JPH06237032A - Semiconductor-laser excited solid laser device - Google Patents

Abstract

PURPOSE:To provide a semiconductor-laser excited solid laser device, in which oscillation efficiency is further made better than conventional devices. CONSTITUTION:In a semiconductor-laser excited solid laser device, a solid laser rod 4 is excited by projecting semiconductor laser beams 2 to said rod 4 and the output beams 9 of laser oscillation are acquired. The laser uses a elliptic mirror 11, in which the radius of curvature in the direction perpendicular to the joint surface 12 of a semiconductor laser 1 is different from that in the direction parallel to the joint surface 12, and the ratio of the former to the latter is equal to the ratio of a spreading angle in the vertical direction to one in the horizontal direction. The mirror has an elliptical cross section perpendicular to an optical axis.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor laser pumped solid state laser device.

[0002]

2. Description of the Related Art A conventional semiconductor laser (Laser-Diode, abbreviated as LD hereinafter) pumped solid-state laser device is as shown in the schematic view of FIG. 3, and LD light 2 emitted from a pumping LD 1 is used.
Is collected by a coupling lens 3 and a solid laser oscillation region 1 is formed from an end surface 5 of a solid laser rod 4 which is a laser medium.
It is incident within 0. On the end face 5 of the solid-state laser rod 4,
A coating is provided that transmits the LD light 2 well and reflects the solid-state laser oscillation light 6. On the other hand, the concave surface 8 of the concave mirror 7 is provided with a coating that reflects the solid laser oscillation light 6 almost (90 to 99%) and slightly transmits it (1 to 10%). The central axes of the end surface 5 of the solid-state laser rod 4 and the concave surface 8 of the concave mirror 7 are coincident with each other to form a laser resonator. The solid-state laser oscillation light 6 excited by the LD light 2 is amplified by this resonator, and a part thereof becomes output light 9 and is emitted from the concave mirror 7.

Such an LD-pumped solid-state laser device has a (1)
It has features such as compactness, (2) long life, and (3) high oscillation efficiency (pump light power / output power).
(1) and (2) are characteristics peculiar to LD, and there are two reasons for (3). One is that since the oscillation wavelength of the LD is single, the absorptivity is good by matching it with the absorption wavelength band of the solid-state laser rod. The other is that the size of the LD light source is smaller than the conventional rare gas discharge lamp (1 mm ² or less) and the divergence angle is small, so that it is condensed by a lens or the like to oscillate the solid laser rod. This is because the injection can be concentrated in the area.
Therefore, spatial matching between the excitation light from the LD and the oscillation region of the solid-state laser rod is a key point for improving the oscillation efficiency. However, since the light emitting pattern of the LD is elliptic as shown in the explanatory view of FIG. 4, there is a problem in that there is a mismatched portion and the efficiency is reduced, as shown by the diagonal lines in the sectional view 5 of the rod end surface 5 in FIG. There is.

[0004]

SUMMARY OF THE INVENTION The present invention has been proposed in view of the above circumstances, and an object thereof is to provide a semiconductor laser pumped solid-state laser device in which the oscillation efficiency is further improved as compared with the prior art. .

[0005]

To this end, the present invention is directed to a semiconductor laser pumped solid-state laser device that excites the solid-state laser rod by injecting the semiconductor laser light into the solid-state laser rod to cause laser oscillation. The radius of curvature in the direction perpendicular to the joining surface of the and the radius of curvature in the horizontal direction are different, and their ratio is equal to the ratio of the divergence angle between the vertical direction and the horizontal direction, and the shape of the cross section perpendicular to the optical axis is an ellipse. It is characterized by using an elliptical mirror.

[0006]

In the semiconductor laser pumped solid-state laser device of the present invention, as the output mirror, the radii of curvature differ between the direction perpendicular to the joining surface of the LD and the direction horizontal to the divergence angle between the direction perpendicular and the direction horizontal. If an elliptical mirror whose cross section perpendicular to the optical axis is equal to the ratio is used, the cross-sectional shape of the oscillation mode of the solid-state laser will also be elliptical.
The LD excitation light coincides with the emission pattern of the D excitation light, the LD excitation light and the solid-state laser oscillation region are spatially matched, and the oscillation efficiency is improved.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a semiconductor laser pumped solid-state laser device of the present invention will be described with reference to the drawings. FIG. 1 is a schematic view of the device, and FIG. 1A shows a cross section perpendicular to an LD bonding surface. (B) shows a cross section horizontal to the LD bonding surface. Figure 2
FIG. 4 is a sectional view of an end surface of a solid-state laser rod. In FIG. 1, 11 has different radii of curvature in the direction perpendicular to the joint surface of LD1 and in the horizontal direction, and the ratio is equal to the ratio of the divergence angle between the direction perpendicular to the joint surface 12 of LD1 and the horizontal direction, This is an elliptical mirror whose cross section perpendicular to the optical axis is elliptical, and the other members are the same as in FIG. LD from LD1
The light 2 is condensed by the coupling lens 3 as in the conventional case, and then the laser oscillation region 10 is emitted from the end face 5 of the solid laser rod 4.
Is injected inside. Then, the beam oscillated by the resonator constituted by the end surface 5 of the solid-state laser rod 4 and the concave surface 8 of the elliptical mirror 11 has an elliptical cross-sectional shape, so that as shown in FIG. Since it matches the cross-sectional shape, the oscillation efficiency increases.

[0008]

In summary, according to the present invention, in a semiconductor laser pumped solid-state laser device which excites a solid-state laser rod by injecting the semiconductor laser light into the solid-state laser rod to cause laser oscillation, a junction surface of the semiconductor laser is used as an output mirror. An elliptical mirror whose radius of curvature in the direction perpendicular to and the radius of curvature in the horizontal direction are different and whose ratio is equal to the ratio of the divergence angle between the vertical direction and the horizontal direction and whose cross section perpendicular to the optical axis is elliptical By using a semiconductor laser pumped solid-state laser device, the oscillation efficiency of which is further improved as compared with the prior art, the present invention is extremely useful industrially.

[Brief description of drawings]

FIG. 1 is a schematic view of an embodiment of a semiconductor laser pumped solid-state laser device of the present invention, where FIG. 1A shows a cross section perpendicular to an LD bonding surface, and FIG. 1B shows a cross section horizontal to the LD bonding surface. Indicates.

FIG. 2 is a sectional view of the end surface of the solid-state laser rod in the above.

FIG. 3 is a schematic diagram of a conventional semiconductor laser pumped solid-state laser device.

FIG. 4 is an explanatory diagram showing a beam divergence state of a semiconductor laser.

FIG. 5 is a cross-sectional view of a solid-state laser rod end surface of a conventional semiconductor-laser-pumped solid-state laser device.

[Explanation of symbols]

 1 Semiconductor laser 4 Solid-state laser rod 11 Elliptical mirror 12 Bonding surface of semiconductor laser

Claims (1)

[Claims] 1. A semiconductor laser-excited solid-state laser device that excites a solid-state laser rod to oscillate the same by injecting the semiconductor laser light into the solid-state laser rod. Is different from the radius of curvature in the horizontal direction and its ratio is equal to the ratio of the divergence angle between the vertical direction and the horizontal direction, and an elliptical mirror whose cross section perpendicular to the optical axis is elliptical is used. Semiconductor laser pumped solid-state laser device.