JP2001156366A - Gas laser oscillating method and gas laser oscillator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain laser beams having the same volume, a large output, a transverse mode and high isotropy in an orthogonal type high-frequency discharge excitation type gas laser oscillator. SOLUTION: Electrodes 23, 25 are arranged without interrupting a laser gas flow on the upstream side and downstream side of the laser gas flow, holding an optical resonator 13 with a folded-back plane introducing laser beams LB crossed at approximately right angles in the flow direction of a laser gas into the flow path of the laser gas 5. A plurality of rod-shaped discharge sections 31, 37 installed to the electrodes 23, 25 are arranged near the folded- back plane 21 of the optical resonator 13 through spaces. Electricity is discharged between the discharge sections 31, 37 for the electrodes on the upstream side and the downstream side by supplying the electrodes 23, 25 on the upstream side and the downstream side with high-frequency AC power, and laser beams LB are oscillated. Since a discharge gap between the electrodes can be narrowed, a leakage current to a discharge vessel is reduced, and power capable of being charged per a unit area is increased.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a laser oscillation method and a laser oscillator.

[0002]

2. Description of the Related Art Conventionally, as a gas laser oscillator 101, as shown in FIGS. 8, 9, 10 and 11, a laser gas 105 containing a CO ₂ gas as a laser medium is provided in a discharge vessel 103. A predetermined amount is filled, and a blower 107 and a heat exchanger 10
9 are provided, and the blower 107
05 is cycled.

In the upper part of the discharge vessel 103 shown in FIGS. 8 to 11, a rear mirror 111, a folding mirror 113, and an output mirror 11 are provided so as to guide a laser beam LB substantially perpendicular to the flow direction of the laser gas 105 into the gas flow path.
An optical resonator 117 composed of an opposing mirror such as 5 is provided. In FIG. 8 or FIG. 11, an electrode 119 vertically opposed is provided so that the discharge current is also substantially orthogonal to the flow direction of the laser gas 105. High-frequency AC power is supplied to the opposing electrodes 119, and this type is a triaxial orthogonal type high-frequency discharge pumped gas laser oscillator.

Incidentally, in order to obtain a higher laser output, it is general that an optical path is folded between a number of opposing mirrors.

Gas laser oscillator 1 shown in FIGS. 8 and 9
Reference numeral 01 denotes a form in which the above-described counter mirror is folded and displaced in the optical resonance space of the laser beam LB in the direction facing the discharge electrode 119, in other words, in a form that is folded in a plane orthogonal to the gas flow.

The gas laser oscillator 101 shown in FIGS. 10 and 11 has a configuration in which the above-described counter mirror is folded back and forth between the discharge electrodes 119 in the optical resonance space of the laser beam LB, in other words, is parallel to the gas flow. It is a form that is folded back in the plane.

[0007]

[0008] By the way, the conventional FIG.
And in the gas laser oscillator 101 in FIG.
Since the optical resonator 117 is folded in a plane orthogonal to the gas flow, the gap between the discharge electrodes 119 is widened and the gas flow rate is reduced, so that the maximum power that can maintain normal discharge also decreases. There is a problem that it is difficult to obtain a large output of the laser beam LB.

In the conventional gas laser oscillator 101 shown in FIGS. 10 and 11, since the optical resonator 117 is folded in a plane parallel to the gas flow, the discharge electrode 119 is formed.
Since the gas flow as the laser medium is non-uniform between the upstream and downstream sides of the gas flow between them, there has been a problem that concentric transverse modes cannot be obtained.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide an orthogonal high-frequency discharge-excited gas laser oscillator having a large output power and a high transverse mode isotropic property in an orthogonal high-frequency discharge pumped gas laser oscillator. An object of the present invention is to provide a gas laser oscillation method for obtaining light and a gas laser oscillator.

[0010]

According to a first aspect of the present invention, there is provided a gas laser oscillating method according to the first aspect of the present invention, in which a laser beam substantially perpendicular to a flow direction of a laser gas is introduced into a laser gas flow path. The electrodes are arranged without interrupting the laser gas flow on the upstream side and the downstream side of the laser gas flow with the optical resonator having the plane interposed therebetween, and a plurality of rod-shaped discharge portions provided on the electrodes are folded back of the optical resonator. By arranging them at intervals in the vicinity of a plane and supplying high-frequency AC power to the upstream and downstream electrodes, discharge is caused between the discharge portions of the upstream and downstream electrodes to oscillate laser light. It is characterized by the following.

Therefore, since the electrodes are arranged on the upstream side and the downstream side of the laser gas flow with the folded plane of the laser beam of the optical resonator interposed therebetween, the discharge gap between the electrodes can be narrowed. As a result, the leakage current to the discharge vessel is reduced, and the power that can be supplied per unit volume is increased, so that it is possible to reduce the size and increase the output of the laser beam.

According to a second aspect of the present invention, there is provided a gas laser oscillator including an optical resonator having a folded plane for guiding a laser beam substantially orthogonal to a flow direction of a laser gas into a flow path of the laser gas. On the upstream side and the downstream side of the laser gas flow across the turning plane, there is provided an electrode provided with a plurality of rod-shaped discharge portions located in the vicinity of the turning plane of the optical resonator via an interval, and the upstream and downstream electrodes are provided. A high-frequency AC power supply for supplying high-frequency AC power is connected to the side electrode.

Therefore, the operation is the same as that of the first aspect, and the electrodes are arranged on the upstream side and the downstream side of the laser gas flow with the folded plane of the laser light of the optical resonator interposed therebetween, so that the discharge gap between the electrodes is formed. Can be narrowed. As a result, the leakage current to the discharge vessel is reduced, and the power that can be supplied per unit volume is increased, so that it is possible to reduce the size and increase the output of the laser beam.

According to a third aspect of the present invention, in the gas laser oscillator according to the second aspect, the optical resonator is provided with a folded plane of the laser light at a position perpendicular to the laser gas flow. It is characterized by the following.

Therefore, since the laser gas flow flows at right angles to the turning plane of the laser light of the optical resonator, the state of the temperature, amplification factor, etc. of the laser gas as the laser medium becomes uniform. As a result, a laser beam having an isotropic transverse mode is obtained.

According to a fourth aspect of the present invention, there is provided a gas laser oscillator according to the second aspect, wherein the upstream electrode is provided on an upstream wall surface of a gas flow path.
An electrode base and a plurality of arch-shaped first rod-shaped electrode portions projecting from the first electrode base toward the downstream direction;
The downstream electrode comprises a second electrode base provided on a wall surface on the downstream side of the gas flow path and a plurality of arch-shaped second rod-shaped body electrode parts protruding from the second electrode base in an upstream direction. The plurality of first rod-shaped electrode portions and the plurality of second rod-shaped electrode portions each include a discharge portion extending in a direction substantially orthogonal to the laser light at a position near the laser light, and The discharge part is configured in parallel along the optical path direction of the laser light.

Therefore, a plurality of first arch-shaped first members are provided.
Since the rod-shaped electrode portion and the plurality of second rod-shaped electrode portions are disposed on the upstream side and the downstream side of the laser gas flow with the folded plane of the laser light of the optical resonator interposed therebetween, a plurality of the rod-shaped electrodes are not interrupted. Since the discharge gap between the discharge portions of the first and second rod-shaped body electrode portions is also narrow, a discharge state with high output efficiency is obtained.

According to a fifth aspect of the present invention, there is provided a gas laser oscillator according to the second aspect, wherein the upstream electrode is provided on a wall surface on an upstream side of a gas flow path.
An electrode base and a plurality of arch-shaped first rod-shaped electrode portions projecting from the first electrode base toward the downstream direction;
The downstream electrode comprises a second electrode base provided on a wall surface on the downstream side of the gas flow path and a plurality of arch-shaped second rod-shaped body electrode parts protruding from the second electrode base in an upstream direction. The plurality of first rod-shaped electrode portions and the plurality of second rod-shaped electrode portions each include a discharge portion extending in a direction substantially parallel to the laser light at a position near the laser light, and the plurality of discharge portions. Are arranged in parallel along a direction substantially orthogonal to the laser beam.

Accordingly, the operation is similar to that of the fourth aspect, and the plurality of first rod-shaped electrode portions and the plurality of second rod-shaped electrode portions having an arch shape are sandwiched by the folded plane of the laser beam of the optical resonator. Since it is arranged on the upstream side and the downstream side of the laser gas flow, the discharge gap between the discharge portions of the plurality of first and second rod-shaped body electrode portions is arranged narrow without interrupting the laser gas flow, so that the output efficiency is high. It becomes a discharge state.

According to a sixth aspect of the present invention, there is provided a gas laser oscillator according to the second aspect, wherein the upstream electrode is provided on an upstream wall surface of a gas flow path.
An electrode base and a plurality of arch-shaped first rod-shaped electrode portions projecting from the first electrode base toward the downstream direction;
The downstream electrode comprises a second electrode base provided on a wall surface on the downstream side of the gas flow path and a plurality of arch-shaped second rod-shaped body electrode parts protruding from the second electrode base in an upstream direction. The plurality of first rod-shaped electrode sections or the plurality of second rod-shaped electrode sections each include a discharge section extending in a direction substantially orthogonal to the laser light at a position near the laser light, and The discharge unit is configured in parallel along the optical path direction of the laser beam, and the plurality of second rod-shaped electrode units or the plurality of first
The rod-shaped body electrode portion includes a discharge portion extending in a direction substantially parallel to the laser light at a position near the laser light, and the plurality of discharge portions are configured in parallel along a direction substantially orthogonal to the laser light. It is characterized by becoming.

Accordingly, the operation is the same as that of the fourth aspect, and the plurality of first rod-shaped electrode portions and the plurality of second rod-shaped electrode portions having an arch shape are sandwiched by the folded plane of the laser beam of the optical resonator. Since it is arranged on the upstream side and the downstream side of the laser gas flow, the discharge gap between the discharge portions of the plurality of first and second rod-shaped body electrode portions is arranged narrow without interrupting the laser gas flow, so that the output efficiency is high. It becomes a discharge state.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a gas laser oscillation method and a gas laser oscillator according to the present invention will be described below with reference to the drawings.

Referring to FIGS. 1 and 2, a gas laser oscillator 1 according to the present embodiment has a discharge vessel 3 in which a predetermined amount of a mixed gas containing, for example, CO ₂ gas as a laser gas 5 as a laser medium is provided. 1 and 2 in the discharge vessel 3, a blower 7 is provided at a lower portion, and the blower 7 circulates a mixed gas (laser gas 5) in a direction of an arrow.

A heat exchanger 11 for cooling the gas heated by the discharge is disposed in the gas circulation path 9.

In this embodiment, a laser beam LB that is substantially perpendicular to the flow direction of the laser gas 5 indicated by a dotted line in the upper part in FIGS. 1 and 2 in the discharge vessel 3 is guided into the gas flow path. In this example, an optical resonator 13 including a total of four opposed mirrors is provided. More specifically, the optical resonator 13 is composed of a total reflection rear mirror 15 and a reflection mirror 17 and a semi-reflection output mirror 19 disposed opposite to the reflection mirror 17 so as to generate a laser gas flow. This is a form that is folded in a plane orthogonal to the plane. That is, the folded plane 21 of the laser beam LB in the optical resonator 13 is orthogonal to the laser gas flow.

On the upstream side and the downstream side of the laser gas flow with the folded plane 21 of the laser beam LB of the optical resonator 13 interposed therebetween, an electrode 23 composed of a large number of rod-like bodies covered with a dielectric,
25 are provided.

In FIG. 1, the electrode 23 on the upstream side of the laser gas flow on the left side is, for example, an electrode base 2 as a first electrode base.
7 is buried in the wall surface on the upstream side of the gas flow path so as not to block the laser gas flow. The electrode base 27 includes a plurality of first rod-shaped electrode portions having an arch shape, for example, as shown in FIG.
In this example, a large number of U-shaped rod-shaped electrode portions 29 are protruded toward the gas flow path, and a large number of rod-shaped electrode portions 29 are formed.
Are arranged at appropriate intervals in the left-right direction in FIG. 2, and are arranged at substantially equal intervals in the present embodiment.

The rod portion in the middle of the rod-shaped electrode portion 29 is the actual discharge portion 31, which is located near the upstream side of the folded plane 21 of the optical resonator 13. In FIGS. 1 and 2, they are arranged so as to extend in the vertical direction. In other words, the discharge portions 31 extend in a direction substantially orthogonal to the laser light LB near the laser light LB.
B are arranged in parallel along the optical path direction of B.

In FIG. 1, the electrode 25 on the downstream side of the laser gas flow on the right side is substantially similar in structure to the electrode 23 on the upstream side, and for example, the electrode base 3 as the second electrode base.
3 is buried in the wall surface on the downstream side of the gas flow path so as not to block the laser gas flow. The electrode base 33 includes a plurality of arc-shaped second rod-shaped electrode portions, for example, as shown in FIG.
In this embodiment, a large number of rod-shaped electrode portions 35 having an inverted U shape are provided so as to protrude into the gas flow path.
5 are arranged at appropriate intervals in the left-right direction in FIG. 2, and are arranged at substantially equal intervals in the present embodiment. Further, in the present embodiment, the rod-shaped electrode portion 29 of the electrode 23 on the upstream side and the rod-shaped electrode portion 35 of the electrode 25 on the downstream side are arranged at positions alternately shifted as shown in FIG. .

The rod-shaped portion in the middle of the rod-shaped electrode portion 35 is an actual discharge portion 37, which is located near the downstream side of the folded plane 21 of the optical resonator 13. In FIGS. 1 and 2, they are arranged so as to extend in the vertical direction. In other words, the discharge portions 37 extend in a direction substantially orthogonal to the laser light LB at a position near the laser light LB.
B are arranged in parallel along the optical path direction of B.

The upstream electrode 23 and the downstream electrode 2
5 is connected via a wire 41 to a high-frequency AC power supply 39 for supplying high-frequency AC power.
A discharge plasma is generated during the process. Therefore, light generated in the discharge plasma is amplified in the optical resonator 13 and laser light LB oscillated from the output mirror 19 is extracted by an output coupler (not shown). The above laser oscillator is a two-axis orthogonal type high-frequency discharge pumped gas laser oscillator.

As described above, since the electrodes 23 and 25 are arranged on the upstream side and the downstream side of the laser gas flow with the folded plane 21 of the optical resonator 13 interposed therebetween, the discharge part 31 of the electrode 23 is formed.
The discharge gap between the electrode and the discharge portion 37 of the electrode 25 can be narrowed. As a result, the leakage current to the discharge vessel 3 is reduced, and the power that can be supplied per unit volume can be increased. Therefore, it is possible to increase the output of the laser beam LB with a small size.

Since the laser gas flow flows at right angles to the folded plane 21 of the optical resonator 13, the flow state of the laser gas 5 is good, so that the state of the laser gas 5 as a laser medium such as the temperature and the amplification factor is uniform. become. Therefore, a laser beam LB having an isotropic transverse mode can be obtained.

Next, a two-axis orthogonal type high-frequency discharge pumped gas laser oscillator 1 according to another embodiment of the present invention will be described.
Will be described.

Referring to FIG. 3 to FIG. 5, the gas laser oscillator 1 has substantially the same structure as the two-axis orthogonal type high-frequency discharge pumped gas laser oscillator 1 of FIGS. 1 and 2 described above. The common members are denoted by the same reference numerals, and different portions will be described in detail.

On the upstream side and the downstream side of the laser gas flow with the folded plane 21 of the optical resonator 13 interposed therebetween, there are provided a number of rod-like electrodes 43 and 45 covered with a dielectric.

In FIG. 3, the left electrode 43 on the upstream side of the laser gas flow is, for example, an electrode base 4 as a first electrode base.
7 is buried in the wall surface on the upstream side of the gas flow path so as not to block the laser gas flow. The electrode base 47 has a plurality of first rod-shaped electrode portions having an arch shape, for example, as shown in FIG.
In FIG. 3, a plurality of rod-shaped body electrode portions 49 having a flat, downward U-shape are provided so as to project into the gas flow path. In the present embodiment, two rod-shaped body electrode portions 49 are provided in FIGS. It is arranged up and down. The number of rod-shaped electrode portions 49 is not particularly limited.

The rod-shaped portion in the middle of the rod-shaped electrode portion 49 is the actual discharge portion 51, which is located near the upstream side of the folded plane 21 of the optical resonator 13. 4 and 5, it is arranged so as to extend in the left-right direction. In other words, the discharge unit 51 extends in a direction substantially parallel to the laser beam LB at a position near the laser beam LB, and the plurality of discharge units 51 are arranged in parallel along a direction substantially orthogonal to the laser beam LB. Are located.

In FIG. 3, the electrode 45 on the downstream side of the laser gas flow on the right side is substantially similar in structure to the above-mentioned electrode 43 on the upstream side.
3 is buried in the wall surface on the downstream side of the gas flow path so as not to block the laser gas flow. The electrode base 53 has a plurality of arc-shaped second rod-shaped electrode portions, for example, as shown in FIG.
In FIG. 3, a plurality of U-shaped rod-shaped body electrode portions 55 are protruded toward the gas flow path, and the plurality of rod-shaped body electrode portions 55 are vertically spaced in FIGS. 3 and 4 at appropriate intervals. In this embodiment, three rod-shaped body electrode portions 55 are arranged at substantially equal intervals. Further, in the present embodiment, the rod-shaped electrode portions 49 of the upstream-side electrodes 43 and the rod-shaped electrode portions 55 of the downstream-side electrodes 45 are arranged at positions shifted alternately as shown in FIG. .

The rod-shaped part in the middle of the rod-shaped electrode part 55 is an actual discharge part 57, which is located near the downstream side of the folded plane 21 of the optical resonator 13. 4 and 5, it is arranged so as to extend in the left-right direction. In other words, the discharge parts 57 extend in a direction substantially parallel to the laser light LB near the laser light LB, and a large number of discharge parts 57 are arranged in parallel along a direction substantially orthogonal to the laser light LB. Are located.

The above-mentioned upstream electrode 43 and the downstream electrode 4
5 is connected via a wire 41 to a high-frequency AC power supply 39 for supplying high-frequency AC power.
The discharge plasma is generated during this period, and its operation is the same as that of the gas laser oscillator 1 shown in FIGS.

Next, a two-axis orthogonal type high frequency discharge pumped gas laser oscillator 1 according to another embodiment of the present invention will be described.
Will be described.

Referring to FIGS. 6 and 7, this gas laser oscillator 1 is a two-axis orthogonal type high frequency discharge pumped gas laser shown in FIGS. 1 and 2 and FIGS. 3 to 5 described above. Since the structure is substantially the same as that of the oscillator 1, common members are denoted by the same reference numerals and different parts will be described in detail.

On the upstream side and downstream side of the laser gas flow with the folded plane 21 of the optical resonator 13 interposed therebetween, there are provided a large number of rod-shaped electrodes 59 and 61 covered with a dielectric. This type has an electrode 23 having a U-shaped rod electrode in a substantially vertical plane as shown in FIGS.
An electrode 25 and an electrode 43 and an electrode 45 each having a plurality of rod-shaped electrodes substantially U-shaped in a horizontal plane as shown in FIGS. 3 to 5 are provided, one on the upstream side and the other on the downstream side. It is a mixed type that is provided on the side and combined.

For example, in FIG. 6, the left electrode 59 on the upstream side of the laser gas flow has two U-shaped electrodes substantially U-shaped in a horizontal plane with the electrode base 47 as shown in FIGS. 6, the electrode 61 on the downstream side of the laser gas flow on the right side in FIG. 6 is connected to the electrode base 3 as shown in FIG. 1 and FIG.
A large number of rod-shaped electrode portions 35 substantially U-shaped in a plane substantially perpendicular to
This is the same as the electrode 25 composed of

The above-mentioned upstream electrode 59 and downstream electrode 6
1 is connected via a wire 41 to a high-frequency AC power supply 39 for supplying high-frequency AC power.
The discharge plasma is generated during this period, and its operation is the same as that of the gas laser oscillator 1 shown in FIGS. 1 and 2 and FIGS. 3 to 5, and a description thereof will be omitted.

The present invention is not limited to the above-described embodiment, but can be embodied in other forms by making appropriate changes.

[0048]

As will be understood from the above description of the embodiment of the invention, according to the first aspect of the present invention, the electrode is located on the upstream side of the laser gas flow with the folded plane of the laser light of the optical resonator interposed therebetween. And the downstream side, the discharge gap between the electrodes can be narrowed. As a result, the leakage current to the discharge vessel is reduced, and the power that can be supplied per unit volume can be increased.

According to the second aspect of the invention, the effect is the same as that of the first aspect, and the electrodes are arranged on the upstream side and the downstream side of the laser gas flow with the folded plane of the laser light of the optical resonator interposed therebetween. Therefore, the discharge gap between the electrodes can be narrowed. As a result, the leakage current to the discharge vessel is reduced, and the power that can be supplied per unit volume can be increased.

According to the third aspect of the present invention, since the laser gas flow is made to flow at right angles to the turning plane of the laser light of the optical resonator, the state of the laser gas as the laser medium, such as the temperature and amplification factor, can be made uniform. As a result, laser light having a transverse mode with good isotropy can be obtained.

According to the fourth aspect of the present invention, the plurality of first rod-shaped electrode portions and the plurality of second rod-shaped electrode portions having an arch shape form a laser gas flow across the folded plane of the laser light of the optical resonator. Since they are arranged on the upstream side and the downstream side, the discharge gap between the discharge portions of the plurality of first and second rod-shaped electrode portions can be narrowed without interrupting the laser gas flow, and a discharge state with high output efficiency can be obtained. it can.

According to the fifth aspect of the present invention, it is the same as the effect of the fourth aspect, wherein the plurality of first rod-shaped electrode portions and the plurality of second rod-shaped electrode portions having an arch shape are formed by a laser of an optical resonator. Since the laser gas flow is arranged upstream and downstream of the light-turning plane, the discharge gap between the discharge portions of the plurality of first and second rod-shaped electrode portions can be narrowed without interrupting the laser gas flow. Thus, a discharge state with high output efficiency can be obtained.

According to the sixth aspect of the present invention, the effect is the same as that of the fourth aspect, wherein the plurality of first rod-shaped electrode portions and the plurality of second rod-shaped electrode portions having an arch shape are formed by a laser of an optical resonator. Since the laser gas flow is arranged upstream and downstream of the light-turning plane, the discharge gap between the discharge portions of the plurality of first and second rod-shaped electrode portions can be narrowed without interrupting the laser gas flow. Thus, a discharge state with high output efficiency can be obtained.

[Brief description of the drawings]

FIG. 1, showing an embodiment of the present invention, is a longitudinal sectional view of a laser oscillator.

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is a longitudinal sectional view of a laser oscillator, showing another embodiment of the present invention.

4 is a sectional view taken along line IV-IV in FIG.

FIG. 5 is a sectional view taken along line VV of FIG. 4;

FIG. 6 shows another embodiment of the present invention, and is a longitudinal sectional view of a laser oscillator.

FIG. 7 is a sectional view taken along line VII-VII of FIG. 6;

FIG. 8 is a longitudinal sectional view of a conventional laser oscillator.

9 is a sectional view taken along line IX-IX in FIG.

FIG. 10 is a longitudinal sectional view of another conventional laser oscillator.

11 is a sectional view taken along line XI-XI in FIG.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 gas laser oscillator 3 discharge vessel 5 laser gas 13 optical resonator 21 folded plane 23, 25, 43, 45, 59, 61 electrode 27, 47 electrode base (first electrode base) 33, 53 electrode base (second electrode base) 29,49 Rod-shaped electrode part (first rod-shaped electrode part) 35,55 Rod-shaped electrode part (second rod-shaped electrode part) 31,37,51,57 Discharge part 39 High-frequency AC power supply

Claims (6)

[Claims] 1. A laser gas flow is interrupted between an upstream side and a downstream side of a laser gas flow across an optical resonator having a folded plane for guiding a laser beam substantially orthogonal to a flow direction of the laser gas into a flow path of the laser gas. A plurality of rod-shaped discharge portions provided on the electrodes are arranged at intervals in the vicinity of the folded plane of the optical resonator, and the electrodes are arranged without performing
A gas laser oscillation method, characterized in that a high-frequency AC power is supplied to the upstream and downstream electrodes to cause discharge between discharge portions of the upstream and downstream electrodes to oscillate laser light. 2. An optical resonator having a folded plane for guiding a laser beam substantially orthogonal to the flow direction of the laser gas into the flow path of the laser gas, and an upstream side of the laser gas flow across the folded plane of the optical resonator. An electrode provided with a plurality of rod-shaped discharge portions located in the vicinity of the folded plane of the optical resonator at intervals on the side and the downstream side, and supplies high-frequency AC power to the upstream and downstream electrodes A gas laser oscillator to which a high-frequency AC power supply is connected. 3. The gas laser oscillator according to claim 2, wherein the optical resonator is provided with a folded plane of the laser light at a position perpendicular to the laser gas flow. 4. An upstream electrode comprising: a first electrode base provided on an upstream wall surface of a gas flow path; and a plurality of arch-shaped first rods protruding from the first electrode base in a downstream direction. And a second electrode base provided on a downstream wall surface of the gas flow path, and a plurality of arch-shaped second electrodes protruding from the second electrode base in the upstream direction. A discharge comprising two rod-shaped electrode portions, wherein the plurality of first rod-shaped electrode portions and the plurality of second rod-shaped electrode portions are extended in a direction substantially orthogonal to the laser light at a position near the laser light. 3. The gas laser oscillator according to claim 2, further comprising: a plurality of discharge units, wherein the plurality of discharge units are configured in parallel along the optical path direction of the laser light. 5. The first electrode base provided on the upstream wall surface of the gas flow path and a plurality of arch-shaped first rods protruding downstream from the first electrode base. And a second electrode base provided on a downstream wall surface of the gas flow path, and a plurality of arch-shaped second electrodes protruding from the second electrode base in the upstream direction. A discharge section comprising two rod-shaped electrode sections, wherein the plurality of first rod-shaped electrode sections and the plurality of second rod-shaped electrode sections extend in a direction substantially parallel to the laser light at a position near the laser light; 3. The gas laser oscillator according to claim 2, wherein the plurality of discharge units are provided in parallel along a direction substantially orthogonal to the laser beam. 6. An upstream electrode comprising: a first electrode base provided on an upstream wall of a gas flow path; and a plurality of arch-shaped first rods protruding downstream from the first electrode base. And a second electrode base provided on a downstream wall surface of the gas flow path, and a plurality of arch-shaped second electrodes protruding from the second electrode base in the upstream direction. A discharge in which the plurality of first rod-shaped electrode portions or the plurality of second rod-shaped electrode portions are extended in a direction substantially orthogonal to the laser light at a position near the laser light; And the plurality of discharge portions are configured in parallel along the optical path direction of the laser light, and the plurality of second rod-shaped electrode portions or the plurality of first rod-shaped electrode portions are located at positions near the laser light. A discharge portion extending in a direction substantially parallel to the laser beam, and Gas laser oscillator according to claim 2, characterized by being configured in parallel along a direction substantially perpendicular to the discharge portion of the number to the laser light.