JPH0378265A - Gas laser oscillator - Google Patents

Abstract

PURPOSE:To clean a mirror keeping a hermetically sealed container sealed by constructing the title device in such a way that the mirror can be moved, and kept sealed by operating moving means. CONSTITUTION:A mirror 23 is fixed at portions of O-rings 8a, 8b, kept sealed, and is protruded in its half part from one end of an adjusting plate 22. It is assumed that a portion of the mirror 23 facing a transparent part 1 is contaminated to a degree to be cleaned. For cleaning of the mirror, one movable screw 29a is first withdrawn near a bent part 26a. Then, the other movable screw 29b is driven to move the mirror 23 toward a bent 26a side along a guide part 30. With this movement, a reflecting surface portion not used and not contaminated is allowed to face the transparent part 1. Further, a contaminated reflecting surface is protruded from the adjusting plate 22 to the outside.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention (Field of Industrial Application) The present invention relates to a gas laser oscillation device, and particularly to the structure of an optical resonator.

(Prior Art) To explain a gas laser oscillation device that circulates a gas laser medium in an airtight container as an example, as shown in FIG. One mirror (3) constituting an optical resonator is attached to a holder (4) at one end of the airtight container.
) is maintained. Although not shown, another holder having the same structure as the holder (4) is attached to the other end of the airtight container (2), and holds the other mirror constituting the optical resonator.

The holder (4') has a bellows (5) coaxially attached around the transparent part (1) and a passage part (6), and the passage part (6) is connected to the transparent part (1). The adjusting plate (7) is coaxially opposed to the bellows (5) and has O-rings (0-rings) on both sides.
8a) and (8b), the mirror (3) consisting of an output mirror or a high output mirror is airtightly attached to the adjustment plate (7),
It consists of a fixing plate (1o) that is fixed with screws (9). The adjustment plate (7) has an adjustment screw (
11) are provided at 3 or 4 locations, and the airtight container (
2), respectively.

(Problems to be Solved by the Invention) When the discharge for exciting the gas laser medium is a pulse operation, a large amount of discharge products are generated in the discharge section. This discharge product is propagated by a shock wave during discharge, or is mixed into the gas laser medium, causes a chemical reaction by the laser light emitted during circulation, and adheres to the mirror (9). When laser oscillation is operated for a long time, the part of the mirror that is hit by the laser beam becomes black and dirty, and this dirt becomes a seed and the dirt progresses at an accelerated rate. Dirt reduces the laser output and burns out the mirror, and conventionally, this contamination was removed while it was still slight to create a clean reflective surface for laser oscillation. However, to remove dirt, use a mirror (3)
Since this is done by removing it from the holder (4), the airtight state of the airtight container (2) will be broken. Therefore, each time the mirror (3) is cleaned, it is necessary to adjust the optical axis of the mirror (3) by evacuation of the airtight container (2), gas replacement, etc., which poses a problem in that it takes too much time to restart laser oscillation. .

The present invention has been made to solve such problems, and an object of the present invention is to provide a gas laser oscillation device that can clean the mirror while maintaining the airtightness of the airtight container.

[Structure of the invention] (Means and effects for solving the problem) An airtight container enclosing a gas laser medium, at least a pair of main discharge electrodes provided in the airtight container, and a pair of mirrors held by a holder. and an optical resonator that is provided at both ends of the airtight container and resonates the laser light generated in the main discharge space, wherein the holder is a transparent holder formed at the end of the airtight container. a bellows attached around the light part; an adjustment plate having a passage part and integrated with the bellows with the passage part facing the transparent part;
A mounting plate for airtightly clamping the mirror together with the adjustment plate, and a moving means for moving the mirror in one direction while maintaining the airtightness, wherein at least approximately half of the mirror is airtight. The adjustment plate has a length that protrudes from the side along the one direction of the adjusting plate, so that the mirror can be alternately cleaned one side at a time while maintaining the airtightness of the airtight container.

(Example) EMBODIMENT OF THE INVENTION Hereinafter, the present invention will be described based on drawings showing examples.

Note that parts common to those in FIG. The side structure will be explained. That is, Fig. 1,
In Fig. 2, an airtight container (2) is provided with an excitation means such as a main discharge electrode inside, and a transparent part (1) is coaxially formed at one end of the airtight container (2). A mirror (3) constituting an optical resonator is held by a holder (20). This holder (20) has a bellows (5) coaxially attached around the transparent part (1) and a passage part (21), and the passage part (21) is connected to the transparent part (1). The adjustment plate (22) is coaxially faced and combined with the bellows (5), and the mirror (23) consisting of an output mirror or a high reflection mirror is connected to the adjustment plate with O-rings (8a) and (8b) interposed on both sides. (22)
A fixing plate (25) is airtightly fixed with screws (9), and mirrors (
A bent part (23) is fixed facing each other along the reflective surface of the mirror (23), is bent at right angles to the airtight container (2) side, and has a female threaded part (24) formed toward the end surface of the mirror (23). 26a
), (28b), a pair of adjusting bodies (27a),
(27b) and the bent portions (26a) and (26b)
A rotatable ball (28a) is screwed onto the tip of each screw.
, (28b), and movable screws (29a) and (29b) whose end surfaces are in contact with the mirror (23) through the screws (29a) and (29b). As shown in Fig. 3, the adjustment plate (22) has a step-shaped guide part (3) that guides the mirror (23) in its linear movement.
0) is formed. Further, the mirror (23) is airtightly fixed by the O-rings (8a) and (8b), and approximately half of the mirror (23) (more than half is preferable) from one end of the adjustment plate (22). (It may be slightly shorter than the half body) has a protruding length. Therefore, the adjustment bodies (27a) and (27b) are formed to a length that allows the mirror (23) to protrude nearly half of each on both sides of the adjustment plate (22). In addition, in the above configuration, the fixing plate (
25) has a passage part (3) coaxially facing the passage part (21>).
1) is formed, but this passage part (31) does not particularly need to be formed when the mirror (23) is a high reflection mirror. The adjusting plate (22) is provided with adjusting screws (11) at 3 or 4 places in order to align the optical axis with the other mirror (not shown) facing the mirror (3), and the rotating screws (11) are provided at the tips of these screws. Each end is brought into contact with the end of the airtight container (2) via freely attached balls (12). In addition, in the above configuration, a part of the mirror (3) is always in contact with the outside air, so
It is desirable to cover the entire holding body 20) with a cover or the like. In addition, although a pair of moving screws were provided in the above embodiment,
If the movable screw and the mirror (3) are configured to rotatably engage with each other at their tips, the movable screw may be provided on either one.

Next, the operation of the above configuration will be explained. Assume that in the state shown in FIG. 2, the portion of the mirror (23) facing the transparent portion (1) is dirty to the extent that it requires cleaning.

At this time, to perform the above cleaning, first move one of the moving screws (
29a) is retracted to a position close to the bent portion (26a). Next, the other moving screw (29b) is driven to move the mirror (23) toward the bent portion (26a) along the guide portion (30). Due to this movement, the clean and unused reflective surface portion faces the transparent portion (1). Moreover, the dirty reflective surface protrudes from the adjustment plate (22) to the outside.

FIG. 4 shows another embodiment of the present invention, in which the movement of a mirror (3), which is an optical resonator, is controlled in accordance with the number of laser shots. That is, (40) is an airtight container (2
), and holders (20) are provided at both ends, as in the above embodiment. In these holding bodies 20), the moving screws (29a) and (29b
) are driven by pulse motors (41a) to (41d), respectively. (42) is a control unit, which includes a control signal generation unit (43) that has an arithmetic function and generates a pulse signal for laser oscillation, a counter (44) for counting the number of the pulse signals, and The set number of times and counter (4) when the mirror (3) starts moving.
4) and a comparator (45) for comparing the number of times. The pulse signal from the control signal generator (43) is sent to the counter (44).
), a trigger signal for laser output is sent to a generator (48) to a high-voltage power source (46) that supplies discharge power to the laser tube (40).

In the embodiment shown in FIG. 4, laser oscillation is started, and laser output is performed by oscillating a pulse signal to the trigger generator (48). The number of times of this output is counted by a counter (44), and when the set number of times is exceeded by a comparator (45), a control signal generator (43) sends a signal to each pulse motor (
Control signals are sent to 41a) to (41d). This control signal is transmitted to six pairs of pulse motors (41a),
(41b), (41C), and (41d) are rotated a predetermined number of rotations in opposite directions between pairs, and the moving screws (29a) and (29b) are rotated in the respective directions to move the mirror (3). move. The control unit (42) is programmed so that in the next movement after this movement, a control signal is generated to perform a rotation opposite to that described above.

[Effect of the invention] Since it is now possible to move the mirror (23) while maintaining airtightness by driving the moving screws (29a) and (29b), the mirror (23) can be moved without interrupting laser oscillation.
By placing an unused or clean reflective surface facing one of the resonators, it is now possible to normalize the dirty reflective surface. Therefore, it is necessary to replace the gas in the airtight container that is the laser tube, which was conventionally done every time the optical resonator was cleaned.
This eliminates the need for various troublesome tasks such as adjusting the optical axis to restart laser oscillation. In addition, by automatically moving the laser, it is now possible to obtain stable laser output.

[Brief explanation of drawings]

FIG. 1 is a side view showing one embodiment of the present invention, and FIG. 2 is a side view showing one embodiment of the present invention.
3 is a sectional view taken along the line II-II in the figure, FIG. 3 is a sectional view taken along the line ■-■ in FIG. 1, and FIG. 4 is an overall configuration diagram showing another embodiment of the present invention. FIG. 5 is a sectional view showing a conventional example. (2) ・Airtight container (3)... Kutsu (5) ・Bellows (8a), (8b) ・0 ring (22);
... Adjustment plate (25) ... Fixed plate

Claims (1)

[Claims] A main discharge space provided at both ends of the airtight container, including an airtight container enclosing a gas laser medium, at least one pair of main discharge electrodes provided in the airtight container, and a pair of mirrors held by a holder. In the gas laser oscillator device, the holder has a bellows attached around a transparent part formed at an end of the airtight container, and a passage part. an adjustment plate that is combined with the bellows with the passage portion facing the transparent portion;
A mounting plate for airtightly clamping the mirror together with the adjustment plate, and a moving means for moving the mirror in one direction while maintaining the airtightness, wherein at least approximately half of the mirror is airtight. A gas laser oscillation device characterized in that the adjustment plate has a length that projects from the side along the one direction of the adjustment plate while being maintained.