JP2000019362A - Optical coupling device for array type semiconductor laser and solid-state laser device using this array type semiconductor laser - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate the manufacture and packaging of a coupling device for an array type semiconductor laser and to assure long-term stable accuracy with a small size. SOLUTION: This coupling device for the array type semiconductor laser has the array type semiconductor laser 1, a cylindrical lens 3 and a light converging device 10. A plurality of LD light 4 which are radiated from the light radiation surface of the array type semiconductor laser 1 and is regulated by the cylindrical lens 3 are made incident from an incident port 5 of this light covering device 10 and progress in respective optical waveguides 6. These light rays are condensed in a coupling part 7 and are emitted as high-density LD light 9 from an exit port 8.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an optical coupling device for an array type semiconductor laser and an array type semiconductor laser pumped solid-state laser.

[0002]

2. Description of the Related Art A semiconductor laser has a high conversion efficiency from electricity to light, does not require a large-scale cooling device, and can be configured compactly. However, there is a limit in increasing the output of a single-stripe semiconductor laser, and it is difficult to use it as it is for laser processing.

On the other hand, an array type semiconductor laser in which 10 to 100 active layer stripes for emitting laser light are linearly arranged to provide a light source having a broken line is known as a high output laser.

FIG. 11 shows the state of emission of LD light (semiconductor laser light) 102 from an array type semiconductor laser 100.

[0005] A plurality of light emitting portions 101a arranged in series
LD light 102 emitted from each light emitting surface 101 has a divergence angle. When the axis parallel to each light emitting surface 101 is the slow axis, and the axis perpendicular to both the LD light traveling direction axis and the slow axis, which is perpendicular to each light emitting surface 101, is the fast axis, the slow speed of the LD light 102 is obtained. The axial divergence angle θ is about 10 degrees at full width at half maximum, and the first axial divergence angle φ is about 4 at full width at half maximum.
Extremely different from 0 degrees. In order to use the LD light 102 from such an array type semiconductor laser 100 for laser processing or the like, it is necessary to obtain a high level of energy by concentrating the LD light 102 in a narrow area. For this reason, Japanese Unexamined Patent Publication No. 7-9
No. 8402 proposes an optical coupling device for an array type semiconductor laser as shown in FIG.

FIG. 12 is a plan view of a conventional optical coupling device for an array type semiconductor laser.

The optical coupling device for an array type semiconductor laser has a configuration including an array type semiconductor laser 111 and a coupling optical device 117.

The array type semiconductor laser 111 has a plurality of light emitting portions 112a arranged linearly.
LD light 114 is emitted from each light emitting surface 112 of 12a.

The coupling optical device 117 has a cylindrical lens 113a, an optical path converter 115, a cylindrical lens 113b, and a condenser lens 116 which are arranged in order along the traveling direction of the LD light 114.

Each LD light 114 emitted from the array type semiconductor laser 111 has a divergence angle θ of about 10 in the slow axis direction.
The light enters the cylindrical lens 113a in a state where the divergence angle φ in the first axis direction is about 40 degrees.
The cylindrical lens 113a converts the divergent light component in the fast axis direction into parallel light while the divergence angle θ in the slow axis direction remains at about 10 degrees. In this state, each L
The D light 114 enters the optical path converter 115. The optical path converter 115 emits each LD light 114 by rotating it 90 degrees with respect to the cross section of each LD light 114 at the time of incidence. Next, in the cylindrical lens 113b, the divergent light component in the slow axis direction is converted into parallel light. As described above, each LD which becomes parallel light in both the slow axis direction and the fast axis direction
Light 114 is coupled by a condenser lens 116. As described above, the output of the LD light 114 is increased.

In addition, for example, "Optics L"
eters, Vol, 21, (1996) p37
5 "," OSA TOPS Vol.10, Advan
cedSolid State Lasers, (19
97) p390 ”,“ Proceedings of the 44th Joint Lecture Meeting on Applied Physics, Spring 1997, No. 3, p986 ”, etc., describes the non-uniformity of LD light in each axial direction using rod lenses and cylindrical lenses. Various devices have been proposed which are made uniform by a combination of optical system elements such as a lens, a plane mirror, and a prism, and then combined by a condenser lens.

[0012]

However, in the above-described conventional optical coupling device, precise alignment between various optical elements was required, but these optical elements are arranged in a three-dimensional space. Therefore, not only is it difficult to perform alignment, but also there is a problem that a long-term misalignment between optical elements occurs, and the long-term stability of the accuracy of the apparatus cannot be maintained.

In addition, there is a problem in that the spatial shape of the LD light must be included in the device, which complicates and enlarges the shape of the device. As a result, there is also a problem that the manufacturing cost increases.

Therefore, the present invention provides an optical coupling device for an array type semiconductor laser which is easy to manufacture and mount, is small in size, can secure stable accuracy for a long period of time, and has a low manufacturing cost, and uses the array type semiconductor laser. It is an object to provide a solid-state laser device.

[0015]

In order to achieve the above object, an optical coupling device for an array type semiconductor laser according to the present invention comprises a plurality of light emitting portions arranged in a straight line, and a plurality of laser emitting portions from each of the light emitting portions. An array-type semiconductor laser that emits light, a cylindrical lens that converts each laser light emitted from the array-type semiconductor laser into parallel light, and a light concentrator that focuses each laser light that has been converted into parallel light by the cylindrical lens. In the optical coupling device for an array type semiconductor laser having the above, the light concentrator is provided between an incident portion on which the respective laser beams are incident, and the respective laser beams as the respective laser beams incident from the incident portion progress. A focusing section for narrowing the distance between the laser beams;
The optical waveguide is characterized by having an optical waveguide including a coupling portion that couples together and an emission portion that emits the laser light combined by the coupling portion.

In the optical coupling device for an array-type semiconductor laser according to the present invention, the plurality of laser lights emitted from the array-type semiconductor laser are converted into parallel light by a cylindrical lens, and are converted into one by a light concentrator. However, since the light concentrator has an optical waveguide in which the incident part, the focusing part, the coupling part, and the emission part are integrally formed, the number of parts is reduced, Not only does the precise alignment of the optical system for focusing the laser light become unnecessary, but also stable accuracy is ensured for a long period of time. In addition, it is no longer necessary to provide a laser beam spatial propagation section in the device.

A plurality of incident portions are arranged at positions corresponding to the arrangement of the respective light emitting portions on a one-to-one basis, and the focusing portion may have a structure in which the laser beams do not interfere with each other until reaching the coupling portion. Alternatively, a plurality of array-type semiconductor lasers may be arranged in parallel such that all the light emitting portions are arranged in a straight line.

The incident portion may have an opening width through which all the laser beams emitted from the cylindrical lens can enter, or the laser beam emitted from the emitting portion is focused on the transmission optical fiber. It may be one having a coupling lens for making it work.

In the optical coupling device for an array type semiconductor laser according to the present invention, a plurality of array type semiconductor lasers, cylindrical lenses, and light concentrators are arranged in parallel, and each laser light emitted from each light concentrator is emitted. In order to further combine the laser beams, the laser beam is incident on the incident portion, the focusing portion narrows the interval between the laser beams as the laser beams incident from the incident portion progress, and the focusing portion focuses the laser beams. A light concentrator different from the above-mentioned light concentrators, comprising an optical waveguide comprising a coupling part for coupling the respective laser lights into one, and an emission part for emitting the laser light coupled at the coupling part. You may have.

Further, the transmission optical fiber may have a coupling lens for condensing the laser light emitted from the emission section of the light focusing / coupling section.

An array-type semiconductor laser-excited solid-state laser device according to the present invention includes an optical coupling device for an array-type semiconductor laser according to the present invention and a laser beam emitted from the optical coupling device for an array-type semiconductor laser. A solid-state laser resonator that emits a solid-state laser, amplifies the solid-state laser, and emits the amplified solid-state laser.

The solid-state laser resonator may include a solid-state laser crystal and a plurality of laser reflecting members.

[0023]

Next, embodiments of the present invention will be described with reference to the drawings. (First Embodiment) FIG. 1 is a plan view of an array type semiconductor laser coupling device according to a first embodiment of the present invention, and FIG.
2 shows side views of the coupling device for array type semiconductor laser shown in FIG.

The coupling device for an array type semiconductor laser according to the present embodiment has an array type semiconductor laser 1, a cylindrical lens 3, and a light concentrator 10.

The array type semiconductor laser 1 has a plurality of light emitting portions 2a arranged in a straight line, and a plurality of LD lights 4 have a divergence angle from each light emitting surface 2 of each of the light emitting portions 2a. And is radiated.

When an axis parallel to each light emitting surface 2 is a slow axis, and an axis perpendicular to both the LD light traveling direction axis and the slow axis taken perpendicular to each light emitting surface 2 is a first axis, each LD Since the divergence angle of the light 4 in the slow axis direction is about 10 degrees in full width at half maximum and the divergence angle in the first axis direction is about 40 degrees in full width at half maximum in the first axis direction, the divergent light in the first axis direction is generated by the cylindrical lens 3. Convert to parallel light.

The light concentrator 10 is an array type semiconductor laser 1
The number of the optical waveguides 6 is equal to the number of the respective light emitting portions 2a, and the arrangement intervals of the respective optical waveguides 6 are narrowed in the traveling direction of the LD light 4 and the optical waveguides 6 are combined into one by the coupling portion 7. Is done.

An end face of the optical waveguide 6 facing the cylindrical lens 3 is an entrance 5 into which each LD light 4 is incident, and the arrangement pitch is arranged so as to be equidistant from each light emitting surface 2. The array type semiconductor laser 1 and the optical concentrator 10 are arranged so that each light emitting surface 2 and the entrance 5 are parallel. Note that, as shown in FIG. 2, since the LD light 4 travels only in a two-dimensional direction parallel to the slow axis and the LD light traveling direction axis, there is no need for alignment in the fast axis direction.

As described above, the cylindrical lens 3
Thus, each LD light 4 obtained by converting the divergent light in the first axis direction into parallel light is efficiently incident on the entrance 5 of the optical concentrator 10. Then, the light travels through each of the optical waveguides 6, is condensed at the coupling section 7, and is emitted from the emission port 8 as high-density LD light 9.

Next, various examples of an array-type semiconductor laser-excited solid-state laser device using the high-density LD light 9 emitted from the array-type semiconductor laser coupling device of the present embodiment for exciting a solid-state laser will be described. This will be described with reference to FIGS.

The semiconductor laser pumped solid-state laser device for array type shown in FIG. 3 has a configuration in which a resonator mirror 51a, a solid-state laser crystal 52, and a resonator mirror 53 are arranged in this order in the traveling direction of the high-density LD light 9. It has become.

The high-density LD light 9 emitted from the emission port 8 of the light concentrator 10 passes through the resonator mirror 51a and enters the solid-state laser crystal 52. When the high-density LD light 9 excites the solid-state laser crystal 52, the solid-state laser crystal 54 emits the solid-state laser light 54 toward the resonator mirror 53. The resonator mirror 51a and the resonator mirror 53 constitute the laser resonator 60 by being installed such that their reflection surfaces face each other. The solid-state laser light 54 sufficiently amplified by the laser resonator 60 passes through the resonator mirror 53 and is emitted to the outside.

In the example shown in FIG. 3, two resonator mirrors 5 are used.
Although 1a and 53 are used, instead of the resonator mirror 51a, a resonator mirror film 51b may be provided integrally on the incident surface side of the solid-state laser crystal 52 for the high-density LD light 9 as shown in FIG. Good.

In this case as well, the laser resonator 61 is composed of the resonator mirror film 51b and the resonator mirror 53.
The resonator mirror film 51b is formed of the high density L of the solid-state laser crystal 52.
Since it is provided integrally on the incident surface side of the D light 9, the number of components can be reduced.

Further, in the example shown in FIG.
A coupling lens 55 is arranged between the laser resonator 62 and the laser resonator 62. The laser resonator 62 has the same configuration as the laser resonator 60 shown in FIG.

The coupling lens 55 condenses the divergent high-density LD light 9 emitted from the exit port 8 and makes it incident on the solid-state laser crystal 52. Thereby, the solid-state laser crystal 52 can be efficiently excited.

In the example shown in FIG. 6, a coupling lens 55 is disposed between the optical concentrator 10 and the laser resonator 63. The laser resonator 63 is the laser resonator 6 shown in FIG.
This is the same configuration as in FIG.

In addition, as shown in FIGS. 5 and 6, the high-density LD light 9 emitted from the array type semiconductor laser coupling device is condensed using the coupling lens 55 and is incident on the solid-state laser crystal 52. Instead, as shown in FIG. 7, a device for making the light enter the transmission optical fiber 56 may be used.

As described above, the LD light 4 from the array-type semiconductor laser 1 is transferred to the cylindrical lens 3 and the optical waveguide 6.
Since the light can be condensed only by the light, the structure is simplified. This eliminates the need for three-dimensional positioning and facilitates securing long-term accuracy stability. Further, the manufacturing cost can be reduced, and the device can be downsized by not including a long space propagation section in the device. (Second Embodiment) Next, a second embodiment of the present invention will be described.
This will be described with reference to a plan view of the coupling device for an array type semiconductor laser shown in FIG.

Although the basic configuration is the same as that of the first embodiment, in the first embodiment, the light converging device 10 condenses the LD light 4 by a plurality of optical waveguides 6 coupled by the coupling unit 7. On the other hand, in the present embodiment, instead of the plurality of optical waveguides 6, the light converging device 20 has one optical waveguide having a shape in which the waveguide width becomes narrower as approaching the emission port 18. The light is condensed by the wave path 16.

As the LD light 14 incident on the optical waveguide 16 advances in the traveling direction, the interval between the LD light 14 narrows according to the shape of the optical waveguide 16, and is finally coupled near the exit port 18, and the light is emitted. The light is emitted from the exit 18 as high-density LD light 19.

The optical waveguide 16 of the present embodiment is the same as the optical waveguide 1
6 is an opening having a width enough to allow the LD light 14 converted by the cylindrical lens 13 to enter, the arrangement pitch of the light emitting surface 12 of the array type semiconductor laser 11 during manufacturing. It can be manufactured without taking into account. (Third Embodiment) In the above-described embodiment, the description has been given with respect to the focusing on one array type semiconductor laser 1 or 11.
In the following, a description will be given of an array-type semiconductor laser coupling device for condensing LD light groups from a plurality of array-type semiconductor laser groups.

FIG. 9 is a plan view showing a coupling device for an array type semiconductor laser according to a third embodiment of the present invention.

The coupling device for an array type semiconductor laser according to the present embodiment includes an array type semiconductor laser 21, a cylindrical lens 23, and a light concentrator 30a, that is, the coupling device for an array type semiconductor laser shown in the first embodiment is connected in parallel. And a light converging device 30b is further added to those arranged in FIG. The light converging device 30b has a structure having a Y-shaped optical waveguide 26b formed of two connection ports 25b and an emission port 28b. The two light concentrators 30a and the added light concentrator 30b are connected to the exit 28 of the light concentrator 30a.
a and the connection port 25b of the optical concentrator 30b.

The LD light 24 emitted from each array-type semiconductor laser 21 is respectively coupled by the two coupling devices for array-type semiconductor lasers shown in the first embodiment, and then is emitted from an emission port 28, and The light enters the Y-shaped optical waveguide 26b from the connection port 25b of the converging device 30b, and is connected to the coupling portion 27b.
Are further combined. Then, it becomes high-density LD light 29 and is emitted from the emission port 28b.

It is to be noted that another set of array type semiconductor laser coupling devices of the present embodiment is arranged in parallel, and a Y-shaped optical waveguide is further connected to the emission port 28b of each light converging device 30b to further form an LD. It is good also as a structure which raises a light density. In addition, the configuration may be such that two or more sets of coupling devices for an array type semiconductor laser are used, and a plurality of Y-shaped optical waveguides are stacked in series.

In the description of this embodiment, the coupling device for array type semiconductor laser shown in the first embodiment is used, but the coupling device for array type semiconductor laser shown in the second embodiment is used. You may. (Fourth Embodiment) FIG. 10 is a plan view of an array type semiconductor laser coupling device according to a fourth embodiment of the present invention.

The coupling device for an array type semiconductor laser according to the present embodiment includes a plurality of array type semiconductor lasers 31 arranged in parallel and a light emitting surface 3 of the plurality of array type semiconductor lasers 31.
A light converging device 40 having an optical waveguide 36 formed with an entrance 35 having the same number as two and the same arrangement pitch.

The collection and coupling of each LD light 34 is exactly the same as in the first embodiment, and therefore will not be described. However, the configuration of this embodiment is applied to a plurality of array type semiconductor lasers 31 to reduce the number of parts. Can be reduced.

[0050]

As described above, according to the present invention, an optical coupling device for an array type semiconductor laser receives a plurality of laser beams emitted from the array type semiconductor laser and converted into parallel light by a cylindrical lens. Incident part, focusing part that narrows the interval as each of these laser lights progresses, coupling part that combines each laser light focused by the focusing part, and emits the laser light that is coupled by the coupling part By having the optical waveguide plate integrally formed with the emitting portion to be
Not only the number of parts is reduced, but also precise positioning of the optical system for focusing the laser beam is not required, and stable accuracy is secured for a long period of time. In addition, it is no longer necessary to provide a laser beam spatial propagation section in the device.

As a result, the manufacture and mounting of the optical coupling device for an array type semiconductor laser can be facilitated, the manufacturing cost can be reduced, and the small-sized and long-term stable accuracy can be secured.

Further, a solid-state laser device using the array-type semiconductor laser of the present invention can provide the same effect.

[Brief description of the drawings]

FIG. 1 is a plan view of an array type semiconductor laser coupling device according to a first embodiment of the present invention.

FIG. 2 is a side view of the coupling device for an array type semiconductor laser shown in FIG.

FIG. 3 is a plan view showing one embodiment of a semiconductor laser pumped solid-state laser device for array type.

FIG. 4 is a plan view showing another embodiment of the semiconductor laser pumped solid-state laser device for array type.

FIG. 5 is a plan view showing an embodiment of an array type semiconductor laser pumped solid-state laser device having a coupling lens.

FIG. 6 is a plan view showing another embodiment of an array type semiconductor laser-excited solid-state laser device having a coupling lens.

FIG. 7 is a plan view of a device that causes a laser beam to be incident on a transmission optical fiber by the array type semiconductor laser coupling device shown in FIG. 1;

FIG. 8 is a plan view of an array type semiconductor laser coupling device according to a second embodiment of the present invention.

FIG. 9 is a plan view of an array type semiconductor laser coupling device according to a third embodiment of the present invention.

FIG. 10 is a plan view of an array type semiconductor laser coupling device according to a fourth embodiment of the present invention.

FIG. 11 is a diagram illustrating the divergence angle of each laser beam emitted from the light emitting surface of the array type semiconductor laser.

FIG. 12 is a diagram showing a configuration of a conventional coupling device for an array type semiconductor laser.

[Explanation of symbols]

1, 11, 21, 31, 100, 111 Array type semiconductor laser 2, 12, 22, 32, 101, 112 Light emitting surface 2a, 12a, 22a, 32a, 101a, 112a
Light radiating section 3, 13, 23, 33, 113a, 113b Cylindrical lens 4, 14, 24, 34, 102, 114 LD light 5, 15, 25a, 35 Entrance port 25b Connection port 6, 16, 26a, 36 Optical waveguide 26b Y-shaped optical waveguides 7, 17, 27a, 27b, 37 Couplings 8, 18, 28a, 28b, 38 Outlets 9, 19, 29, 39 High-density LD light 10, 20, 30a, 30b Optical concentrator 51a, 53 resonator mirror 51b resonator mirror film 52 solid-state laser crystal 54 solid-state laser light 55 coupling lens 56 transmission optical fiber 60, 61, 62, 63 laser resonator 115 optical path converter 116 condenser lens 117 coupling optical device

Claims (10)

[Claims] An array type semiconductor laser in which a plurality of light emitting portions are linearly arranged, and a plurality of laser beams are emitted from each of the light emitting portions; In an optical coupling device for an array-type semiconductor laser, comprising: a cylindrical lens that forms parallel light; and a light concentrator that converges each laser light that has been converted into parallel light by the cylindrical lens. An incident part to be incident, a focusing part that narrows an interval between the laser lights as the laser light incident from the incident part progresses, and combine the laser lights focused by the focusing part into one. An optical coupling device for an array-type semiconductor laser, comprising: an optical waveguide including a coupling portion that performs coupling and an emission portion that emits the laser light coupled by the coupling portion. 2. A plurality of the incident portions are arranged at positions corresponding to the arrangement of the light emitting portions on a one-to-one basis, and the focusing portions interfere with each other until the laser beams reach the coupling portion. 2. The optical coupling device for an array-type semiconductor laser according to claim 1, wherein the optical coupling device has a structure not to perform. 3. The optical coupling device for an array-type semiconductor laser according to claim 1, wherein a plurality of the array-type semiconductor lasers are arranged in parallel such that all the light emitting portions are arranged linearly. . 4. The optical coupling device for an array-type semiconductor laser according to claim 1, wherein the incident portion has an opening width through which all the laser beams emitted from the cylindrical lens can be incident. 5. The optical coupling device for an array-type semiconductor laser according to claim 1, further comprising a coupling lens for converging the laser light emitted from the emission section onto the transmission optical fiber. . 6. A plurality of array-type semiconductor lasers, cylindrical lenses, and light concentrators are respectively arranged in parallel, and the laser light emitted from each of the light concentrators is further combined into one. An incident section on which each laser beam is incident; a focusing section for narrowing an interval between the laser beams as the laser beams incident from the incident section advance; and a laser beam focused by the focusing section. 3. The optical concentrator according to claim 1, further comprising a light concentrator different from each of the light concentrators provided with an optical waveguide including a coupling unit coupled to one and an emission unit that emits the laser light coupled by the coupling unit. 4. 4. The optical coupling device for an array-type semiconductor laser according to item 1. 7. The optical coupling device for an array-type semiconductor laser according to claim 5, further comprising a coupling lens for converging the laser light emitted from the emission portion of the light focusing coupling portion to the transmission optical fiber. 8. An optical coupling device for an array-type semiconductor laser according to claim 1, wherein the solid-state laser is irradiated with a laser beam emitted from the optical coupling device for an array-type semiconductor laser. A solid-state laser resonator that emits light, amplifies the solid-state laser, and then emits the amplified solid-state laser. 9. The array-type semiconductor laser-pumped solid-state laser device according to claim 8, wherein said solid-state laser resonator includes a solid-state laser crystal and a plurality of laser reflecting members. 10. The array-type semiconductor laser-pumped solid-state laser according to claim 8, further comprising a coupling lens for condensing the laser light emitted from the optical coupling device for an array-type semiconductor laser in the solid-state laser resonator. apparatus.