JPS62112387A - Surface pumping type laser - Google Patents

Abstract

PURPOSE:To improve the efficiency of a surface pumping laser and induce uniform excitation by making the shape of a converging mirror a complex elliptical surface. CONSTITUTION:In x-y coordinates, with the center of a laser medium 1 as an origin, the sectional area of the medium is (a)X(b), the center position of a lamp (x, y)=(+ or -c, 0) and the outside diameter of the lamp is denoted by (d). Corresponding to the dimensions (a)-(d), x0, y0, x1, y1, A and B are selected to make the curved surface of a converging mirror 5 a complex elliptical surface expressed by an ellipse equation. With this constitution, very little portions of the lights emitted from the lamp 2 reenter the lamp 2 after they are reflected by the complex elliptical surface of the converging mirror 5 and the most portions of the reflected lights enter the respective parts of the laser medium 1 uniformly. Therefore, the efficiency of the laser can be improved and uniform excitation can be induced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] This invention relates to increasing the efficiency of single-plane pumping lasers and making the excitation uniform.

[Conventional technology]

FIG. 2 is a sectional view of a condenser tube of a conventional surface pumping type laser. In Fig. 2, (1) is a flat laser medium, (2+ is a linear lamp for optically exciting the laser medium (1), (3) is the optical path of the light emitted from the lamp (2),
(4) converts the light (3) emitted from the lamp (2) into the laser medium (
1) shows a single ellipsoidal focusing mirror for focusing on.

In the E configuration, the centers of the two lamps (2) are placed at each focal point of a single elliptical condenser mirror (4). The light (3) emitted from the lamp (2) by this
points to another elliptical focal point and its optical path converges on the laser medium (1).

[Problem that the invention seeks to solve]

However, in the configuration described above, the light emitted from the lamp tends to gather in the center of the laser medium.

It is not possible to uniformly excite each part of the laser medium.

Of the light emitted from the lamp, many rays are reflected by the condenser mirror and enter the lamp again after one reflection.

Because these rays pass through the interior of a highly absorbing lamp, they suffer from losses and low overall CO efficiency.

The present invention aims to solve these problems, uniformize the excitation of a laser medium, and improve efficiency.

[First step to solve the problem] What is the surface pumping laser involved in your invention?

It uses a condensing mirror that is a combination of multiple elliptical curved surfaces.

[For production]

In this invention, after the light emitted from the lamp is reflected by the compound elliptical curved surface used as the condenser mirror, the light re-enters the lamp only at a low rate, while the light is uniformly distributed to each part of the laser medium. It will be incident on .

〔Example〕

FIG. 1 is a sectional view of a condenser tube showing an embodiment of a surface pumping type laser according to the present invention. Same shape as Figure 2,
For the laser medium (1) and lamp (2) in the same arrangement,
When viewed from the laser medium (1), by employing a condensing mirror 5) that combines a plurality of elliptical curved surfaces.

There is also an f, - ray coming out behind the lamp (2). The light reaches the laser medium (1) without re-entering the lamp (2), and the light rays are not concentrated on each part of the laser medium (1).

Here, in order to express the curved shape of the condensing mirror f5+ with an equation,
An xy coordinate system is shown in FIG. At this time, the laser medium (1
) is the origin. The cross-sectional dimensions of the laser medium (1) are aXb
, the lamp center position is (x, y) = (±e, 0)
2/B.

It is expressed as At this time, '0-3'O,"1.,!/1.
A, B are a.

Select the highest value according to the values of b, c, and d.

for example. Using a laser medium with a cross-sectional dimension of 15111 x 6 mm and a lamp with an outer diameter of 9 mm, place the lamp at the position (a;, y) = (±24.0) in the xy coordinate system described above.1 In this case, In the equation of the compound elliptic surface mentioned above.

x(3=0. y□=3. r1=0. y1=0.
A=38. Let the curved surface represented by B=9 be a condensing mirror. This compound elliptic surface is.

Long sleeve radius 331. Compared to the case of using a single elliptical curved surface with a minor axis radius of 18, the calculation results from ray tracing show that the light collection efficiency is 1696 degrees higher, and the distribution of light energy received by the laser medium is as shown in Figure 3. As can be seen, when using a condensing mirror with a single elliptic curved surface as shown in FIG. The sex is opposite.

〔Effect of the invention〕

As described below, this invention has the effect of uniformizing the efficiency and excitation by making the shape of the condensing mirror a compound elliptical curved surface.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a condenser tube of a surface pumping type laser showing an embodiment of the present invention, FIG. 2 is a sectional view of a conventional surface pumping type laser, and FIG. FIG. 4 shows the distribution of received light energy in the laser medium when a condensing mirror is used, and FIG. 4 shows the distribution of received light energy in the laser medium when a condensing mirror with a compound elliptic curve is used. In the figure, (1) is the laser medium, (2) is the lamp, (
4) is a condensing mirror with a single elliptical curved surface, and (5) is a condensing mirror with a compound elliptic curved surface. In addition, the same or equivalent parts in FIG. 0 are given the same reference numerals.

Claims (1)

[Claims] A flat laser medium, two linear lamps that optically excite the laser medium, and a device that collects light from the lamps onto the laser medium, the origin of which is located on a cross section perpendicular to the axis of the lamps. When an xy orthogonal coordinate system is taken with the medium center and the x axis as a line connecting the two lamp centers, if the cross-sectional shape is x≧x_1 and y≧y_1, then (x-
x_0)^2/A^2+(y-y_0)^2/B^2=
1, for x≧x_1, y≦−y_1, (x−x_0)＾2
/A^2+(y+y_0)^2/B^2=1, x≦-x
_1, for y≧y_1, (x+x_0)^2/A^2+(
y−y_0)^2/B^2=1, x≦−x_1, y≦−
For y_1, (x+x_0)^2/A^2+(y+y_0
)^2/B^2=1, and in this case x_0, y_0,
1. A surface pumping type laser comprising: a converging mirror having a compound elliptic curved surface in which x_1, y_1, A, and B are expressed as positive real numbers.