JPS63241972A - Gas laser device - Google Patents

Abstract

PURPOSE:To effectively generate a short wavelength light that can preliminarily ionize a discharge space efficiently by forming pin electrodes for preliminarily ionizing a discharge space in a shape by which an equal electric field is obtainable to raise a discharge starting voltage of the electrode. CONSTITUTION:A pair of holding plates 3 are disposed oppositely in space in an elevational direction in a laser tube 1. An anode 3 is mounted on a holding plate 2 above it, and a cathode 4 is mounted on the plate 2 under it. In this case, the ends of upper and lower electrodes 5, 6 are formed in spherical sections 11, which are formed in sufficiently larger diameter than the shaft 12 of the electrodes 5, 6. The ends of the electrodes 5, 6 are formed in a shape capable of obtaining an equal electric field in case of discharging. Thus, a discharge starting voltage of the electrodes 5, 6 is enhanced, and a short wavelength light capable of efficiently preliminarily ionizing the discharge space is efficiently generated.

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 laser gas as a laser medium with discharge energy to output laser light.

(Prior Art) Generally, in an atmospheric pressure or high pressure horizontal discharge excitation type laser device, for example, CO2, N,
2, a laser gas mixed with f-1e, etc., and a laser gas for excimer are accommodated, and the main 1! consists of an anode and a cathode. The poles are spaced apart and facing each other. The energy of the discharge generated between the main electrodes excites the laser gas to oscillate laser light, and the discharge space between the main electrodes is pre-ionized using a pre-ionization device prior to the discharge between the main electrodes. , so that discharge between the main electrodes is likely to occur.

A pin electrode is known as the above-mentioned preliminary ionization device. In other words, a pair of pin electrodes whose ends face each other with a predetermined gap in between are arranged at regular intervals on the sides of the main electrode, a discharge is generated between the ends of these pin electrodes, and the ultraviolet rays generated by the discharge are generated. The discharge space is pre-ionized with light having a short wavelength.

Such short wavelength light is effectively generated by high energy discharge. Therefore, such light emission containing a large amount of short wavelength light is concentrated at the time of discharge initiation, and is obtained particularly when the discharge initiation voltage is high.

In order to obtain a high discharge starting voltage, it is conceivable to increase the gap between the pair of pin electrodes.

However, if the gap is made large, the stability of the discharge will be impaired, so the gap cannot be made very large.

(Problems to be Solved by the Invention) As described above, in the past, it was difficult to obtain a high discharge starting voltage, and therefore a sufficient preliminary ionization effect by the pin electrode could not be obtained.

This invention was made based on the above circumstances, and its purpose is to improve pre-ionization in the discharge space by increasing the starting voltage of the discharge that occurs between the ends of a pair of pin electrodes. An object of the present invention is to provide a gas laser device that can perform the following steps.

[Effects of the Invention] (Means and Effects for Solving the Problems) In order to solve the above problems, the present invention provides a laser tube and at least a pair of main electrodes disposed in the laser tube in a spaced-apart manner. and a pin electrode that generates a preliminary discharge and pre-ionizes the discharge space between these main electrodes before exciting it with the discharge of the main electrode, and an equal electric field can be obtained during preliminary discharge with this pin electrode. shape, thereby increasing the discharge starting voltage.

(Example) An embodiment of the present invention will be described below with reference to the drawings.

FIG. 2 shows a gas laser device, which includes a laser tube 1. As shown in FIG. This laser tube 1 contains a laser gas which is a mixture of various gases. Furthermore, a pair of holding plates 2 are disposed within the laser tube 1 so as to be spaced apart from each other in the vertical direction. An anode 3 is attached to the upper holding plate 2, and a cathode 4 is attached to the lower holding plate 2. Therefore, the anode 3 and the cathode 4 face each other at a predetermined interval, and a discharge space S is formed between them.

An upper pin electrode 5 and a lower pin electrode 6 are disposed on both sides of the anode 3 and cathode 4, respectively, with their one ends facing each other with a predetermined interval apart, and are constant along the longitudinal direction of the pair of electrodes 3.4. arranged at intervals. The other end of the upper pin electrode 5 is fixed to the upper holding plate 2 via the peaking capacitor 7, and the other end of the lower pin electrode 6 is fixed to the lower holding plate 2.

A high voltage switch 7a is connected to the anode 3 and cathode 4.

A main capacitor 8 and a high voltage power supply 9 are sequentially connected in parallel. Therefore, when the high voltage switch 7a is closed, the energy stored in the main capacitor 8 causes a discharge between the upper pin electrode 5 and the lower pin electrode 6.
When the discharge space S is sufficiently pre-ionized by the discharge, a main discharge is generated between the anode 3 and the cathode 4, the laser gas is excited, and the laser beam is completely irradiated.

The ends of the upper pin electrode 5 and the lower pin electrode 6 are formed into spherical parts 11, as shown in FIG.

This spherical portion 11 is formed to have a sufficiently larger diameter than the shaft portion 12 of the pin electrode 5.6, so that the shaft portion 12 does not have any influence upon discharge. That is, the end portions of each of the pin electrodes 5.6 are formed in a shape that provides a uniform electric field during discharge.

In this way, by making the ends of each pin electrode 5.6 into a shape that allows an equal electric field to be obtained, the discharge starting voltage can be adjusted without increasing the gap between the ends of the upper pin electrode 5 and the lower pin electrode 6. can be made higher. In other words, there is a clear relationship between the equality of electric fields and the discharge starting voltage, as shown in Figure 3, and according to the structure of the present invention, equality within the range indicated by a in the figure can be obtained. However, if the ends of the pin electrodes are simply made into a rounded shape as in the conventional method, only the uniformity within the range indicated by b in the figure can be obtained. Therefore, according to the present invention, the wavelength of the ultraviolet rays generated during pre-ionization can be made into a shorter range by increasing the firing voltage, so that pre-ionization can be performed effectively.

Note that the present invention is not limited to the above embodiment, and the end of the pin electrode 5.6 may be formed into a Rogowski-shaped electrode portion 15 as shown in FIG. The shape may be any shape as long as it can provide a uniform electric field.

[Effects of the Invention] As described above, in the present invention, the pin electrode for pre-ionizing the discharge space has a shape that allows a uniform electric field to be obtained. Therefore, since the discharge starting voltage at the pin electrode can be increased, it is possible to effectively generate short wavelength light that can efficiently pre-ionize the discharge space.

[Brief explanation of drawings]

Fig. 1 is an enlarged view of the end of a pin electrode showing an embodiment of the present invention, Fig. 2 is a configuration diagram of the entire gas laser device, and Fig. 3 is an explanation of the relationship between the discharge N start voltage and the equality of the electric field. FIG. 4 is an enlarged view of the end of a pin electrode showing another embodiment of the present invention. 1... Laser tube, 3... Anode, 4... Cathode, 5.
6... Pin electrode, 11... Spherical part. Applicant's agent Patent attorney Takeshi Suzue Industry 1 diagram
Figure 4 2nd cause

Claims (1)

[Claims] A laser tube, at least one pair of main electrodes disposed in the laser tube in a spaced-apart manner, and a discharge space between these main electrodes that is pre-ionized by generating a preliminary discharge before exciting the discharge space between the main electrodes by the discharge of the main electrodes. 1. A gas laser device comprising: a pin electrode, the pin electrode being formed in a shape that allows a uniform electric field to be obtained during preliminary discharge.