JPH0249483A - Laser amplifier - Google Patents

Abstract

PURPOSE:To easily extract the highly dense energy of a laser medium by a method wherein a pair of convex lenses, which enable parallel light rays to converge, are provided before and behind a laser medium, and a reflecting mirror provided with a V-shaped reflective surface is provided to one of the outsides of the lenses. CONSTITUTION:A pair of convex lenses 6A and 6B transmissive to laser rays are provided to an incident side and the other side of laser rays respectively sandwiching a laser medium 3 so as to face each other. A reflecting mirror 7 provided on the other side are formed into a cornered cube whose two reflective planes function in such a manner that one of them serves as an incident plane and the other functions as a returning plane. Laser rays incident on the mirror 7 are all reflected in parallel with the incident light rays, and the converging points of laser rays incident on a primary axis of the convex lenses are coincident with each other independently of the incident position. Light rays incident on and reflected from the mirror 7 become positively parallel through correction even if the mirror 7 deviates positionally. By these processes, a highly dense energy of a laser medium can be easily extracted.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a laser amplifier, and particularly to the configuration of an optical path.

(Prior Art) One of the laser media, for example, carbon dioxide gas, has a low density and cannot increase the excitation intensity, so in order to obtain high output, laser light is passed over a wide area and amplified.

That is, in FIG. 3 showing an example of a conventional laser amplifier, the incident light 1 passes through one side of the excitation region 3 from the upper right of the page and enters the reflection mirror 4A at the upper left.

After being bent and incident on the reflection mirror 4B on the lower right, it is bent again (that is, in an inverted Z shape) and passes through the other side of the excitation region 3 and exits to the left to become the output light 2.

However, since the incident light 1 passes through the excitation region only once, for example, in a device using a high-density laser medium such as an excimer laser, the entire energy in the medium cannot be utilized.

Therefore, there is an amplifier with an optical path configured as shown in FIG.

That is, in FIG. 4, incident light 1 incident from the upper right to the lower left passes through the excitation region 3 obliquely from the upper right to the lower right, and enters the reflecting mirror 4A at the lower left and the reflecting mirror 4B located slightly to the left above. Then, it is further bent to the right, passes through the center of the excitation region 3, and enters the reflection mirror 4C on the right side, and then is further bent by the reflection mirror 4D located at the lower right and slightly to the left, diagonally moving the excitation region 3 from the lower right to the upper left. It passes through and becomes emitted light 2.

However, this not only increases the number of reflecting mirrors, but also cannot be used for devices that extract high energy from a narrow area, such as single-dye lasers.

Therefore, an amplifier having an optical path configuration as shown in FIG. S may be considered. That is, in FIG. 5, the laser beam 1 incident from the upper right is condensed through the convex lens 5A, enters the excitation region 3, spreads at the center, enters the convex lens 5B at the lower left, becomes parallel light, and enters the lower left. The light is incident on the 4th reflecting mirror. Then, this incident light is bent upward and enters the reflection mirror 4F located slightly to the left, then bent to the right to become parallel light, condensed by the convex lens 5C, focused at the center of the excitation region 3, and spread out to the right. The convex lens 5D converts the light into parallel light, which enters the reflecting mirror 4H located downward and slightly to the left by the reflecting mirror 4G, is reflected and condensed by the convex lens 5E, passes through the condensing point of the excitation region 3 and the convex lens 5F, and becomes parallel outgoing light 2. becomes.

(Problem to be Solved by the Invention) However, in a laser amplifier with this optical path configuration, the density of the laser light at the focal point of the excitation region increases, and the energy of the medium used in a dye laser can be sufficiently extracted.
The number of lenses increases, the optical system becomes complicated, and the optical axis becomes difficult to adjust.

SUMMARY OF THE INVENTION An object of the present invention is to provide a laser amplifier that can extract energy from a high-density laser medium with a simple optical system.

[Structure of the invention]

(Means and Effects for Solving the Problems) The present invention provides a pair of convex lenses in front and rear of a high-density laser medium with the flat surfaces facing inside, and a 7-shaped A reflecting mirror having a shaped reflecting surface is provided, and a laser beam is incident on one side of one surface of the convex lens on the other side from the other side outside the convex lens, and is focused in a laser medium,
This transmitted light is reflected by the reflecting mirror through a convex lens on one side, folded back in parallel, and focused into the laser medium, thereby extracting energy from a high-density laser medium with a simple optical path configuration. .

(Example) Hereinafter, an example of the laser amplifier of the present invention will be described with reference to the drawings.

In Fig. 1, the convex lens 6 from one side on the left side of the page to the right side
The incident light 1 that has entered the upper part of the surface of A is condensed at the center of the excitation medium 3 on the right side, spreads out, and enters the upper back surface of the convex lens 6B on the right side.

The parallel light enters the upper slope of the corner cube-shaped mirror 7 provided at its right end, and is reflected downward at right angles. Then, this reflected light is reflected to the left at a right angle on the lower slope of the mirror 7, passes through the lower part of the convex lens 6B, is converged at the center of the excitation medium 3, and spreads again to reach the lower part of the left convex lens 6A. The output light 2 is parallel and exits to the left.

According to the laser amplifier having such a configuration, the laser beam incident on the mirror 7 is always reflected in parallel with the incident light, and the laser beam incident on the main axis of the convex lens 6 has a condensing point that coincides regardless of the incident position. do. Further, even if the mirror 7 is misaligned, the incident light and the reflected light on the mirror 7 are corrected and always become parallel, making it possible to provide a laser amplifier with a stable optical axis.

FIG. 2 shows another embodiment in which the optical path focused on the excitation medium 3 is doubled.

In FIG. 2, the convex lenses 6C and 6D in FIG. 2
They may be placed side by side. ), on the left side is the same mirror 7 as in Figure 1.
is used.

In this case, the excitation energy in the excitation region increases, so
It is possible to extract more energy at a higher density.

Further, the optical axis adjustment only needs to be done by arranging the lenses and adjusting the initial incident optical axis.

Note that in the above embodiment, the corner cube-shaped mirror 7
．． 9, this may be a corner cube prism, and although a planocompex lens is used as the convex lens, a meniscus lens may also be used.

〔Effect of the invention〕

As described above, according to the present invention, in a laser amplifier that extracts energy by passing high-density laser light through a high-density laser medium, a convex lens for converging parallel light is provided at the front and rear of the laser medium, and a right-angled Since a reflecting mirror with a 7-shaped reflecting surface is used, a laser amplifier that can extract energy from a high-density laser medium with a simple configuration can be obtained.

[Brief explanation of the drawing]

FIG. 1 is an optical path configuration diagram showing one embodiment of the laser amplifier of the present invention, FIG. 2 is an optical path configuration diagram showing another embodiment of the invention,
3 to 5 are optical path configuration diagrams of a conventional laser amplifier. 1...Incoming light 2...Outgoing light 3...Laser medium 6...Convex lens 7...Reflecting mirror (8733) Attorney Akira (and 1 other person) Fig.

Claims (1)

[Claims] Laser light that has passed through from one side of an excitation region of a high-density laser medium to the other side is reflected by a reflecting mirror on the other side, and this reflected light is allowed to pass through to the one side of the excitation region. In a laser amplifier that excites the laser medium and amplifies the laser beam, a pair of convex lenses that transmit the laser beam are arranged with flat surfaces facing each other on an incident side of the laser beam and the other side with the laser medium in between. A laser amplifier characterized in that the reflecting mirror on the other side has a reflecting surface shaped like a corner cube, with one surface serving as an incident surface and the other surface serving as a folding surface.