JPH06232482A - Gas laser equipment - Google Patents

Abstract

PURPOSE:To provide a gas laser equipment which improves the efficiency of laser oscillation using dielectric electrodes. CONSTITUTION:Outer shells 7b and 8b having a capacitive coupling control section, are formed on both sides of electrodes 7a and 8a to control the dispersion of discharge; no dielectric is provided above the electrodes 7a and 8a to evade the concentration of stress due to discharge.

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 which oscillates or amplifies laser light by applying a high-frequency voltage between electrodes to cause discharge, and more particularly to a gas laser device which uses a dielectric material in a discharge space. The present invention relates to a gas laser device designed to make power density uniform.

[0002]

2. Description of the Related Art FIG. 9 shows a schematic configuration of a conventional gas laser device. In FIG. 9, the pair of dielectric electrodes 1 is
The laser gas is arranged so as to face the discharge space 2 which circulates in the direction indicated by the arrow A. The dielectric electrode 1 is configured by covering an electrode portion 3 having a long shape in a direction orthogonal to the laser gas flow (direction orthogonal to the paper surface) with an outer shell portion 4 made of a dielectric material. In the cross-flow gas laser device configured as described above, when a high-frequency voltage is applied from the high-frequency power source 5 between the electrode portions 3, the laser gas flowing in the discharge space 2 is excited, and here, although not shown in the drawing, a sheet of paper is drawn. By arranging the resonator in a direction perpendicular to the plane, laser light is generated in a direction perpendicular to the paper surface.
In this case, since the outer shell 4 made of a dielectric material is present around the electrode portion 3, the power density in the discharge space 2 is made uniform, a uniform discharge can be ignited, and a stable laser is produced. Output can be obtained.

[0003]

In order to improve the laser oscillation efficiency, it is necessary to increase the frequency of the high frequency voltage applied between the electrode parts 3 to at least 700 kHz or higher. However, when the output frequency of the high-frequency power source 5 is increased, discharge is generated on both sides of the electrode part 3 due to capacitive coupling through the outer shell part 4 made of a dielectric material provided so as to cover the electrode part 3. Therefore, there is a problem that it is difficult to sufficiently improve the laser oscillation efficiency even though the output frequency of the high frequency power source 5 is increased.

Further, in some cases, there is a problem that the laser oscillation efficiency is lowered against the initial purpose. Therefore, an object of the present invention is to provide a gas laser device that can improve the laser oscillation efficiency by using a dielectric electrode.

[0005]

In order to achieve the above object, the present invention provides, in the invention as set forth in claim 1, at least a pair of dielectrics comprising an outer shell part made of a dielectric material around the electrode part. In a gas laser device which arranges body electrodes in a state of sandwiching a discharge space and oscillates or amplifies laser light by applying a high-frequency voltage between the electrode parts to perform discharge, the gas electrodes are provided on both sides of the electrode parts. It is characterized in that a capacitive coupling suppressing portion having a relative dielectric constant smaller than that of the outer shell portion is provided.

Further, in the invention according to claim 2,
In addition to the configuration of the invention described in claim 1, a space portion formed by surrounding a cross section of the capacitive coupling suppressing portion perpendicular to the laser optical axis with a dielectric is provided. .

According to the invention of claim 3, claim 1
In addition to the configuration of the invention described above, an electrode storage chamber for storing an electrode portion that is sandwiched between two capacitive coupling suppressing portions and surrounded by a dielectric on the discharge space side is provided. To do.

In the invention described in claim 4, claim 3
In addition to the configuration of the invention described above, a cooling passage for flowing a cooling medium is further provided in the electrode portion housed in the electrode housing chamber.

According to the invention of claim 5, claim 2
In addition to the configuration of the invention described above, an insulating gas is further introduced into the space. According to a sixth aspect of the invention, in addition to the configuration of the fifth aspect of the invention, the insulating gas pressure Pi further satisfies the condition that Pi ≥P, where P is the gas pressure in the gas laser device. It is characterized by.

In the invention described in claim 7, claim 1
In addition to the configuration of the invention described above, a capacitive coupling suppressing portion having a relative dielectric constant smaller than that of the outer shell portion is further provided in the longitudinal direction of the electrode portion.

According to the invention of claim 8, claim 1
In addition to the configuration of the invention described above, the metal electrode forming the electrode portion is surrounded by an insulator, and capacitive coupling suppressing portions are provided on both sides of the insulator.

[0012]

According to the invention of any one of claims 1 to 8, when a high frequency voltage is applied between the electrode parts of the pair of dielectric electrodes, the laser gas is generated in the discharge space formed between the dielectric electrodes. It is excited to generate laser light.
In this case, since the outer shell made of a dielectric material exists around the electrode portion, the power density in the discharge space becomes uniform. In addition, since there are capacitive coupling suppression parts on both sides of the electrode part that have a smaller relative dielectric constant than the outer shell part, it is possible to prevent discharge from being dispersed to both sides of the electrode part even when a high frequency voltage is applied to the electrode part. As a result, the laser oscillation efficiency can be improved.

According to the configuration of the second aspect of the invention, since the capacitive coupling suppressing portion is constituted by the space portion, by enclosing the insulating gas in the space portion, the relative dielectric constant in that portion is extremely reduced. Therefore, it is possible to sufficiently reduce the capacitive coupling through the space, and it is possible to enhance the effect of suppressing the dispersion of discharge.

According to the structure of the third aspect of the invention, there is provided an electrode housing chamber for housing an electrode portion which is sandwiched between two capacitive coupling suppressing portions and which is surrounded by a dielectric on the discharge space side. By providing the above, since the upper surface of the electrode portion is not composed of a dielectric, stress caused by discharge does not occur in this portion, and reliability of the dielectric electrode can be improved.

According to the structure of the fourth aspect of the invention, since the cooling passage for flowing the cooling medium is provided in the electrode portion, the temperature rise of the electrode portion can be suppressed, so that the electrode in the dielectric electrode can be suppressed. It is possible to prevent the occurrence of strain between the outer shell and the outer shell due to the difference in coefficient of thermal expansion between the two.

According to the structure of the fifth aspect of the invention, since the insulating gas is enclosed in the space, the relative permittivity in that portion becomes extremely small. Therefore, it becomes possible to avoid dielectric breakdown in the capacitive coupling portion, and it is possible to obtain the effect of suppressing the dispersion of discharge.

According to the sixth aspect of the invention, the pressure of the insulating gas is set to Pi and the gas pressure in the laser device is set to P.
Then, by satisfying the condition that Pi ≧ P,
It is possible to avoid dielectric breakdown in the capacitive coupling portion in the space portion, and the effect of suppressing the discharge dispersion becomes more reliable.

According to the configuration of the invention described in claim 7, while suppressing the discharge from being dispersed in the longitudinal direction of the electrode portion,
It is possible to suppress dielectric breakdown between the longitudinal direction of the electrode portion and the laser container, etc., and it is possible to reduce the size of the device.

According to the eighth aspect of the present invention, the metal electrode forming the electrode portion is covered with an insulating material, and the capacitive coupling suppressing portions are provided on both sides of the insulating material, thereby suppressing the dispersion of the discharge. The effect can be obtained.

[0020]

Embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a first embodiment according to the present invention, and shows a cross sectional structure of a cross flow type gas laser device in which a gas flow is orthogonal to an output optical axis. In FIG. 1, a first dielectric electrode 7 is disposed in the center of the upper part of a wind tunnel container 6 having a rectangular cross section so as to face the inside of the wind tunnel container 6.

A second dielectric electrode 8 forming a pair with the first dielectric electrode 7 is arranged in the center of the wind tunnel container 6, and both dielectric electrodes 7 and 8 are arranged in the arranged state. Discharge space 9
It is configured to intervene. In this case, the upper surface of the second dielectric electrode 8 is formed so as to be parallel to the lower surface of the first dielectric electrode 7.

A blower 10 for circulating the laser gas and a heat exchanger 11 for cooling the laser gas are arranged in the lower part of the wind tunnel container 6. The laser gas is circulated in the direction of arrow B by the blower 10 and is cooled by the heat exchanger 11 after flowing through the discharge region.

Now, the specific structure of the first dielectric electrode 7 and the second dielectric electrode 8 will be described with reference to FIGS. 2 and 3 as well, but since they have the same structure, they will be described below. Describes only the first dielectric electrode 7,
The description of the second dielectric electrode 8 will be omitted by assigning the same subscript to the same portion as the first dielectric electrode 7.

That is, the first dielectric electrode 7 has an electrode portion 7a having a rectangular cross section and formed in a long shape in a direction orthogonal to the laser gas flow (direction perpendicular to the paper surface) and the electrode portion 7a. The outer shell 7b is made of a dielectric material such as ceramics and is provided so as to surround the upper surface thereof. In this case, the outer shell portion 7b is separated by the partition walls 7c, 7
It is formed in a state of being adjacent to the electrode portion 7a by d, and by inserting the electrode portion 7a in the central portion, the left and right space portions have a relative dielectric constant smaller than that of the outer shell portion 7b. , 7f.

A more detailed cross-sectional view of the first dielectric electrode 7 is shown in FIG. The electrode portion 7a is a metal electrode 12
And a conductive rubber 13 which is a conductive material, and an insulating rubber 14 which is an insulating material. Water 15, which is a cooling medium, flows in the metal electrode 12. Conductive rubber 1
3 is used to bring the outer shell portion 7b and the metal electrode 12 into close contact with each other. The insulating rubber 14 plays a role of relaxing the electric field of the metal electrode 12.

Here, the water 15 as the cooling medium is flown into the metal electrode 12, but a cooling unit for flowing the cooling medium may be arranged so as to be in contact with the metal electrode or near the metal electrode.

The outer shell 7 is formed without using the conductive rubber 13.
The metal electrode 12 may be directly bonded to b. Furthermore, FIG.
In the relation between the dielectric thickness ΔX1 below the electrode portion 7a and the dielectric thickness ΔX2 below the space portions 7e and 7f, the relation is ΔX1 ≧
It satisfies △ X2.

The operation of this embodiment will be described below. As shown in FIG. 1, when a high frequency voltage is applied from a high frequency power supply 16 between the electrode portions 7a, 8a of the first dielectric electrode 7 and the second dielectric electrode 8, the laser gas flowing in the discharge space 9 Are excited, and the laser beam 17 is generated in the direction perpendicular to the paper surface by the resonator arranged in the direction perpendicular to the paper surface not shown in the figure. Here, since the outer shell portions 7b and 8b made of a dielectric material are present around the electrode portions 7a and 8a, a uniform high frequency discharge is achieved in the discharge space 9, and a stable laser output can be obtained. .

In this case, capacitive coupling suppressing portions 7e, 7f and 8e, 8f having extremely small relative permittivity are present on both sides of the electrode portions 7a, 8a, and the thickness ΔX1 of the dielectric material under the electrode portion 7a is Thickness of the dielectric below the space 7e, 7f ΔX
Since it is thicker than 2, the discharge is prevented from being unnecessarily dispersed on both sides of the electrode portions 7a and 8a even under the condition where the high frequency voltage is applied as described above.

As a result, the loss due to unnecessary discharge can be suppressed, so that the output frequency of the high frequency power source 16 is set to 7
It is possible to increase the frequency to 00 kHz or higher, and thus the laser oscillation efficiency can be improved.

Further, since the side of the electrode portions 7a, 8a facing the dielectric on the discharge surface side is not composed of a dielectric, the stress concentrated in this region due to discharge ignition can be removed, and the dielectric electrode Improves reliability. The discharge space side is surrounded by the dielectric material, but the side facing the discharge surface side is not surrounded by the dielectric material, which is advantageous in that the electrode parts 7a and 8a can be easily manufactured.

Water 15 as a cooling medium is provided in the metal electrode 12.
Since the cooling passage for flowing the electric current is provided, the temperature rise of the electrode portions 7a, 8a can be suppressed, so that the dielectric electrodes 7, 8
It is possible to prevent the occurrence of strain between the electrode portions 7a, 8a and the outer shell portions 7b, 8b due to the difference in coefficient of thermal expansion between the two.

In addition, the capacitive coupling suppressors 7e, 7f, 8e,
It is possible to reduce the relative permittivity in the space portion forming 8f by communicating these with the atmosphere or by establishing an extremely low pressure vacuum state in which discharge is difficult to ignite.

In this case, the capacitive coupling suppressors 7e, 7
The relative permittivity of the space forming f, 8e, and 8f becomes smaller. Therefore, it becomes possible to avoid dielectric breakdown in the capacitive coupling portion, and it is possible to obtain the effect of suppressing the dispersion of discharge.

Next, a second embodiment according to the present invention will be described with reference to FIGS. The same parts as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

FIG. 4 shows a cross-sectional structure of a lateral flow type laser device in which the gas flow is orthogonal to the output optical axis. In this embodiment, a blower 10 for circulating a laser gas having a gas pressure P and a heat exchanger 11 for cooling the laser gas are arranged in the lower part of the wind tunnel container 6.

In addition, the capacitive coupling suppressing sections 7e, 7f, 8e,
The space forming 8f is filled with nitrogen, which is an insulating gas having a gas pressure of Pi. The gas pressure Pi of the insulating gas and the gas pressure P of the laser gas satisfy the condition of Pi ≥P.

According to this embodiment, by enclosing the insulating gas in the space, it is possible to reduce the relative permittivity in that space, thereby sufficiently reducing the capacitive coupling through the space. Therefore, the dispersion of discharge can be suppressed.

Further, since the relationship between the pressure Pi of the insulating gas and the gas pressure P in the laser device satisfies the condition Pi ≥P, it is possible to avoid dielectric breakdown in the capacitive coupling portion in the space. It becomes possible and the effect of suppressing the dispersion of discharge becomes more reliable.

As the insulating gas, air, laser gas or the like may be used in addition to nitrogen. If laser gas is used as the insulating gas, laser oscillation will not be hindered even if the insulating gas leaks from the space.

Next, a third embodiment according to the present invention will be described with reference to FIG. The cross-sectional structure of the lateral flow laser device is the same as in FIG. The same parts as those of the first and second embodiments are designated by the same reference numerals and the description thereof will be omitted.

FIG. 6 is a longitudinal sectional view at the center of FIG.
It is a figure which shows the detail of the vertical cross section of the dielectric electrode of the gas laser apparatus in FIG. A metal electrode 12 covered with an insulating rubber 14 from a high frequency power source 16 at approximately the center in the longitudinal direction of the electrode portion.
The relative permittivity is smaller than that of the lead wire portion 17 for applying a high frequency voltage to the water, the water supply portion (inlet) 18a for supplying the water 15 as the cooling medium to the metal electrode 12, and the outer shell portion 7b. There is a longitudinal capacitive coupling suppressing portion 19a. Further, the capacitive coupling suppressing portions 7e, 7e are provided at the longitudinal end portions of the outer shell portion 7b.
A lid 20a is provided to keep the pressure in f, 8e, and 8f constant.
Is attached, and the lid 20a is provided with a gas supply hole 21a inside so that gas can be supplied from the outside. Although not shown in the drawing, the left side of the lead wire portion 17 has the same structure as the right side of FIG. 6, and includes a water supply portion (outlet) 18b, a longitudinal capacity coupling portion 19b,
A lid 20b and a gas supply hole 21b are provided. Since the action and effect on the left side are the same as those on the right side, the right side will be described below.

In this embodiment, since there is the longitudinal capacitive coupling suppressing portion 19a on the right side of the insulating rubber 14, since this space is filled with the laser gas and the relative dielectric constant is 1, the electrode portion of the electrode portion is Dispersion of discharge can be suppressed in the same manner as on both sides. In addition, the capacitance between the longitudinal end of the metal electrode 12 and the laser container or the like can be reduced (stray capacitance can be suppressed, high-frequency power can be efficiently supplied to the discharge part), and the high-frequency insulation distance can be reduced. Becomes

That is, the high-frequency insulation distance is Σdi /
Since εi (di: the actual length of the material that becomes i, εi: the relative permittivity of the material that becomes i), if the dielectric breakdown electric field of the material is the same, it is better to use a material with a lower relative permittivity. Insulation distance can be reduced. In this embodiment,
The area of the insulating rubber 14 (relative permittivity 3.5) is reduced, and the area of the laser gas space (relative permittivity 1) is increased.
Here, the relative permittivity of these is the relative permittivity of the outer shell portion 7b (=
10) Less than.

In this embodiment, the longitudinal capacitive coupling suppressing portion is set to the laser gas atmosphere, but the insulating gas may be sealed in the same manner as in the case where both sides of the electrode portion are formed.
Next, a fourth embodiment according to the present invention will be described with reference to FIGS.

The same parts as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted. FIG. 7 shows a cross section of a cross-flow laser device in which the gas flow is orthogonal to the output optical axis.

In this embodiment, a blower 10 for circulating the laser gas and a heat exchanger 11 for cooling the circulating laser gas are arranged in the lower portion of the wind tunnel container 6.

The dielectric electrodes 22 and 23 are connected to the electrode portion 2
2a, 23a and outer shell parts 22b, 23b. Since the structures of the dielectric electrodes 22 and 23 are the same, the dielectric electrode 22 will be described below.

FIG. 8 shows details of the dielectric electrode 22. Figure 8
Is a cross section of the dielectric electrode 22 (half of the center is shown)
It is a figure which shows the discharge current distribution during discharge obtained by the calculation.

The dielectric electrode comprises an electrode portion 22a and an outer shell portion 22.
b (glass, ceramic, etc.). The electrode portion 22a is a metal electrode 24 through which water 15 as a cooling medium flows.
An insulator 25 (for example, insulating rubber or the like) that covers the metal electrode 24, and the capacitive coupling suppressing portion 2 that is not surrounded by a dielectric.
6a. The present dielectric electrode is symmetrical, and although not shown, the capacitive coupling suppressing portion 26b is provided on the left side of the insulator 25. Since the configurations are the same on the left and right sides, only the right side will be described below. Since the insulator 25 is in the laser gas atmosphere, the spatial electric field indicated by E in the figure is made lower than the discharge electric field in order to prevent dielectric breakdown in the capacitive coupling suppressing portion 26a. Therefore, the insulator is provided with the electric field relaxation region 27a in order to relax the spatial electric field. In this case, a radius of curvature of 5 mm or more is required.

According to this embodiment, the distribution of the discharge current I is as shown in FIG. That is, when the electrode width W 0 = 20 mm, the insulator thickness W 1 = 10 mm, the insulator height H = 20 mm, the relative permittivity of the insulator is 3.5, and the radius of curvature of the electric field relaxation region is 7 mm, the electrode is The leakage discharge current value IL at a distance of 17 mm from the right end is about 3% of the maximum value. At this time, since the spatial electric field is equal to or lower than the discharge electric field, dielectric breakdown does not occur in the capacitive coupling suppressor 26a.

Considering the laser extraction efficiency, the spread of discharge at the laser light extraction position must be IL = 10% or less. In the above example, W1 = 10mm, IL
-10%. In order to efficiently extract the laser light, at least the electrode must be the downstream end of the upstream end of the laser light extraction. The condition for the upstream end of the laser beam extraction to be the downstream end of the electrode is that when the laser beam with a beam diameter of 20 mm is extracted, the center of the laser beam is about 20 mm downstream from the discharge center and the width W1 of the insulator is 20 mm. Corresponding to. At this time, CO2 molecules excited upstream of the beam are carried to the laser gas flow up to the laser beam region, so that no large loss occurs.

Therefore, the width W1 of the insulator is 20 mm or less, and the width of the electrode portion 22a in the gas flow direction is W0 + 2 × W1 =
It will be 60 mm or less. In this example, the capacitive coupling suppressor was provided in the gas flow direction.However, a method of covering the metal electrode used in this example with an insulator was used to provide a similar capacitive coupling suppressor also in the longitudinal direction of the electrode. In addition, it is possible to suppress the spread of the discharge in the longitudinal direction, reduce the capacitance between the longitudinal end of the metal electrode and the laser container, and reduce the high-frequency insulation distance.

In addition, the present invention is not limited to the above-mentioned embodiments, but can be modified in various ways without departing from the scope of the invention. The present invention can be applied not only to CO2 lasers but also to other gas lasers such as CO lasers and excimer lasers.

[0055]

As is apparent from the above description, according to the present invention, the electrode portion around which the high frequency voltage is applied,
In a gas laser device in which at least a pair of dielectric electrodes having an outer shell made of a dielectric material are arranged so as to sandwich a discharge region, the relative permittivity from the outer shell is higher than the outer shell on both sides of the electrode section of the dielectric electrode. With the structure in which the capacitive coupling suppressing portion having a small value is provided, the discharge is suppressed from being dispersed to both sides of the electrode portion even when a high frequency voltage is applied to the electrode portion. Therefore, it is possible to provide a gas laser device that can improve the laser oscillation efficiency while having a structure using the dielectric electrode.

According to the second aspect of the present invention, since the transverse section of the capacitive coupling suppressing section which is perpendicular to the optical axis is composed of the space formed by being surrounded by the dielectric, the capacitive coupling is suppressed. The relative permittivity in the suppressing portion can be reduced, and the effect of suppressing the dispersion of discharge can be obtained.

Further, according to the invention of claim 3, 2
An electrode accommodating chamber for accommodating the electrode part is formed in a space surrounded by the dielectric on the discharge surface side, sandwiched between two capacitive coupling suppressing parts. Therefore, since the side of the discharge surface that faces the dielectric is not made of a dielectric, stress concentration in the dielectric that occurs due to discharge can be relieved, and the work involved in electrode fabrication It will be easier.

Further, according to the invention of claim 4, when the cooling medium is made to flow into the electrode portion housed in the electrode housing chamber, the temperature rise of the electrode portion is suppressed, and the electrode portion in the dielectric electrode is suppressed. It is possible to prevent the inconvenience caused by the occurrence of strain between the outer shell and the outer shell due to the difference in the coefficient of thermal expansion.

According to the fifth aspect of the invention, since the insulating gas is enclosed in the space, the relative permittivity in that portion becomes small. Therefore, it becomes possible to avoid dielectric breakdown in the capacitive coupling portion, and it is possible to obtain the effect of suppressing the dispersion of discharge.

Further, according to the invention described in claim 6, when the pressure of the insulating gas is P i and the laser gas pressure in the gas laser device is P, the space P i ≧ P is satisfied, It is possible to avoid dielectric breakdown in the capacitive coupling part in the part, and the effect of suppressing the discharge dispersion becomes more reliable.

According to the invention described in claim 7, by providing the capacitive coupling suppressing portion having a relative dielectric constant smaller than that of the outer shell portion in the longitudinal direction of the electrode portion, dispersion of discharge in the longitudinal direction is suppressed,
In addition, the insulation distance can be reduced and the device can be downsized.

According to the invention described in claim 8, the metal electrode forming the electrode portion is covered with an insulating material, and the capacitive coupling suppressing portions are provided on both sides of the insulating material to suppress the dispersion of the discharge. The effect can be obtained.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a gas laser device showing a first embodiment according to the present invention.

FIG. 2 is a perspective view, partly in section, of a pair of dielectric electrodes of the gas laser device in FIG.

FIG. 3 is a diagram showing details of a cross section of a dielectric electrode of the gas laser device in FIG.

FIG. 4 is a cross-sectional view of a gas laser device showing a second embodiment according to the present invention.

5 is a diagram showing details of a cross section of the dielectric electrode in FIG.

FIG. 6 is a view showing details of a vertical cross section of the dielectric electrode in FIG. 1, which is a third embodiment of the present invention.

FIG. 7 is a cross-sectional view of a gas laser device showing a fourth embodiment according to the present invention.

FIG. 8 is a view showing a cross section of the dielectric electrode (half is shown from the center) and a discharge current distribution during discharge.

FIG. 9 is a schematic configuration diagram of a conventional gas laser device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Dielectric electrode, 2 ... Discharge space, 3 ... Electrode part, 4 ... Outer shell part, 5 ... High frequency power supply,
6 ... Wind tunnel container, 7, 8 ... Dielectric electrode, 7a, 8a ... Electrode part (electrode storage part), 7b, 8b ... Outer shell part, 7c, 7
d, 8c, 8d ... Partition walls, 7e, 7f, 8e, 8f ... Capacitive coupling suppressing section, 9 ... Discharge space, 10 ... Blower,
11 ... Heat exchanger 12 ... Metal electrode, 13 ... Conductive rubber, 14 ...
Insulating rubber 15 ... Water, 16 ... High-frequency power supply, 19a ... Longitudinal direction capacitive coupling suppressing part, 22, 23 ... Dielectric electrodes 22a, 23a ... Electrode part, 25 ...
Insulator 26a ... Capacitance coupling suppression unit, 27a
... electric field relaxation region

Front page continued (72) Inventor Toru Tamagawa 2-1, Ukishima-cho, Kawasaki-ku, Kawasaki-shi, Kanagawa Stock company Toshiba Hamakawasaki factory

Claims (8)

[Claims] 1. At least a pair of dielectric electrodes, each having an outer shell made of a dielectric material provided around the electrode parts, are arranged in a state of sandwiching a discharge space, and a high-frequency voltage is applied between the electrode parts. A gas laser device that oscillates or amplifies laser light by causing electric discharge by providing a capacitive coupling suppressing part having a relative dielectric constant smaller than that of the outer shell part on both sides of the electrode part. 2. The gas laser device according to claim 1, wherein a space portion formed by surrounding a cross section of the capacitive coupling suppressing portion perpendicular to the laser optical axis with a dielectric is provided. 3. An electrode housing chamber for housing an electrode portion which is sandwiched between two capacitive coupling suppressing portions and is surrounded by a dielectric on the side of the discharge space is provided. The gas laser device described. 4. The gas laser device according to claim 3, wherein a cooling passage through which a cooling medium flows is provided in the electrode portion housed in the electrode housing chamber. 5. The gas laser device according to claim 2, wherein an insulating gas is introduced into the space. 6. The gas laser device according to claim 5, wherein the insulating gas pressure Pi satisfies a condition of Pi ≧ P, where P is the gas pressure in the gas laser device. 7. The gas laser device according to claim 1, wherein a capacitive coupling suppressing portion having a relative dielectric constant smaller than that of the outer shell portion is provided in a longitudinal direction of the electrode portion. 8. The gas laser device according to claim 1, wherein in the electrode portion, a metal electrode is surrounded by an insulator, and capacitive coupling suppressing portions are provided on both sides of the insulator.