JPH02241072A - Gas laser equipment - Google Patents

Abstract

PURPOSE:To enable the shock wave raised by the discharge between a cathode and an anode to be absorbed by a method wherein at least one out of the cathode or the anode is composed of an exterior body formed of a hollow metallic sheet and core material as a shock absorber filled in the envelope. CONSTITUTION:The title gas laser is composed of a laser tube 1 sealed with gas laser medium, a main electrode comprising a cathode 3 and an anode 21 separately and oppositely arranged in the laser tube 1, a high voltage power supply 5 impressing the cathode 3 and the anode 21 with voltage, preionization means 6, 7a preliminarily ionizing the discharge space before the main discharge occurred between the cathode 3 and the anode 21 while at least one out of the cathode 3 or the anode 21 is composed of an envelope 22 formed of a metallic sheet and a core material 23 as a shock absorber filled in the envelope 22. For example, the said preionization means 6, 7a are to be multiple pairs of pin electrodes 6, 7a with their ends separately and oppositely arranged while at least one out of the opposite pairs of the pin electrodes 6, 7a is to be structured with elasticity and shock absorbing properties.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a gas laser device that excites a gas laser medium with discharge energy to emit laser light.

(Prior Art) Generally, in a gas laser device such as a TEA CO2 laser or an excimer laser, a cathode and an anode, which constitute a main electrode, are placed in a laser tube containing a gas laser medium and are spaced apart from each other. By generating a main discharge, the gas laser medium is excited to emit laser light.

Prior to generating the main discharge between the cathode and anode,
The space between the cathode and the anode, that is, the discharge space, is pre-ionized by a pre-ionization means so that laser oscillation can be performed efficiently.

As such a conventional gas laser device, there is one having a structure shown in FIG. In other words, 1 in the figure is a laser tube,
This laser tube 1 houses a gas laser medium in which gases such as CO2, N2, and He are mixed. Further, a pair of holding plates 2 are arranged in the laser tube 1 so as to be spaced apart from each other and facing each other. A cathode 3 and an anode 4 constituting a main electrode are held and fixed on opposing surfaces of each holding plate 2 in an electrically conductive state. These cathodes 3 and anodes 4 are connected to a high voltage power source 5
and the anode 4 is grounded.

Of the pair of holding plates 2, one holding plate 2 provided with the cathode 3 has a peaking capacitor 6 for waveform shaping.
Upper pin electrodes 6 are provided on both sides of the cathode 3 at predetermined intervals along the longitudinal direction via a, and a lower pin electrode 7 is provided on the other holding plate 2 with its tip facing the upper pin electrode 6. It is provided.

Further, within the laser tube 1, a fan 8 for circulating a gas laser medium in the direction of the arrow, and a heat exchanger 9 are disposed upstream of the fan 8.

In the gas laser device having such a configuration, when the high voltage power supply 5 is activated and electrical energy is supplied, a discharge occurs between the opposing end surfaces of the upper pin electrode 6 and the lower pin electrode 7, and UV light (ultraviolet light) is generated. light) is generated. The UV light pre-ionizes the space between the cathode 3 and the anode 4, that is, the discharge space. As the pre-ionization of the discharge space progresses and the voltage between the cathode 3 and the anode 4 increases, a main discharge occurs between these electrodes 3.4, and the laser beam is directed to each electrode 3.4 in a direction perpendicular to the discharge direction. 4 along the longitudinal direction.

However, in the gas laser device having such a configuration, when a main discharge occurs between the cathode 3 and the anode 4, a shock wave is generated in the discharge space by the main discharge. The shock wave not only spreads to the surroundings, but also causes damage to the cathode 3 and anode 4.
It reflects back and forth between these many times. Therefore,
Since the impact of the shock wave makes the flow of the gas laser medium in the discharge space unstable, the laser light emitted from the discharge space also becomes unstable. In particular, when the number of repetitions of laser oscillation is increased, this tendency becomes more noticeable, and thus it becomes difficult to increase the number of repetitions.

Furthermore, the shock waves generated in the discharge space are generated not only by the main discharge generated between the cathode 3 and the anode 4, but also by the discharge generated between the upper pin electrode 6 and the lower pin electrode 7, which pre-ionize the discharge space. However, the impact of the shock wave may also cause the laser oscillation to become unstable.

(Problem to be Solved by the Invention) Conventionally, a shock wave is generated by the discharge between the cathode and the anode or the discharge between the two electrodes that pre-ionizes the discharge space, and the impact of the shock wave causes the flow of the gas laser medium. became unstable, and the laser beam could no longer be oscillated in a stable state.

The present invention was made based on the above circumstances, and its first object is to provide a gas laser device capable of absorbing shock waves generated by discharge between a cathode and an anode. It is in.

A second object of the present invention is to provide a gas laser device capable of absorbing shock waves generated by discharge between pin electrodes for pre-ionizing a discharge space.

[Structure of the Invention] (Means and Effects for Solving the Problems) In order to solve the above problems, the present invention described in claim 1 includes a laser tube in which a gas laser medium is sealed, and spaced-apart and opposing laser tubes in the laser tube. a main electrode consisting of a cathode and an anode arranged as a main electrode; a high-voltage power source that applies a voltage between the cathode and the anode;
Pre-ionization means for pre-ionizing the discharge space prior to the main discharge occurring between the cathode and the anode; It consists of a core material filled in the exterior body that absorbs shock.

This allows the core material to absorb the impact of the shock waves generated by the main discharge.

Further, the present invention as set forth in claim 2 provides a main electrode consisting of a laser tube containing a gas laser medium, a cathode and an anode disposed in a spaced-apart manner in opposition to each other within the laser tube; A high-voltage power supply that applies a voltage between the cathode and the anode, and pre-ionization means that pre-ionizes the discharge space prior to the main discharge occurring between the cathode and the anode, the pre-ionization means having tips separated and facing each other. It consists of a plurality of sets of pin electrodes arranged, and at least one of the pair of opposing pin electrodes has a structure that can be expanded and contracted or can absorb shock.

Thereby, the impact of the shock wave caused by the discharge generated between the pair of pin electrodes is absorbed by the pin electrode.

(Embodiment) An embodiment of the present invention will be described below with reference to FIGS. 1 to 3. Incidentally, the same parts as those in the configuration shown in FIG. 6 are given the same symbols, and the explanation will be omitted.

That is, in the present invention, the anode 21 includes an exterior body 22 formed in a hollow shape with a semi-cylindrical cross section with an open lower surface side and joined to the holding plate 2a by a thin metal plate, and this exterior body 2.
2 and a core material 23 filled therein. Both the retaining plate 2a and the core material 23 are made of cork, rubber, or
It is made of materials that can absorb the impact of shock waves, such as lead.

The anode 21 is provided with flanges 22a provided on both sides of the exterior body 22 in the width direction fixed to the holding plate 2a with bolts 24.

Furthermore, among the pair of pin electrodes constituting the pre-ionization means,
The lower pin electrode 7a is made of a material that absorbs shock waves, similar to the holding plate 2a and the core material 23. When the material forming the lower pin electrode 7a is non-conductive such as cork or rubber, a conductive metal plate such as copper is placed on the upper end surface of the pin electrode 7a as shown in FIG. 24 is attached to the metal plate 24, and one end of a coiled conducting wire 26 is connected to this metal plate 24. The other end of this conductive wire 26 is connected to the high voltage power supply 5. In addition, the exterior body 22 of the anode 21
A bolt 24 fixed to the holding plate 2a and electrically connected to the exterior body 22 is also connected to the high voltage power source 5 in the same way as the conductive wire 26.

In the gas laser device having such a configuration, the high voltage power supply 5
When activated, the upper pin electrode 6' and the lower pin electrode 7a
A discharge occurs between the two and generates UV light, which flows into the discharge space to pre-ionize the discharge space. When the preliminary ionization of the discharge space progresses sufficiently in this manner, a main discharge occurs between the cathode 3 and the anode 21, and laser light is output in a direction perpendicular to the direction of the discharge.

When a discharge is generated between the upper pin electrode 6 and the lower pin electrode 7a when pre-ionizing the discharge space, a shock wave is generated in the axial direction of each pin electrode 6.7a due to the discharge. The impact of the shock wave caused by the discharge between the pin electrodes 6.7a is
Since the lower pin electrode 7a is made of a material that absorbs impact, the impact is absorbed by the lower pin electrode 7a. Moreover, since the holding plate 2a on which the lower pin electrode 7a is erected is also made of a material that absorbs impact, the impact transmitted from the lower pin electrode 7a to the holding plate 2a is also absorbed. Therefore, the flow of the laser medium gas is prevented from being disturbed by the shock wave generated by pre-ionizing the discharge space.

Further, following the pre-ionization, a main discharge occurs between the cathode 3 and the anode 21, and when a shock wave is generated between them due to the main discharge, the shock wave of the shock wave is transmitted to the exterior body of the anode 21.
Shock waves that are absorbed by the core material 23 filled in the housing 2 and transmitted from the exterior body 22 to the retaining plate 2a are absorbed by the retaining plate 2a. Therefore, since the impact caused by the main discharge generated between the cathode 3 and the anode 21 is well absorbed, disturbances in the flow of the laser medium gas due to the main discharge are also prevented.

In this way, if the flow of the laser medium gas flowing through the discharge space is prevented from being disturbed by the impact of the shock waves generated by the pre-ionization or the main discharge, it is possible to output laser light with a high repetition rate.

Note that the structure of the pin electrode for absorbing impact may be as shown in FIG. 4 or FIG. 5.

That is, in FIG. 4, when the lower pin electrode 7a is made of an electrically insulating shock-absorbing material, the outer peripheral surface of the pin electrode 7a is replaced with the conductive wire 26 shown in the above embodiment. was covered with a metal mesh 31, a metal plate 24 was fixed to the upper end of the metal mesh 31, and the other end was connected to the high voltage power source 5. With such a structure, inductance can be reduced compared to the case where a coiled conductive wire 26 is used.

Further, in the structure shown in FIG. 5, the lower pin electrode 7a is made of a metal bellows 32. According to such a structure, the bellows 32 elastically expands and contracts in the axial direction due to the impact of the shock wave. It can deform and absorb the impact.

Further, in each of the above embodiments, the anode 21 and the lower pin electrode 7a have a structure that absorbs shock, but the cathode 3 and the upper pin electrode 6 may also have a structure that absorbs shock, and in short, at least one of them absorbs shock. Any structure that does so is fine.

[Effects of the Invention] As described above, the present invention as set forth in claim 1 is characterized in that at least one of the cathode and the anode is made of an exterior body made of a hollow metal plate, and a core filled in the hollow part of the exterior body. It was constructed from materials. Therefore, the core material absorbs the impact of the shock wave generated in the discharge space by the main discharge, and the flow of the gas laser medium can be prevented from being disturbed, so that laser light can be output with high repetition rate.

Further, according to the invention described in claim 2, the prefN
At least one of the pair of opposing pin electrodes used as the Ti separating means was configured to be stretchable or shock absorbing. Therefore, it is possible to absorb the shock wave generated when pre-ionizing the discharge space, prevent disturbances in the flow of the gas laser medium, and output laser light in a stable state.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a gas laser device showing an embodiment of the present invention, FIG. 2 is an enlarged sectional view of a cathode and an anode, and FIG.
This figure is a perspective view of the pin electrode, FIGS. 4 and 5 are sectional views of the pin electrode showing other embodiments of the present invention, and FIG.
The figure is a sectional view of a conventional gas laser device. 1... Laser tube, 3... Cathode, 5... High voltage power supply,
6... Upper pin electrode, 7a... Lower pin electrode, 21
... Anode, 22 ... Exterior body, 23 ... Core material, 3
2...Bellows. Figure 4 Figure 5

Claims (2)

[Claims] (1) a main electrode consisting of a laser tube in which a gas laser medium is sealed, a cathode and an anode arranged spaced apart and facing each other within the laser tube, and a high-voltage power source that applies a voltage between the cathode and the anode; Pre-ionization means for pre-ionizing the discharge space prior to the main discharge occurring between the cathode and the anode; A gas laser device characterized by comprising a core material filled in an exterior body and absorbing shock. (2) a main electrode consisting of a laser tube containing a gas laser medium, a cathode and an anode arranged spaced apart and facing each other within the laser tube, and a high-voltage power source that applies a voltage between the cathode and the anode; and a pre-ionization means for pre-ionizing the discharge space prior to the main discharge occurring between the cathode and the anode, the pre-ionization means comprising a plurality of sets of pin electrodes disposed with their tips spaced apart and facing each other. A gas laser device characterized in that at least one of the pair of opposing pin electrodes has a structure that is expandable and retractable or absorbs shock.