JPH05160477A - Solid-state laser device - Google Patents

Abstract

PURPOSE:To provide a solid-state laser device to obtain a laser oscillator in which the intensity distribution and flaring angle of laser output light are uniform in radial directions. CONSTITUTION:A solid-state laser device is provided with a pumping light condensing mechanism 13, in which a laser rod 5 and a rod-shaped pumping lamp 6 are arranged in a cylindrical, elliptical reflection mirror 4 fitted into a rectangular paralleled member 8, and a holding mechanism 7 to hold the pumping light condensing mechanism, and further the rectangular paralleled member is constituted in such a way that the plane sectional shape perpendicular to its central axis may be a regular polyhedron or circle having a center on the central axis and the central axis coincide with the central axis of the laser rod.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solid-state laser device suitable for use in a laser oscillator.

[0002]

2. Description of the Related Art Generally, in a laser oscillator, electric power is supplied from a laser power source to an excitation lamp of a solid-state laser device so that the excitation lamp is turned on. When the light is incident on the solid-state laser medium by the condenser, the solid-state laser medium is excited to cause laser oscillation, and laser light is emitted from the output mirror.

A conventional solid-state laser device is constructed as shown in FIGS. 9 and 10, and FIG. 9 is an exploded perspective view, FIG.
0 is a sectional view. In the figure, reference numeral 1 is a lid, 2 is an excitation light condensing mechanism, and is composed of a rectangular parallelepiped member 3, a cylindrical elliptical reflecting mirror 4, a rod-shaped solid laser medium 5, and a rod-shaped excitation lamp 6.
Reference numeral 7 denotes a recess 9 and a through hole 10 provided in the rectangular parallelepiped member 8.
And a recess 9 of the holding mechanism 7.
The excitation light condensing mechanism 2 is fitted to and is covered with the lid 1.
The reference numeral 12 is the central axis of the rectangular parallelepiped member 3 and at the same time the central axis of the excitation light focusing mechanism 2.

By the way, a laser oscillator is constructed by using a solid-state laser device in which a solid-state laser medium 5 and an excitation lamp 6 are arranged so as to coincide with the two focal axes of the cylindrical elliptical reflecting mirror 4. , When performing laser oscillation, the cylindrical elliptical reflecting mirror 4
The excitation light is likely to be condensed in the major axis direction of the elliptical cross section, and the excitation distribution is biased. As a result, the cross-sectional shape of the laser light output from the laser oscillator becomes elliptical, and the divergence angle differs between the major axis direction and the minor axis direction.

[0005]

The conventional solid-state laser device as described above often causes a problem when utilizing laser light. Therefore, in a multistage laser oscillator using a plurality of solid-state laser devices, the individual solid-state laser devices as a whole are tilted and fixed, for example, by 90 degrees, so that the laser oscillator as a whole produces uniform excitation. A method for improving the quality of laser light has been implemented. However, with this method, the structure for holding the solid-state laser device becomes complicated and large, and it is difficult to obtain the intended effect in a stable manner, and the adjustment becomes complicated. It is an object of the present invention to provide a solid-state laser device capable of obtaining a laser oscillator in which the intensity distribution and spread angle of laser output light are uniform in the radial direction.

[0006]

SUMMARY OF THE INVENTION The present invention provides a pumping light condensing mechanism in which a rod-shaped solid laser medium and a rod-shaped pumping lamp are arranged in a cylindrical elliptical reflecting mirror formed in a rectangular parallelepiped member. The rectangular parallelepiped member has a cross-sectional shape in a plane perpendicular to the central axis, which is a regular polygon or a circle centered on the central axis. The solid-state laser device is configured so that the central axis and the central axis of the solid-state laser medium coincide with each other.

[0007]

According to the present invention, the direction of the excitation distribution is rotated by rotating only the excitation light converging mechanism with respect to the optical axis without changing the components of the apparatus, and the multistage laser oscillator is rotated. The entire excitation distribution can be made uniform.
As a result, it is possible to obtain a laser oscillator in which the intensity distribution and spread angle of the laser output light are uniform in the radial direction.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings.

The solid-state laser device according to the present invention is constructed as shown in FIGS. 1 and 2. In the present invention, the pumping light collecting mechanism 13 is improved. Let's start from 13.

If the same parts as those in the conventional example (FIG. 9) are designated by the same reference numerals, the excitation light focusing mechanism 13 has a rectangular parallelepiped member 1.
4, a cylindrical elliptical reflecting mirror 4, a rod-shaped solid-state laser medium 5, and a rod-shaped excitation lamp 6. That is, the rectangular parallelepiped member 14 is eccentrically provided with a cylindrical elliptic cylinder, and the cylindrical elliptical reflecting mirror 4 is formed on the inner surface thereof. Inside the cylindrical elliptical reflecting mirror 4, one rod-shaped solid-state laser medium 5 that produces an optical amplification effect and one rod-shaped excitation lamp 6 that excites this solid-state laser medium 5 are arranged at predetermined intervals. It is located at.

In this case, the rectangular parallelepiped member 14 is formed in a regular polygonal shape having a center on the central axis 15, for example, a square, as shown in the drawing, in a plane perpendicular to the central axis 15. The central axes 15 of the rectangular parallelepiped member 14 are parallel to the central axes of the cylindrical elliptical reflecting mirror 4, the rod-shaped solid laser medium 5, and the rod-shaped excitation lamp 6. Further, according to the present invention, the central axis 15 of the rectangular parallelepiped member 14 and the central axis of the solid laser medium 5 are aligned with each other. Moreover, the solid-state laser medium 5 and the excitation lamp 6 are arranged so as to coincide with the two focal axes of the cylindrical elliptical reflecting mirror 4. On the other hand, the holding mechanism 7 in which the above-mentioned excitation light condensing mechanism 13 is housed and held comprises a rectangular parallelepiped member 8 having a recess 9 and through holes 10 and 11, and the recess 9 of the holding mechanism 7
The excitation light condensing mechanism 13 described above is fitted to and the lid 1 is covered.

Now, as described above, the central axis 15 of the rectangular parallelepiped member 14, that is, the central axis of the excitation light converging mechanism 13 is the solid-state laser.
If the excitation light converging mechanism 13 has a structure that coincides with the central axis (optical axis) of the medium 5 and that the section of the excitation light condensing mechanism 13 in a plane perpendicular to the central axis is a square centered on the central axis. , 90 about the central axis of the pumping light focusing mechanism 13 only
It becomes possible to rotate by degrees, and the cylindrical elliptical reflecting mirror 4
The major axis direction of the solid laser medium 5 can be rotated by 90 degrees with respect to the central axis of the solid laser medium 5.

That is, the bias of the excitation distribution is 9 with respect to the optical axis.
It is possible to rotate by 0 degrees. This makes it possible to change the bias direction of the excitation distribution even if the holding mechanism 7 and the excitation light focusing mechanism 13 are one type of component. Further, the major axis direction of the elliptical cross section of the tubular elliptical reflecting mirror 4 may be an arbitrary angle with the side surface or the bottom surface of the excitation light converging mechanism 13, but if this is set to 45 degrees, The excitation light focusing mechanism 13 can be miniaturized.

If the solid-state laser device of the present invention as described above is adopted, the excitation distribution can be obtained with an inexpensive and simple structure without increasing the kinds of parts, the trouble of maintenance work, and the increase of adjustment points. It is possible to obtain a uniform multistage laser oscillator.

FIG. 2 shows a four-stage laser oscillator in which the solid-state laser device of the present invention is adopted.
Reference numerals 5 and 16 are mirrors, 17 is a major axis direction of the elliptical cross section, and 18 is a laser output light pattern. (Other Embodiment) FIGS. 4 to 8 show another embodiment of the present invention, in which the same effect as the above embodiment can be obtained.

That is, in the above embodiment, the excitation light condensing mechanism 13 is used.
The outer shape of the rectangular parallelepiped member 14, that is, the cross-sectional shape on a plane perpendicular to the central axis of the rectangular parallelepiped member 14 is formed in a square shape having a center on the central axis, but the shape is not limited to the square shape, and may be a regular polygonal shape, for example. A regular rectangular parallelepiped member 1 as shown in FIG.
Excitation light condensing mechanism 20 consisting of 9, positive 6 as shown in FIG.
It is also possible to use the excitation light condensing mechanism 22 composed of a rectangular parallelepiped member 21. Along with this, the holding mechanism 2 of FIG.
The concave portion 24 of No. 3 has a regular triangular cross section, and the concave portion 26 of the holding mechanism 25 in FIG. 5 corresponds to a regular hexagonal sectional shape, and the lid 27 also corresponds.

Generally, when the sectional shape of the rectangular parallelepiped member, that is, the excitation light condensing mechanism is an n-polygon, it is possible to rotate the bias of the excitation distribution by (360 ÷ n) degrees.
Further, if the angle between the major axis direction of the elliptical cross section and the side surface of the excitation light condensing mechanism is 90 × (n−2) / n degrees, the size can be minimized.

Further, an excitation light condensing mechanism 29 composed of a rectangular parallelepiped member 28 having a circular cross section as shown in FIG. 6 may be used.
Accordingly, the recess 31 of the holding mechanism 30 has a circular cross section, and the lid 32 also has a corresponding cross section. In this case, the bias of the excitation distribution can be rotated at an arbitrary angle.

The central axes of the rectangular parallelepiped members 19, 21 and 28 coincide with the central axis of the solid laser medium 5. Further, in each drawing, the illustration of the excitation lamp 6 is omitted for convenience.

Further, FIGS. 7 and 8 show the case where two cylindrical elliptical reflecting mirrors 33, 34 and 35, 36 continuously formed on the rectangular parallelepiped member 14 having a square cross section are used. Elliptical reflectors 33, 34 and 35, 36
The solid-state laser medium 5 is arranged at the focal point common to the two, and the excitation lamps 6a and 6b are arranged at the focal points of the cylindrical elliptical reflecting mirrors 33, 34 and 35, 36, respectively. Of course, it is also possible to use two or more tubular elliptical reflecting mirrors.

[0021]

According to the present invention, since the excitation light condensing mechanism whose cross-sectional shape with respect to the optical axis is a regular polygon or a circle centered on the optical axis is used, the components of the apparatus are completely changed. Without rotating the pumping light converging mechanism alone with respect to the optical axis, the direction of the pumping distribution can be rotated to make the pumping distribution of the entire multistage laser oscillator uniform.
As a result, it is possible to obtain a laser oscillator in which the intensity distribution and spread angle of the laser output light are uniform in the radial direction.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing a solid-state laser device according to an embodiment of the present invention.

FIG. 2 is a sectional view showing a solid-state laser device of the present invention.

FIG. 3 is a perspective view showing a laser oscillator using the solid-state laser device of the present invention.

FIG. 4 is an exploded perspective view showing another embodiment of the present invention.

FIG. 5 is an exploded perspective view showing another embodiment of the present invention.

FIG. 6 is an exploded perspective view showing another embodiment of the present invention.

FIG. 7 is a perspective view showing another embodiment of the present invention.

FIG. 8 is a perspective view showing another embodiment of the present invention.

FIG. 9 is an exploded perspective view showing a conventional solid-state laser device.

FIG. 10 is a sectional view showing a conventional solid-state laser device.

[Explanation of symbols]

1 ... Lid, 4 ... Cylindrical ellipsoidal mirror, 5 ... Solid-state laser medium, 6
... Excitation lamp, 7 ... Holding mechanism, 8 ... Rectangular member, 9 ... Recess, 10, 11 ... Through hole, 13 ... Excitation light condensing mechanism, 14 ...
Rectangular member, 15 ... Central axis.

Claims (1)

[Claims] 1. An excitation light condensing mechanism in which a rod-shaped solid-state laser medium and a rod-shaped excitation lamp are arranged in a cylindrical elliptical reflecting mirror formed in a rectangular parallelepiped member, and the excitation light condensing mechanism is held. In the solid-state laser device having a holding mechanism for holding, the rectangular parallelepiped member has a cross-sectional shape in a plane perpendicular to the central axis thereof, which is a regular polygon or a circle centered on the central axis, and A solid-state laser characterized in that the axis and the central axis of the solid-state laser medium coincide with each other.
The device.