JPH06224502A - Gas laser discharge part - Google Patents

Abstract

PURPOSE:To provide an excellent gas discharge part which makes possible the minimization of a gas laser device through the simplification of its construction and in which stably and frequently repeated operation can be realized at low cost by effectively removing the laser gas dissolved and heated through glow discharge out of the discharge area. CONSTITUTION:A pair of counterposed main electrodes 1a and 1b in a gas container are connected with current terminals 5a and 5b, and the main electrode 1b is formed of a dielectric. In addition, a cylindrical dielectric 2a is directly arranged on the surface on the glow discharge 4 side of the electrode 1b, and a conductor 3a is passed through the dielectric 2a, then the dielectric 3a is connected to the terminal 5a of the counter electrode 1a.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas laser discharge unit, and more particularly to a gas laser discharge unit having an improved structure for performing preionization.

[0002]

2. Description of the Related Art Generally, in a discharge excitation type gas laser device, a laser gas is supplied to a gas laser discharge section to generate a spatially uniform glow discharge, and this discharge excites the laser gas to generate a laser to generate an optical resonance. The laser output is taken out by the action of the vessel. As a device of this kind,
Pulsed laser devices such as a laterally excited pulsed CO2 laser and an excimer laser are known. This pulse laser device has a problem that it is difficult to uniformly ignite the glow discharge because the laser gas pressure is higher than the atmospheric pressure and further contains a gas component having a strong electron adhering property. Therefore, in the pulse laser device, a uniform glow discharge is usually generated by applying a high-speed pulse voltage to the discharge part to generate a corona discharge which is a preliminary discharge.

A conventional example of the gas laser discharge unit in the above-described gas laser device will be specifically described with reference to FIG. FIG. 4 is a configuration diagram showing a configuration of a conventional gas laser discharge unit and an excitation power supply circuit. Reference numerals 1a and 1b denote a pair of main electrodes made of a dielectric material, and these main electrodes 1a and 1b form a gas laser discharge part. The main electrodes 1a and 1b are arranged to face each other in a gas container (not shown) that is airtightly filled with laser gas. Further, a gas flow path (not shown) is formed in the gas container. This gas flow path includes a blower fan and a heat exchanger, and the main electrodes 1a and 1b are connected to each other.
The laser gas is sent to the. Further, an optical resonator (not shown) for extracting a laser output is arranged in a direction orthogonal to the opposing axes of the main electrodes 1a and 1b (a direction substantially perpendicular to the plane of the drawing). It is set up.

Current terminals 5a and 5b are electrically connected to the surfaces of the main electrodes 1a and 1b which do not face each other. Of these, the current terminal 5b is grounded. On the other hand, the current terminal 5a is drawn into the laser gas from an insulator (not shown) that mechanically supports the main electrode 1a,
It is connected to one end of the capacitor (C1) 6 and also connected to one end of the charging inductance 9. The other end of the capacitor (C1) 6 is grounded via the switch 10a and is also connected to the high voltage power supply (HV) 11a. The other end of the charging inductance 9 is grounded. The switch 10a is a trigger power supply (TS)
This trigger power supply (TS) 1 is connected to 12a.
It is controlled by 2a. Trigger power supply (TS) 12
a is connected to the pulse generator (PG) 13.

Further, 2c in the figure is a dielectric. A conductor 3 electrically contacting the dielectric 2c is provided on the dielectric 2c.
c and 3d are provided. The conductors 3c and 3d and the dielectric 2c are arranged so as to be close to the gap between the main electrodes 1a and 1b. The conductor 3d is grounded. On the other hand, the conductor 3c is covered with an insulator (not shown) and drawn out from the laser gas to be connected to one end of the capacitor (C2) 7 and also connected to one end of the charging resistor 8. There is. The other end of the capacitor (C2) 7 is grounded via the switch 10b and also has a high voltage power supply (HV).
It is connected to 11b. The other end of the charging resistor 8 is grounded. The switch 10b is connected to a trigger power supply (TS) 12b and is controlled by the trigger power supply (TS) 12b. The trigger power supply (TS) 12b is connected to the pulse generator (PG) 13. The capacitors, resistors, and inductances described above may be configured as a single unit or may be configured by connecting a plurality of them in parallel.

The gas laser device having the above structure operates as follows. First, high voltage power supply (HV) 11b
Charges the capacitor (C2) 7 through the charging resistor 8. Then, when the switch 10b is closed, the potential of the capacitor (C2) 7 on the switch 10b side becomes the ground potential, so that the potential on the conductor 3d side is inverted. Furthermore, dielectric 2
When the potential shifts to c and the voltage applied to the conductor 3c and the dielectric 2c becomes equal to or higher than the discharge breakdown voltage of the laser gas, the conductor 3
Corona discharge (not shown) that causes pre-ionization is generated between c and the dielectric 2c.

On the other hand, when the high voltage power supply (HV) 11a charges the capacitor (C1) 6 through the charging inductance 9 and the switch 10a is closed, the capacitor (C1) 6 is closed.
Potential is inverted and switch 10 of capacitor (C1) 6
The potential on the a side becomes the ground potential. In addition, the main electrodes 1a and 1b
Laser gas is supplied between them. And the main electrode 1
When the voltage between a and 1b becomes equal to or higher than the discharge breakdown voltage of the laser gas, glow discharge 4 is generated here. Since the corona discharge which is the preliminary discharge is generated as described above, the glow discharge 4 should be uniformly ignited even if the laser gas pressure is higher than the atmospheric pressure and contains a gas component having strong electron adhesion. You can

A laser gas is excited by the glow discharge 4 to generate a laser, and the laser light is orthogonal to the opposing axes of the main electrodes 1a and 1b by the action of an optical resonator (not shown). Is emitted in a direction substantially perpendicular to the plane of the paper on which is drawn. In addition, glow discharge 4
Occurs immediately after the corona discharge (not shown) that is the pre-ionization, and the time difference between the two discharges at this time is controlled by the pulse generator (PG) 13. In addition, the switch 10a,
The switching voltage of 10b is the trigger power supply (TS) 12a, 12
b.

By the way, in the gas laser discharge part,
When the glow discharge 4 is generated between the main electrodes 1a and 1b, a part of the laser gas is decomposed and heated. If the glow discharge 4 is formed again between the main electrodes 1a and 1b in the state where the decomposed and heated laser gas exists in the discharge region, the glow discharge 4 contracts, and the arc discharge easily occurs.
This arc discharge has a high temperature and a large current density. When this arc discharge occurs, laser oscillation becomes impossible, and high repetition operation cannot be performed. Therefore, the gas flow path formed in the gas container always sends the laser gas between the main electrodes 1a and 1b, and the decomposed and heated laser gas can be removed to the outside of the discharge region by the sent laser gas. It is being appreciated.

[0010]

However, the following problems have been pointed out in the above conventional techniques. That is, in the above gas laser discharge part, two systems of member groups are provided in order to generate two discharges, a corona discharge for pre-ionization and a glow discharge 4. One is a dielectric 2c, conductors 3c and 3d, a capacitor (C2) 7, a resistor 8, a switch 10b, a high voltage power supply (H
V) 11b and trigger power supply (TS) 12b are a group of members that generate corona discharge, and the other is the main electrode 1a,
1b, current terminals 5a and 5b, capacitor (C1) 6, inductance 9, switch 10a, high voltage power supply (HV) 1
1a, trigger power supply (TS) 12a glow discharge 4
Is a group of members that generate.

As described above, in the prior art, there are two systems for generating corona or glow discharge. Therefore, the capacitors 6, 7 and the high voltage power supplies 11a, 1
1b, switches 10a, 10b, trigger power supply (TS)
A total of two 12a and 12b are provided, one for each system. Therefore, the number of constituent members of the conventional gas laser discharge part is considerably large, and the structure is complicated. As a result, there is a problem that the size of the gas laser device is increased.

In the above gas laser discharge part, the conductors 3c and 3d and the dielectric 2c are connected to the main electrodes 1a and 1b.
Since it is arranged close to the gap, it becomes an obstacle to the gas flow path. Therefore, the gas flow of the laser gas sent from the gas flow path is disturbed, and the laser gas decomposed and heated by the glow discharge 4 cannot be sufficiently removed to the outside of the discharge region, which causes a problem. If the decomposed and heated laser gas remains in the discharge region, the problem of high-repetitive operation becomes unstable. Therefore, conventionally, the laser gas is sufficiently removed to the outside of the discharge region by taking measures such as increasing the output of the gas passage, but in this case, by increasing the output of the gas passage,
Since the cost increases, there is a drawback that the economic burden becomes large.

The present invention has been made to solve the above problems, and the purpose thereof is to contribute to downsizing of a gas laser device by simplifying the structure and to decompose and heat by glow discharge. An object of the present invention is to provide an excellent gas laser discharge part that can realize stable high repetition operation at low cost by efficiently removing the laser gas outside the discharge region.

[0014]

In order to achieve the above object, a gas laser discharge part of the present invention has a current terminal connected to a pair of main electrodes opposed to each other in a gas container, and at least one of the main electrodes. Is composed of a dielectric, and a cylindrical dielectric is directly arranged on the glow discharge side surface of the main electrode, a conductor is passed through the cylindrical dielectric, and the conductor is connected to a current terminal of the opposing main electrode. It is characterized by having done.

[0015]

In the present invention having the above construction,
By arranging the tubular dielectric directly on the main electrode having at least one as a dielectric, and connecting the conductor passing through the tubular dielectric to the current terminal connected to the opposing main electrode,
It is possible to form a circuit that generates a corona discharge that causes preionization. Therefore, the conventionally used members necessary for preionization, that is, the trigger power supply, the switch, the high-voltage power supply, and their accessories are unnecessary.

Further, since the tubular dielectric for pre-ionization is directly arranged on the surface of the main electrode on the glow discharge side, there is no member which becomes an obstacle to the gas flow path. Therefore, even in the low-power gas passage, the laser gas decomposed and heated by glow discharge can be sufficiently removed to the outside of the discharge region.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be specifically described below with reference to FIG. The same members as those in the conventional technique shown in FIG. 4 are designated by the same reference numerals and the description thereof will be omitted.

(1) First Embodiment FIG. 1 FIG. 1 is a configuration diagram showing a configuration and an excitation power supply circuit of the first embodiment. Main electrodes 1a and 1b are arranged to face each other in a gas container (not shown) that is airtightly filled. Of these, the main electrode 1b is made of a dielectric material. The main electrode 1b is installed via the current terminal 5b. Also,
On the surface of the main electrode 1b on the glow discharge 4 side, cylindrical dielectrics 2a, 2a are directly arranged in parallel at the upper edge and the lower edge. A conductor 3a is passed through the cylindrical dielectric 2a, and a small gap is formed between the conductor 3a and the main electrode 1b. The conductor 3a is the main electrode 1
b is connected to the current terminal 5a on the side of the main electrode 1a that faces it. The arrows in the figure indicate the gas flow of the laser gas formed in the gas container. This gas flow is the main electrode 1a,
It is designed to pass between 1b. The current terminals 5a,
The excitation power supply circuit to which 5b is connected uses the glow discharge part of the circuit shown in FIG. 4, as is apparent from the figure.

The first embodiment having the above construction is
It works as follows. First, in the initial state, the switch 10a is open, and the capacitor (C1) 6 is charged through a route of high voltage power supply (HV) 11a-capacitor (C1) 6-inductance 9-ground. Then, the trigger power supply (T which received the signal from the pulse generator (PG) 13
S) 12a closes the switch 10a, the electric charge stored in the capacitor (C1) 6 becomes the current terminal 5a-conductor 3
Through the a-cylindrical dielectric 2a, a corona discharge (not shown) for pre-ionization is generated in a minute gap with the main electrode 1b. Immediately after that, glow discharge 4 is generated between the main electrodes 1a and 1b. This glow discharge 4 excites a laser gas to generate a laser, and the action of an optical resonator (not shown) causes the laser light to be directed in a direction orthogonal to the opposing axes of the main electrodes 1a and 1b (in the plane of the drawing). The light is emitted in a direction substantially perpendicular to the above).

In the above-described first embodiment, the cylindrical dielectric 2a is directly arranged on the main electrode 1b made of a dielectric material and having a ground potential, and the conductor 3a passing through the cylindrical dielectric 2a is connected to the main electrode. By connecting to the current terminal 5a on the side of the main electrode 1a opposite to 1b, it is possible to form a circuit for generating a corona discharge which is a preliminary ionization. Therefore, conventionally used members necessary for preionization, that is, the trigger power supply 12b, the switch 10b, the high voltage power supply 11b, and the capacitor (C2) 7 shown in FIG. 4 are unnecessary. Therefore, compared with the conventional gas laser discharge part, the number of constituent members can be significantly reduced, and the simplification of the structure can be promoted. As a result, it is possible to contribute to miniaturization of the gas laser device.

Further, since the cylindrical dielectric 2a is directly arranged on the surface of the main electrode 1b on the glow discharge 4 side, there is no member which becomes an obstacle to the gas flow flowing through the gas flow path. Therefore, the gas flow smoothly even in the low power gas flow path,
The laser gas decomposed and heated by the glow discharge 4 can be sufficiently removed outside the discharge region. Such a first
According to the embodiment, it is possible to realize stable, high-repetition operation without requiring cost because a gas passage having a low output is sufficient.

(2) Second Embodiment ... FIG. 2 FIG. 2 is a block diagram showing a second embodiment. In the second embodiment, both the main electrodes 1a and 1b are made of a dielectric material. On the surface of the main electrodes 1a and 1b facing each other on the glow discharge 4 side, a cylindrical dielectric 2a is provided at the upper edge of the main electrode 1b, and a cylindrical dielectric 2b is provided at the lower edge of the main electrode 1a.
Each one is placed directly. Cylindrical dielectric 2
Conductors 3a and 3b are passed through a and 2b, and a minute gap is formed between the conductors 3a and 3b and the main electrode 1b. The conductor 3a is connected to the current terminal 5a on the main electrode 1a side, and the conductor 3b is connected to the current terminal 5b on the main electrode 1b side. The circuit to which the current terminals 5a and 5b are connected has the same configuration as that shown in FIG.

According to the second embodiment having the above-mentioned structure, the same effects as those of the first embodiment can be exhibited, and at the same time, the following effects can be expected. That is, even when an oscillating current is generated between the main electrodes 1a and 1b and the voltage distribution is reversed, a corona discharge (not shown) for preionization can be formed, and a uniform glow discharge 4 is formed immediately after that. Therefore, it is possible to obtain a stable laser output.

(3) Third Embodiment ... FIG. 3 FIG. 3 is a block diagram showing a third embodiment. The third embodiment is
A cylindrical dielectric 2 is attached to the main electrodes 1a and 1b made of a dielectric.
A structural feature is that a groove 14 is formed so that a and 2b are filled with the cylindrical dielectrics 2a and 2b. Further, in the third embodiment, both the main electrodes 1a and 1b are made of a dielectric material. Furthermore, the main electrodes 1a facing each other,
On the surface of the glow discharge 4 side of the main electrode 1b, the cylindrical dielectrics 2a and 2a are provided one by one at the upper and lower side edges of the main electrode 1b, and the cylindrical dielectrics 2b and 2b are provided at the upper and lower side edges of the main electrode 1a. Book by book
A total of four cylindrical dielectrics are directly arranged.

According to the third embodiment having such a structure, since the grooves 14 are filled in the cylindrical dielectrics 2a and 2b, the gas flow smoothly flows along the surfaces of the main electrodes 1a and 1b. , The gas flow is not disturbed. Therefore, a stable gas flow can be secured, and a stable laser output can be obtained even during high repetition operation. Further, it goes without saying that it has the same effects as the first and second embodiments.

The present invention is not limited to the above embodiment, but the shape, number and size of the constituent members can be changed as appropriate.

[0027]

As described above, according to the gas laser discharge part of the present invention, the corona discharge for preionization is provided by the simple structure in which the cylindrical dielectric is directly arranged on the main electrode composed of the dielectric. It is possible to eliminate the need for a member for forming the structure, simplify the structure, and contribute to downsizing of the gas laser device. In addition, since the cylindrical dielectric is directly arranged on the main electrode, there is no member that becomes an obstacle to the gas flow path, and the decomposed and heated laser gas can be efficiently removed completely outside the discharge region. As a result, stable high repetition operation can be realized at low cost.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a configuration and an excitation power supply circuit of a first embodiment of a gas laser discharge unit of the present invention.

FIG. 2 is a configuration diagram of a second embodiment of a gas laser discharge unit of the present invention.

FIG. 3 is a configuration diagram of a third embodiment of a gas laser discharge unit of the present invention.

FIG. 4 is a configuration diagram showing a configuration of a conventional gas laser discharge unit and an excitation power supply circuit.

[Explanation of symbols]

 1a, 1b Main electrodes 2a, 2b Cylindrical dielectric 3a, 3b Conductor 4 Glow discharge 5a, 5b Current terminal 14 Groove

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Ken Sato 2-1, Ukishima-cho, Kawasaki-ku, Kawasaki-shi, Kanagawa Inside the Toshiba Hamakawasaki Plant (72) Inventor Akira Ishii, No. 2 Ukishima-cho, Kawasaki-ku, Kawasaki-shi, Kanagawa No. 1 Incorporated company Toshiba Hamakawasaki factory (72) Inventor Toru Tamagawa No. 2 Ukishimacho, Kawasaki-ku, Kawasaki-shi, Kanagawa No. 2 Incorporated company Toshiba Hamakawasaki factory (72) Yuji Okita 2 Harumicho, Fuchu-shi, Tokyo 1st at 24 Toshiba FA System Engineering Co., Ltd.

Claims (1)

[Claims] 1. A pair of main electrodes are arranged to face each other in a gas container airtightly filled with laser gas, a gas flow path for sending the laser gas is formed between the main electrodes, and the laser gas is supplied to the main electrode to glow. In a gas laser discharge part for generating a discharge and exciting a laser gas by this discharge to generate a laser, a current terminal is connected to the main electrode, at least one of the main electrodes is made of a dielectric, and a glow of the main electrode is formed. A gas laser discharge part, wherein a cylindrical dielectric is directly arranged on a surface on a discharge side, a conductor is passed through the cylindrical dielectric, and the conductor is connected to a current terminal of an opposing main electrode.