JP7502151B2 - Semiconductor Laser Module - Google Patents

Description

The present invention relates to a semiconductor laser module.

As a conventional semiconductor laser module, for example, Patent Document 1 describes a laser combining optical device that arranges multiple single-emitter LDs side by side and combines the laser light emitted from each single-emitter LD. The single-emitter LD has a light-emitting element that emits laser light and a sealing package that hermetically seals the light-emitting element.

JP 2016-103317 A

However, in the laser combining optical device described in the above-mentioned Patent Document 1, for example, the light-emitting element is hermetically sealed by a sealing package, so it is difficult to place a collimating lens that forms parallel light in close proximity to the light-emitting element, and as a result, the beam size of the laser light emitted from the collimating lens tends to be large. As a result, in the laser combining optical device, the beam size of the laser light beam composed of multiple laser lights emitted from each collimating lens in multiple single-emitter LDs becomes large, and as a result, the distance required to focus the laser light beam becomes longer, and there is a risk of the overall length of the laser combining optical device becoming longer.

Therefore, the present invention has been made in consideration of the above, and aims to provide a semiconductor laser module that can prevent the module from becoming too large.

In order to solve the above-mentioned problems and achieve the object, the semiconductor laser module according to the present invention is characterized in that it comprises a base part formed in a plate shape and dividing a first space part and a second space part in a first direction, a semiconductor laser element that emits laser light, and a cover that covers the semiconductor laser element, and a plurality of laser light emitters that are provided at a position where the laser light can be emitted into the first space part, a folding optical system that is provided at an end part of one side of the base part in the second direction when a direction intersecting the first direction is a second direction, and that folds back the plurality of laser light beams emitted from the plurality of laser light emitters into the first space part and heading toward the one side of the second direction into the second space part and toward the other side of the second direction, a focusing optical system that is provided in the second space part and focuses the plurality of laser light beams folded back by the folding optical system, and an external emission part that emits the plurality of laser light beams focused by the focusing optical system from the second space part to the outside.

It is preferable that the semiconductor laser module further includes a compression optical system that is provided in the second space and compresses the plurality of laser beams folded back by the folding optical system in a parallel state, and emits the compressed plurality of laser beams to the focusing optical system.

In the semiconductor laser module, it is preferable that the semiconductor laser module further includes a reflective optical system that is provided in the first space and reflects the laser light, and the laser light emitters are arranged side by side along the second direction at an end of the base part on one side of the third direction in the third direction, when a direction intersecting the first direction and the second direction is defined as a third direction, and emit the laser light beams to the first space part along the third direction, and the reflective optical system reflects the laser light beams emitted from the laser light emitters toward the folding optical system along the second direction.

In the above semiconductor laser module, it is preferable that the multiple laser light emitters are arranged in a positional relationship such that the first axis directions of the multiple laser lights emitted toward the reflection optical system are aligned along the second direction, the reflection optical system is arranged in a positional relationship such that the first axis directions of the multiple reflected laser lights are aligned along the third direction, the folding optical system is arranged in a positional relationship such that the first axis directions of the multiple folded laser lights are aligned along the third direction, and the focusing optical system is arranged in a positional relationship such that the multiple laser lights folded by the folding optical system are focused along the third direction parallel to the first axis directions of the multiple laser lights.

The semiconductor laser module of the present invention is equipped with a folding optical system that folds back multiple laser beams emitted from multiple laser beam emitters, thereby preventing the module from becoming large.

FIG. 1 is a perspective view showing a configuration example of a first space portion side of a semiconductor laser module according to an embodiment. FIG. 2 is a perspective view showing a configuration example of the second space portion side of the semiconductor laser module according to the embodiment. FIG. 3 is an exploded perspective view showing an example of the configuration of a semiconductor laser module according to an embodiment. FIG. 4 is a perspective view showing an example of changing the optical path of laser light by an optical path changing prism according to the embodiment. FIG. 5 is a perspective view showing an example of the folding of laser light by a folding prism according to the embodiment. FIG. 6 is a schematic plan view illustrating an example of propagation of laser light through the first space portion according to the embodiment. FIG. 7 is a schematic plan view illustrating an example of propagation of laser light through the second space portion according to the embodiment.

The following describes in detail the form (embodiment) for carrying out the present invention with reference to the drawings. The present invention is not limited to the contents described in the following embodiment. The components described below include those that a person skilled in the art can easily imagine and those that are substantially the same. Furthermore, the configurations described below can be combined as appropriate. Various omissions, substitutions, or modifications of the configuration can be made without departing from the spirit of the present invention.

[Embodiment]
A semiconductor laser module 1 according to an embodiment will be described with reference to the drawings. The semiconductor laser module 1 emits a laser beam bundle obtained by concentrating laser beams LB emitted from a plurality of laser beam emitters 20 to the outside. The semiconductor laser module 1 can realize a high optical output that cannot be achieved by a single laser beam emitter by using the laser beam bundle. Such a high-output semiconductor laser module 1 is suitable for laser welding and laser processing, and in particular, a semiconductor laser module 1 having a visible laser beam wavelength is used for metal processing and the like. As shown in FIGS. 1 to 3, the semiconductor laser module 1 includes a housing 10, a plurality of laser beam emitters 20, a water cooling mechanism 30, a plurality of optical path changing prisms 40 as an optical path changing optical system, a plurality of reflecting mirrors 50 as a reflecting optical system, a folding prism 60 as a folding optical system, a compression prism 70 as a compression optical system, a condenser lens 80, and an external emission unit 90.

In the following description, the direction along the thickness of the base portion 11 of the housing 10 is referred to as the thickness direction (first direction) Z. The thickness direction Z can also be said to be a direction perpendicular to the mounting surface of the base portion 11 on which optical components are mounted. The direction in which the multiple laser light emitters 20 are arranged is referred to as the arrangement direction (second direction) X. The arrangement direction X can also be said to be a direction along the long side of the rectangular base portion 11. The direction in which the laser light LB is emitted from the multiple laser light emitters 20 is referred to as the depth direction (third direction) Y. The depth direction Y can also be said to be a direction along the short side of the rectangular base portion 11. The thickness direction Z, the arrangement direction X, and the depth direction Y intersect with each other and are typically perpendicular to each other.

The semiconductor laser module 1 is configured by assembling a plurality of optical components to the base portion 11 of the housing 10. Specifically, the semiconductor laser module 1 includes a plurality of laser light emitters 20 provided on one side of the base portion 11 in the depth direction Y, a plurality of reflecting mirrors 50 provided on the first mounting surface 11a of the base portion 11 and facing the plurality of laser light emitters 20 along the depth direction Y, a plurality of optical path changing prisms 40 provided between the plurality of laser light emitters 20 and the plurality of reflecting mirrors 50, a folding prism 60 provided on one side of the arrangement direction X of the base portion 11 and facing the plurality of reflecting mirrors 50 along the arrangement direction X, and a compression prism 70 and a condenser lens 80 provided on the second mounting surface 11b of the base portion 11. The semiconductor laser module 1 will be described in detail below.

The housing 10 is to which optical components are attached. As shown in FIG. 1 and FIG. 2, the housing 10 is composed of a base portion 11, four side walls 12 to 15, and a fixing plate 16. The base portion 11 is formed in a plate shape, has a predetermined thickness in the thickness direction Z, and is formed in a substantially rectangular shape when viewed from the thickness direction Z. The base portion 11 has a first mounting surface 11a for mounting an optical component on one side in the thickness direction Z, and a second mounting surface 11b for mounting another optical component on the other side in the thickness direction Z. The periphery of the base portion 11 is surrounded by the side walls 12 to 15. For example, the base portion 11 has a side wall portion 12 at one end in the depth direction Y, a side wall portion 13 at the other end in the depth direction Y, a side wall portion 14 at one end in the arrangement direction X, and a side wall portion 15 at the other end in the arrangement direction X, and these side walls 12 to 15 are erected along the thickness direction Z. The base portion 11 is surrounded by the four side walls 12 to 15 and is located in the center of the four side walls 12 to 15 in the thickness direction Z. As a result, the base portion 11 and the four side walls 12 to 15 form a first space P on one side in the thickness direction Z and a second space Q on the other side in the thickness direction Z. That is, the first space P is a space surrounded by the surface on one side of the base portion 11 (first mounting surface 11a) and the parts of the four side walls 12 to 15 on one side in the thickness direction Z. The second space Q is a space surrounded by the surface on the other side of the base portion 11 (second mounting surface 11b) and the parts of the four side walls 12 to 15 on the other side in the thickness direction Z. In this way, the base portion 11 divides the first space P and the second space Q with respect to the thickness direction Z.

As shown in FIG. 3 and the like, the side wall portion 12 has a recess 12a. The recess 12a is recessed toward the base portion 11 along the depth direction Y, and is provided with a plurality of laser light emitters 20 and optical path changing prisms 40, which will be described later. The recess 12a has a plurality of fixing portions 12b and an opening 12c. Each of the fixing portions 12b is formed in a groove shape along the thickness direction Z, and is arranged in a row along the arrangement direction X. Each of the fixing portions 12b fixes one optical path changing prism 40. The opening 12c is a through hole that penetrates the side wall portion 12 along the depth direction Y, and is provided at the bottom of the recess 12a. The opening 12c is formed in an elongated hole shape along the arrangement direction X at the bottom of the recess 12a, and this elongated hole is formed from one side to the other side of the arrangement direction X. The opening 12c communicates between the first space P on one side of the side wall 12 in the depth direction Y and the space on the other side of the side wall 12 in the depth direction Y (the space on the recess 12a side). The opening 12c faces along the depth direction Y a portion (the end on the first space P side in the thickness direction Z) of each of the multiple optical path changing prisms 40 fixed to the recess 12a of the side wall 12 by the multiple fixing parts 12b. This allows the multiple optical path changing prisms 40 to emit laser light LB into the first space P through the opening 12c, as described below.

3 and the like, the side wall portion 14 has a recess 14a. The recess 14a is recessed toward the base portion 11 along the arrangement direction X, and a folded prism 60, which will be described later, is provided therein. The recess 14a has a first opening 14b and a second opening 14c. The first opening 14b is a through hole that penetrates the side wall portion 14 along the arrangement direction X, and is provided at the bottom of the recess 14a. The first opening 14b is formed in an elongated hole shape along the depth direction Y at the bottom of the recess 14a. The first opening 14b communicates with the first space P on one side of the arrangement direction X of the side wall portion 14 and the space on the other side of the arrangement direction X of the side wall portion 14 (the space on the recess 14a side). The second opening 14c is a through hole that penetrates the side wall portion 14 along the arrangement direction X, and is provided at the bottom of the recess 14a. The second opening 14c is formed in a long hole shape along the depth direction Y at the bottom of the recess 14a. The second opening 14c communicates with the second space Q on one side of the arrangement direction X of the sidewalls 14 and the space on the other side of the arrangement direction X of the sidewalls 14 (the space on the recess 14a side). The first opening 14b and the second opening 14c are arranged side by side along the thickness direction Z. The first reflection surface 61 of the folding prism 60 is aligned with the first opening 14b, and the second reflection surface 62 of the folding prism 60 is aligned with the second opening 14c. As a result, the folding prism 60 reflects the laser light LB incident from the first space P through the first opening 14b to the second reflection surface 62 side by the first reflection surface 61, as described later, and can emit the laser light LB reflected by the second reflection surface 62 to the second space Q through the second opening 14c.

As shown in FIG. 2, the side wall portion 15 has an opening 15a. The opening 15a is a through hole that penetrates the side wall portion 15 along the arrangement direction X, and is formed in a circular shape. The opening 15a communicates with the second space portion Q on one side of the side wall portion 15 in the arrangement direction X and the space portion on the other side of the side wall portion 15 in the arrangement direction X. The opening 15a is provided with an external emission portion 90, which will be described later.

The fixing plate 16 fixes the laser light emitters 20 in a positioned state. The fixing plate 16 is provided on the side wall portion 12, and covers the entire recess 12a of the side wall portion 12 when provided on the side wall portion 12. The fixing plate 16 is provided with a plurality of openings 16a. The plurality of openings 16a fix the laser light emitters 20 in a state where each of the laser light emitters 20 is positioned. Each of the plurality of openings 16a is formed in a circular shape and penetrates along the depth direction Y. The plurality of openings 16a are arranged in two rows along the arrangement direction X. When the fixing plate 16 is assembled to the side wall portion 12, each of the plurality of laser light emitters 20 is inserted into each of the plurality of openings 16a. As a result, the fixing plate 16 can fix the plurality of laser light emitters 20 in a state where they are properly positioned on the side wall portion 12 of the housing 10. At this time, some of the laser light emitters 20 are housed in the recesses 12a of the side wall 12.

The multiple laser light emitters 20 emit laser light LB. As shown in FIG. 3, each laser light emitter 20 includes a semiconductor laser element 21, a cover 22, and a collimating lens 23 (see FIG. 6).

The semiconductor laser element 21 is an element that emits laser light LB, and is, for example, a laser diode having a single light-emitting point. The semiconductor laser element 21 is, for example, a laser diode having an oscillation wavelength in the short wavelength range of 500 nm or less that has excellent absorption in metals. The semiconductor laser element 21 emits laser light LB when a current is applied. The laser light LB emitted from the semiconductor laser element 21 propagates while spreading along the fast axis direction and the slow axis direction that intersects (is perpendicular to) the fast axis direction. Here, the fast axis is the stacking direction of the active layer of the semiconductor laser, and is the direction in which the spread angle of the laser light LB is larger. The slow axis is the direction in which the spread angle of the laser light LB is smaller than that of the fast axis.

The cover 22 covers the semiconductor laser element 21. The cover 22 is formed of, for example, a metal, and as shown in FIG. 4, includes a base 22a to which the semiconductor laser element 21 is attached, a cylindrical tube portion 22b extending from the base 22a along the emission direction (depth direction Y) of the semiconductor laser element 21, and a cover lens (not shown) provided at an opening of the tube portion 22b on the opposite side to the base 22a and closing the opening. The cover 22 covers the semiconductor laser element 21 in an airtight sealed state, and protects the semiconductor laser element 21. As a result, the cover 22 can suppress a decrease in the reliability of the semiconductor laser element 21.

The collimating lens 23 adjusts the diffused light to parallel light. The collimating lens 23 is provided in the cylindrical portion 22b of the cover 22, and is disposed on the outer side of the cover lens in the cylindrical portion 22b (the opposite side to the semiconductor laser element 21). The collimating lens 23 adjusts the laser light LB emitted from the semiconductor laser element 21 to parallel light, that is, collimates it.

The multiple laser light emitters 20 configured as described above are provided at positions capable of emitting laser light LB in the first space P. The multiple laser light emitters 20 are arranged in a line along the direction X at one end (side wall portion 12) of the base portion 11 of the housing 10 in the depth direction Y. The multiple laser light emitters 20 are assembled to the side wall portion 12 of the housing 10, for example, in a state where they are positioned at the multiple openings 16a of the fixing plate 16. Here, the multiple laser light emitters 20 are configured to include a first laser light emitter group 20A and a second laser light emitter group 20B, as shown in FIG. 3. The first laser light emitter group 20A and the second laser light emitter group 20B are each configured of approximately the same number of laser light emitters 20. In this example, the first laser light emitter group 20A is composed of 13 laser light emitters 20, and the second laser light emitter group 20B is composed of 12 laser light emitters 20. In the first laser light emitter group 20A, a plurality of laser light emitters 20 are arranged along the arrangement direction X. In the second laser light emitter group 20B, another plurality of laser light emitters 20 are arranged along the arrangement direction X. The second laser light emitter group 20B is located on one side of the first laser light emitter group 20A along the thickness direction Z. In other words, the plurality of laser light emitters 20 are formed in two stages along the thickness direction Z, that is, the first laser light emitter group 20A and the second laser light emitter group 20B. The plurality of laser light emitters 20 are arranged in a staggered manner with the gap between adjacent laser light emitters 20 as narrow as possible.

In the multiple laser light emitters 20, the first laser light emitter group 20A and the second laser light emitter group 20B emit laser light LB toward the reflection mirror 50 along the depth direction Y. At this time, as shown in Figures 4 and 6, the first laser light emitter group 20A and the second laser light emitter group 20B have the optical axis of each first laser light emitter 20a of the first laser light emitter group 20A and the optical axis of each second laser light emitter 20b of the second laser light emitter group 20B alternately shifted along the arrangement direction X. In other words, when viewed from the thickness direction Z, the optical axis of the first laser light emitter 20a and the optical axis of the second laser light emitter 20b do not overlap, and the optical axis of the first laser light emitter 20a and the optical axis of the second laser light emitter 20b are alternately positioned at equal intervals along the arrangement direction X. In other words, when viewed from the thickness direction Z, the optical axis of the second laser light emitter 20b is located between the optical axis of the adjacent first laser light emitter 20a and the optical axis of the first laser light emitter 20a. By arranging the laser light emitters 20 in two stages in this way, it is possible to prevent the width of the laser light emitters 20 in the arrangement direction X from becoming too long.

The multiple laser light emitters 20 are arranged in a positional relationship such that the first axis directions of the multiple emitted laser beams LB are aligned along the arrangement direction X. In the multiple laser light emitters 20, the semiconductor laser element 21 is covered by the cover 22, so the first axis direction can be adjusted by rotating the cover 22 around the optical axis, and the first axis direction can be adjusted more easily than in the case where the semiconductor laser element 21 is provided on a substrate. In addition, since the multiple laser light emitters 20 are arranged in a positional relationship such that the first axis directions of the multiple emitted laser beams LB are aligned along the arrangement direction X, there is no need to change the first axis direction using a dedicated optical component, for example, and the number of dedicated optical components can be reduced.

The water-cooling mechanism 30 cools the multiple laser light emitters 20. The water-cooling mechanism 30 has a housing 31 and a water-cooling pipe 32.

The housing 31 is formed of a metal with high thermal conductivity and is configured in a rectangular parallelepiped shape. The housing 31 has a mounting surface 31a (see FIG. 3). The mounting surface 31a is a portion on which the multiple laser light emitters 20 are mounted. The mounting surface 31a is provided with multiple through holes 31b. The electric wires of the multiple laser light emitters 20 are inserted into each of the multiple through holes 31b. The housing 31 is fixed in a state in which the mounting surface 31a on which the multiple laser light emitters 20 are mounted is in contact with a metallic fixing plate 16 that positions the multiple laser light emitters 20. At this time, the multiple laser light emitters 20 mounted on the mounting surface 31a are inserted into each of the multiple openings 16a of the fixing plate 16 and positioned. In the housing 31, heat generated by the multiple laser light emitters 20 is conducted to the metallic fixing plate 16, and the heat conducted to the fixing plate 16 is conducted to the housing 31.

The water-cooled pipe 32 is a pipe through which cooling water flows. The water-cooled pipe 32 discharges heat from the multiple laser light emitters 20 that is conducted to the housing 31 to the outside by the flow of cooling water, thereby cooling the multiple laser light emitters 20.

The multiple optical path changing prisms 40 change the optical path of the laser light LB, and change the optical path of at least some of the laser light LB emitted from the multiple laser light emitters 20. As shown in FIG. 3, the multiple optical path changing prisms 40 are fixed to multiple fixing parts 12b of the recess 12a provided in the side wall part 12 of the housing 10. The optical path changing prisms 40 are arranged in a positional relationship such that the first axis direction of each of the multiple laser lights LB aligned by the optical path changing prisms 40 is along the arrangement direction X. As shown in FIG. 3 and FIG. 4, the multiple optical path changing prisms 40 are formed in a periscope shape, and are formed in the shape of an oblique prism consisting of a parallelogram whose side surface is obliquely intersected with the top surface and the bottom surface. The multiple optical path changing prisms 40 have a first reflecting surface 41, a second reflecting surface 42, and a main body part 43. The main body part 43 is formed of a material that transmits the laser light LB, such as optical glass.

The first reflecting surface 41 is provided on the bottom surface of one side of the main body 43 in the thickness direction Z (the second laser light emitter group 20B side). The first reflecting surface 41 is formed at an angle of approximately 45 degrees on the bottom surface of one side of the main body 43 in the thickness direction Z, and is configured to totally reflect the laser light LB. The first reflecting surface 41 is provided at an angle with respect to the depth direction Y and the thickness direction Z, and is arranged facing the laser light emitter 20 of the second laser light emitter group 20B along the depth direction Y. The first reflecting surface 41 reflects the laser light LB emitted from the laser light emitter 20 of the second laser light emitter group 20B along the depth direction Y toward the second reflecting surface 42 along the thickness direction Z.

The second reflecting surface 42 is provided on the top surface of the other side in the thickness direction Z of the main body 43 (the first laser light emitter group 20A side). The second reflecting surface 42 is formed on the top surface of the other side in the thickness direction Z of the main body 43 at an angle of approximately 45 degrees and parallel to the first reflecting surface 41, so that the second reflecting surface 42 totally reflects the laser light. That is, the second reflecting surface 42 is provided at an angle with respect to the depth direction Y and the thickness direction Z, and is formed parallel to the first reflecting surface 41. The second reflecting surface 42 reflects the laser light LB reflected by the first reflecting surface 41 along the thickness direction Z toward the multiple reflecting mirrors 50 along the depth direction Y.

The multiple optical path changing prisms 40 configured in this manner change the optical path of the laser light LB emitted from the multiple second laser light emitters 20b of the second laser light emitter group 20B. For example, as shown in FIG. 4, the multiple optical path changing prisms 40 reflect the second laser light LB2 emitted from the multiple second laser light emitters 20b of the second laser light emitter group 20B along the depth direction Y to the second reflecting surface 42 side along the thickness direction Z by the first reflecting surface 41, and guide it to the position of the first laser light LB1 emitted from the first laser light emitter 20a of the first laser light emitter group 20A. Then, the multiple optical path changing prisms 40 reflect the second laser light LB2 guided to the position of the first laser light LB1 to the multiple reflecting mirrors 50 side along the depth direction Y by the second reflecting surface 42, and form the multiple aligned laser lights LB in which the first laser light LB1 and the second laser light LB2 are aligned in a row along the direction X.

The multiple reflection mirrors 50 reflect the laser light LB. As shown in FIG. 3, the multiple reflection mirrors 50 are provided in the first space P and mounted on the first mounting surface 11a of the base portion 11. The multiple reflection mirrors 50 are arranged along the arrangement direction X and are arranged in a stepped manner along the depth direction Y from the multiple laser light emitters 20 side toward the opposite side of the multiple laser light emitters 20. For example, the multiple reflection mirrors 50 are positioned such that each of the reflection mirrors 50 is shifted along the depth direction Y. The reflection mirrors 50 are arranged in a positional relationship such that the first axis direction of each of the reflected multiple laser lights LB is along the depth direction Y. The multiple reflection mirrors 50 are provided in the same number as the multiple laser light emitters 20, and each has a main body 51 and a reflection surface 52.

The main body 51 is formed in the shape of a triangular prism, and has a triangular bottom surface, a triangular top surface, and three rectangular side surfaces. The bottom surface of the main body 51 is fixed to the first mounting surface 11a of the base 11. The main body 51 has three side surfaces, one of which has a reflective surface 52 formed on it.

The reflecting surface 52 reflects the laser light LB. The reflecting surface 52 is formed by forming a dielectric multilayer film on the side of the main body 51. The reflecting surfaces 52 are arranged along the arrangement direction X, and are arranged in a stepped manner along the depth direction Y from the side of the laser light emitters 20 to the opposite side of the laser light emitters 20. For example, the reflecting surfaces 52 are positioned such that each reflecting surface 52 is shifted from the other reflecting surfaces 52 along the depth direction Y. The reflecting surfaces 52 are arranged facing each of the laser light emitters 20 along the depth direction Y, and facing the folding prism 60 along the arrangement direction X. The reflecting surfaces 52 are inclined at about 45° with respect to the depth direction Y and at about 45° with respect to the arrangement direction X, and reflect the laser light LB at an angle of about 90°. The reflecting surfaces 52 are arranged in a positional relationship such that the intervals between the laser light LB before reflection become narrower after reflection. The multiple reflecting surfaces 52 reflect the multiple aligned laser beams LB emitted from the multiple laser beam emitters 20 along the depth direction Y and formed by the optical path changing prism 40 toward the folding prism 60 along the alignment direction X.

The folding prism 60 folds the laser light LB to change the optical path. The folding prism 60 is provided at one end (side wall 14) of the base 11 of the housing 10 in the arrangement direction X, and is disposed in a recess 14a formed in the side wall 14 of the housing 10. The folding prism 60 is provided in a positional relationship in which the first axis direction of each of the folded laser light LB is along the depth direction Y. As shown in Figures 3 and 5, the folding prism 60 is formed in the shape of a quadrangular prism with a pair of faces that are trapezoidal. The folding prism 60 has a first reflecting surface 61, a second reflecting surface 62, and a main body 63.

The main body 63 is formed of a material that transmits the laser light LB, such as optical glass. The main body 63 has a first trapezoidal surface portion 63a, a second trapezoidal surface portion 63b, a first parallel surface portion 63c, a second parallel surface portion 63d, a first inclined surface portion 63e, and a second inclined surface portion 63f. The first trapezoidal surface portion 63a is formed in a trapezoidal shape, faces the second trapezoidal surface portion 63b along the depth direction Y, and is provided parallel to the second trapezoidal surface portion 63b. The second trapezoidal surface portion 63b is formed in a trapezoidal shape, faces the first trapezoidal surface portion 63a along the depth direction Y, and is provided parallel to the first trapezoidal surface portion 63a. The first trapezoidal surface portion 63a and the second trapezoidal surface portion 63b have the same trapezoidal shape. The first parallel surface portion 63c is formed in a rectangular shape, faces the second parallel surface portion 63d along the arrangement direction X, and is provided parallel to the second parallel surface portion 63d. The second parallel surface portion 63d is formed in a rectangular shape smaller than the first parallel surface portion 63c, faces the first parallel surface portion 63c along the arrangement direction X, and is provided parallel to the first parallel surface portion 63c. The first inclined surface portion 63e is formed in a rectangular shape, faces the second inclined surface portion 63f along the thickness direction Z, and is provided at an incline with respect to the arrangement direction X and the thickness direction Z. The second inclined surface portion 63f is formed in a rectangular shape, faces the first inclined surface portion 63e along the thickness direction Z, and is provided at an incline with respect to the arrangement direction X and the thickness direction Z. The first inclined surface portion 63e and the second inclined surface portion 63f have the same shape, and are arranged so that the distance between them in the thickness direction Z gradually increases from the second parallel surface portion 63d side toward the first parallel surface portion 63c side.

The first reflecting surface 61 is provided on the first inclined surface portion 63e of the main body portion 63. The first reflecting surface 61 is formed at an angle of 45 degrees on the first inclined surface portion 63e of the main body portion 63 to form a total reflecting surface. The first reflecting surface 61 is aligned with the first opening 14b of the recess 14a of the housing 10. The first reflecting surface 61 reflects the laser light LB that is reflected by the multiple reflecting mirrors 50 along the arrangement direction X and passes through the first opening 14b toward the second reflecting surface 62 along the thickness direction Z.

The second reflecting surface 62 is provided on the second inclined surface portion 63f of the main body portion 63. The second reflecting surface 62 is formed at an angle of 45 degrees to the second inclined surface portion 63f of the main body portion 63 and at a right angle to the first reflecting surface 61, thereby forming a total reflection surface. The second reflecting surface 62 is aligned with the second opening 14c of the recess 14a of the housing 10. The second reflecting surface 62 reflects the laser light LB reflected by the first reflecting surface 61 along the thickness direction Z toward the compression prism 70 along the arrangement direction X. The laser light LB reflected by the second reflecting surface 62 passes through the second opening 14c and propagates toward the compression prism 70.

As shown in FIG. 5, the folding prism 60 configured in this manner folds back the laser light LB emitted from the multiple laser light emitters 20 into the first space P and reflected by the multiple reflecting mirrors 50 toward one side of the arrangement direction X from the first space P to the second space Q, and directs it toward the other side of the arrangement direction X (the compression prism 70 side) in the second space Q.

The compression prism 70 compresses the laser light LB. For example, the compression prism 70 may be a set of two anamorphic prisms. The compression prism 70 has a first compression prism 71 and a second compression prism 72.

When viewed from the thickness direction Z, the first compression prism 71 is formed in the shape of a right-angled triangle. As shown in FIG. 2, the first compression prism 71 is provided in the second space Q, mounted on the second mounting surface 11b of the base portion 11, and fixed by a fastener 73. The first compression prism 71 has an entrance surface 71a, an exit surface 71b, and a main body portion 71c. The main body portion 71c is formed from a material that transmits the laser light LB, such as optical glass.

The incident surface 71a is the part where the laser light LB is incident, and is provided on one side of the main body part 71c in the arrangement direction X (the folding prism 60 side) and formed parallel to the depth direction Y. The incident surface 71a receives the laser light LB emitted from the folding prism 60 along the arrangement direction X in a straight line without refracting the laser light LB. The laser light LB incident on the incident surface 71a propagates through the main body part 71c towards the exit surface 71b.

The exit surface 71b is a portion that emits the laser light LB, and is provided on the other side of the arrangement direction X of the main body portion 71c (the second compression prism 72 side) and intersects with the depth direction Y. The exit surface 71b refracts the laser light LB that has propagated through the main body portion 71c in a state of parallel light and emits it to the second compression prism 72.

When viewed from the thickness direction Z, the second compression prism 72 is formed in a right-angled triangle shape and is smaller than the first compression prism 71. The second compression prism 72 is provided in the second space Q, mounted on the second mounting surface 11b of the base portion 11, and arranged at a stage subsequent to the first compression prism 71. The second compression prism 72 is arranged, for example, between the first compression prism 71 and the focusing lens 80. The second compression prism 72 is fixed to the second mounting surface 11b of the base portion 11 by a fastener 74. The second compression prism 72 has an entrance surface 72a, an exit surface 72b, and a main body portion 72c. The main body portion 72c is formed from a material that transmits the laser light LB, such as optical glass.

The incident surface 72a is the part where the laser light LB is incident, and is provided on one side of the arrangement direction X of the main body portion 72c (the first compression prism 71 side) and intersects with the depth direction Y. The incident surface 72a receives the laser light LB emitted from the first compression prism 71 in a straight line without refracting the laser light LB. The laser light LB incident on the incident surface 72a propagates through the main body portion 72c toward the exit surface 72b.

The exit surface 72b is a portion that emits the laser light LB, and is provided on the other side (the condenser lens 80 side) of the arrangement direction X of the main body portion 72c, and intersects with the depth direction Y. The exit surface 72b refracts the laser light LB that has propagated through the main body portion 72c in a state of parallel light and emits it to the condenser lens 80.

The first compression prism 71 and the second compression prism 72 can change the compression ratio of the laser light LB by adjusting the relative positional relationship (distance, angle). In this embodiment, the compression ratio of the laser light LB is approximately three times. The first compression prism 71 compresses the multiple laser lights LB emitted from the folding prism 60 in a state of parallel light along the depth direction Y, and emits the compressed multiple laser lights LB to the second compression prism 72. The second compression prism 72 compresses the multiple laser lights LB emitted from the first compression prism 71 in a state of parallel light along the depth direction Y, and emits the compressed multiple laser lights LB to the focusing lens 80.

The focusing lens 80 focuses the laser light LB. For example, a cylindrical lens can be used as the focusing lens 80. The focusing lens 80 has a first focusing lens 81 and a second focusing lens 82 as a focusing optical system.

The first focusing lens 81 focuses the multiple laser beams LB along the first axis direction. The first focusing lens 81 is provided in the second space Q and fixed to the second mounting surface 11b of the base portion 11. The first focusing lens 81 is provided in a positional relationship such that the multiple laser beams LB emitted from the compression prism 70 are focused along the depth direction Y parallel to the respective first axis directions. The first focusing lens 81 has a curved surface portion 81a, a flat surface portion 81b, and a main body portion 81c. The main body portion 81c is formed from a material that transmits the laser beams LB, such as optical glass.

The curved surface portion 81a is provided on one side (compression prism 70 side) of the main body portion 81c in the arrangement direction X. When viewed from the thickness direction Z, the curved surface portion 81a has a convex curved shape (e.g., a circular arc shape, an elliptical arc shape, a parabolic shape). The curved surface portion 81a refracts the laser light LB emitted from the compression prism 70 and focuses it along the depth direction Y parallel to the fast axis direction. The laser light LB focused by the curved surface portion 81a propagates through the main body portion 81c toward the flat portion 81b.

The flat portion 81b is provided on the other side (the second focusing lens 82 side) of the main body portion 81c in the arrangement direction X. When viewed from the thickness direction Z, the flat portion 81b has a flat shape that is parallel to the depth direction Y.

The second focusing lens 82 focuses the laser light LB along the slow axis direction. The second focusing lens 82 is provided in the second space Q, mounted on the second mounting surface 11b of the base portion 11, and disposed downstream of the first focusing lens 81. The second focusing lens 82 is disposed, for example, between the first focusing lens 81 and the external emission portion 90. The second focusing lens 82 has a curved surface portion 82a, a flat surface portion 82b, and a main body portion 82c. The main body portion 82c is formed from a material that transmits the laser light LB, such as optical glass.

The curved surface portion 82a is provided on one side (first focusing lens 81 side) of the main body portion 82c in the arrangement direction X. When viewed from the depth direction Y, the curved surface portion 82a has a convex curved shape (e.g., a circular arc shape, an elliptical arc shape, a parabolic shape). The curved surface portion 82a refracts the laser light LB emitted from the first focusing lens 81 and focuses it along the thickness direction Z parallel to the slow axis direction. The laser light LB focused by the curved surface portion 82a propagates through the main body portion 82c toward the flat portion 82b.

The planar portion 82b is provided on the other side (external emission portion 90 side) of the main body portion 82c in the arrangement direction X. When viewed from the thickness direction Z, the planar portion 82b has a planar shape that is parallel to the depth direction Y.

The external emission unit 90 emits the laser light LB to the outside. The external emission unit 90 has a main body tube portion 91 and a tip holding portion 92.

The main body tube portion 91 is formed in a cylindrical shape, and one end in the arrangement direction X is fitted into the opening 15a of the housing 10 (see FIG. 2). The main body tube portion 91 is provided on its inside with a holding member (not shown) that holds the optical fiber 100. This holding member holds the end of the optical fiber 100 in a positional relationship in which the laser light LB focused by the focusing lens 80 is incident on the end of the optical fiber 100.

The tip holding section 92 holds the optical fiber 100. The tip holding section 92 is provided at the other end of the main body tube section 91 in the arrangement direction X, and holds the optical fiber 100 extending from the other end side of the main body tube section 91 in the arrangement direction X to the outside. The external emission section 90 configured in this manner emits the multiple laser beams LB focused by the focusing lens 80 to the outside via the optical fiber 100.

Next, a propagation example of the laser light LB will be described. FIG. 6 is a schematic plan view showing a propagation example of the laser light LB in the first space P according to the embodiment. FIG. 7 is a schematic plan view showing a propagation example of the laser light LB in the second space Q according to the embodiment. As shown in FIG. 6, the plurality of laser light emitters 20 emit the plurality of laser lights LB to the first space P along the depth direction Y. The plurality of laser light emitters 20 emit the first laser light LB1 from the plurality of first laser light emitters 20a of the first laser light emitter group 20A in a state in which the respective first axis directions are aligned along the arrangement direction X, and emit the second laser light LB2 from the plurality of second laser light emitters 20b of the second laser light emitter group 20B in a state in which the respective first axis directions are aligned along the arrangement direction X. The second laser light LB2 emitted from the second laser light emitters 20b is guided along the thickness direction Z by each of the optical path changing prisms 40 to the position of the first laser light LB1 emitted from the first laser light emitters 20a of the first laser light emitter group 20A. The first laser light LB1 and the second laser light LB2 are aligned in a row along the arrangement direction X with their fast axis directions aligned along the arrangement direction X. The aligned laser light LB aligned in a row by the optical path changing prisms 40 is incident on the reflection mirrors 50 along the depth direction Y with their fast axis directions aligned along the arrangement direction X. The laser light LB incident on the reflection mirrors 50 along the depth direction Y is reflected by the reflection mirrors 50 along the arrangement direction X. The multiple laser beams LB reflected by the multiple reflecting mirrors 50 are folded back by the folding prism 60 with their respective first axis directions aligned along the depth direction Y, and are emitted to the compression prism 70 in the second space Q (see FIG. 7). The multiple laser beams LB emitted to the compression prism 70 are compressed by the compression prism 70. The multiple laser beams LB compressed by the compression prism 70 are emitted to the condenser lens 80 with their respective first axis directions aligned along the depth direction Y. The multiple laser beams LB emitted to the condenser lens 80 are condensed along the depth direction Y by the condenser lens 80 with their respective first axis directions aligned along the depth direction Y. The multiple laser beams LB condensed by the condenser lens 80 are emitted to the external emission section 90.

As described above, the semiconductor laser module 1 according to the embodiment includes a base portion 11, a plurality of laser light emitters 20, a folding prism 60, a first condensing lens 81, and an external emission portion 90. The base portion 11 is formed in a plate shape and divides the first space portion P and the second space portion Q in the thickness direction Z. The plurality of laser light emitters 20 have a semiconductor laser element 21 that emits laser light LB and a cover 22 that covers the semiconductor laser element 21, and are provided at a position where the laser light LB can be emitted into the first space portion P. The folding prism 60 is provided at an end portion on one side of the arrangement direction X of the base portion 11, and folds back the plurality of laser lights LB emitted from the plurality of laser light emitters 20 to the first space portion P and toward one side of the arrangement direction X into the second space portion Q and toward the other side of the arrangement direction X. The first condensing lens 81 is provided in the second space portion Q and condenses the plurality of laser lights LB folded back by the folding prism 60. The external emission section 90 emits the multiple laser beams LB focused by the first focusing lens 81 to the outside from the second space section Q.

With this configuration, the semiconductor laser module 1 covers the semiconductor laser element 21 with the cover 22, so that the reliability of the semiconductor laser element 21 can be ensured. In addition, when the semiconductor laser module 1 uses a plurality of laser light emitters 20 with the semiconductor laser element 21 covered with the cover 22, it is difficult to arrange the collimator lens 23 in close proximity to the semiconductor laser element 21. Therefore, the beam size of the laser light LB emitted from the collimator lens 23 becomes large, and the distance required to focus the laser light beam becomes long, and the overall length of the semiconductor laser module 1 tends to become long. However, since the folding prism 60 folds the plurality of laser lights LB back into the second space Q of the base portion 11, the overall length of the semiconductor laser module 1 can be shortened compared to the case where the plurality of laser lights LB are not folded back, and as a result, the module can be prevented from becoming large. As a result, the semiconductor laser module 1 can suppress warping and twisting of the base portion 11, so that the output power of the laser light LB can be stabilized and a decrease in reliability can be suppressed.

The semiconductor laser module 1 further includes a compression prism 70 that is provided in the second space Q, compresses the multiple laser beams LB reflected by the reflecting mirror 50 and folded back by the folding prism 60 in a parallel light state, and emits the compressed multiple laser beams LB to the first focusing lens 81. With this configuration, the semiconductor laser module 1 can reduce the size of the first focusing lens 81 compared to a case where the compression prism 70 is not provided, and therefore the focal length of the first focusing lens 81 can be shortened, and as a result, the module can be prevented from becoming large. In addition, the semiconductor laser module 1 can reduce the size of the relatively expensive first focusing lens 81, and therefore the component costs can be reduced.

The semiconductor laser module 1 further includes a reflection mirror 50 that is provided in the first space P and reflects the laser light LB. The multiple laser light emitters 20 are provided in a line along the arrangement direction X at one end of the base portion 11 in the depth direction Y, and emit multiple laser lights LB into the first space P along the depth direction Y. The reflection mirror 50 reflects the multiple laser lights LB emitted from the multiple laser light emitters 20 toward the folding prism 60 along the arrangement direction X. With this configuration, if the semiconductor laser module 1 does not include the reflection mirror 50, it is necessary to provide the multiple laser light emitters 20 on one side of the arrangement direction X of the base portion 11 (the side opposite the folding prism 60), in which case the width length of the base portion 11 in the arrangement direction X may increase, and the module may become larger. However, by providing the reflection mirror 50, the width length of the base portion 11 in the arrangement direction X can be prevented from increasing, and as a result, the module can be prevented from becoming larger.

In the semiconductor laser module 1, the multiple laser light emitters 20 are arranged in a positional relationship such that the first axis direction of each of the multiple emitted laser lights LB is along the arrangement direction X. The reflecting mirror 50 is arranged in a positional relationship such that the first axis direction of each of the multiple reflected laser lights LB is along the depth direction Y. The folding prism 60 is arranged in a positional relationship such that the first axis direction of each of the multiple folded laser lights LB is along the depth direction Y. The first focusing lens 81 is arranged in a positional relationship such that the multiple laser lights LB reflected by the folding prism 60 are focused along the depth direction Y parallel to the first axis direction. With this configuration, the semiconductor laser module 1 does not need to change the first axis direction to a desired direction, for example, by a dedicated optical component. In other words, the semiconductor laser module 1 does not need to change the first axis direction of the laser light LB emitted by the multiple laser light emitters 20 to the focusing direction (depth direction Y) focused by the first focusing lens 81 using a dedicated optical component, so the optical components can be reduced.

In the semiconductor laser module 1, the multiple laser light emitters 20 include a first laser light emitter group 20A consisting of multiple laser light emitters 20 arranged along the arrangement direction X, and a second laser light emitter group 20B consisting of other multiple laser light emitters 20 arranged along the arrangement direction X and located on one side of the first laser light emitter group 20A along a thickness direction Z intersecting the arrangement direction X. The multiple laser light emitters 20 include the first laser light emitter group 20A and the second laser light emitter group 20B that emit laser light LB along the depth direction Y, and the optical axis of each first laser light emitter 20a of the first laser light emitter group 20A and the optical axis of each second laser light emitter 20b of the second laser light emitter group 20B are alternately shifted along the arrangement direction X. The optical path changing prism 40 is disposed facing each of the laser light emitters 20 of the second laser light emitter group 20B along the depth direction Y, and guides the multiple second laser lights LB2 emitted from each of the laser light emitters 20 of the second laser light emitter group 20B along the depth direction Y to the positions of the multiple first laser lights LB1 emitted from each of the laser light emitters 20 of the first laser light emitter group 20A along the thickness direction Z, forming multiple aligned laser lights LB in which the multiple first laser lights LB1 and the multiple second laser lights LB2 are aligned in a row along the direction X.

With this configuration, the semiconductor laser module 1 covers the semiconductor laser element 21 with the cover 22, so the laser light emitter 20 is larger than in a conventional semiconductor laser module in which the semiconductor laser element 21 is not covered with the cover 22 and is provided on a substrate. When the laser light emitters 20 are arranged side by side, the length of the multiple laser light emitters 20 in the arrangement direction X tends to be long. However, by arranging the multiple laser light emitters 20 in two stages, the module can be prevented from becoming large. Furthermore, even when the multiple laser light emitters 20 are arranged in two stages, the semiconductor laser module 1 forms multiple laser beams LB aligned in a row by the optical path changing prism 40, so that the multiple laser beams LB can be properly focused.

In the semiconductor laser module 1, the reflection mirror 50 is disposed opposite the multiple laser light emitters 20 along the depth direction Y, and reflects the aligned multiple laser light LB formed by the optical path changing prism 40 along the alignment direction X. The first focusing lens 81 focuses the aligned multiple laser light LB reflected by the reflection mirror 50. With this configuration, the semiconductor laser module 1 can prevent the module from becoming too large.

[Modifications]
In the above description, the semiconductor laser module 1 is described as having the compression prism 70, but the present invention is not limited thereto, and the semiconductor laser module 1 may not have the compression prism 70. In this case, the semiconductor laser module 1 may adjust the size of the condenser lens 80 to condense light.

The semiconductor laser module 1 has been described as having a reflecting mirror 50, but is not limited thereto and may not have a reflecting mirror 50. In this case, the semiconductor laser module 1 may have multiple laser light emitters 20 arranged on one side of the arrangement direction X (the side opposite the folding prism 60).

An example has been described in which the multiple laser light emitters 20, the optical path changing prism 40, the reflecting mirror 50, the folding prism 60, and the first focusing lens 81 are arranged in a positional relationship such that the first axis direction is aligned along a specified direction, but this is not limited to this, and the first axis direction may be changed by optical components.

The housing 10 may further include a cover member that closes the first space P, the second space Q, and the recess 14a.

The multiple optical path changing prisms 40 and the folding prisms 60 are not limited to prisms, but may have other configurations such as a combination of reflective members (mirrors).

The compression prism 70 has been described as an example in which an anamorphic prism is applied, but this is not limited thereto, and other compression optical systems may also be applied.

The focusing lens 80 has been described as being a cylindrical lens, but is not limited to this and other focusing optical systems may be used.

1 Semiconductor laser module 11 Base portion 20 Laser beam emitter 20A First laser beam emitter group 20B Second laser beam emitter group 21 Semiconductor laser element 22 Cover 40 Optical path changing prism (optical path changing optical system)
50 Reflecting mirror (reflection optical system)
60 Folding prism (folding optical system)
70 Compression prism (compression optical system)
81 First condenser lens (condensing optical system)
90 External emission portion LB Laser light LB1 First laser light LB2 Second laser light P First space portion Q Second space portion Z Thickness direction (first direction)
X Arrangement direction (second direction)
Y Depth direction (third direction)

Claims (4)

a base portion formed in a plate shape and dividing the first space portion and the second space portion in a first direction;
a plurality of laser beam emitters each including a semiconductor laser element that emits a laser beam and a cover that covers the semiconductor laser element, the laser beam emitters being provided in the first space at positions capable of emitting the laser beam;
a folding optical system that is provided at an end portion on one side of the base portion in the second direction when a direction intersecting the first direction is defined as a second direction, folding back a plurality of laser beams that are emitted from the plurality of laser beam emitters to the first space portion and proceed toward the one side of the second direction to the second space portion and directs the laser beams toward the other side of the second direction;
a focusing optical system that is provided in the second space and focuses the plurality of laser beams that are folded back by the folding optical system;
an external emission unit that emits the plurality of laser beams collected by the collecting optical system from the second space to the outside;
A semiconductor laser module comprising: The semiconductor laser module according to claim 1, further comprising a compression optical system that is provided in the second space, compresses the plurality of laser beams folded back by the folding optical system in a parallel state, and emits the compressed plurality of laser beams to the focusing optical system. a reflection optical system provided in the first space portion and reflecting the laser light,
When a direction intersecting the first direction and the second direction is defined as a third direction, the plurality of laser beam emitters are arranged side by side along the second direction at an end portion on one side of the base portion in the third direction, and emit the plurality of laser beams to the first space portion along the third direction,
3 . The semiconductor laser module according to claim 1 , wherein the reflection optical system reflects the laser beams emitted from the laser beam emitters along the second direction toward the folding optical system. the plurality of laser beam emitters are disposed in a positional relationship such that fast axis directions of the respective plurality of laser beams emitted toward the reflection optical system are aligned along the second direction,
the reflection optical system is provided in a positional relationship in which fast axis directions of the reflected laser beams are aligned along the third direction,
the folding optical system is provided in a positional relationship such that fast axis directions of the folded laser beams are aligned along the third direction,
4. The semiconductor laser module according to claim 3, wherein the focusing optical system is positioned so as to focus the plurality of laser beams folded by the folding optical system along the third direction parallel to the first axis direction.

Images