direction from the light emitting point 11e of the semiconductor laser element 11 to the second optical axis A2 are different from each other. A third distance D3 in the first direction from the light emitting point 12e of the semiconductor laser element 12 to the second optical axis is greater than the first distance D1.

In this way, by using each collimating element in the semiconductor laser device 1, it is no longer necessary to align the distance from each light emitting point to the optical axis of the laser light incident on each reflecting mirror. In other words, it is no longer necessary to align the difference between the height of each light emitting point from the bottom surface 6a and the height of each mirror mounting surface from the bottom surface 6a. This increases the degree of freedom in arranging each semiconductor laser element. For example, it becomes possible to reduce the height of each semiconductor laser element from the bottom surface 6a. This makes it possible to improve the heat dissipation characteristics of each semiconductor laser element by connecting a heat sink to the bottom 6.

Furthermore, in the semiconductor laser device 1 according to this embodiment, the difference between the height of the light emitting point 11e of the semiconductor laser element 11 from the bottom surface 6a and the height of the light emitting point 12e of the semiconductor laser element 12 from the bottom surface 6a may be smaller than the difference between the height of the mirror mounting surface 81 from the bottom surface 6a and the height of the mirror mounting surface 82 from the bottom surface 6a. In other words, the distance in the first direction from the light emitting point 11e of the semiconductor laser element 11 to the light emitting point 12e of the semiconductor laser element 12 may be smaller than a fourth distance D4 in the first direction from the first optical axis A1 to the second optical axis A2.

In this way, the difference in height between each semiconductor laser element and the bottom surface 6a can be reduced, which makes it easier to mount each semiconductor laser element. Furthermore, when a heat sink is connected to the bottom 6 and heat is dissipated from the bottom 6, the heat dissipation characteristics change depending on the distance between each semiconductor laser element and the bottom surface 6a. Therefore, by reducing the difference in height between each semiconductor laser element and the bottom surface 6a, the difference in heat dissipation characteristics between each semiconductor laser element can be reduced. This makes it possible to reduce the difference in characteristics such as the wavelength of each laser light from each semiconductor laser element.

In addition, in the semiconductor laser device 1 according to this embodiment, the multiple semiconductor laser elements 10 to 15 may be placed on the same plane.

This makes it even easier to mount the multiple semiconductor laser elements 10-15. Also, for example, when wiring the multiple semiconductor laser elements 10-15 using metal wires W to supply current to the semiconductor laser elements, the height of the bond portion of the wire bond can be made uniform, making wire bonding easier.

In addition, in the semiconductor laser device 1 according to this embodiment, the FAST axis direction of the multiple semiconductor laser elements 10 to 15 may be the height direction from the bottom surface 6a.

This improves the heat dissipation characteristics of each semiconductor laser element.

The semiconductor laser device 1 according to this embodiment may also include a deflection element 40 (first deflection element) disposed between the semiconductor laser element 11 and the reflecting mirror 71, which gives a first direction component to the propagation direction of the laser light L1B; a parallelization element 51 disposed between the deflection element 40 and the reflecting mirror 71, which deflects the propagation direction of the laser light L1C, which has been given the first direction component in the propagation direction, in a direction parallel to the mirror installation surface 81; a deflection element 40 (second deflection element) disposed between the semiconductor laser element 12 and the reflecting mirror 72, which gives a first direction component to the propagation direction of the laser light L2B; and a parallelization element 52 disposed between the deflection element 40 and the reflecting mirror 72, which deflects the propagation direction of the laser light L2C, which has been given the first direction component in the propagation direction, in a direction parallel to the mirror installation surface 82.

As a result, the propagation direction of each laser light can be made parallel to each mirror installation surface without installing each semiconductor laser element at a height corresponding to each mirror installation surface, and the height of each laser light can be guided to the height at which it is incident on each reflecting mirror.

In addition, in the semiconductor laser device 1 according to this embodiment, the parallelizing element 51 may be installed on the mirror installation surface 81, and the parallelizing element 52 may be installed on the mirror installation surface 82.

This makes it easier to guide each laser beam from each parallelizing element to each reflecting mirror. It also makes it easier to adjust the height of each parallelizing element.

Furthermore, in the semiconductor laser device 1 according to this embodiment, the laser light L1C between the deflection element 40 and the parallelization element 51 and the laser light L2C between the deflection element 40 and the parallelization element 52 are parallel, and the distance between the deflection element 40 and the parallelization element 52 may be longer than the distance between the deflection element 40 and the parallelization element 51.

This allows the difference in height between the light emitting point 12e of the semiconductor laser element 12 from the bottom surface 6a and the height of the mirror mounting surface 82 from the bottom surface 6a to be greater than the difference in height between the light emitting point 11e of the semiconductor laser element 11 from the bottom surface 6a and the height of the mirror mounting surface 81 from the bottom surface 6a.

In addition, in the semiconductor laser device 1 according to this embodiment, each of the deflection element 40, the parallelization element 51, and the parallelization element 52 may be a transmissive deflection element.

In addition, in the semiconductor laser device 1 according to this embodiment, the transmissive deflection element is a prism having an entrance surface and an exit surface, and the entrance surface and the exit surface do not have to be parallel. This makes it possible to adjust the angle of the optical path deflection more precisely than the installation angle of the prism.

The semiconductor laser device 1 according to this embodiment may also include a FAST axis collimator lens 31 disposed between the semiconductor laser element 11 and the collimating element 51.

This makes it possible to suppress an increase in the spot size of the laser light L1A in the FAST axis direction.

The semiconductor laser device 1 according to this embodiment may also include a SLOW axis collimator lens 61 disposed between the FAST axis collimator lens 31 and the reflecting mirror 71.

This makes it possible to suppress an increase in the spot size of the laser light L1D in the SLOW axis direction.

Furthermore, in the semiconductor laser device 1 according to this embodiment, the laser light L1F emitted from the reflecting mirror 71 and the laser light L2F emitted from the reflecting mirror 72 may have parallel propagation directions, and the positions of the laser light L1F in the FAST axis direction may not overlap, and the positions of the laser light L1F in the SLOW axis direction may overlap.

In this way, by making the propagation directions of the laser light L1F and the laser light L2F parallel and aligning the position of the laser light L1F in the SLOW axis direction, the laser light L1F and the laser light L2F can be easily focused onto the optical fiber 4, etc. Furthermore, by not overlapping the positions of the laser light L1F and the laser light L2F in the FAST axis direction, it is possible to prevent the laser light intensity from becoming locally high, thereby preventing deterioration and damage to optical elements such as the optical fiber 4 into which each laser light is incident.

[1-3. Modification 1]
A semiconductor laser device according to Modification 1 of the present embodiment will be described. The semiconductor laser device according to this modification differs from the above-described semiconductor laser device 1 mainly in that the laser light is deflected downward by a deflection element. The semiconductor laser device according to this modification will be described below with reference to FIGS. 5 and 6, focusing on the differences from the semiconductor laser device 1.

FIGS. 5 and 6 are plan and side views showing the configuration of a semiconductor laser device 1a according to this modified example. As shown in FIG. 5, the semiconductor laser device 1a according to this modified example includes a housing 2, a plurality of semiconductor laser elements 10-12, a plurality of submounts 20-22, a plurality of FAST axis collimator lenses 30-32, a deflection element 40a, a plurality of parallelizing elements 51a, 52a, a plurality of SLOW axis collimator lenses 60-62, a plurality of reflecting mirrors 70-72, a plurality of mirror mounting surfaces 80a-82a, an optical fiber 4, and current introduction terminals 9a, 9b.

In this modified example, the semiconductor laser device 1a has a multi-stage base 8a with multiple mirror mounting surfaces 80a to 82a.

The multiple mirror mounting surfaces 80a-82a are surfaces on which the multiple reflective mirrors 70-72 are respectively mounted. The multiple mirror mounting surfaces 80a-82a differ from one another in height from the bottom surface 6a. Specifically, the mirror mounting surface 81a is lower in height from the bottom surface 6a than the mirror mounting surface 80a, and the mirror mounting surface 82a is lower in height from the bottom surface 6a than the mirror mounting surface 81a. The mirror mounting surface 80a is at the same height as the upper surface of the multi-stage base 8a. The mirror mounting surfaces 81a, 82a are formed at a lower position than the upper surface, and there is a step between the ends of the mirror mounting surfaces 81a, 82a and the upper surface of the multi-stage base 8a.

In addition, in this modified example, the semiconductor laser elements 10-12, the submounts 20-22, the FAST-axis collimator lenses 30-32, and the deflection element 40a are arranged on the upper surface of the multi-stage base 8a. The SLOW-axis collimator lens 60 and the reflecting mirror 70 are arranged on the mirror mounting surface 80a.

6, the deflection element 40a according to this modification is disposed between the semiconductor laser elements 11, 12 and the reflecting mirrors 71, 72, and is a deflection element that gives a height component from the bottom surface 6a to the propagation direction of the laser light L1B, L2B. In this modification, the deflection element 40a is disposed between the multiple FAST axis collimator lenses 31, 32 and the multiple parallelizing elements 51a, 52a, and deflects the laser light L1B, L2B downward (i.e., in the negative direction in the X-axis direction). The deflection element 40a deflects the laser light L1B, L2B at the same angle. The deflection element 40a is disposed between the semiconductor laser element 11 (first semiconductor laser element) and the reflecting mirror 71 (first reflecting mirror), and is an example of a first deflection element that gives a height component from the bottom surface 6a to the propagation direction of the laser light L1B (first laser light). The deflection element 40a is also an example of a second deflection element that is disposed between the semiconductor laser element 12 (second semiconductor laser element) and the reflecting mirror 72 (second reflecting mirror) and provides a height component from the bottom surface 6a to the propagation direction of the laser light L2B (second laser light).

The multiple parallelizing elements 51a, 52a are disposed between the deflection element 40a and the reflecting mirrors 71, 72, respectively, and are deflection elements that deflect the propagation direction of the laser light L1C, L2C in a direction parallel to the mirror mounting surfaces 81a, 82a. In this modified example, the multiple parallelizing elements 51a, 52a are mounted on the mirror mounting surfaces 81a, 82a, respectively. As a result, the heights from the bottom surface 6a at the positions where the multiple parallelizing elements 51a, 52a are mounted are different from each other. The heights from the bottom surface 6a at the mounting positions decrease in the order of the parallelizing elements 51a, 52a. The distance in the Z-axis direction from the corresponding semiconductor laser element of each of the parallelizing elements 51a, 52a increases as the height from the bottom surface 6a of the mounting position of each parallelizing element decreases. This allows the distance of each of the parallelizing elements 51a and 52a from the deflection element 40a to be different depending on the height from the bottom surface 6a of the installation position of each parallelizing element.

In this embodiment, a step is formed between the end of the mirror mounting surface 81a, 82a closer to the semiconductor laser elements 11, 12 and the upper surface of the multi-stage base 8a. A deflection element 40a is installed on the upper surface of the multi-stage base 8a near this step. The distance in the Z-axis direction from the step to the parallelizing element 51a is longer than the distance in the Z-axis direction from the step to the deflection element 40a. This reduces the blocking of the laser light by the multi-stage base 8a between the deflection element 40a and the parallelizing element 51a, as shown in FIG. 6.

In addition, the distance in the Z-axis direction from each of the SLOW-axis collimator lenses 60-62 to each semiconductor laser element becomes smaller as the height of each SLOW-axis collimator lens from the bottom surface 6a decreases. This makes it possible to align the optical path length between each SLOW-axis collimator lens and each semiconductor laser element.

The semiconductor laser device 1a having such a configuration also achieves the same effects as the semiconductor laser device 1 according to the first embodiment.

[1-4. Modification 2]
A semiconductor laser device according to Modification 2 of the present embodiment will be described. The semiconductor laser device according to this modification is different from the semiconductor laser device 1a according to Modification 1 described above mainly in that the laser light is also deflected upward by a deflection element. The semiconductor laser device according to this modification will be described below with reference to FIGS. 7 and 8, focusing on the differences from the semiconductor laser device 1a according to Modification 1.

FIGS. 7 and 8 are plan and side views showing the configuration of a semiconductor laser device 1b according to this modified example. As shown in FIG. 7, the semiconductor laser device 1b according to this modified example includes a housing 2, a plurality of semiconductor laser elements 10-14, a plurality of submounts 20-24, a plurality of FAST axis collimator lenses 30-34, deflection elements 40a, 40b, a plurality of parallelizing elements 51a-54a, a plurality of SLOW axis collimator lenses 60-64, a plurality of reflecting mirrors 70-74, a plurality of mirror mounting surfaces 80a-84a, an optical fiber 4, and current introduction terminals 9a, 9b.

In this modified example, the semiconductor laser device 1b has a multi-stage base 8b with multiple mirror mounting surfaces 80a to 84a.

The multiple mirror mounting surfaces 83a, 84a are surfaces on which the multiple reflective mirrors 73, 74 are respectively mounted. The multiple mirror mounting surfaces 80a-84a differ from one another in height from the bottom surface 6a. Specifically, the mirror mounting surface 83a is higher from the bottom surface 6a than the mirror mounting surface 80a, and the mirror mounting surface 84a is higher from the bottom surface 6a than the mirror mounting surface 83a.

In addition, in this modified example, the multiple semiconductor laser elements 10-14, the multiple submounts 20-24, the multiple FAST axis collimator lenses 30-34, and the deflection elements 40a, 40b are arranged on the upper surface of the multi-stage base 8b.

8, the deflection element 40b in this modified example is disposed between the semiconductor laser elements 13, 14 and the reflecting mirrors 73, 74, and is a deflection element that imparts a height component from the bottom surface 6a to the propagation direction of the laser beams L3B, L4B. In this modified example, the deflection element 40b is disposed between the multiple FAST axis collimator lenses 33, 34 and the multiple parallelizing elements 53a, 54a, and deflects the laser beams L3B, L4B upward (i.e., in the positive direction in the X-axis direction). The deflection element 40b deflects the laser beams L3B, L4B at the same angle. The deflection element 40b is disposed between the semiconductor laser element 13 and the reflecting mirror 73, and is an example of a first deflection element that imparts a height component from the bottom surface 6a to the propagation direction of the laser beam L3B. In addition, the deflection element 40b is disposed between the semiconductor laser element 14 and the reflection mirror 74, and is also an example of a second deflection element that gives the propagation direction of the laser light L4B a component in the height direction from the bottom surface 6a. Here, the semiconductor laser element 13 and the semiconductor laser element 14 are examples of the first semiconductor laser element and the second semiconductor laser element, respectively. The reflection mirrors 73 and 74 are examples of the first reflection mirror and the second reflection mirror, respectively. The laser light L3B and the laser light L4B are examples of the first laser light and the second laser light, respectively.

The parallelizing elements 53a, 54a are disposed between the deflection element 40b and the reflecting mirrors 73, 74, respectively, and are deflection elements that deflect the propagation direction of the laser beams L3C, L4C in a direction parallel to the mirror mounting surfaces 83a, 84a. In this modified example, the parallelizing elements 53a, 54a are mounted on the mirror mounting surfaces 83a, 84a, respectively. As a result, the heights from the bottom surface 6a at the positions where the parallelizing elements 53a, 54a are mounted are different from each other. The parallelizing elements 53a, 54a are higher in height from the bottom surface 6a at the mounting positions in this order.

The semiconductor laser device 1b having this configuration also achieves the same effects as the semiconductor laser device 1a according to the first modification.

In addition, in this modified example, the distance in the Z-axis direction between the end of the mirror mounting surface 83a located between the deflection element 40b and the parallelization element 53a and the installation position of the parallelization element 53a is smaller than the distance in the Z-axis direction between the end and the deflection element 40b. This reduces the blocking of the laser light L3C by the multi-stage base 8b.

(Embodiment 2)
A semiconductor laser device according to a second embodiment will be described. The semiconductor laser device according to this embodiment differs from the semiconductor laser device 1 according to the first embodiment in that the semiconductor laser element is disposed in an airtight package. The semiconductor laser device according to this embodiment will be described below, focusing on the differences from the semiconductor laser device 1 according to the first embodiment.

[2-1. Basic configuration
The basic configuration of a semiconductor laser device according to this embodiment will be described with reference to Fig. 9. Fig. 9 is a perspective view showing the configuration of a semiconductor laser device 101 according to this embodiment. In this manner, the semiconductor laser device 101 includes a housing 2, a plurality of semiconductor laser elements 10 to 12, a plurality of submounts 20 to 22, a plurality of FAST axis collimator lenses 30 to 32, a deflection element 40, and a plurality of the parallelizing elements 51 and 52, a plurality of slow axis collimator lenses 60 to 62, a plurality of reflecting mirrors 70 to 72, a plurality of mirror installation surfaces 80 to 82, an optical fiber 4, and current input terminals 9a and 9b. In this embodiment, the semiconductor laser device 101 further includes an airtight package 107. The semiconductor laser device 101 also includes a multi-stage base 108 having a plurality of mirror mounting surfaces 80 to 82. In this embodiment, the number of semiconductor laser elements etc. is three, but similarly to the first embodiment, the number of semiconductor laser elements etc. may be four or more.

The airtight package 107 is a package that hermetically seals at least one of the multiple semiconductor laser elements 10-12. In this embodiment, the airtight package 107 is a single package that hermetically seals the multiple semiconductor laser elements 10-12. The submounts 20-22 are also hermetically sealed within the airtight package 107. The airtight package 107 has a light-transmitting window 117 for emitting each laser light from the multiple semiconductor laser elements 10-12 to the outside of the airtight package 107.

As described above, the semiconductor laser device 101 according to this embodiment includes an airtight package 107 that hermetically seals at least one of the multiple semiconductor laser elements 10 to 12.

As a result, for example, when multiple semiconductor laser elements 10-12 include AlGaInN-based semiconductors and emit laser light with wavelengths ranging from blue light to ultraviolet light, it is possible to suppress deterioration of each semiconductor laser element due to organic matter adhering to the light-emitting point of each semiconductor laser element.

The semiconductor laser device 101 according to this embodiment also includes a single airtight package 107 that hermetically seals the semiconductor laser element 11 (first semiconductor laser element) and the semiconductor laser element 12 (second semiconductor laser element). This allows for a simpler configuration than when each of the multiple semiconductor laser elements 10 to 12 is individually airtight sealed. Also, the airtight package 107 can be attached to the housing 2 more easily than when multiple airtight packages are used.

[2-2. Detailed configuration example of airtight package]
A detailed configuration example of the hermetic package 107 of the semiconductor laser device 101 according to this embodiment will be described with reference to Fig. 10. Fig. 10 is a perspective view showing a detailed configuration example of the hermetic package 107 according to this embodiment. In Fig. 10, in order to show the inside of the hermetic package 107, a lid covering an opening P01 of the hermetic package 107 is removed.

The airtight package 107 has a first package P21, a light-transmitting window 117, and a lid (not shown).

As shown in FIG. 10, the first package P21 has a frame body P20, a package bottom P30, and a power supply member formed on the frame body P20. In the first package P21, the frame body P20 is stacked and fixed to the package bottom P30.

The package bottom P30 is a plate-shaped member made of an inorganic material with high thermal conductivity. The package bottom P30 may be made of a metal such as Cu or a Cu alloy, or may be made of a ceramic or polycrystalline material such as AlN, SiC, or diamond.

The frame body P20 is a frame-shaped member that exists mainly around the periphery of the package bottom P30 and has an opening P01 that opens in the center when viewed from above. The opening P01 has a rectangular shape when viewed from above. The frame body P20 is a member whose main material is an inorganic insulating material such as alumina ceramic or AlN ceramic. The upper surface of the portion near the center of the package bottom P30 that is not covered by the frame body P20 becomes the semiconductor laser element mounting surface.

Power supply members are provided inside and on the surface of the frame P20. The power supply members are made up of an anode extraction electrode P31, a cathode extraction electrode P34, an anode electrode P32, and a cathode electrode P35, which are made up of patterned metal wiring.

An opening (not shown) for extracting laser light is formed on one side of the first package P21. A light-transmitting window 117 is provided in the frame body P20 so as to cover the opening.

The anode extraction electrode P31 is an electrode that connects the anode electrode P32 to a current introduction terminal 9a that is arranged outside the airtight package 107, and the cathode extraction electrode P34 is an electrode that connects the cathode electrode P35 to a current introduction terminal 9b that is arranged outside the airtight package 107. The anode extraction electrode P31 and the cathode extraction electrode P34 are formed on the upper surface of the frame body P20.

The anode extraction electrode P31 and the cathode extraction electrode P34 are electrically connected to the anode electrode P32 and the cathode electrode P35, respectively, by metal wiring, via electrodes, etc.

As described above, the airtight package 107 can form an airtight space by the package bottom P30, the frame body P20, the light-transmitting window 117, and the lid.

The semiconductor laser elements 10 to 12 are arranged in the airtight space of the airtight package 107. In this configuration example, the semiconductor laser elements 10 to 12 are arranged on a single submount 120. In other words, the submount 120 is a member in which the submounts 20 to 22 are integrated.

Four patterned metal films 126-129 are arranged on the upper surface of the submount 120 and are insulated from one another. The four metal films 126-129 are arranged in the Y-axis direction. The semiconductor laser elements 10-12 are placed on the metal films 126-128, respectively, via conductive bonding members. The four metal films 126-129 are made of one or more metal films of, for example, Ni, Cu, Pt, and Au. In this embodiment, the submount 120 is a separate component from the first package P21, but it may be formed integrally as part of the first package P21.

The cathode electrode P35 is connected to the metal film 129 by a metal wire W. The metal film 129 is connected to an electrode on the top surface of the semiconductor laser element 12 by a metal wire W. The metal film 128 is connected to an electrode on the top surface of the semiconductor laser element 11 by a metal wire W. The metal film 127 is connected to an electrode on the top surface of the semiconductor laser element 10 by a metal wire W. The metal film 126 is connected to the anode electrode P32 by a metal wire W.

This allows multiple semiconductor laser elements 10 to 12 to be connected in series. Note that in this configuration example, the semiconductor laser elements 10 to 12 are mounted on the submount 120 in a junction-down configuration, but they may also be mounted in a junction-up configuration.

Furthermore, a FAST axis collimator lens 130 is disposed on the optical path of the laser beams L0A to L2A (not shown in FIG. 10) inside the package. The FAST axis collimator lens 130 is an integrated combination of the FAST axis collimator lenses 30 to 32.

As described above, by hermetically sealing the semiconductor laser elements 10-12 and the like within the airtight package 107, deterioration of the semiconductor laser elements 10-12 and the like can be suppressed.

[2-3. Detailed configuration example according to the modified example]
A detailed configuration example according to a modification of this embodiment will be described. This modification differs from the above detailed configuration example mainly in that the semiconductor laser elements 10 to 12 are integrated. Below, the detailed configuration example according to this modification will be described with reference to Fig. 11, focusing on the differences from the above detailed configuration example. Fig. 11 is a perspective view showing the internal configuration of an airtight package 107 according to the modification of this embodiment.

As shown in FIG. 11, the semiconductor laser elements 10 to 12 according to this modification are integrated to form a semiconductor laser array 110. In other words, the semiconductor laser elements 10 to 12 are included in the semiconductor laser array 110, which is a single element. The three optical waveguides formed in the semiconductor laser array 110 correspond to the semiconductor laser elements 10 to 12. In this modification, an electrode is formed on the upper surface of the semiconductor laser array 110 to integrally cover at least the portions corresponding to the three optical waveguides. Also, an electrode is formed on the lower surface of the semiconductor laser array 110 to integrally cover at least the portions corresponding to the three optical waveguides. By using such a semiconductor laser array 110, the multiple semiconductor laser elements 10 to 12 can be mounted together, simplifying the manufacturing process. Also, since there is no need to adjust the relative positions of the multiple semiconductor laser elements 10 to 12, the manufacturing process can be further simplified.

In this modified example, two patterned metal films 126, 129 are arranged on the upper surface of the submount 120 and are insulated from each other. The semiconductor laser array 110 is placed on the metal film 126 via a conductive bonding material.

The cathode electrode P35 is connected to the metal film 129 by a metal wire W. The metal film 129 is connected to the electrode on the top surface of the semiconductor laser array 110 by a metal wire W. The metal film 126 is connected to the anode electrode P32 by a metal wire W.

This makes it possible to realize semiconductor laser elements 10 to 12 connected in parallel.

The detailed configuration example of this modified example also achieves the same effects as the detailed configuration example above.

(Embodiment 3)
A semiconductor laser device according to a third embodiment will be described. The semiconductor laser device according to this embodiment differs from the semiconductor laser device 1 according to the first embodiment mainly in that the deflection element and the parallelization element have a reflecting surface. The semiconductor laser device according to this embodiment will be described below with reference to Figs. 12 and 13, focusing on the differences from the semiconductor laser device 1 according to the first embodiment.

FIGS. 12 and 13 are a plan view and a side view, respectively, showing the configuration of a semiconductor laser device 201 according to this embodiment.

As shown in FIG. 12, the semiconductor laser device 201 includes a housing 2, a plurality of semiconductor laser elements 10-12, a plurality of reflecting mirrors 70-72, a focusing lens 90, a plurality of mirror mounting surfaces 80-82, submounts 20-22, FAST axis collimator lenses 30-32, a deflection element 240, parallelizing elements 251, 252, SLOW axis collimator lenses 60-62, an optical fiber 4, and current introduction terminals 9a, 9b.

In this embodiment, the semiconductor laser elements 10 to 12 are disposed on the bottom surface 6a via submounts 20 to 22, respectively.

The mirror mounting surface 80 is the bottom surface 6a. The semiconductor laser device 201 has a multi-stage base 208 having mirror mounting surfaces 81 and 82.

The deflection element 240 is disposed between the semiconductor laser elements 11, 12 and the reflecting mirrors 71, 72, and is a deflection element that gives a height component from the bottom surface 6a to the propagation direction of the laser beams L1B, L2B. In this embodiment, the deflection element 240 is an optical element having a reflecting surface 240a. In this embodiment, the deflection element 240 is a rectangular prism-shaped optical element whose upper surface is the reflecting surface 240a. As shown in FIG. 13, the laser beams L1B, L2B are reflected by the reflecting surface 240a of the deflection element 240, so that an upward component from the bottom surface 6a is given to the propagation direction of the laser beams L1B, L2B, and the laser beams L1C, L2C are emitted from the deflection element 240.

The multiple parallelizing elements 251, 252 are disposed between the deflection element 240 and the reflecting mirrors 71, 72, and are deflection elements that deflect the propagation direction of the laser beams L1C, L2C in a direction parallel to the mirror mounting surfaces 81, 82. The multiple parallelizing elements 251, 252 are prisms having reflecting surfaces 251a, 252a, respectively. An anti-reflection film is provided on the entrance surface and exit surface of each of the multiple parallelizing elements 251, 252 to reduce reflection. The laser beams L1C, L2C incident on the entrance surfaces of the multiple parallelizing elements 251, 252 are reflected by the reflecting surfaces 251a, 252a, respectively, and are emitted from the exit surface as laser beams L1D, L2D. In this embodiment, the laser beams L1C and L2C are incident perpendicularly to the incident surfaces of the parallelizing elements 251 and 252, respectively, and the laser beams L1C and L2C are emitted perpendicularly from the exit surfaces of the parallelizing elements 251 and 252, respectively.

As described above, reflective deflection elements may be used as the deflection element 240 and the parallelization elements 251 and 252. The semiconductor laser device 201 according to this embodiment also achieves the same effects as the semiconductor laser device 1 according to the first embodiment.

(Embodiment 4)
A semiconductor laser device according to a fourth embodiment will be described. The semiconductor laser device according to this embodiment differs from the semiconductor laser device 1 according to the first embodiment mainly in that the laser light emitted from the semiconductor laser element has a component in the height direction. The semiconductor laser device according to this embodiment will be described below, focusing on the differences from the semiconductor laser device 1 according to the first embodiment.

[4-1. Configuration]
The configuration of a semiconductor laser device according to this embodiment will be described with reference to FIGS.

FIGS. 14 and 15 are a perspective view and a side view, respectively, showing the configuration of a semiconductor laser device 301 according to this embodiment.

As shown in FIG. 14, the semiconductor laser device 301 includes a housing 2, a plurality of semiconductor laser elements 10-12, a plurality of reflecting mirrors 70-72, a focusing lens 90, a plurality of mirror mounting surfaces 80-82, submounts 20-22, FAST axis collimator lenses 30-32, parallelizing elements 50-52, SLOW axis collimator lenses 60-62, and an optical fiber 4. Note that current introduction terminals and the like are omitted from the illustrations in FIGS. 14 and 15. Current introduction terminals and the like may also be omitted from the following drawings.

The semiconductor laser elements 10-12 according to this embodiment are mounted on a laser mounting surface 307a that is inclined at an angle of 5 degrees to 20 degrees with respect to the bottom surface 6a. As a result, as shown in FIG. 15, the propagation direction of the laser beams L0A-L2A emitted from the semiconductor laser elements 10-12 is inclined at an angle of 5 degrees to 20 degrees and has a height component from the bottom surface 6a. Therefore, in this embodiment, the FAST axis direction of the laser beams L0A-L2A is not parallel to the X-axis direction. The propagation direction of the laser beams L0A-L2A emitted from the semiconductor laser elements 10-12 has an upward (positive X-axis) component. Therefore, in this embodiment, the deflection element 40 used in the first embodiment and the like is not required. This allows the configuration of the semiconductor laser device 301 to be simplified.

Also in this embodiment, as in embodiment 1, the multiple semiconductor laser elements 10 to 12 are arranged on the same plane.

In this embodiment, the semiconductor laser device 301 has a multi-stage base 308 having mirror mounting surfaces 80 to 82 and a laser mounting surface 307a.

Similar to the semiconductor laser device 1 according to the first embodiment, the semiconductor laser device 301 according to the present embodiment also includes a first parallelizing element (parallelizing element 51) that is disposed between the first semiconductor laser element (semiconductor laser element 11) and the first reflecting mirror (reflecting mirror 71) and deflects the propagation direction of the first laser light (laser light L1B) in a direction parallel to the first mirror mounting surface (mirror mounting surface 81), and a second parallelizing element (parallelizing element 52) that is disposed between the second semiconductor laser element (semiconductor laser element 12) and the second reflecting mirror (reflecting mirror 72) and deflects the propagation direction of the second laser light (laser light L2B) by 5 degrees or more and 20 degrees or less in a direction parallel to the second mirror mounting surface (mirror mounting surface 82).

In the semiconductor laser device 301 according to this embodiment, the first laser light between the first semiconductor laser element and the first collimating element and the second laser light between the second semiconductor laser element and the second collimating element are parallel, and the distance between the second semiconductor laser element and the second collimating element is longer than the distance between the first semiconductor laser element and the first collimating element. The distance in the Z-axis direction from the corresponding semiconductor laser element of each of the collimating elements 50 to 52 increases as the height of each collimating element from the bottom surface 6a increases. This allows the distance from each of the collimating elements 50 to 52 to each semiconductor laser element to be different depending on the height of the installation position of each collimating element. The collimating elements 50 to 52 are installed near the ends of the mirror installation surfaces 80 to 82 that are closer to the semiconductor laser elements 10 to 12, respectively. The collimating elements 50 to 52 may be installed in areas on the laser installation surface 307a near the ends of each mirror installation surface.

The distance from each semiconductor laser element to each mirror mounting surface increases as the height of each mirror mounting surface from the bottom surface 6a increases. Also, as the height of each mirror mounting surface from the bottom surface 6a increases, the length of each mirror mounting surface in the propagation direction (Z-axis direction) of each laser light (L0D to L2D, L0E to L2E) of each mirror mounting surface decreases. The end of each mirror mounting surface is directly connected to the laser mounting surface 307a. This allows each laser light to propagate along the laser mounting surface 307a and each mirror mounting surface. Therefore, it is possible to reduce the blocking of each laser light by the multi-stage base 308. Also, by arranging each optical element on the laser mounting surface 307a or each mirror mounting surface, it is possible to control each laser light. The laser mounting surface 307a is inclined with respect to the bottom surface 6a, and the height from the bottom surface 6a decreases as it moves away from the end of each mirror mounting surface.

The laser beams L0B to L2B propagate parallel to the laser mounting surface 307a between the semiconductor laser elements 10 to 12 and the collimating elements 50 to 52. The laser beams L0B to L2B also propagate parallel to each other between the semiconductor laser elements 10 to 12 and the collimating elements 50 to 52.

As described above, the semiconductor laser device 301 according to this embodiment differs from the semiconductor laser device 1 according to the first embodiment in that the propagation direction of each laser light emitted from each semiconductor laser element has a component in the height direction from the bottom surface 6a. However, in the semiconductor laser device 301 according to this embodiment, as in the semiconductor laser device 1 according to the first embodiment, as shown in FIG. 15, the first distance D1 in the first direction from the light emitting point 11e of the semiconductor laser element 11 to the first optical axis A1 of the laser light L1E incident on the reflecting mirror 71 and the second distance D2 in the first direction from the light emitting point 11e of the semiconductor laser element 11 to the second optical axis A2 of the laser light L2E incident on the reflecting mirror 72 are different from each other. In addition, the third distance D3 in the first direction from the light emitting point 12e of the semiconductor laser element 12 to the second optical axis A2 of the laser light L2E incident on the reflecting mirror 72 is greater than the first distance D1.

As a result, the semiconductor laser device 301 according to this embodiment also achieves the same effects as the semiconductor laser device 1 according to the first embodiment.

[4-2. Modification 1]
A semiconductor laser device according to Modification 1 of the present embodiment will be described. The semiconductor laser device according to this modification is different from the semiconductor laser device 301 according to the fourth embodiment mainly in that the propagation direction of the laser beams L0A-L2A emitted from the multiple semiconductor laser elements 10-12 has a downward component. The semiconductor laser device according to this modification will be described below with reference to FIGS. 16 and 17, focusing on the differences from the semiconductor laser device 301 according to the fourth embodiment.

FIGS. 16 and 17 are a perspective view and a side view, respectively, showing the configuration of a semiconductor laser device 301a according to this modified example.

As shown in FIG. 16, the semiconductor laser device 301a includes a housing 2, a plurality of semiconductor laser elements 10-12, a plurality of reflecting mirrors 70-72, a focusing lens 90, a plurality of mirror mounting surfaces 80a-82a, submounts 20-22, FAST-axis collimator lenses 30-32, parallelizing elements 50-52, SLOW-axis collimator lenses 60-62, and an optical fiber 4.

In this modified example, the semiconductor laser device 301a includes a multi-stage base 308a having mirror mounting surfaces 80a-82a and a laser mounting surface 307a. The multiple mirror mounting surfaces 80a-82a have different heights from the bottom surface 6a. Specifically, the mirror mounting surface 81a is lower in height from the bottom surface 6a than the mirror mounting surface 80a, and the mirror mounting surface 82a is lower in height from the bottom surface 6a than the mirror mounting surface 81a.

The multiple semiconductor laser elements 10-12 in this modified example are mounted on a laser mounting surface 307a that is inclined with respect to the bottom surface 6a. As a result, as shown in FIG. 17, the propagation direction of the laser beams L0A-L2A emitted from the multiple semiconductor laser elements 10-12 has a component in the height direction from the bottom surface 6a. The propagation direction of the laser beams L0A-L2A emitted from the multiple semiconductor laser elements 10-12 has a downward component. Therefore, in this modified example, the deflection element 40 used in the first embodiment and the like is not required. This allows the configuration of the semiconductor laser device 301a to be simplified.

In this modified example, similar to the fourth embodiment, the multiple semiconductor laser elements 10 to 12 are arranged on the same plane.

The distance in the Z-axis direction from each of the parallelizing elements 50-52 to each semiconductor laser element increases as the height from the bottom surface 6a of the installation position of each parallelizing element decreases. This makes it possible to vary the distance from each semiconductor laser element to each parallelizing element depending on the height of the installation position of each parallelizing element. The parallelizing elements 50-52 are installed near the ends of the mirror installation surfaces 80-82 that are closer to the semiconductor laser elements 10-12. The parallelizing elements 50-52 may also be installed in areas on the laser installation surface 307a near the ends of each mirror installation surface.

The distance from each semiconductor laser element to each mirror mounting surface increases as the height of each mirror mounting surface from the bottom surface 6a decreases. Also, as the height of each mirror mounting surface from the bottom surface 6a decreases, the length of each mirror mounting surface in the propagation direction (Z-axis direction) of each laser light (L0D-L2D, L0E-L2E) decreases. In other words, the lower the height of the mirror mounting surface from the bottom surface 6a among the mirror mounting surfaces 80a-82a, the shorter the length in the propagation direction (Z-axis direction) of the laser light. The end of each mirror mounting surface is directly connected to the laser mounting surface 307a. This allows each laser light to propagate along the laser mounting surface 307a and each mirror mounting surface. Therefore, it is possible to reduce the blocking of each laser light by the multi-stage base 308a. Also, by arranging each optical element on the laser mounting surface 307a or each mirror mounting surface, it is possible to control each laser light. The laser mounting surface 307a is inclined relative to the bottom surface 6a, and the height from the bottom surface 6a increases as it moves away from the end of each mirror mounting surface.

The laser beams L0B to L2B propagate parallel to the laser mounting surface 307a between the semiconductor laser elements 10 to 12 and the collimating elements 50 to 52. The laser beams L0B to L2B also propagate parallel to each other between the semiconductor laser elements 10 to 12 and the collimating elements 50 to 52.

The semiconductor laser device 301a according to this modified example also achieves the same effects as the semiconductor laser device 301 according to the fourth embodiment.

[4-3. Modification 2]
A semiconductor laser device according to Modification 2 of the present embodiment will be described. The semiconductor laser device according to this modification is different from the semiconductor laser device 301a according to Modification 1 mainly in that the laser mounting surface on which the multiple semiconductor laser elements 10 to 12 are mounted is parallel to the bottom surface 6a, and the mirror mounting surface is inclined with respect to the bottom surface 6a. The semiconductor laser device according to this modification will be described below with reference to FIG. 18, focusing on the differences from the semiconductor laser device 301a according to Modification 1.

FIG. 18 is a side view showing the configuration of a semiconductor laser device 301b according to this modified example.

As shown in FIG. 18, the semiconductor laser device 301b includes a plurality of semiconductor laser elements 10-12 ( semiconductor laser elements 10 and 11 are not shown), a plurality of reflecting mirrors 70-72, a plurality of mirror mounting surfaces 80a-82a, submounts 20-22 ( submounts 20 and 21 are not shown), FAST axis collimator lenses 30-32 (FAST axis collimator lenses 30 and 31 are not shown), parallelizing elements 50-52, and SLOW axis collimator lenses 60-62.

The semiconductor laser device 301b includes a laser base 307 having a laser mounting surface 307b, and a multi-stage base 308b having a plurality of mirror mounting surfaces 80a to 82a. The laser base 307 and the multi-stage base 308b may be separate bodies or may be integrated together.

The semiconductor laser device 301b differs from the semiconductor laser device 301a of the first modification in the configuration of the multi-stage base 308b and the laser base 307.

The semiconductor laser device 301b according to this modified example includes a laser base 307 having a laser mounting surface 307b parallel to the lower surface 308ba (or bottom surface 6a) of the multi-stage base 308b. Since the semiconductor laser elements 10 to 12 are mounted on the laser mounting surface 307b, the propagation direction of the laser beams L0A to L2A emitted from the semiconductor laser elements 10 to 12 does not include a component in the height direction from the bottom surface 6a.

On the other hand, the mirror mounting surfaces 80-82 on which the reflective mirrors 70-72 are mounted are inclined at an angle of 5 degrees to 20 degrees with respect to the lower surface 308ba (or bottom surface 6a) of the multi-stage base 308b. The multiple mirror mounting surfaces 80-82 are parallel to each other. The heights of the ends of the multiple mirror mounting surfaces 80-82 that are closer to each semiconductor laser element from the bottom surface 6a are the same. The height of the ends may be the same as the height of the laser mounting surface 307b.

The height of the multistage base 308b from the bottom surface 6a of the area between the multiple mirror mounting surfaces 80-82 and the multiple semiconductor laser elements 10-12 is lower than the height of the bottom surface 6a of each light emitting point of the semiconductor laser elements 10-12. This reduces the blocking of each laser light by the multistage base 308b. In this modified example, the position of the end of the multistage base 308b close to each semiconductor laser element coincides with the end of the multiple mirror mounting surfaces 80-82. In other words, there is no component of the multistage base 8 located between each mirror mounting surface and the laser base 307. This reduces the blocking of each laser light by the multistage base 308b, and makes the multistage base 308b lighter.

In this modification, the parallelizing elements 50-52 impart a height component (an upward component in this modification) to the propagation direction of the laser beams L0B-L2B, respectively, so that the propagation direction of the laser beams L0D-L2D emitted from the parallelizing elements 50-52 becomes parallel to the mirror installation surfaces 80-82, respectively. The distance in the Z-axis direction from each of the parallelizing elements 50-52 to each semiconductor laser element increases as the height from the bottom surface 6a of the installation position of the reflecting mirror corresponding to each parallelizing element decreases. This makes it possible to make the distance from each semiconductor laser element to each parallelizing element different depending on the installation position of the reflecting mirror corresponding to each parallelizing element. The parallelizing elements 50-52 are installed near the ends of the mirror installation surfaces 80-82, respectively, that are closer to the semiconductor laser elements 10-12.

The distance from the end of each mirror mounting surface closest to each semiconductor laser element increases as the height from the bottom surface 6a of the installation position of each reflecting mirror installed on each mirror mounting surface decreases. Also, the optical path length of the laser light propagating along each mirror mounting surface decreases as the height from the bottom surface 6a of the installation position of each reflecting mirror installed on each mirror mounting surface decreases.

Each mirror mounting surface may be directly connected to the laser mounting surface 307a at the end closest to the laser mounting surface 307a. In this case, the multi-stage base 308b may be integrated with the laser base 307.

The laser beams L0B to L2B propagate parallel to the laser mounting surface 307a between the semiconductor laser elements 10 to 12 and the collimating elements 50 to 52. The laser beams L0B to L2B propagate in the positive direction of the Z axis, parallel to the bottom surface 6a. In addition, the laser beams L0B to L2B propagate parallel to each other between these points.

In this modified example, as in the first embodiment, as shown in FIG. 18, the first distance D1 in the first direction from the light emitting point 11e of the semiconductor laser element 11 to the optical axis (first optical axis A1) of the laser light L1E incident on the reflecting mirror 71 and the second distance D2 in the first direction from the light emitting point 11e of the semiconductor laser element 11 to the optical axis (second optical axis A2) of the laser light L2E incident on the reflecting mirror 72 are different from each other. The third distance D3 in the first direction from the light emitting point 12e of the semiconductor laser element 12 to the second optical axis A2 is greater than the first distance D1. In other words, the difference between the height of the light emitting point 12e of the semiconductor laser element 12 from the bottom surface 6a and the average height of the mirror installation surface 82 from the bottom surface 6a is greater than the difference between the height of the light emitting point 11e of the semiconductor laser element 11 from the bottom surface 6a and the average height of the mirror installation surface 81 from the bottom surface 6a.

Therefore, the semiconductor laser device 301b according to this modified example also achieves the same effects as those of the first embodiment.

Furthermore, the semiconductor laser device 301b according to this modification also achieves the same effects as the semiconductor laser device 301a according to modification 1.

(Embodiment 5)
A semiconductor laser device according to embodiment 5 will be described. The semiconductor laser device according to this embodiment differs from the semiconductor laser device 301 according to embodiment 4 mainly in that the laser light emitted from the semiconductor laser element is perpendicular to the bottom surface 6a. The semiconductor laser device according to this embodiment will be described below, focusing on the differences from the semiconductor laser device 301 according to embodiment 4.

[5-1. Configuration]
The configuration of a semiconductor laser device according to this embodiment will be described with reference to FIGS.

FIGS. 19 and 20 are a perspective view and a side view, respectively, showing the configuration of a semiconductor laser device 401 according to this embodiment.

As shown in FIG. 19, the semiconductor laser device 401 includes a housing 2, a plurality of semiconductor laser elements 10-12, a plurality of reflecting mirrors 70-72, a focusing lens 90, a plurality of mirror mounting surfaces 80-82, submounts 20-22, FAST-axis collimator lenses 30-32, parallelizing elements 450-452, SLOW-axis collimator lenses 60-62, and an optical fiber 4.

The semiconductor laser device 401 comprises a laser mounting surface 407a on which multiple semiconductor laser elements 10-12 are mounted, and a multi-stage base 408 having multiple mirror mounting surfaces 80-82. The laser mounting surface 407a perpendicularly intersects with the multiple mirror mounting surfaces 80-82 and the bottom surface 6a. The multiple semiconductor laser elements 10-12 according to this embodiment are mounted on a laser mounting surface 407b that perpendicularly intersects with the bottom surface 6a and the multiple mirror mounting surfaces 80-82. As a result, the propagation direction of the laser light L0A-L2A emitted from the multiple semiconductor laser elements 10-12 has a component in the height direction from the bottom surface 6a. The laser light L0A-L2A emitted by the multiple semiconductor laser elements 10-12 propagates upward (positive in the X-axis direction). The collimating elements 450-452 respectively deflect the laser beams L0B-L2B emitted by the semiconductor laser elements 10-12 (laser beams L0B-L2B obtained by collimating the laser beams L0A-L2A emitted by the semiconductor laser elements 10-12 by the FAST-axis collimator lenses 30-32) by 90 degrees. The collimating elements 450-452 respectively deflect the laser beams L0B-L2B in the positive direction in the Z-axis direction. In this embodiment, the collimating elements 450-452 are reflective deflection elements made of a triangular prism having a reflecting surface and a right-angled triangular base. The laser beams L0B-L2B incident on the incident surfaces of the collimating elements 450-452 are reflected by the reflecting surfaces of the collimating elements 450-452 and are emitted from the reflecting surfaces as laser beams L0D-L2D via the emitting surfaces. In other words, the laser beams L0D to L2D are the reflected beams of the laser beams L0B to L2B that are reflected by the reflecting surfaces of the collimating elements 450 to 452, respectively. In this embodiment, the laser beams L0B to L2B are incident perpendicularly on the incident surfaces of the collimating elements 450 to 452, respectively, and the laser beams L0D to L2D are emitted perpendicularly from the exit surfaces of the collimating elements 450 to 452.

The parallelizing elements 450-452 are installed on the outside of the corner where the laser mounting surface 407a and the multiple mirror mounting surfaces 80-82 intersect perpendicularly, on a line extended to the emission side of the semiconductor laser elements 10-12, and at the same height as each of the reflecting mirrors 70-72. In this embodiment, the parallelizing elements 450-452 are installed on the mirror mounting surfaces 80-82, respectively. Each parallelizing element is installed in a state where it protrudes from each mirror mounting surface in a direction parallel to each mirror mounting surface, in a direction approaching the optical axis of the laser beams L0B-L2B. This allows each laser beam to be incident on the reflecting surface of each parallelizing element. The reflecting surface of each parallelizing element is arranged in a state where it is inclined with respect to each mirror mounting surface and the laser mounting surface 407a. In this embodiment, the inclination angle of the reflecting surface of each parallelizing element with respect to each mirror mounting surface and the laser mounting surface 407a is 45 degrees. In addition, the parallelizing elements 450 to 452 may be reflective mirrors and may be installed on a surface other than the mirror installation surface. For example, the parallelizing elements 450 to 452 may be installed on the laser installation surface 407a.

20, in the semiconductor laser device 401 according to this embodiment, a first distance D1 in a first direction from the light emitting point 11e of the semiconductor laser element 11 to the optical axis (first optical axis A1) of the laser light L1E incident on the reflecting mirror 71 and a second distance D2 in a first direction from the light emitting point 11e of the semiconductor laser element 11 to the optical axis (second optical axis A2) of the laser light L2E incident on the reflecting mirror 72 are different from each other. A third distance D3 in the first direction from the light emitting point 12e of the semiconductor laser element 12 to the second optical axis A2 is greater than the first distance D1. In this embodiment, since the laser lights L1A, L2A, L1B, and L2B propagate in a direction perpendicular to the first optical axis A1 and the second optical axis A2, the first distance D1 is equal to the sum of the optical path length of the laser light L1A and the optical path length of the laser light L1B (i.e., the optical path length from the light emitting point 11e to the intersection of the reflecting surface of the parallelizing element 451 and the first optical axis A1). Furthermore, the second distance D2 and the third distance D3 are equal to the sum of the optical path length of the laser light L2A and the optical path length of the laser light L2B (i.e., the optical path length from the light emitting point 12e to the intersection of the reflecting surface of the parallelizing element 452 and the second optical axis A2).

Furthermore, the semiconductor laser device 401 according to this embodiment also exhibits the same effects as the semiconductor laser device 301 according to embodiment 4.

In addition, in this embodiment, the optical axis of the laser light is deflected by 90 degrees using each parallelizing element, thereby reducing the dimension of the semiconductor laser device 401 in the Z-axis direction.

[5-2. Modifications]
A semiconductor laser device according to a modification of the present embodiment will be described. The semiconductor laser device according to this modification differs from the semiconductor laser device 401 according to the fifth embodiment mainly in that the propagation direction of the laser beams L0A-L2A emitted from the plurality of semiconductor laser elements 10-12 is downward. The semiconductor laser device according to this modification will be described below with reference to FIG. 21, focusing on the differences from the semiconductor laser device 401 according to the fifth embodiment.

FIG. 21 is a perspective view showing the configuration of a semiconductor laser device 401a according to this modified example.

As shown in FIG. 21, the semiconductor laser device 401a includes a housing 2, a plurality of semiconductor laser elements 10-12, a plurality of reflecting mirrors 70-72, a focusing lens 90, a plurality of mirror mounting surfaces 80-82, submounts 20-22, FAST axis collimator lenses 30-32, parallelizing elements 50-52, SLOW axis collimator lenses 60-62, and an optical fiber 4.

The semiconductor laser device 401a comprises a laser mounting surface 407b on which multiple semiconductor laser elements 10-12 are mounted, and a multi-stage base 408a having multiple mirror mounting surfaces 80-82. The multi-stage base 408a has a lower surface 408ba and mirror mounting surfaces 80-82 that are parallel to and face the lower surface 408ba. The mirror mounting surfaces 80-82 have different heights from the bottom surface 6a, with the heights from the bottom surface increasing in the order of mirror mounting surfaces 82, 81, and 80. The laser mounting surface 407b perpendicularly intersects with the multiple mirror mounting surfaces 80-82 and the bottom surface 6a. The laser mounting surface 407b extends upward from the ends of the mirror mounting surfaces 80-82 that are closer to the semiconductor laser elements 10-12, in the opposite direction to the lower surface 408ba. In a cross section seen from the Y-axis direction, the laser mounting surface 407b and the mirror mounting surfaces 80 to 82 form an L-shape, and the multi-stage base 408a has a recessed portion in the L-shape. In other words, the multi-stage base 408a has a stepped upper surface including the mirror mounting surfaces 80 to 82, and has a first plate-like portion extending along the bottom surface 6a, and a second plate-like portion connected to the plate-like portion, including the laser mounting surface 407b, and standing on the bottom surface 6a. The multiple semiconductor laser elements 10 to 12 according to this embodiment are mounted on the laser mounting surface 407b that perpendicularly intersects with the bottom surface 6a and the multiple mirror mounting surfaces 80 to 82. As a result, the propagation direction of the laser beams L0A to L2A (not shown in FIG. 21) emitted from the multiple semiconductor laser elements 10 to 12 has a component in the height direction from the bottom surface 6a. The laser beams L0A to L2A emitted by the semiconductor laser elements 10 to 12 propagate downward (negative direction in the X-axis direction). The parallelizing elements 450 to 452 respectively deflect the laser beams L0B to L2B emitted by the semiconductor laser elements 10 to 12 (laser beams L0B to L2B obtained by collimating the laser beams L0A to L2A emitted by the semiconductor laser elements 10 to 12 by the FAST-axis collimator lenses 30 to 32) by 90 degrees. The parallelizing elements 450 to 452 respectively deflect the laser beams L0B to L2B in the positive direction in the Z-axis direction. The parallelizing elements 450 to 452 are reflective deflection elements having a reflecting surface. The parallelizing elements 450 to 452 are installed near the ends of the mirror installation surfaces 80 to 82 that are closer to the semiconductor laser elements 10 to 12. The parallelizing elements 450 to 452 may be reflecting mirrors.

The semiconductor laser device 401a according to this modified example also achieves the same effects as the semiconductor laser device 401 according to the fifth embodiment.

(Other embodiments)
Although the semiconductor laser device according to the present disclosure has been described above based on the embodiments and modifications, the present disclosure is not limited to these embodiments and modifications. As long as the modifications do not deviate from the gist of the present disclosure, the scope of the present disclosure also includes modifications that a person skilled in the art may make to the embodiments, and other forms constructed by combining some of the components in the embodiments and modifications.

For example, in each embodiment, instead of placing each SLOW-axis collimator lens between each parallelizing element and each reflecting mirror, each SLOW-axis collimator lens may be placed between each semiconductor laser element (or each FAST-axis collimator lens) and each parallelizing element, or between each semiconductor laser element (or each FAST-axis collimator lens) and each deflection element. Below, an example in which the above-mentioned modification is applied to the semiconductor laser device 1 according to embodiment 1 will be described with reference to Figures 22 and 23. Figure 22 is a perspective view showing the configuration of a semiconductor laser device 1c according to modification 3 of embodiment 1. Figure 23 is a perspective view showing the configuration of a semiconductor laser device 1d according to modification 4 of embodiment 1.

As shown in FIG. 22, the semiconductor laser device 1c according to the third modification differs from the semiconductor laser device 1 according to the first embodiment in the configuration and arrangement of the SLOW-axis collimator lens 60c. The SLOW-axis collimator lens 60c according to the third modification is disposed between the multiple parallelizing elements 51-55 and the multiple semiconductor laser elements 11-15, and between the reflecting mirror 70 and the semiconductor laser element 10. More specifically, the SLOW-axis collimator lens 60c is disposed between the deflection element 40 and the multiple FAST-axis collimator lenses 31-35, and between the reflecting mirror 70 and the FAST-axis collimator lens 30.

The SLOW-axis collimator lens 60c has a configuration in which multiple SLOW-axis collimator lenses 60-65 arranged in the Y-axis direction are integrated. In the third modification, the SLOW-axis collimator lens 60c corresponding to multiple laser beams is arranged in the area between the deflection element 40 and the multiple semiconductor laser elements 10-15, that is, in the area where the multiple laser beams are in the same plane, making it possible to arrange the multiple SLOW-axis collimator lenses 60-65 on the same plane. Therefore, in the third modification, the multiple SLOW-axis collimator lenses 60-65 can be easily integrated. Furthermore, the integration of the multiple SLOW-axis collimator lenses 60-65 makes it easier to install the SLOW-axis collimator lens 60c.

In addition, in the third modification, since the slow axis collimator lenses are not arranged on the mirror mounting surfaces, it is possible to shorten the length of each mirror mounting surface in the Z-axis direction. This allows the dimensions of the multi-stage base 8 to be reduced, making it possible to reduce the weight of the multi-stage base 8.

The semiconductor laser device 1d according to the fourth modification shown in FIG. 23 differs from the semiconductor laser device 1c according to the third modification mainly in that it has multiple deflection elements 41-45 instead of the deflection element 40, and in the arrangement of the multiple deflection elements 41-45 and the multiple parallelizing elements 51-55.

The multiple deflection elements 41 to 45 in the fourth modification are disposed between the SLOW-axis collimator lens 60c and the multiple parallelizing elements 51 to 55, respectively. In the fourth modification, the SLOW-axis collimator lens 60c and the multiple deflection elements 41 to 45 are disposed on the laser base 7.

The distance in the Z-axis direction from each deflection element to each semiconductor laser element decreases as the height of the corresponding parallelizing element and reflecting mirror from the bottom surface 6a increases. Meanwhile, the position of each parallelizing element in the Z-axis direction is the same. In other words, the distance in the Z-axis direction between each deflection element and each parallelizing element increases as the height of each parallelizing element from the bottom surface 6a increases. This allows each laser light to propagate to each of the parallelizing elements that are installed at different heights. Note that, even in the fourth modification, the propagation directions of the multiple laser lights propagating between the multiple deflection elements 41-45 and the multiple parallelizing elements 51-55 are parallel to each other and inclined with respect to the bottom surface 6a.

The lengths of the multiple mirror mounting surfaces in the Z-axis direction in the fourth modified example may be equal. This allows the edges of the multiple mirror mounting surfaces to be formed on the same plane, making it easier to manufacture the multi-stage base 8d having multiple mirror mounting surfaces. Each parallelizing element is disposed near the end of each mirror mounting surface that is closer to each semiconductor laser element.

The semiconductor laser devices according to the third and fourth modifications of the first embodiment as described above also achieve the same effects as the semiconductor laser device 1 according to the first embodiment.

In addition, in the fourth embodiment and the first and second variations of the fourth embodiment, instead of placing the parallelizing element on the mirror mounting surface, the parallelizing element may be placed on the laser mounting surface that is inclined with respect to the bottom surface. In this case, the parallelizing element is placed near the end of the laser mounting surface that is closer to the reflecting mirror.

Furthermore, the above embodiment may be modified, substituted, added, omitted, etc. in various ways within the scope of the claims or their equivalents.

The semiconductor laser device according to the present disclosure is particularly useful as a high-brightness, high-power laser light source, for example, a laser light source for processing, a laser light source for displays, a laser light source for medical use, etc.

REFERENCE SIGNS LIST 1, 1a, 1b, 1c, 1d, 101, 201, 301, 301a, 301b, 401, 401a Semiconductor laser device 2 Housing 3 Side wall 4 Optical fiber 6 Bottom 6a Bottom surface 7, 307 Laser base 7a, 307a, 307b, 407a, 407b Laser installation surface 8, 8a, 8b, 8d, 108, 208, 308, 308a, 308b, 408, 408a Multi-stage base 8ba, 308ba, 408ba Bottom surface 9a, 9b Current input terminal 9c Wiring member 10, 11, 12, 13, 14, 15 Semiconductor laser element 10e, 11e, 12e, 13e, 14e, 15e Emission point 20, 21, 22, 23, 24, 25, 120 Submount 30, 31, 32, 33, 34, 35, 130 FAST axis collimator lens 40, 40a, 40b, 41, 42, 43, 44, 45, 240 Deflection element 50, 51, 51a, 52, 52a, 53, 53a, 54, 54a, 55, 251, 252, 450, 451, 452 Parallelization element 60, 60c, 61, 62, 63, 64, 65 SLOW axis collimator lens 70, 71, 72, 73, 74, 75 Reflection mirror 80, 80a, 81, 81a, 82, 82a, 83, 83a, 84, 84a, 85 Mirror installation surface 90 Condenser lens 107 Airtight package 110 Semiconductor laser array 117 Light-transmitting window 126, 127, 128, 129 Metal film 240a, 251a, 252a Reflecting surface A1 First optical axis A2 Second optical axis D1 First distance D2 Second distance D3 Third distance D4 Fourth distance L0A, L0B, L0D, L0E, L0F, L1A, L1B, L1C, L1D, L1E, L1F, L2A, L2B, L2C, L2D, L2E, L2F, L3A, L3B, L3C, L3D, L3E, L3F, L4A, L4B, L4C, L4D, L4E, L4F, L5A, L5B, L5C, L5D, L5E, L5F Laser light P01 Opening P20 Frame P21 First package P30 Package bottom P31 Anode lead-out electrode P32 Anode electrode P34 Cathode lead-out electrode P35 Cathode electrode W Metal wire

Claims (26)

1. A housing having a bottom surface;
   a first semiconductor laser element and a second semiconductor laser element disposed in the housing;
   a first reflecting mirror that reflects a first laser beam emitted from the first semiconductor laser element;
   a second reflecting mirror that reflects a second laser beam emitted from the second semiconductor laser element;
   a condenser lens that condenses the first laser light reflected by the first reflecting mirror and the second laser light reflected by the second reflecting mirror;
   a first mirror mounting surface on which the first reflecting mirror is mounted;
   a second mirror mounting surface on which the second reflecting mirror is mounted,
   the first mirror installation surface and the second mirror installation surface are parallel to each other,
   The first mirror installation surface and the second mirror installation surface are not on the same plane,
   the first semiconductor laser element has a first light-emitting point from which the first laser light is emitted,
   the second semiconductor laser element has a second light-emitting point from which the second laser light is emitted,
   an optical axis of the first laser light incident on the first reflecting mirror is defined as a first optical axis;
   an optical axis of the second laser light incident on the second reflecting mirror is defined as a second optical axis;
   When a direction passing through the first light emitting point and perpendicular to the first optical axis is defined as a first direction,
   a first distance in the first direction from the first light-emitting point to the first optical axis and a second distance in the first direction from the first light-emitting point to the second optical axis are different from each other,
   a third distance in the first direction from the second light emitting point to the second optical axis is greater than the first distance.
2. a first deflection element disposed between the first semiconductor laser element and the first reflecting mirror, the first deflection element providing a component of the first direction in a propagation direction of the first laser light;
   a first collimating element disposed between the first deflection element and the first reflecting mirror and configured to deflect a propagation direction of the first laser light in a direction parallel to a surface on which the first mirror is placed;
   a second deflection element disposed between the second semiconductor laser element and the second reflecting mirror and configured to give a component of the first direction to a propagation direction of the second laser light;
   2. The semiconductor laser device according to claim 1, further comprising: a second collimating element disposed between the second deflection element and the second reflecting mirror and configured to deflect a propagation direction of the second laser light in a direction parallel to a mounting surface of the second mirror.
3. A housing having a bottom surface;
   a first semiconductor laser element and a second semiconductor laser element disposed in the housing;
   a first reflecting mirror that reflects a first laser beam emitted from the first semiconductor laser element;
   a second reflecting mirror that reflects a second laser beam emitted from the second semiconductor laser element;
   a condenser lens that condenses the first laser light reflected by the first reflecting mirror and the second laser light reflected by the second reflecting mirror;
   a first collimating element disposed between the first semiconductor laser element and the first reflecting mirror and configured to deflect a propagation direction of the first laser light;
   a second collimating element disposed between the second semiconductor laser element and the second reflecting mirror and configured to deflect a propagation direction of the second laser light;
   the first semiconductor laser element has a first light-emitting point from which the first laser light is emitted,
   the second semiconductor laser element has a second light-emitting point from which the second laser light is emitted,
   an optical axis of the first laser light incident on the first collimating element and an optical axis of the second laser light incident on the second collimating element are parallel to each other;
   an optical axis of the first laser light incident on the first reflecting mirror and an optical axis of the second laser light incident on the second reflecting mirror are parallel to each other;
   an optical axis of the first laser light incident on the first reflecting mirror is inclined with respect to an optical axis of the first laser light incident on the first collimating element;
   an optical axis of the first laser light incident on the first reflecting mirror is defined as a first optical axis;
   an optical axis of the second laser light incident on the second reflecting mirror is defined as a second optical axis;
   When a direction passing through the first light emitting point and perpendicular to the first optical axis is defined as a first direction,
   a first distance in the first direction from the first light-emitting point to the first optical axis and a second distance in the first direction from the first light-emitting point to the second optical axis are different from each other,
   a third distance in the first direction from the second light emitting point to the second optical axis is greater than the first distance.
4. a first mirror mounting surface on which the first reflecting mirror is mounted;
   The semiconductor laser device according to claim 3 , further comprising: a second mirror mounting surface on which the second reflecting mirror is mounted.
5. a first deflection element disposed between the first semiconductor laser element and the first collimation element, the first deflection element providing a component of the first direction in a propagation direction of the first laser light;
   5. The semiconductor laser device according to claim 3, further comprising a second deflection element disposed between the second semiconductor laser element and the second collimating element, the second deflection element providing a component of the first direction in a propagation direction of the second laser light.
6. the first laser light between the first deflection element and the first collimation element and the second laser light between the second deflection element and the second collimation element are parallel to each other;
   The semiconductor laser device according to claim 2 , wherein a distance between the second deflection element and the second collimating element is longer than a distance between the first deflection element and the first collimating element.
7. the first collimating element is disposed on the first mirror mounting surface;
   The semiconductor laser device according to claim 2 , wherein the second collimating element is disposed on the second mirror mounting surface.
8. The semiconductor laser device according to claim 2 , wherein each of the first deflection element, the first collimating element, the second deflection element, and the second collimating element is a transmissive deflection element.
9. the transmissive deflection element is a prism having an entrance surface and an exit surface,
   The semiconductor laser device according to claim 8 , wherein the entrance surface and the exit surface are not parallel to each other.
10. 10. The semiconductor laser device according to claim 1, wherein a FAST axis direction of each of the first semiconductor laser element and the second semiconductor laser element is a height direction from the bottom surface.
11. 5. The semiconductor laser device according to claim 1, wherein a propagation direction of laser light emitted from each of the first semiconductor laser element and the second semiconductor laser element has a component in a height direction from the bottom surface.
12. a first collimating element disposed between the first semiconductor laser element and the first reflecting mirror and configured to deflect a propagation direction of the first laser light to a direction parallel to a surface on which the first mirror is placed;
    2. The semiconductor laser device according to claim 1, further comprising: a second collimating element disposed between the second semiconductor laser element and the second reflecting mirror and configured to deflect a propagation direction of the second laser light to a direction parallel to a mounting surface of the second mirror.
13. the first laser light between the first semiconductor laser element and the first collimating element and the second laser light between the second semiconductor laser element and the second collimating element are parallel,
    The semiconductor laser device according to claim 12 , wherein a distance between the second semiconductor laser element and the second collimating element is longer than a distance between the first semiconductor laser element and the first collimating element.
14. The semiconductor laser device according to claim 12 , wherein the first collimating element and the second collimating element respectively deflect the first laser light and the second laser light by 90 degrees.
15. the first collimating element is disposed on the first mirror mounting surface;
    15. The semiconductor laser device according to claim 12, wherein the second collimating element is disposed on the second mirror mounting surface.
16. 16. The semiconductor laser device according to claim 12, wherein each of the first collimating element and the second collimating element is a transmissive deflection element.
17. the transmissive deflection element is a prism having an entrance surface and an exit surface,
    The semiconductor laser device according to claim 16 , wherein the entrance surface and the exit surface are not parallel to each other.
18. 18. The semiconductor laser device according to claim 2, further comprising a fast axis collimator lens disposed between the first semiconductor laser element and the first collimating element.
19. 20. The semiconductor laser device according to claim 18, further comprising a slow-axis collimator lens disposed between the fast-axis collimator lens and the first reflecting mirror.
20. 20. The semiconductor laser device according to claim 1, wherein a distance in the first direction from the first light-emitting point to the second light-emitting point is smaller than a distance in the first direction from the first optical axis to the second optical axis.
21. 21. The semiconductor laser device according to claim 1, wherein the bottom surface is flat.
22. 22. The semiconductor laser device according to claim 1, wherein the first semiconductor laser element and the second semiconductor laser element are disposed on the same plane.
23. 23. The semiconductor laser device according to claim 1, further comprising an airtight package that hermetically seals at least one of the first semiconductor laser element and the second semiconductor laser element.
24. 24. The semiconductor laser device according to claim 1, further comprising a single hermetic package that hermetically seals the first semiconductor laser element and the second semiconductor laser element.
25. 25. The semiconductor laser device according to claim 1, wherein the first semiconductor laser element and the second semiconductor laser element are included in a single element.
26. The semiconductor laser device according to any one of claims 1 to 25, wherein the first laser light emitted from the first reflecting mirror and the second laser light emitted from the second reflecting mirror have parallel propagation directions, the first laser light emitted from the first reflecting mirror does not overlap in the FAST axis direction, and the first laser light emitted from the first reflecting mirror overlaps in the SLOW axis direction.

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