JPH0199271A - Gas laser oscillator - Google Patents

Abstract

PURPOSE:To reduce the adhesion of an impurity to a mirror and the like at the time of replacing the mirror and to increase the life of medium gas by incorporating a mirror section detachably controlled to a laser tube in a mirror replacing box isolated from the external atmosphere. CONSTITUTION:A mirror replacing box 10 isolated from the external atmosphere is provided, and a mirror 14 is contained in the box. The mirror 14 is pressed to a laser tube 1 at the time of laser oscillation. The connection of the mirror 14 employed at present to the tube 1 is released at the time of replacing the mirror, and the mirror 14 is replaced with a new mirror to be replaced. In this case, the interior of the box 10 is isolated from the outer atmosphere, and since the replacement is conducted in the box 10, the adhesion of an impurity to the new replaced mirror in a mirror section can be remarkably reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a gas laser oscillation device that excites a laser medium gas to perform laser oscillation.

[Conventional technology]

Generally, when a laser is caused to oscillate, a situation occurs in which the laser medium gas in the laser tube reacts with impurities in the laser tube, resulting in a decrease in laser output. In particular, rare gas halide excimer lasers use corrosive HCJ and F2 as laser medium gases to obtain high-power ultraviolet laser light, so when laser oscillation is performed, these corrosive laser medium gases are released into the laser. Various impurity gases in the laser medium gas such as CCI, CF,
The concentration of S, CJ, Co2.02°4 4 I 4 F20 increases. On the other hand, mirrors for laser oscillation are constantly exposed to strong ultraviolet laser light, so
The impurity gas contained in the laser medium gas causes a photochemical reaction on the mirror, and impurities are deposited on the inner surface of the mirror along the laser beam pattern. This impurity layer absorbs and reflects the laser beam, reducing the laser output. was.

Conventionally, in order to replace a mirror with accumulated impurities, the mirror must be replaced while N2 gas or rare gas is flowing inside the laser tube, or as shown in FIG. A valve 52 is provided at the mirror 53.
When replacing the mirror 53, the valve 52 is closed to make the inside of the laser tube 5o airtight, and then the mirror 53 is replaced.

[Problem that the invention seeks to solve]

However, when replacing the mirror 53 in the above manner, although it is possible to prevent impurities from flowing into the laser tube 50, since the newly replaced mirror was exposed to the atmosphere, its surface does not contain F20. ．． Impurities such as CO2 are piled up.

Further, on the inner wall of the laser tube 50 and its outlet 51, H
(Since the gases L and F2 have been adsorbed, when the mirror 53 is removed, the gases HCj and F24:02.T-
(20, The problem is that gases in the atmosphere such as Co2 are rapidly adsorbed, and when a new mirror is installed and the laser oscillates again, the gases in the atmosphere adsorbed on the inner wall of the outlet 51 are released and stacked on the mirror 1. Another problem was that the life of the laser medium gas was shortened.

SUMMARY OF THE INVENTION An object of the present invention is to provide a gas laser oscillation device that can significantly reduce the adhesion of impurities to mirrors and the like when replacing mirrors for laser oscillation, and can extend the life of the laser medium gas.

[Means for solving problems]

The present invention provides a gas laser oscillation system comprising a laser tube and a mirror section that is controlled to be attached to and detached from the laser tube, and the mirror section is housed in a mirror exchange box that can be isolated from the outside atmosphere. This device improves the problems of the prior art described above.

[Effect]

In the present invention, a mirror exchange box that can be isolated from the outside atmosphere is provided, and a mirror section is housed within this mirror exchange box. During laser oscillation, the currently used mirror in the mirror section is pressed against the laser tube, but when replacing the mirror, the currently used mirror and laser tube are uncoupled and this mirror is used as a new replacement mirror. exchange to.

At this time, the inside of the mirror replacement box is isolated from the outside atmosphere, and the replacement operation is performed inside the mirror replacement box, so that the adhesion of impurities to the new replacement mirror whose mirror part has been replaced can be significantly reduced. Can be done.

〔Example〕

Embodiments of the present invention will be described below based on the drawings.

FIG. 1 is a side sectional view of the gas laser oscillation device of the present invention, and FIG.
The figure is a sectional view taken along the line A-A in FIG. 1.

In FIGS. 1 and 2, the outlet 2 of the laser tube 1 has
A bellows 4 is attached, and a flange 5 provided with a sealing material 6 is welded to the tip of the bellows 4. A support member 8 is connected to the end wall 3 of the laser tube 1 by screws 7, and a mirror exchange box 10 is connected to the support member 8 by screws 9. Note that the support member 8 is provided with sealing materials 11 and 12, and these sealing materials 11.1
2 inside the laser tube 1 and the mirror exchange box 1
The inside of the chamber 13 of No. 0 is completely isolated from the atmosphere. Furthermore, the interior of the chamber 13 of the mirror exchange box 10 can be evacuated by opening and closing the valve 23, or can be refilled with rare gas or N2 gas.

Furthermore, a mirror 14 is arranged opposite the flange 5. As shown in FIG. 3, the mirror 14 is held in a rectangular pedestal 15 in a vacuum-tight manner with a sealing material 16 interposed therebetween, and is screwed with screws 17. Furthermore, the pedestal 15 is slidably disposed within a groove of a movable member 18 for moving the mirror 14 closer to or away from the flange 5. The distance between the movable member 18 and the support member 8 is adjusted by a plurality of screws 19, so that the mirror 14 can be brought into contact with the flange 5 or separated from the flange 5. Note that each of the plurality of screws 19 is
A screwdriver 20 (
The interior of the chamber 13 is shut off from the atmosphere by the sealing material 21), so that the interior of the support member 8 is moved forward or backward.

A screw 19 between the movable member 18 and the support member 8 is provided to prevent the bellows 4 from being deformed and the optical axis of the mirror 14 to be distorted when the chamber 13 is evacuated for laser medium gas exchange. A spring 22 is provided to prevent this.

Referring also to FIG. 2, a replacement mirror 30 is slidably positioned within the chamber 13 of the mirror replacement box 10 within a groove of a guide member 31. As shown in FIG. Inside the guide member 31, a diagonal heater 32 for heating the mirror 30 is provided on the side facing the replacement mirror 30. In addition, the replacement mirror 30 is attached to a rod 33 to which a sealing material 35 is attached.
is moved toward the movable member 18 by pushing out. On the opposite side of the movable member 18 from the guide member 31, there is a guide member 3 that guides the mirror 15 that is pushed out when the replacement mirror 3o is guided by the movable member 18.
4 is positioned.

The operation of the gas laser oscillation device having such a configuration will be described next.

During the oscillation operation of the gas laser oscillator, the mirror 14 is pressed by the seven flange 5, and the inside of the laser tube 1 and the inside of the chamber 13 are completely isolated by the sealing material 6 of the seven flange 5.

If the oscillation is performed in such a state and impurities adhere to the inner surface of the mirror 14, the laser output will decrease, so attach the mirror replacement box 10 to the laser tube 1 and replace the mirror 14 with a replacement mirror 30. In this replacement operation, as described above, the inside of the laser tube 1 and the inside of the chamber 13 are completely shut off, and then the pulp 23 is opened to evacuate the inside of the chamber 13, and then the mirror 30 for replacement is removed. is heated by the heater 32 to raise the temperature and degas the mirror 30. Next, lower the temperature of the heater 32, close the valve 23, turn the screwdriver 20, and use the screw 19 to remove the movable member 181, the pedestal 15, and the mirror 14. to retreat. As the mirror 14 retreats, the flange 5 that was pressed against it also moves while coming into contact with the mirror 14 due to the action of the bellows 4. When the flange 5 moves a predetermined amount, its protrusion 24 touches the support member 8. It meets the protrusion 25 and stops there.

This causes the mirror 14 to separate from the flange 5.

When the screw 19 is further turned, the movable member 18 moves to the guide member 31.
．． 34 and stops there. At this time, the ends of the movable part 18 that guide the stand M15 are aligned with the grooves of the guide members 31 and 34, as shown in FIG.

Next, by pushing out the rod 33, the degassed replacement mirror 30 is pushed out along the groove of the guide member 31. As a result, the replacement mirror 30 is guided by the groove of the movable member 18 and positioned at the position of the previously used mirror 14. At this time, the mirror 14 and the stand [15 on which it was attached] are pushed out by the mirror 30, and the guide member 34
It is guided into the groove and fits there.

In this way, when a replacement mirror 30 is positioned at a predetermined position on the movable member 18 instead of the mirror 14, the screwdriver 20 is turned to tighten the plurality of screws 19, and the mirror 30 is pressed against the flange 5. As a result, the inside of the laser tube 1 and the inside of the chamber 13 are cut off, and the laser oscillation operation can be performed again.

In addition, in the above-described operation during degassing of the replacement mirror 30, when the heating temperature is set to 100°C to 200°C and the heating time is set to about 1 hour, water H20 as an impurity almost disappears, and water H20 as an impurity disappears. The most important CO2 is also 1/1
It was possible to reduce the number to about 0.00.

As described above, according to this embodiment, the mirror exchange box 10 that can be completely shut off from the outside atmosphere is provided, and when replacing the mirror, the chamber 13 of the mirror exchange box 10 is evacuated, and the mirror 30 for replacement is removed. Since the mirror is replaced after being gassed and completely isolated from the outside atmosphere, there are almost no impurities attached to the surface of the replaced mirror 30, and the laser tube 1 at the time of mirror replacement is
The situation in which impurity gas is adsorbed on the inner wall of the laser tube 1 is extremely effectively prevented, and the laser oscillation can be performed without reducing the laser output without forming a passivation film over the entire inside of the laser tube 1 again after replacing the mirror. Furthermore, by preventing impurities from adhering to the replaced mirror 30, etc., the life of the laser medium gas can be extended.

〔Effect of the invention〕

As explained above, according to the present invention, the mirror unit that is controlled to be attached to and detached from the laser tube is housed in the mirror exchange box that can be isolated from the outside atmosphere, so when replacing the mirror, there is no need to The attachment of impurities can be significantly reduced and the life of the laser medium gas can be increased.

[Brief explanation of the drawing]

FIG. 1 is a side sectional view of the gas laser oscillation device of the present invention, and FIG.
The figures are a sectional view taken along the line A--A in FIG. 1, FIG. 3 is a perspective view of a mirror attached to a pedestal, and FIG. 4 is a sectional view of a conventional gas laser oscillation device. 1...Laser tube, 10...Mirror exchange box, 1
4...Mirror, 30...Replacement mirror, 32...
・Heater patent applicant: Hamamatsu Photonics Co., Ltd. Representative Patent attorney Masaharu Uemoto Figure 2 Figure 3 Figure 4

Claims (1)

[Scope of Claims] 1) It is characterized by comprising a laser tube and a mirror section that is controlled to be attached to and detached from the laser tube, and the mirror section is housed in a mirror exchange box that can be isolated from the outside atmosphere. Gas laser oscillation device. 2) The mirror unit includes a replacement mirror and a heating device for raising the temperature of the replacement mirror, and when the mirror is replaced, the replacement mirror is degassed by the heating device. A gas laser oscillation device according to claim 1.