JPH07245442A - Laser device - Google Patents

Abstract

PURPOSE:To prolong the life of a laser gas and a preionization electrode by a method wherein the preionization electrode is composed of a synthetic quartz glass tube, wherein a vacuum gas or a low pressure gas having a small amount of impurities and ultraviolet rays are easily generated is sealed, and a pin gap electrode in which an arc discharge end is sealed in the synthetic quartz glass tube. CONSTITUTION:An auxiliary ionization electrode is constructed in such a manner that a number of pin gap electrodes B are sealed in a rod-like synthetic quartz glass tube A leaving regular intervals. A vacuum gas or a low pressure gas, with a small amount of impurities which easily generates ultraviolet ray is sealed in the synthetic quartz glass tube A. Each pin gap electrode B is arranged in pectinate form and has an electrode base B, and it is constructed in such a manner that the end of arc discharge is positioned in the synthetic quartz glass tube A. As a result, the pin gap electrodes B do not come in contact with the laser gas, and the electrodes B themselves are prevented from being deteriorated by the laser gas.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser device using atmospheric pressure lateral discharge excitation (TEA), and more particularly to a preionization electrode for automatic ultraviolet preionization.

[0002]

2. Description of the Related Art Excimer lasers, carbon dioxide (CO ₂ ) lasers, and nitrogen (N ₂ ) laser devices have a pumping circuit in which the rate of current rise of a triggertron, thyratron, etc., as shown in FIG. A gas input / discharge switch 1 having a large (di / dt) is used, and by switching the high voltage charge of the capacitor 2 is transferred to the peaking capacitor 3, the preionization electrode (pin gap array) 4 ₁ of the laser device body 4 is made uniform. to cause an arc discharge, by using the ultraviolet rays generated therefrom to obtain a pre-ionization of the gas, the long plate-shaped pair of main electrodes 4 _2, 4 main discharge between ₂ (glow discharge)
To get

The blower 4 ₃ generates a nitrogen gas flow between the main electrodes 4 ₂ and 4 ₂ , and the heat exchanger 4 ₄ cools the nitrogen gas. In addition, the nitrogen gas is configured to be disposable while being pulled by a vacuum pump.

As another conventional example, an automatic preionization capacity transfer type TEA-incorporating an excimer laser design technique is used.
N ₂ laser (Laser research, February 1990 issue, P28-3)
There is also 2).

[0005]

In the conventional configuration,
Both the preionization electrode 4 ₁ and the main electrode 4 ₂ are located in the atmosphere of the laser gas.

Here, the preliminary ionization electrode 4 ₁ carries out arc discharge, and the main electrode 4 ₂ carries out glow discharge. Although any discharge causes contamination / deterioration of the laser gas, arc discharge is a major cause of contamination / deterioration of the laser gas.

[0007] Therefore, the arc discharge by preionization electrode 4 ₁ is shorten the life of the laser gas. Further, since the preionization electrode 4 ₁ is exposed to the laser gas which is a mixed gas, there is a problem that the life of the electrode 4 ₁ itself is shortened and the life of the laser device itself is shortened.

Such a problem exists in a laser device having a pin gap array-shaped preionization electrode such as an excimer laser or a carbon dioxide gas laser.

It is an object of the present invention to provide a laser device having a structure that extends the life of the laser gas and the preionization electrode.

[0010]

In order to solve the above-mentioned problems, the present invention applies a high-voltage large-current pulse to a preionization electrode of a laser apparatus main body through a peaking capacitor to cause arc discharge to the preionization electrode. In the laser device in which laser light is pre-ionized by using ultraviolet rays generated from the pre-ionization electrode to obtain glow discharge between a pair of main electrodes in the laser gas, the pre-ionization electrode is The structure is characterized by providing a synthetic quartz glass tube in which a small amount of low-pressure gas that easily emits ultraviolet rays is sealed, and a pin gap electrode whose arc discharge end is sealed in the synthetic quartz glass tube.

[0011]

Function: By causing arc discharge of the pin gap electrode in the synthetic quartz glass tube, contamination / deterioration of laser gas due to arc discharge is prevented. Moreover, the pin gap electrode itself is prevented from being exposed to the laser gas to prevent deterioration of the pin gap electrode itself.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a block diagram of an apparatus showing an embodiment of the present invention. Portions figure differs from FIG. 3, the preionization electrode 4 ₅
In the structure of. Reference numeral 5 is a pulse power supply which includes a conventional discharge switch 1 and a capacitor 2 and generates a pulse current.

[0013] preionization electrode 4 _5, a side view in FIG. 2 (a) and as shown in a sectional view (b), the interval number of pins gap electrodes B constant in the synthetic quartz glass tube A rod-shaped It has an enclosed structure.

The synthetic quartz glass tube A is filled with a vacuum or a low-pressure gas (for example, helium, neon, nitrogen, etc.) which has a small amount of impurities and easily emits ultraviolet rays. Each pin gap electrode B has an electrode base B ₁ and is arranged in a comb shape so that the arc discharge end is located inside the synthetic quartz glass tube A.

The pin gap electrode B is of an automatic preionization type in which a pair of electrode bases B ₁ are supported and connected between _one of the main electrodes 4 ₂ and the peaking capacitor 3. The connection between the pin gap electrode 4 ₅ and the main electrode 4 ₂ may be the same as that shown in FIG.

In this embodiment, a synthetic quartz glass tube A
Has a high ultraviolet transmittance. Therefore, ultraviolet rays generated by arc discharge in a pin gap electrode B to be sealed in the synthetic quartz glass tube A can cause pre-ionization of the laser gas in the main electrode 4 ₂ portions transmitted through the synthetic quartz glass tube A. Glow discharge can be generated in the main electrode 4 ₂ by this preliminary ionization.

Here, since the arc discharge end of the pin gap electrode B is enclosed in the synthetic quartz glass tube A, there is no contact with the laser gas and it is possible to prevent the laser gas from being contaminated and deteriorated by the arc discharge. . At the same time, the pin gap electrode B itself can be prevented from being deteriorated by the laser gas.

The excitation circuit shown by the pulse power supply 5 has
Instead of the gas-filled discharge switch 1, it is possible to replace the pulse current obtained by the switch operation of the semiconductor switch with a completely solid-state excitation circuit that performs pulse compression by the magnetic switch operation of the saturable transformer.

[0019]

As described above, according to the present invention, the preionization electrode comprises a synthetic quartz glass tube filled with a low-pressure gas which is vacuum or has a small amount of impurities and easily emits ultraviolet rays, and the arc discharge end has the above-mentioned synthetic quartz. Since the structure is such that the pin gap electrode enclosed in the glass tube is provided, the following effects are obtained.

(1) Since the arc discharge of the pin gap electrode is limited to the inside of the synthetic quartz glass tube, it is possible to prevent the contamination and deterioration of the laser gas due to the arc discharge and extend the life thereof.

(2) It is possible to prevent the pingap electrode from being exposed to the laser gas, prevent deterioration of the pingap electrode itself, and prolong its life.

[Brief description of drawings]

FIG. 1 is a device configuration diagram of an embodiment.

FIG. 2 is a side view (a) and a sectional view (b) of a preionization electrode.

FIG. 3 shows an example of a conventional nitrogen laser device.

[Explanation of symbols]

1 ... Discharge switch with gas 3 ... Peaking capacitor 4 ... Laser device body 4 ₂ ... Main electrode 4 ₃ ... Blower 4 ₄ ... Heat exchanger 4 ₅ ... Pre-ionization electrode 5 ... Pulse power supply A ... Synthetic quartz glass tube B ... Pin gap electrode

Continuation of front page (51) Int.Cl. ⁶ Identification number Office reference number FI Technical indication location H01S 3/223 E (72) Inventor Yoshiyoshi Hara 2-1-1 Osaki, Shinagawa-ku, Tokyo Stock company Shameidensha

Claims (1)

[Claims] 1. A high-voltage, high-current pulse is applied to a preionization electrode of a laser apparatus main body through a peaking capacitor to cause arc discharge in the preionization electrode, and ultraviolet rays generated from the preionization electrode are used. In a laser device for obtaining preionization of laser gas and for glow discharge between a pair of main electrodes in the laser gas, the preionization electrode is a synthetic quartz in which a low-pressure gas having a vacuum or few impurities and which easily emits ultraviolet rays is enclosed. A laser device comprising a glass tube and a pin gap electrode having an arc discharge end sealed in the synthetic quartz glass tube.