JP2003279885A - Semiconductor laser beam converging device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily and efficiently converge light without increasing the cost by rearranging divided laser beams for which a thin and long laser beam from a light source is divided in a longitudinal direction so as to make the respective optical path lengths equal to each other in a semiconductor laser beam converging device. <P>SOLUTION: The semiconductor laser beam converging device comprises: a semiconductor laser chip 11 radiating a thin and long laser beam group; a dividing optical system 20 for dividing the laser beam collimated by a collimator lens 12 in a slow axis direction; a displacing optical system 30 for mutually displacing the divided laser beams in a tast axis direction; and a parallelizing optical system 40 for parallelizing the displaced respective divided laser beams in the tast axis direction. The dividing optical system 20, the displacing optical system 30 and the parallelizing optical system 40 are set so as to make the respective optical path lengths of first and second laser beams LB1 and LB2 equal to each other. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for condensing laser light emitted from a semiconductor laser having a plurality of emitters.

[0002]

2. Description of the Related Art Conventionally, as a condensing device of this type, as shown in Japanese Patent Laid-Open No. 2001-111147, a plurality of emitters long in a first direction for emitting a laser beam are arranged in the first direction. A semiconductor laser which is provided on the front side surface so as to be linearly arranged and emits a laser beam group in a second direction substantially perpendicular to the front side surface, and is arranged in front of this semiconductor laser to throw the laser beam group. A collimator lens that refracts in the fast axis direction, which is almost perpendicular to the axial direction, and collimates, and a laser beam group that is placed in front of this collimator lens and that is collimated in the fast axis direction, and is split into multiple slow axis directions. Then, at least one of the divided laser beams that are long in the slow axis direction is displaced above or below the plane in which the laser beam group has traveled, and each divided laser beam is divided. A parallel means for injection side by side parallel to the fast axis direction Zabimu, the parallel laser beams emitted from the parallel means that a focusing lens for focusing are known.

In the condensing device having such a configuration, the laser beam emitted from the semiconductor laser travels at a predetermined divergence angle in the slow axis direction and the fast axis direction, and is collimated in the fast axis direction by the collimator lens. As a result, the laser beam becomes horizontally long in the slow axis direction. This laser beam is reflected by the first prism 2
It is divided into two laser beams and emitted in opposite directions. The first laser beam directly reaches the condenser lens and is condensed (converged), and the second laser beam is reflected by the second prism and folded back to be parallel to the first laser beam in the fast axis direction. It is adjacent and reaches the condenser lens to be condensed (converged).

[0004]

However, in the above-mentioned conventional technique, the optical path length of the second laser beam is longer than that of the first laser beam by the amount of folding.
On the other hand, since the first and second laser beams are not collimated in the slow axis direction, that is, they are spherical waves,
As the optical path length becomes longer, it spreads in the slow axis direction and the cross-sectional area becomes larger. Therefore, the cross-sectional area of the second laser beam that reaches the condenser lens is larger than the cross-sectional area of the first laser beam that reaches the condenser means, so that the light is condensed at a position separated from the condenser lens by a predetermined distance. Moreover, since the cross-sectional area of the second laser beam is also larger than the cross-sectional area of the focused first laser beam, there is a problem that the focusing efficiency of the focusing device is lowered. In order to deal with this problem, the curvature of each part of the condenser lens reached by the first laser beam and the second laser beam is changed so that light is condensed (converged) at a position separated from the condenser lens by a predetermined distance. It is also conceivable to make the cross-sectional areas of each of the laser beams described above) identical.
However, in order to realize this, the condensing lens has to have a special shape, for example, a shape in which the portions where the first and second laser beams hit each other have different curvatures, and the condenser lens is manufactured in that shape. Is difficult, and even if it can be manufactured, it is expensive.

Therefore, an object of the present invention is to increase the cost by rearranging the divided laser beams obtained by dividing the elongated laser beam from the light source in the longitudinal direction in the condensing device so that the respective optical path lengths become equal to each other. It is to collect light easily and efficiently without inviting.

[0006]

In order to solve the above-mentioned problems, a structural feature of the invention according to claim 1 is that a plurality of emitters, which are long in the slow axis direction and emit laser light, are arranged in a line in the slow axis direction. A semiconductor laser provided, a collimator lens for collimating the laser light, a laser beam collimated by the collimator lens is split in the slow axis direction, and the split laser light is displaced in the fast axis direction orthogonal to the slow axis direction. In the semiconductor laser beam condensing device having means for arranging the displaced divided laser beams in parallel in the fast axis direction and a condenser lens for condensing the parallel divided laser beams, the means is a semiconductor laser. It is because the optical path lengths of the respective divided laser beams from to the condenser lens are set to be equal to each other.

Further, the structure of the invention according to claim 2 is to collimate the laser light with a semiconductor laser having a plurality of emitters which are long in the slow axis direction and which are arranged in a line in the slow axis direction. A collimator lens, a splitting unit that splits the laser beam collimated by the collimator lens into at least two in the slow axis direction, and a displacing unit that displaces each split split laser beam in the fast axis direction orthogonal to the slow axis direction. In the semiconductor laser light condensing device having parallel means for arranging the displaced divided laser beams in parallel in the fast axis direction and a condenser lens for condensing the parallel divided laser beams, the dividing means, the displacing means, and The parallel means is set so that the optical path lengths of the divided laser beams from the semiconductor laser to the condenser lens are equal to each other. .

Further, the constitutional feature of the invention according to claim 3 is that a semiconductor laser having a plurality of emitters for emitting laser light arranged in parallel in the slow axis direction, a collimator lens for collimating the laser light, Splitting means for splitting the laser beam collimated by the collimator lens into two in the slow axis direction, and polarization splitting means for splitting each half laser beam into two quarter laser beams having different polarization directions. , A polarization combining means for combining again the quarter laser beams having different polarization directions, which are split by the polarization splitting means, and the quarter laser beams, which are multiplexed by the polarization combining means, are thrown. A half having displacement parallel means for displacing each other in the fast axis direction orthogonal to the axial direction and juxtaposed in the fast axis direction, and a condenser lens for condensing the parallel split laser beams. In the body laser beam condensing device, the splitting means, the polarization splitting means, the polarization multiplexing means, and the displacement paralleling means are set so that the optical path lengths of the split laser beams from the semiconductor laser to the condenser lens are equal to each other. It is in.

Further, the structural feature of the invention according to claim 4 is that a semiconductor laser having a plurality of emitters for emitting laser light arranged in parallel in the slow axis direction, a collimator lens for collimating the laser light, Splitting displacement means for splitting the laser light collimated by the collimator lens into two in the slow axis direction and displacing the split half laser light in the first axial direction orthogonal to the slow axis direction.
Polarization splitting means for splitting each split half laser light into quarter laser light having different polarization directions and quarter laser light split by each polarization splitting means having different polarization directions are provided. Polarization combining means for combining again, parallel means for arranging each quarter laser light combined by each polarization combining means in the fast axis direction, and collecting means for collecting the parallel divided laser light. In the semiconductor laser light condensing device having a light lens, the splitting displacement means, the polarization splitting means, the polarization multiplexing means and the parallel means are arranged such that the optical path lengths of the respective split laser light from the semiconductor laser to the condensing lens are equal to each other. Has been set to.

[0010]

In the invention according to claim 1 configured as described above, the laser beam group elongated in the slow axis direction, which is emitted from the semiconductor laser and collimated by the collimator lens, is divided into a plurality of groups. Split,
These split laser beams shortened in the longitudinal direction are rearranged in the direction perpendicular to the longitudinal direction and reach the condenser lens. Since each of the split laser beams thus reached has the same optical path length, the spread in the longitudinal direction is the same, and the cross sections of the respective laser beams reaching the condenser lens are the same. Therefore, the rearranged laser beams can be efficiently condensed by the condenser lens.

In the invention according to claim 2 configured as described above, the laser beam group elongated in the slow axis direction emitted from the semiconductor laser and collimated by the collimator lens is divided into a plurality of pieces in the slow axis direction by the dividing means. The split laser light shortened in the longitudinal direction is
The displacement means displaces it in the fast axis direction, the parallel means rearranges it in the direction perpendicular to the longitudinal direction, and reaches the condenser lens. Since each of the split laser beams thus reached has the same optical path length, the spread in the longitudinal direction is the same, and the cross sections of the respective laser beams reaching the condenser lens are the same. Therefore, the rearranged laser beams can be efficiently condensed by the condenser lens.

In the invention according to claim 3 configured as described above, the laser beam group elongated in the slow axis direction emitted from the semiconductor laser and collimated by the collimator lens is divided into two by the dividing means in the slow axis direction. , These half laser beams shortened in the longitudinal direction are
Each of the polarization splitting means splits the laser light into two quarter laser beams having different polarization directions. Then, the quarter-laser light is recombined by the polarization-combining means into the quarter-laser light to increase the density of the light. Each of these combined quarter-laser lights is displaced in the fast axis direction by the displacement paralleling means, rearranged in the direction perpendicular to the longitudinal direction, and reaches the condenser lens. Since each of the split laser beams thus reached has the same optical path length, the spread in the longitudinal direction is the same, and the cross sections of the respective laser beams reaching the condenser lens are the same. Therefore, the rearranged laser beams can be efficiently condensed by the condenser lens.

In the invention according to claim 4 configured as described above, the laser beam group elongated in the slow axis direction emitted from the semiconductor laser and collimated by the collimator lens is divided into two by the dividing displacement means in the slow axis direction. These divided half laser beams are displaced from each other in the fast axis direction orthogonal to the slow axis direction, and the respective divided half laser beams are divided into quarter laser beams having different polarization directions by the polarization splitting means. The light is divided into two parts. Then, the quarter-laser light is recombined by the polarization-combining means into the quarter-laser light to increase the density of the light. Each of the combined quarter-laser lights is rearranged in the direction perpendicular to the longitudinal direction by the parallel means and reaches the condenser lens. Since each of the split laser beams thus reached has the same optical path length, the spread in the longitudinal direction is the same, and the cross sections of the respective laser beams reaching the condenser lens are the same. Therefore, the rearranged laser beams can be efficiently condensed by the condenser lens.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION A first embodiment of a semiconductor laser beam focusing device according to the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view showing this light collecting device. Note that the right direction and the upward direction toward the front side surface (emission surface) of the semiconductor laser chip 11 (described later) are defined as the x-axis positive direction and the y-axis positive direction, respectively, and the vertical front direction of the front side surface of the semiconductor laser chip 11 is The z axis is in the positive direction. Also, the optical path of the laser beam is indicated by an arrow.

This condensing device comprises a light source 10, a collimator lens 12, a splitting optical system 20, a displacement optical system 30, a parallel optical system 40 and a condensing lens 50.

The light source 10 is an emitter 1 which is horizontally long in the x-axis direction.
The semiconductor laser chip 11 is provided with 1a aligned in the x-axis direction. The semiconductor laser chip 11 has external dimensions of 10 mm × 0.2 mm × 1 mm (x
(Axis direction × y-axis direction × z-axis direction), and on the front side surface of the semiconductor laser chip 11, an emitter 11a formed in a size of 150 μm × 1 μm (x-axis direction × y-axis direction) is 500 μm.
Are provided in the x-axis direction at a pitch of. The S-polarized laser beam LB is emitted from each of these emitters 11a in the positive direction of the z-axis (direction perpendicular to the emission surface). The emitted laser beam LB spreads in the slow axis direction (x-axis direction) and the fast axis direction (y-axis direction) with a predetermined divergence angle. In this specification, the slow axis direction and the fast direction refer to the cross-sectional longitudinal direction of the laser beam and the direction orthogonal to this longitudinal direction, respectively.

In front of the semiconductor laser chip 11, a collimator lens 12 is arranged so as to face the front side surface of the semiconductor laser chip 11. The collimator lens 12 refracts the laser beam LB emitted from the emitter 11a only in the y-axis direction to collimate (collimate) the laser beam LB.
On the other hand, each laser beam LB is not collimated in the x-axis direction and travels while spreading in the x-axis direction at a predetermined divergence angle.

A split optical system 20 is arranged in front of the collimator lens 12. The split optical system 20 is composed of a right-angled prism 21 whose top and bottom surfaces are right-angled isosceles triangles, and each side surface is a total reflection surface. The right-angle prism 21 has a half of the laser beam LB group (first laser beam LB
1) which is reflected in the positive direction of the x-axis and is incident on the other side surface of the other half of the laser beam LB group (second laser beam LB
2) is arranged so as to reflect in the negative direction of the x-axis. As a result, the laser beam LB group collimated by the collimator lens 12 is divided into two in the x-axis direction and emitted in mutually different directions, that is, in the x-axis positive direction and the x-axis negative direction. At this time, the slow axes of the first and second laser beams LB1 and LB2 are converted into the z-axis direction.
The optical path lengths of the two laser beams LB1 and LB2 from the light source 10 to the rectangular prism are equal to each other.

The displacement optical system 30 includes a row of emitters 11a provided on the semiconductor laser chip 11 by bending the respective laser beams LB1 and LB2 incident from the split optical system 20 in a three-dimensional manner (xz plane). The optical path is changed above or below (the xz plane in which the laser beam LB group emitted from the emitter 11a provided in the semiconductor laser chip 11 travels), and is composed of the first and second displacement optical systems 31 and 32. Has been done. The optical path lengths of both displacement optical systems 31 and 32 are set to be equal to each other.

The first displacement optical system 31 is composed of a plurality of (for example, four) rectangular prisms 31a to 31d as reflecting means. Similar to the above-mentioned right-angled prism 21, each of the right-angled prisms 31a to 31d has an upper surface and a bottom surface that are right-angled isosceles triangles, and each side surface is a total reflection surface. In the first displacement optical system 31, the side surface (for example, the side surface facing at a right angle) is used to reflect the laser beam LB. Of these four right-angled prisms 31a to 31d, the first and second right-angled prisms 31a and 31b are arranged along the xz plane including a row of the emitters 11a described above.

The first right-angle prism 31a is a split optical system 2
First laser beam LB1 traveling from 0 in the positive direction of the x-axis
And is reflected in the positive direction of the z-axis. At this time, the slow axis of the first laser beam LB1 is converted to the x-axis direction. The second right-angle prism 31b receives the laser beam LB1 traveling in the positive direction of the z-axis from the first right-angle prism 31a and reflects it in the positive direction of the y-axis. At this time, the first laser beam L
The fast axis of B1 is converted to the z-axis direction.

Third and fourth rectangular prisms 31c, 3
1d is arranged above an xz plane including a row of emitters 11a, and the third rectangular prism 31c receives a laser beam LB1 which travels in the positive y-axis direction from the second rectangular prism 31b. Reflect in the negative x-axis direction. At this time, the slow axis of the first laser beam LB1 is converted to the y-axis direction. The fourth right-angle prism 31d receives the laser beam LB1 traveling in the negative direction of the x-axis from the third right-angle prism 31c and reflects it in the negative direction of the y-axis. At this time, the slow axis of the first laser beam LB1 is converted to the x-axis direction. The right angle prisms 31a to 31d described above are
The optical path length from the splitting optical system 20 to the first rectangular prism 31a and the optical path length from the third rectangular prism 31c to the fourth rectangular prism 31d are arranged to be equal to each other.

The second displacement optical system 32 also has a plurality (for example, four) as the reflection means, like the first displacement optical system 31.
The right angle prisms 32a to 32d. These rectangular prisms 32a to 32d are used for the first displacement optical system 3
It is a rectangular prism similar to 1. Of these four right-angle prisms 32a to 32d, the first and second right-angle prisms 32a and 32b are respectively arranged along the xz plane including a row of the emitters 11a described above, and the first right-angle prism 32a is x from the split optical system 20.
The second laser beam LB2 traveling in the negative axis direction is incident and reflected in the positive z-axis direction. At this time, the slow axis of the second laser beam LB2 is converted to the x-axis direction. The second right-angle prism 32b receives the laser beam LB2 traveling in the positive direction of the z-axis from the first right-angle prism 32a and reflects it in the negative direction of the y-axis. At this time, the second laser beam LB2
The fast axis of is converted to the z-axis direction.

Third and fourth right angle prisms 32c, 3
2d is arranged below the xz plane including a row of emitters 11a, and the third rectangular prism 32c receives the laser beam LB2 which travels in the negative y-axis direction from the second rectangular prism 32b. Reflect in the positive x-axis direction. At this time, the slow axis of the second laser beam LB2 is converted to the y-axis direction. The fourth right-angle prism 32d receives the laser beam LB2 traveling from the third right-angle prism 32c in the positive x-axis direction and reflects the laser beam LB2 in the positive y-axis direction. At this time,
The slow axis of the second laser beam LB2 is converted to the x-axis direction.

The above-mentioned right angle prisms 32a to 32a are provided.
2d is a first right-angle prism 32a from the split optical system 20.
And the optical path lengths from the third rectangular prism 32c to the fourth rectangular prism 32d are equal to each other, and these optical path lengths are from the split optical system 20 to the first displacement optical system 31.
Is arranged so as to be equal to the optical path length to the first right-angled prism 31a constituting the above. Further, the optical path length from the first right-angled prism 32a to the second right-angled prism 32b constitutes the first right-angled prism 3 which constitutes the first displacement optical system 31.
The optical path length from 1a to the second rectangular prism 31b is equal to the optical path length. Further, the optical path length from the second right angle prism 32b to the third right angle prism 32c constitutes the second right angle prism 3 which constitutes the first displacement optical system 31.
It is arranged so as to be equal to the optical path length from 1b to the third rectangular prism 31c.

In the middle of the fourth rectangular prisms 31d and 32d which form the first and second displacement optical systems 31 and 32,
The parallel optical system 40 is arranged, and the parallel optical system 40
Is a laser beam in which the laser beams LB1 and LB2 respectively incident from the first and second displacement optical systems 31 and 32 are changed in optical path in the same direction and are arranged in parallel in a direction perpendicular to the longitudinal direction of the cross section (y-axis direction) and emitted. Is. The parallel optical system 40 is configured by a right-angle prism similar to the right-angle prism 21 that constitutes the split optical system 20, that is, from a right-angle prism 41 whose top and bottom surfaces are right-angled isosceles triangles and each side surface is a total reflection surface. It is configured. This right angle prism 41
Is the first and second laser beams LB1 and LB respectively incident on the pair of side surfaces and the other side surface that sandwich the right angle.
2 is arranged so as to reflect 2 in the positive direction of the z-axis. Thereby, the first laser beam L incident from the positive direction of the y-axis
B1 and the second laser beams LB2 incident from the y-axis negative direction are arranged in parallel with each other in the y-axis direction and emitted as a parallel laser beam LB group in the z-axis positive direction. At this time, the slow axis and the fast axis of the first and second laser beams LB1 and LB2 are in the x-axis and y-axis directions, respectively. The optical path lengths of both laser beams LB1 and LB2 from the fourth right-angle prisms 31d and 32d forming the first and second displacement optical systems 31 to 32 to the right-angle prism 41 forming the parallel optical system 40 are equal to each other. It is like this.

On the optical axis of the parallel laser beam LB group emitted from the parallel optical system 40, a condenser lens 50 (converging lens) is arranged parallel to the xy plane. The condenser lens 50 is a convex lens, and the incident laser beam L
The focus is on the group B.

In the condensing device according to the embodiment configured as described above, when the laser beam LB is emitted from each emitter 11a provided on the front side surface of the semiconductor laser chip 11, the emitted laser beam LB group is collimated. It is collimated only in the y-axis direction by the lens 12 and emitted as an elongated laser beam LB group in the x-axis direction (slow axis direction). This elongated laser beam LB group is divided into two in the x-axis direction by the division optical system 20, and each divided laser beam LB shortened in the longitudinal direction (slow axis direction).
The (first and second laser beams LB1 and LB2) are respectively displaced by the displacement optical system 30 in the y-axis positive direction and the y-axis negative direction, and the two laser beams LB thus displaced are displaced.
1, LB2 are rearranged by the parallel optical system 40 in the direction perpendicular to the longitudinal direction (fast axis direction) and reach the condenser lens 50. At this time, the first and second laser beams LB1 and LB2 are both laser beams L
Since B1 and LB2 have the same optical path length, the condenser lens 5
The two laser beams LB1 and LB2 that have reached 0 have the same spread in the longitudinal direction (the slow axis direction), that is, the laser beams LB1 and LB2 have the same cross section in the condenser lens 50. Therefore, the rearranged laser beams LB1 and LB2 can be efficiently condensed by the condenser lens 50.

In the above-described first embodiment, the arrangement of the plurality of right angle prisms forming the first and second displacement optical systems 31 and 32 may be changed as in the following example. At this time, the optical path lengths of both displacement optical systems 31 and 32 must be set to be equal to each other. For example,
Second right-angled prism 31 constituting the first displacement optical system 31
b may be arranged on the plane where the third and fourth rectangular prisms 31c and 31d are arranged. At this time, the first right-angled prism 31a enters the first laser beam LB1 traveling in the positive direction of the x-axis from the split optical system 20 and reflects it in the positive-direction of the y-axis, and the second right-angled prism 31b has the first prism 31b. Laser beam LB traveling from the right-angle prism 31a in the positive direction of the y-axis
1 to be reflected in the positive direction of the z-axis, and the third right-angle prism 31c is made to enter the laser beam LB1 traveling in the positive direction of the z-axis from the second right-angle prism 31b and reflected in the negative direction of the x-axis. Just set it. Further, the second right-angle prism 32b forming the second displacement optical system 32 may be arranged on the plane where the third and fourth right-angle prisms 32c and 32d are arranged. At this time, the first right-angled prism 32a receives the second laser beam LB2 traveling in the negative direction of the x-axis from the split optical system 20 and reflects it in the negative-direction of the y-axis, and the second right-angled prism 32b has the first prism 32b. A laser beam LB2 traveling in the negative direction of the y-axis is incident from the right-angle prism 32a and reflected in the positive direction of the z-axis, and a third right-angle prism 32c is a laser beam LB traveling in the positive direction of the z-axis from the second right-angle prism 32b.
It may be set so that 2 is incident and reflected in the positive direction of the x-axis.

Next, a light collecting device according to a second embodiment of the present invention will be described with reference to FIG. The present embodiment is different from the first embodiment in that the arrangement of a plurality of right-angle prisms constituting the split optical system 20 and the first and second displacement optical systems 31 and 32 is changed.
Different from the embodiment. At this time, the first divisional optical system 20 and the first and second displacement optical systems 31 and 32 are formed.
The optical path lengths of the second laser beams LB1 and LB2 must be set to be equal to each other. In addition,
The same components as those in the first embodiment described above are designated by the same reference numerals, and the description thereof will be omitted.

Similar to the above-mentioned right-angled prism 21, the split optical system 20 has a pair of right-angled prisms 2 whose upper and bottom surfaces are right-angled isosceles triangles and whose side surfaces are total reflection surfaces.
It is composed of 2, 23. These right angle prisms 2
In 2 and 23, side surfaces (for example, side surfaces facing each other at a right angle)
Is used to reflect the laser beam LB. And
The first right-angle prism 22 makes half of the laser beam LB group (first laser beam LB1) incident on side surfaces facing each other at a right angle and reflects it in the positive direction of the y-axis, and the second right-angle prism 23 makes the laser The other half of the beam LB (second laser beam LB2) is arranged so as to be incident on the side surfaces facing each other at a right angle and reflected in the y-axis negative direction. This allows
The fast axes of the first and second laser beams LB1 and LB2 are converted to the z-axis direction.

The first displacement optical system 31 has a first
To the fourth right-angled prisms 31a to 31d,
It is located above the xz plane, which includes a row of 1a.
At this time, the first right-angled prism 31a is connected to the split optical system 20.
The first laser beam LB1 traveling in the positive direction of the y-axis is incident from the first right-angled prism 22 and is reflected in the positive direction of the x-axis (the slow axis is converted into the y-axis direction), and the second right-angle prism 31b. From the first rectangular prism 31a enters the laser beam LB1 traveling in the positive direction of the x-axis and reflects it in the positive direction of the z-axis (the fast axis is converted to the x-axis direction), and the third rectangular prism 31c is the second prism. The laser beam LB1 traveling in the positive direction of the z-axis is incident from the right-angle prism 31b and is reflected in the negative direction of the x-axis (the fast axis is converted to the z-axis direction).

Further, the first displacement optical system 32 has a first
To the fourth right angle prisms 32a to 32d,
It is placed below the xz plane containing a row of 1a.
At this time, the first right-angled prism 32a is connected to the split optical system 20.
Second laser beam LB2 traveling in the y-axis negative direction from the second right-angled prism 23 and reflected in the x-axis negative direction (the slow axis is converted into the y-axis direction), and the second right-angled prism 32b Is incident on the laser beam LB2 traveling in the negative direction of the x-axis from the first right-angled prism 32a and reflected in the positive direction of the z-axis (the fast axis is converted to the x-axis direction), and the third right-angled prism 32c is changed to the second prism 32c. The laser beam LB2 traveling in the positive direction of the z-axis is incident from the right-angle prism 32b and is reflected in the positive direction of the x-axis (the fast axis is converted to the z-axis direction). Also in the light-collecting device according to the second embodiment configured as described above, the same operation and effect as those of the above-described first embodiment can be obtained.

Further, a light collecting device according to a third embodiment of the present invention will be described with reference to FIG. In this embodiment,
This is different from the first embodiment in which four right-angle prisms are used in that the first and second displacement optical systems 31 and 32 are each formed by using three right-angle prisms as reflecting means. At this time, the optical path lengths of both displacement optical systems 31 and 32 must be set to be equal to each other. Also,
An image rotator 81 is provided in the second displacement optical system 32. The same components as those in the first embodiment described above are designated by the same reference numerals, and the description thereof will be omitted.

Specifically, the splitting optical system 20 is composed of a right-angled prism whose top and bottom surfaces are right-angled isosceles triangles and each side surface is a total reflection surface, like the right-angled prism 21 described above. Is a half of the laser beam LB group incident from the light source 10 (first laser beam LB
1) as it is in the positive direction of the z-axis, and the laser beam L
The other half of the group B (second laser beam LB2) is arranged so as to be incident on the side surfaces facing each other at a right angle and reflected in the positive direction of the x-axis. As a result, the slow axes of the first and second laser beams LB1 and LB2 are in the x-axis and z-axis directions.

Each of the right-angle prisms 31a to 31c constituting the first displacement optical system 31 has an upper surface and a bottom surface which are isosceles right triangles, and each side surface is a total reflection surface, like the right-angle prism 21 described above. These three right angle prisms 31
The first right-angled prism 31a among the a to 31c is arranged along the xz plane including a row of the emitters 11a described above, and the first right-angled prism 31a travels from the light source 10 in the positive z-axis direction. One laser beam LB1 is incident and reflected in the positive direction of the y-axis. At this time, the fast axis of the first laser beam LB1 is converted to the z-axis direction. The second and third right-angle prisms 31b and 31c are arranged above the xz plane including one row of the emitters 11a, and the second right-angle prism 31b is the first right-angle prism 3.
1a from which a laser beam LB1 traveling in the positive direction of the y-axis is incident and reflected in the negative direction of the x-axis (first laser beam LB1
Is converted to the y-axis direction), and the third rectangular prism 31c receives the laser beam LB1 traveling from the second rectangular prism 31b in the negative x-axis direction and reflects it in the negative y-axis direction. At this time, the slow axis of the first laser beam LB1 is converted to the x-axis direction.

Each of the right-angled prisms 32a to 32c constituting the second displacement optical system 32 has an upper surface and a bottom surface which are right-angled isosceles triangles and each side surface is a total reflection surface, like the right-angled prism 21 described above. These three right angle prisms 32
The first right-angled prism 32a among the a to 32c is arranged along the xz plane including a row of the emitters 11a described above, and the first right-angled prism 32a is arranged in the negative direction of the x-axis from the second split optical system 20. Second laser beam L which travels to
B2 is incident and reflected in the negative y-axis direction. At this time, the second
The first axis of the laser beam LB2 is converted to the x-axis direction.

The second and third right angle prisms 32b, 3
2c is arranged below an xz plane including a row of emitters 11a, and the second right-angle prism 32b receives a laser beam LB2 traveling from the first right-angle prism 32a in the y-axis negative direction and then the z-axis. Reflects in the positive direction. At this time, the fast axis of the second laser beam LB2 is converted to the z-axis direction.

The second and third right angle prisms 32b, 3
An image rotator 81 (for example, an image rotation prism) is installed on the optical axis between 2c. The image rotator 81 rotates the incident laser beam by 90 degrees clockwise about the optical axis and emits it, whereby the slow axis and the fast axis of the second laser beam LB2 are in the x-axis direction and in the x-axis direction, respectively. Converted in the y-axis direction.

The third right-angle prism 32c has a second
The laser beam LB2 traveling in the positive direction of the z-axis is incident from the right-angle prism 32b and is reflected in the positive direction of the y-axis. At this time, the fast axis of the second laser beam LB2 is converted to the z-axis direction. Also in the light condensing device according to the third embodiment configured as described above, it is possible to obtain the same operation and effect as those of the above-described first embodiment. In addition, in the above-described third embodiment, the image rotator 81 is 32
Although it is installed between b and 32c, it is not limited to this and may be installed at any place on the optical path of the second laser beam LB2.

Further, in each of the above-mentioned embodiments,
According to the present invention, two laser beam LB groups emitted from each emitter 11a provided on the front side surface of the semiconductor laser chip 11 are used.
Although the invention is applied to the semiconductor laser light condensing device for dividing, it is not limited to this case, and it may be applied to the semiconductor laser light condensing device for dividing the laser beam LB group into three or more.

Next, a fourth embodiment of the present invention will be described with reference to FIG. FIG. 4 is a perspective view showing the light collecting device. In the present embodiment, the S-polarized laser beam LB group emitted from each emitter 11a provided on the front side surface of the semiconductor laser chip 11 is divided into two, and the half laser beam LB (first and second laser beams) is divided. Beams LB1, LB
2) has different polarization directions (S-polarized light and P-polarized light)
First and second polarization splitting optical systems 61 and 62 for respectively splitting into the quarter laser beam LB, and first and second splitting and splitting the quarter laser beam LB having mutually different polarization directions. It differs from the first embodiment described above in that the two-polarization multiplexing optical systems 71 and 72 are provided. The same components as those in the first embodiment described above are designated by the same reference numerals, and the description thereof will be omitted.

Specifically, the first and second polarization splitting optical systems 61 and 62 and the first and second polarization multiplexing systems are provided between the splitting optical system 20 and the first and second displacement optical systems 31 and 32, respectively. Optical systems 71 and 72 are provided. The first polarization splitting optical system 61 includes the first and second right angle prisms 61a, 6a.
1b and a half-wave plate 61c. The first right-angled prism 61a is composed of a right-angled prism whose top and bottom surfaces are right-angled isosceles triangles and whose side surfaces are total reflection surfaces, like the right-angled prism 21 described above. Right angle prism 2
One half (quarter laser beam LB) of the first laser beam LB1 incident from No. 1 is passed through, and the other half (quarter laser beam LB) is incident on the side surfaces facing each other at a right angle, and the z-axis is positive. Arrange so that it reflects in the direction. This allows
The slow axis and the fast axis of the passed quarter laser beam are the z-axis direction and the y-axis direction, and the slow axis and the fast axis of the reflected quarter laser beam are the x-axis direction and the y-axis direction.

The second right-angle prism 61b is also composed of a right-angle prism similar to the above-mentioned right-angle prism 21, and the right-angle prism 61b is a quarter laser beam incident from the right-angle prism 21 forming the split optical system 20. LB
(Half of the first laser beam LB1) is arranged so as to be incident on side surfaces facing each other at a right angle and reflected in the positive direction of the z-axis.
At this time, the slow axis of the reflected quarter laser beam is converted to the x-axis direction. The half-wave plate 61c converts the polarization direction of the incident laser beam LB from S-polarized light to P-polarized light and emits it. The quarter-wave laser beam LB (first polarized light beam LB) incident from the first rectangular prism 61a (first The other half of the laser beam LB1) is arranged on the optical axis. At this time, the slow axis and the fast axis of the emitted quarter laser beam remain in the x-axis direction and the y-axis direction. Therefore, the first laser beam LB1 incident from the rectangular prism 21 of the split optical system 20 is split into two in the longitudinal direction (slow axis direction), and the split quarter laser beams LB have different polarization directions. .

The first polarization multiplexing optical system 71 comprises a first rectangular prism 71a and a polarization beam splitter 71b. The first right-angled prism 71a is composed of a right-angled prism whose upper and bottom surfaces are right-angled isosceles triangles and whose side surfaces are total reflection surfaces, like the right-angled prism 21 described above. Optical system 6
The 1st right-angled prism 61a which constitutes 1 is arranged so that the quarter laser beam LB traveling in the positive direction of the z-axis is incident on the side surfaces facing each other at a right angle and reflected in the positive direction of the x-axis.
As a result, the slow axis of the reflected quarter laser beam LB is converted to the z-axis direction. The polarization beam splitter 71b is for injecting two laser beams LB having mutually different polarization directions, superimposing them on each other, combining them, and increasing the output per unit area of the light and emitting them. The polarization beam splitter 71b is a second polarization beam splitter 71b that constitutes a first polarization splitting optical system 61.
Of the S-polarized quarter laser beam LB that travels in the positive direction of the z-axis from the right-angle prism 61b, and P that travels in the positive direction of the x-axis from the first right-angle prism 71a that constitutes the first polarization multiplexing optical system 71. It is arranged so that a quarter-polarized laser beam LB is incident and emitted in the positive direction of the z-axis. As a result, the slow axis and the fast axis of the emitted quarter laser beam LB become the x-axis direction and the y-axis direction, respectively. Therefore, the two quarter laser beams LB are recombined so that the first laser beam LB1 becomes approximately one quarter in the longitudinal direction (slow axis direction), and the displacement optical system 31
It is incident on the rectangular prism 31b. The subsequent steps are the same as those in the first embodiment.

The first polarization splitting optical system 61 and the first polarization multiplexing optical system 71 are arranged so that the optical path lengths of the quarter laser beam LB entering the polarization beam splitter 71b are equal. .

Similarly to the first polarization splitting optical system 61, the second polarization splitting optical system 62 also includes first and second right-angle prisms 62.
It is composed of a and 62b and a half-wave plate 62c. As a result, the second laser beam LB2 incident from the rectangular prism 21 of the split optical system 20 is split into two in the longitudinal direction, and the split quarter laser beams LB have different polarization directions. In addition, the second polarization multiplexing optical system 72
Also, like the first polarization multiplexing optical system 71, it is also composed of a first rectangular prism 72a and a polarization beam splitter 72b. As a result, the two quarter laser beams LB are recombined, and the second laser beam LB2 becomes approximately one quarter in the longitudinal direction. Further, the second polarization splitting optical system 62 and the second polarization multiplexing optical system 72 include a polarization beam splitter 72b.
Are arranged so that the respective optical path lengths of the quarter laser beam LB that is incident on are equal to each other.

In the condensing device according to the fourth embodiment configured as described above, the laser beam LB group elongated in the slow axis direction (x-axis direction) emitted from the semiconductor laser and collimated by the collimator lens 12 is: The split optical system 20 splits the light into two in the longitudinal direction (slow axis direction). Then, the half laser beam LB shortened in the longitudinal direction (first and second laser beams LB
1, LB2) is a first and second polarization splitting optical system 61,
62 divides the laser beam LB into two quarters each having a different polarization direction. These quarter laser beams LB are transmitted to the first and second polarization combining optical systems 71, 7
It is multiplexed by 2 and the density of light is increased. further,
These combined quarter laser beams LB are
Then, the light is displaced in the fast axis direction by the second displacement optical systems 31 and 32, rearranged in the direction perpendicular to the longitudinal direction (fast axis direction), and reaches the condenser lens 50. Both quarter laser beams LB that have reached these
Have the same optical path length, they have the same spread in the longitudinal direction, and the cross sections of the quarter laser beams reaching the condenser lens 50 are the same. Therefore, the rearranged quarter laser beams can be efficiently condensed by the condenser lens 50.

In the above-described fourth embodiment, the laser beam LB collimated by the collimator lens 12 is split into two in the slow axis direction, and first the first and second polarization splitting optical systems 61 and 62 are used. Each half laser beam LB divided into two is divided into quarter laser beams LB whose polarization directions are different from each other.
After re-combining the quarter laser beams LB that are divided by the polarization combining optical systems 71 and 72 and have different polarization directions, each of the combined quarter laser beams LB is orthogonal to the slow axis direction. The laser beams LB collimated by the collimator lens 12 are arranged such that they are displaced from each other in the fast axis direction and arranged in parallel in the fast axis direction.
The group is divided into two in the slow axis direction, first, these divided half laser beams LB are displaced from each other in the fast axis direction orthogonal to the slow axis direction, and then the first and second
Each half laser beam LB split into two by the polarization splitting optical systems 61 and 62 is split into quarter laser beams LB whose polarization directions are different from each other, and the first and second polarization multiplexing optical systems 71 and 72 are split. Alternatively, the quarter laser beams LB that are divided by the different polarization directions may be combined again, and the combined quarter laser beams LB may be arranged in parallel in the fast axis direction.

In each of the above-mentioned embodiments,
Although the light source 10 is provided with only one semiconductor laser chip 11 in which the emitters 11a are provided in one row, a plurality of the semiconductor laser chips 11 may be laminated and provided.

Further, in each of the above-mentioned embodiments,
Although each side surface of the rectangular prism is used as the reflecting means, a total reflection mirror may be used instead of this.

[Brief description of drawings]

FIG. 1 is a perspective view showing a semiconductor laser light condensing device according to a first embodiment of the present invention.

FIG. 2 is a perspective view showing a semiconductor laser light condensing device according to a second embodiment of the present invention.

FIG. 3 is a perspective view showing a semiconductor laser light condensing device according to a third embodiment of the present invention.

FIG. 4 is a perspective view showing a semiconductor laser light condensing device according to a fourth embodiment of the present invention.

[Explanation of symbols]

10 ... Light source, 11 ... Semiconductor laser chip, 11a ... Emitter, 12 ... Collimator lens, 20 ... Dividing optical system, 3
0 ... Displacement optical system, 31, 32 ... 1st and 2nd displacement optical system, 40 ... Parallel optical system, 50 ... Condensing lens.

Claims (4)

[Claims] 1. A semiconductor laser in which a plurality of emitters, which are long in the slow axis direction, for emitting laser light are provided in a row in the slow axis direction, a collimator lens for collimating the laser light, and a laser beam collimated by the collimator lens. Is divided in the slow axis direction, the divided laser beams are displaced in the fast axis direction orthogonal to the slow axis direction, and the displaced divided laser beams are arranged in parallel in the fast axis direction. In the semiconductor laser light condensing device having a condensing lens for condensing the divided laser light, the means is set such that the optical path lengths of the respective divided laser lights from the semiconductor laser to the condensing lens are equal to each other. A semiconductor laser light condensing device characterized in that 2. A semiconductor laser provided with a plurality of emitters, which are long in the slow axis direction, for emitting laser light in a row in the slow axis direction, a collimator lens for collimating the laser light, and a laser beam collimated by the collimator lens. Is divided into at least two in the slow axis direction, displacement means for displacing each divided laser beam in the fast axis direction orthogonal to the slow axis direction, and each displaced divided laser beam in the fast axis direction. In a semiconductor laser light condensing device having parallel means for arranging in parallel in a direction and a condensing lens for condensing the parallel divided laser light, the dividing means, the displacing means, and the parallel means condense light from the semiconductor laser. A semiconductor laser characterized in that the optical path lengths of the respective divided laser beams to the lens are set to be equal to each other. Condenser. 3. A semiconductor laser in which a plurality of emitters for emitting laser light are arranged side by side in the slow axis direction, a collimator lens for collimating the laser light, and laser light collimated by the collimator lens in the slow axis direction. Splitting means for splitting into two, polarization splitting means for splitting each split half laser light into quarter laser light having different polarization directions, and polarization directions split by each polarization splitting means. Polarization combining means for recombining different quarter laser beams, and each quarter laser light combined by each polarization combining means are displaced from each other in the fast axis direction orthogonal to the slow axis direction. A semiconductor laser light condensing device having a displacement paralleling means arranged in parallel in the fast axis direction and a condensing lens for condensing the parallel divided laser light, The splitting means, the polarization splitting means, the polarization multiplexing means and the displacement paralleling means are set such that the optical path lengths of the split laser beams from the semiconductor laser to the condenser lens are equal to each other. Light concentrator. 4. A semiconductor laser in which a plurality of emitters for emitting laser light are arranged side by side in the slow axis direction, a collimator lens for collimating the laser light, and laser light collimated by the collimator lens in the slow axis direction. Dividing and displacing means for dividing the halved laser light into two and displacing the divided halved laser light with each other in the fast axis direction orthogonal to the slow axis direction, and the halved laser light divided into two quadrants having different polarization directions. Polarization splitting means for splitting the laser light into one laser beam, polarization splitting means for splitting again the quarter laser beams split by the polarization splitting means and having different polarization directions, and splitting by each polarization splitting means. A semi-conductor having parallel means for arranging each of the quarter-wave laser beams shunted in parallel in the first axis direction, and a condenser lens for condensing the parallel split laser beams. In the body laser light condensing device, the division displacement means, the polarization division means, the polarization combining means and the parallel means are set so that the optical path lengths of the respective divided laser lights from the semiconductor laser to the condenser lens are equal to each other. A semiconductor laser light condensing device characterized in that