JPH05299741A - Gas laser apparatus - Google Patents

Abstract

PURPOSE:To make an apparatus small-sized by reducing the insulating distance of discharge electrodes. CONSTITUTION:An electric current is supplied to a first discharge electrode 14a and a second discharge electrode 14b from a high-frequency power-supply circuit 19 via a matching device 18 and feeders 17a, 17b. The feeders 17a, 17b are set to be nearly the same length size. The output of the high-frequency power-supply circuit 19 applies a high-frequency AC voltage whose phase has been inverted alternately to the feeders 17a, 17b. Since the ground capacity, in terms of an alternating current, of the feeders 17a, 17b becomes nearly equal, the high-frequency voltage whose phase has been inverted alternately is applied to the individual discharge electrodes 14a, 14b. As a result, it is possible to apply a nearly double high-frequency voltage between the discharge electrodes 14a, 14b. Thereby, the insulating distance of the individual discharge electrodes 14a, 14b can be reduced and an apparatus can be made small-sized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas laser device for oscillating laser light by applying an alternating voltage between electrodes.

[0002]

2. Description of the Related Art As a gas laser device for applying an AC voltage between electrodes, there is, for example, one using an RF (Radio Frequency) power supply in which the frequency of the AC voltage is in a high frequency range. FIG. 3 shows an outline of the electrical configuration of the RF power supply 1 and the oscillator head 2, which will be briefly described below.

That is, in the RF power supply 1, a stable high frequency signal obtained from the crystal oscillator is output by the excitation unit 3, and the high frequency signal is amplified by the vacuum tube type power amplifier 4 and output as a high frequency voltage. The high frequency voltage is impedance-converted by the impedance matching device 5 and applied to the plurality of pairs of discharge electrodes 6 of the oscillator head 2.

The oscillator head 2 comprises a discharge tube, a plurality of pairs of discharge electrodes 6 and a resonator 7, and a laser gas is circulated inside the discharge tube. Then, when a high frequency voltage is applied to the discharge electrode 6 arranged on the outer side between the discharges, a high frequency discharge due to capacitive coupling is generated in the discharge tube to excite the laser gas. As a result, pulsed laser light is generated from the discharge tube.

In the gas laser device using the RF power supply 1 as described above, since the discharge electrode can be arranged outside the discharge tube, the electrode is not sputtered and gas deterioration is small, and the discharge power density can be increased at a low voltage. There are various advantages such as being safe and compact, and facilitating modulation in the RF power source.

[0006]

By the way, in the above-described conventional laser device, the AC power supply is composed of a vacuum tube type power supply circuit, and in this case, one of the discharge electrodes is set to the ground potential. , RF with such a configuration
When the output voltage of the power supply 1 is increased, the high-frequency voltage is directly applied to the other discharge electrode, so that it is necessary to set the insulation distance large, which causes a problem that the miniaturization of the device is restricted.

The present invention has been made in view of the above circumstances, and an object thereof is to make it possible to set the insulation distance of the discharge electrode to be relatively short even when the AC voltage applied to the discharge electrode is high. Another object of the present invention is to provide a gas laser device that can be downsized.

[0008]

DISCLOSURE OF THE INVENTION The present invention is directed to a gas laser device including a container whose inside is filled with a laser gas, at least a pair of discharge electrodes, and an AC power source connected to the discharge electrodes. In addition, the AC power supply and the pair of discharge electrodes are connected by power supply lines having substantially the same length, and the AC power supplies apply alternating voltages to the power supply lines, the phases of which are inverted from each other. It has a feature in the place.

[0009]

According to the gas laser device of the present invention, the alternating current power supply gives an alternating voltage whose phase is inverted to the power supply line, and the power supply line is set to have substantially the same length dimension for each discharge electrode. An AC voltage having a mutually inverted phase is applied to the pair of discharge electrodes. At this time, since the applied voltage between the discharge electrodes is the difference between the AC voltages applied to the respective discharge electrodes, an AC voltage which is substantially doubled is applied. Therefore, it suffices to apply an AC voltage that is approximately half the applied voltage between the discharge electrodes to each discharge electrode.
In each discharge electrode, the potential with respect to ground can be lowered, which eliminates the need to set the insulation distance to be large in proportion to the applied voltage, and the overall size of the device can be reduced.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a lateral flow type gas laser device will be described below with reference to FIGS.

In FIG. 2 showing the outline of the overall structure, a cross section is approximately U inside an external wind tunnel 11 as a rectangular container.
An internal wind tunnel 12 having a letter shape and made of stainless steel, iron or aluminum is provided. A flat plate-shaped first dielectric 13a made of ceramics or the like is provided in the center of the upper surface of the external wind tunnel 11, and a second dielectric similar to the first dielectric 13a is provided in the center of the upper surface of the internal wind tunnel 12. The bodies 13b are arranged at opposite positions.

These first and second dielectrics 13a, 1
The outer wind tunnel 11 and the inner wind tunnel 1 are attached to the outer wind tunnel 11 and the inner wind tunnel 12 in an airtight manner.
A space region A between the space 2 and the space 2 is formed in an airtight state with respect to the external space. The first discharge electrode 14a is fixed to the center of the upper surface of the first dielectric 13a, the second discharge electrode 14b is fixed to the center of the lower surface of the second dielectric 13b, and the inside of the internal wind tunnel 12 is It is formed so as to communicate with the external space.

A laser gas is enclosed in a space region A between the outer wind tunnel 11 and the inner wind tunnel 12,
A blower 15 and a heat exchanger 16 are disposed on the inner bottom of the. The laser gas in the space area A is blower 1
It is circulated in the direction of arrow P by 5 and is cooled when passing through the heat exchanger 16.

Next, referring to FIG. 1, the first and second discharge electrodes 14a and 14b are respectively connected to power supply lines 17a and 17b.
The matching device 18 is connected via b, and the matching device 18 is connected to a high frequency power supply circuit 19 as an AC power supply. In this case, the power supply lines 17a and 17b are of substantially the same length and are set to have substantially the same AC-to-ground impedance.

The matching unit 18 is composed of coils 18a, 18a connected in series to the power feeding path and capacitors 18b, 18b connected between the power feeding paths, and a high frequency voltage from a high frequency power supply circuit 19 as an AC power source. Power supply line 17
a, 17b.

The high frequency power supply circuit 19 is composed of a direct current conversion circuit and an inverter circuit composed of a static induction transistor (SIT), converts commercial power supply into a high frequency voltage and outputs it, and the phases thereof are mutually inverted. The high frequency voltage is output.

According to this structure, when a high frequency voltage is output from the high frequency power supply circuit 19, power is supplied to the first and second discharge electrodes 14a and 14b through the matching unit 18 and the power supply lines 17a and 17b. Become so. As a result, an AC discharge is generated in the space region A between the first and second dielectrics 13a and 13b, the laser gas flowing inside is excited, and the laser light L is directed in the direction of the paper surface of the drawing. On the other hand, it occurs in the right angle direction.

In this case, since the lengths of the power supply lines 17a and 17b are set to be substantially the same, the capacitances to ground are substantially the same, and the power supply lines 17a and 17b are the same.
When a voltage whose phase is inverted to each other is applied to the power supply lines 17a and 17b, the voltages are transmitted under the same conditions, so that the voltages applied to the first and second discharge electrodes 14a and 14b are also substantially phase inverted from each other. It will be in the state of doing. Therefore, the first
As the applied voltage between the second discharge electrodes 14a and 14b, there is a difference between them, so that a high-frequency voltage of about twice is applied.

As a result, approximately double the voltage can be applied with the voltage between the discharge electrodes 14a, 14b and the ground being set to a relatively small value, so that the discharge electrodes 14 can be applied.
There is no need to increase the insulation distance between a and 14b, and there is an advantage that the device can be downsized accordingly.

In the above embodiment, the case where the present invention is applied to the lateral flow type gas laser device has been described. However, the present invention is not limited to this and may be applied to the axial flow type gas laser device. ..

[0021]

According to the gas laser device of the present invention, the lengths of the power supply lines are set to be substantially the same length, and AC voltages having mutually inverted phases are applied from the AC power supply to these power supply lines. Therefore, an AC voltage can be applied to each of the pair of discharge electrodes in a state where their phases are inverted. As a result, the applied voltage between the pair of discharge electrodes is substantially double the AC voltage. Therefore, by applying an AC voltage having a low ground potential to each discharge electrode, the applied voltage between the discharge electrodes can be increased, so that the insulation distance with respect to the discharge electrodes can be set to a small value. It has an excellent effect of miniaturization.

[Brief description of drawings]

FIG. 1 is an electrical configuration diagram showing an embodiment of the present invention.

[Fig. 2] Vertical side view of the overall configuration

FIG. 3 is a view corresponding to FIG. 1 showing a conventional example.

[Explanation of symbols]

11 is an external wind tunnel (container), 12 is an internal wind tunnel, 13a, 1
3b is the first and second dielectrics, and 14a and 14b are the first dielectrics.
And a second discharge electrode, 15 is a blower, 16 is a heat exchanger, 17a and 17b are power supply lines, 18 is a matching unit, 19 is a high frequency power supply circuit (AC power supply), A is a space region, and L is a laser beam. ..

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hirokatsu Suzuki 2121 Nobuo, Asahi-cho, Mie-gun, Mie Prefecture Inside the Toshiba Mie factory (72) Inventor Toru Tamagawa 2-1, Ukishima-cho, Kawasaki-ku, Kawasaki-shi, Kanagawa No. Stock Company Toshiba Hamakawasaki Factory

Claims (1)

[Claims] 1. A container whose inside is filled with laser gas,
In a gas laser device including at least a pair of discharge electrodes and an AC power supply connected to the discharge electrodes, the AC power supply and the pair of discharge electrodes are connected by a power supply line having substantially the same length, and A gas laser device characterized in that an AC voltage having a mutually inverted phase is applied from an AC power source to each of these power supply lines.