JPH0983089A - Metal vapor laser - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high efficient, high output metal vapor laser by blocking a gas flow flowing on the flow of buffer gas toward a window thereby suppressing generation of abnormal discharge and reducing the optical loss due to the window. SOLUTION: A gas is introduced through gas introduction piping 10a, 10b coupled with hermetic containers 1, 6 and discharged through gas discharge piping 21 coupled with hermetic containers. A laser medium metal 9 is set in the hermetic container and caused to discharge through discharge electrodes 7, 8 disposed therein. An oscillated laser light is outputted through windows 3a, 3b fixed to the vicinity of opposite end parts of hermetic container. In such a metal vapor laser, the gas discharge piping 21 is coupled with the hermetic container at a position farther from the windows 3a, 3b than the position where the gas introduction piping 10a, 10b are coupled with hermetic containers.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metal vapor laser device, and more particularly, to introducing gas from a gas introducing pipe connected to an airtight container and exhausting the gas from a gas exhausting pipe connected to the airtight container, The present invention relates to a metal vapor laser device in which a laser medium metal is placed in a container and a laser beam is oscillated by causing discharge in the airtight container through a plurality of discharge electrodes arranged in the airtight container.

[0002]

2. Description of the Related Art As is well known, lasers are used in various fields by taking advantage of characteristics such as excellent directivity and coherence of laser light. For example, it has been applied to laser fusion and laser processing by focusing on its light-collecting property and high energy density. On the other hand, recently, focusing on the monochromaticity of laser light, it selectively selects only the target substance. It is excited to be used for high purification and removal of impurities.

A conventional metal vapor laser device will be described below. FIG. 14 is a schematic cross-sectional view of an oscillation tube of a metal vapor laser device, wherein reference numeral 1 indicates an outer tube, and the outer tube 1 is a cathode outer tube 1a, 1b, an insulating outer tube 1c, an anode outer tube 1d, 1e.
It is composed of The cathode outer tubes 1a and 1b and the anode outer tubes 1d and 1e are made of a conductive material. Cathode outer tube 1
A buffer gas inlet 10 is connected to a side of a, and an exhaust port 11 is connected to a side of the anode outer tube 1e. A protective tube 2 is coaxially arranged inside the outer tube 1.
Both ends of are connected to the outer tube 1 in an airtight manner. A hollow heat insulating layer 5 is formed in the space between the outer tube 1 and the protective tube 2. The hollow heat insulating layer 5 can be evacuated into a vacuum heat insulating layer by a gas control device (not shown), or can be filled with a gas having an appropriate heat insulating property to form a gas heat insulating layer.

Brewster windows 3a are provided at both ends of the outer tube 1.
3b is attached, whereby both open ends of the outer tube 1 are closed and the inside of the protective tube 2 is in an airtight state. Protection tube 2
A heat insulating material layer 4 is formed inside. An inner pipe 6 is arranged at an axially intermediate portion inside the heat insulating material layer 4. A cathode 7 attached to the cathode outer tube 1b and an anode 8 attached to the anode outer tube 1d are arranged so as to sandwich the inner tube 6 from both sides in the axial direction. On the inner wall surface of the inner tube 6, for example, metal particles 9 such as gold (Au) or copper (Cu) are placed.

Oscillation of the metal vapor laser device configured as described above is performed as follows. After the inside of the inner pipe 6 is brought to a high vacuum state by the exhaust pipe 11, a discharge buffer gas such as helium (He) or neon (Ne) is supplied into the inner pipe 6 through the gas introduction pipe 10. A high voltage is applied between the cathode 7 and the anode 8 to generate discharge plasma. Then, the inner tube 6 is heated by the discharge,
The metal particles 9 are heated and evaporated, the generated metal vapor is excited by electrons in the plasma, and the generated light is amplified by an optical resonator (not shown) through the Brewster windows 3a and 3b to oscillate laser light.

At this time, in order to remove impurities in the protective tube 2 caused by a leak or the like, the internal pressure is maintained at about several tens Torr, and several ml / min from the gas introduction pipe 10 is maintained.
A small amount of buffer gas is flown and exhausted from the exhaust pipe 11.

In order to efficiently generate a laser beam and extract a larger output, the stable discharge is maintained and the plasma is optimized, and the window (Brewster window 3a,
It is important to prevent contamination of 3b) and efficiently extract light.

[0008]

However, FIG.
When the gas introduction pipe 10 and the exhaust pipe 11 are installed as shown in FIG. 5, a buffer gas flows from the cathode side to the anode side. On the flow of this buffer gas, metal vapor as a laser medium, electrode materials generated by sputtering, etc., and impurity particles such as the inner tube 6 and heat insulating material are also carried, and as a result, adhere to the electrodes and windows on the downstream side. To do.

The laser medium metal or electrode material adhered by forming uneven surfaces on the electrodes 7 and 8 causes abnormal discharge, and if the adhered material is thickly deposited, it interferes with the optical path. Contamination of the window lowers the transmittance and lowers the oscillation output.

Therefore, an object of the present invention is to solve the above problems of the prior art, to prevent the flow of gas toward the window by riding on the flow of buffer gas, thereby suppressing the occurrence of abnormal discharge, and An object of the present invention is to provide a highly efficient and high-output metal vaporization laser device that reduces light loss.

[0011]

In order to achieve the above object, a metal vapor laser device according to the present invention introduces gas from a gas introducing pipe connected to an airtight container and exhausts gas connected to the airtight container. While evacuating from the pipe for use, a laser medium metal is placed in the airtight container and discharged in the airtight container through a discharge electrode arranged in the airtight container, and oscillated laser light is emitted from the airtight container. In a metal vapor laser device that outputs to the outside through windows installed near both ends, the gas exhaust pipe is located farther from the window than the position at which the gas introduction pipe is connected to the airtight container. And is connected to the airtight container.

Gas is introduced from a gas introducing pipe connected to the airtight container and exhausted from a gas exhausting pipe connected to the airtight container, and a laser medium metal is placed in the airtight container to form the airtight container. In a metal vapor laser device that discharges in the airtight container via a discharge electrode arranged in the container, and outputs the oscillated laser light to the outside through a window attached near both ends of the airtight container, The gas exhaust pipe is connected to the airtight container at a position farther from the discharge electrode than at a position where the gas introduction pipe is connected to the airtight container.

According to the first aspect of the present invention, the gas exhaust pipe is connected to the airtight container at a position farther from the window than at the position where the gas introduction pipe is connected to the airtight container. When the introduced buffer gas, etc. flows in the airtight container, the flow direction is formed away from the window, so that impurity particles and laser medium metal flowing with the buffer gas are prevented from adhering to the window. it can.

Further, in claim 2, the gas exhaust pipe is
Since the gas introduction pipe is connected to the airtight container at a position farther from the discharge electrode than the position where the gas introduction pipe is connected to the airtight container, when the buffer gas or the like introduced from the gas introduction pipe flows in the airtight container. Since the flow direction is formed in the direction away from the discharge electrode, it is possible to eliminate abnormal discharge due to adhesion of impurity particles and laser medium metal flowing together with the buffer gas to the discharge electrode.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. A first embodiment of the present invention will be described with reference to FIG. FIG. 1 is a schematic sectional view of an oscillation tube of a metal vapor laser device. Reference numeral 1 indicates an outer tube, and the outer tube 1 is a cathode outer tube 1a, 1b, an insulating outer tube 1c, an anode outer tube 1.
d, 1e. The cathode outer tube 1a is connected and extended at one end of the cathode outer tube 1b, and the other end of the cathode outer tube 1b faces one end of the insulating outer tube 1c.
The other end of c is opposed to one end of the outer anode tube 1d, and the outer outer tube 1e is connected and extended at the other end of the outer anode tube 1d. The cathode outer tubes 1a and 1b and the anode outer tubes 1d and 1e are made of a conductive material. The cathode outer tube 1b and the anode outer tube 1d are insulated by an insulating outer tube 1c interposed therebetween.

A tubular buffer gas inlet 10a and a tubular buffer gas inlet 10b are connected to the respective side portions of the cathode outer tube 1a and the anode outer tube 1e.

A protective tube 2 is coaxially arranged in the outer tube 1, and both ends of the protective tube 2 are hermetically connected to the ends of the cathode outer tube 1b and the anode outer tube 1d, respectively. ing. A hollow heat insulating layer 5 is formed in the space between the outer tube 1 and the protective tube 2. The hollow heat insulating layer 5 can be evacuated into a vacuum heat insulating layer by a gas control device (not shown), or can be filled with a gas having an appropriate heat insulating property to form a gas heat insulating layer.

Brewster windows 3a and 3b are attached to both ends of each of the cathode outer tube 1a and the anode outer tube 1e, whereby both open ends of the outer tube 1 are closed and the protective tube 2 is provided. The inside of the is airtight.

Inside the protective tube 2, there is a breathable heat insulating material 4.
0 is inserted to form the heat insulating material layer 4. An inner pipe 6 is arranged at an axially intermediate portion inside the heat insulating material layer 4.

An exhaust pipe 21 is connected to the central side surface of the protective pipe 2. The exhaust pipe 21 is located at a substantially middle portion between the windows (between the Brewster window 3a and the Brewster window 3b). The exhaust pipe 21 is installed at the Brewster window 3
It is set at a position as far as possible from a, 3b and electrodes 7, 8. The exhaust port 21 projects from the anode outer tube 1d and is connected to a vacuum pump (not shown). The inner pipe 6 has a vent hole at a position corresponding to the exhaust pipe 21.

A tubular cathode 7 and an anode 8 are arranged so as to be sandwiched from both sides in the axial direction of the inner tube 6 with a gap therebetween. The cathode 7 is attached to the cathode outer tube 1b, and the anode 8 is attached to the anode outer tube 1d. On the inner wall surface of the inner tube 6, for example, metal particles 9 such as gold (Au) or copper (Cu) are placed.

The metal vapor laser device of this embodiment is operated as follows. First, the inside of the inner pipe 6 is exhausted to the exhaust pipe 21.
After being evacuated by a vacuum pump such as a rotary pump (not shown) connected to the above to make a high vacuum state, a gas supply pipe (not shown) is passed through the gas introducing pipe 10a inside the inner pipe 6 to, for example, helium (He), neon (Ne). A discharge buffer gas such as is supplied at a predetermined pressure. Each terminal of the cathode outer tube 1b and the anode outer space 1d is connected to each terminal of a pulse high voltage power supply (not shown), and a high voltage pulse is applied between the cathode 7 and the anode 8 to generate plasma in the inner tube. .

The inner tube 6 is heated by the plasma, copper vapor is generated from the copper metal particles 9, the copper vapor is excited by the electrons in the plasma, and the generated light is generated by the Brewster window 3
Laser light is oscillated by being amplified by an optical resonator (not shown) through a and 3b. During this time, in order to remove impurities in the protective tube 2 caused by leakage or the like, the gas introduction pipes 10a and 10a
A small amount of buffer gas of about several to several tens of ml / min is caused to flow from b, and the buffer gas is exchanged. The buffer gas introduced from the gas introduction pipes 10a and 10b near both ends of the outer pipe 1 is exhausted from the exhaust pipe 21 in the central portion.

According to the structure of this embodiment, the gas introducing pipes 10a and 10b are provided near both ends of the outer pipe 1, while the exhaust pipe 21 is provided near the central portion of the inner pipe 6 in the longitudinal direction. Therefore, the gas flow direction generated upon exchanging the buffer gas is the direction from the windows (Brewster windows 3a, 3b) at both ends toward the central portion of the inner pipe 6. As a result, the impurity fine particles and the laser medium metal particles are not carried toward the Brewster windows 3a and 3b and the electrodes 7 and 8 near both ends of the outer tube 1, and the impurity fine particles and the like adhere to the windows. It is possible to prevent a decrease in transmission efficiency.

Although the temperature of the vicinity of the end of the inner pipe 6 and the installation position of the discharge electrodes 7 and 8 is lower than the temperature of the central part of the inner pipe 6, the exhaust pipe 21 extends in the longitudinal direction of the inner pipe 6. Since it is provided in the vicinity of the central portion, it is possible to prevent the metal of the laser medium from adhering to the end portion of the inner tube 6 and the discharge electrodes 7 and 8. As a result, discharge is stabilized and highly efficient laser oscillation can be obtained.

When the exhaust pipe 21 is not provided in the vicinity of the central portion of the outer pipe 1 or the inner pipe 6 in the longitudinal direction, the temperature near the windows (Brewster windows 3a, 3b) is increased by radiation outside the windows. However, since there is no temperature drop due to such radiation, the central part is maintained at a high temperature, so that the temperature distribution in the axial direction of the inner wall of the inner pipe 6 becomes non-uniform. As a result, the copper vapor density distribution in the axial direction becomes non-uniform, which has a negative effect on obtaining good characteristics of laser oscillation.

On the other hand, when the exhaust port 21 is provided in the vicinity of the central portion in the longitudinal direction of the outer pipe 1 or the inner pipe 6 as in the present embodiment, the flow of gas toward the outside is reflected by the outer pipe 1d. The temperature of the central part is lowered by the absence of. Therefore, the distribution of the inner wall temperature of the inner tube 6 in the axial direction is made uniform, and the laser oscillation characteristics are improved.

Further, the exhaust device is connected to the laser main body through an insulating portion for safety, but conventionally, if metal particles mixed with gas and flowing out adhere to the insulating portion, the insulating property deteriorates.
There was a risk of electrical short circuit. On the other hand, in the present embodiment, the gas exhausted from the exhaust pipe 21 passes through the heat insulating material 40, and the heat insulating material 40 functions as a filter.
It is possible to prevent the metal particles and the impurity particles from reaching the exhaust device, and prevent the insulation property of the exhaust device from deteriorating.

In order to make the gas flow associated with the exhaust gas symmetrical with respect to the rotation angle around the axial line, the number of exhaust pipes 21 connected to the protective pipe 2 should be two or more around the axial line. Good.

Next, another embodiment of the present invention will be described with reference to FIGS. 9 on the side of the inner pipe 6
Four holes 22a, 22b, 22 with an angular interval of 0 degree
c and 22d are formed. Also, four holes are formed on the side surface of the protective tube 2 at positions facing the holes 22a, 22b, 22c, 22d.
Four ventilation holes 23a, 23b, 23c, and 23d which penetrate the heat insulating material 40 are formed between a, 22b, 22c, and 22d. Two exhaust pipes 21a and 21b are provided on the side surface of the protective pipe 2 so as to project outward from the side surface of the outer pipe 1 so as to communicate with the two opposed vent holes 23a and 23c.

The heat insulating material 40 also has a large number of small holes and is breathable by itself, but the ventilation holes 23a, 23b, 23c, 2
By providing 3d, the inside of the inner pipe 6 can be exhausted more efficiently.

The holes 22a and the like and the ventilation holes 23a and the like may be arbitrary in number and size, and the positions need not be evenly arranged.

Next, FIG. 4 shows another embodiment. In the heat insulating material layer 4 portion corresponding to the positions of the exhaust pipes 21a and 21b, the heat insulating material 24a having a coarser composition than the heat insulating material 40 is used.
24d is arranged. Instead of the example shown in FIG. 3, the vent holes 23a and the like are not provided. In this embodiment, since the ventilation holes 23a and the like are not provided, the heat insulating property is not lowered, and the composition of the heat insulating materials 24a to 24d is coarse, so that the conductance of the exhaust gas is larger than that of the other portions, and the internal efficiency is improved. The inside of the pipe 6 can be exhausted.

Next, FIG. 5 shows still another embodiment. In the embodiment example shown in FIG. 5, a heat insulating material 24 having a coarser composition different from that of the heat insulating material 40 is arranged in a cylindrical shape in an appropriate width in a portion of the heat insulating material layer 4 below the exhaust pipe 21.
In a portion of the inner pipe 6 below the heat insulating material 24, a hole 22a and the like are formed as in the case shown in FIG. 2, for example. Also in the present embodiment, since the ventilation holes 23a as shown in FIG. 3 are not provided, the heat insulating property does not become lower, and the composition of the heat insulating material 24 is coarse, so that the conductance of exhaust gas is larger than the other portions, The inside pipe 6 can be efficiently exhausted.

Next, FIG. 6 shows another embodiment. In the embodiment example shown in FIG. 6, the inner pipe 6 includes two inner pipes 6a and 6a.
and a gap 6 at the center of the lower position of the exhaust pipe 21.
The inner pipe 6a and the inner pipe 6b are arranged so as to form c.
For example, when the inner pipe 6 is made of alumina, the inner pipe 6 has holes 2
It is not always easy to provide 2a or the like. According to this embodiment, the inside of the inner pipe 6 can be efficiently exhausted without providing the hole 22a or the like in the inner pipe 6.

Next, FIG. 7 shows still another embodiment.
In the embodiment example shown in FIG. 7, the heat insulating material layer 4 is divided into two heat insulating material layers 4 a and 4 b, and a heat insulating material is formed so as to form a gap 4 c in the central portion below the exhaust pipe 21. A layer 4a and a heat insulating layer 4b are provided. Holes corresponding to the holes 22a and the like are provided at the position of the inner pipe 6 facing the gap 4c. According to the present embodiment example, the heat insulating material layer 4 a and the heat insulating material layer 4
The inside of the inner pipe 6 can be efficiently exhausted with a simple configuration in which the b and b are arranged so as to form the gap 4c. In implementation, these may be appropriately combined and used.

In carrying out the invention, it is possible to use the examples shown in FIGS. 2 to 7 in combination as appropriate in accordance with the required manufacturing conditions and the like.

Next, FIG. 8 shows another embodiment. FIG.
Shows only a one-sided cross section having an axially symmetric relationship with respect to the axis 42. Therefore, all of the members shown in FIG.
It has a cylindrical shape that is axisymmetric with respect to. In the embodiment shown in FIG. 8, the protective tube 2 is divided into a protective tube 2a and a protective tube 2b, and ring-plate-shaped flange portions 44, 4 are provided in the divided portions.
4 are formed. The cathode outer tube 1b is also divided into two parts, and the ring plate-shaped flange part 4 is formed in the divided part.
6 are formed. The flange portions 44, 44 and the flange portions 46, 46 are hermetically connected to each other with an O-ring (not shown) interposed therebetween.

A circular tubular member 48 is attached to the upper edges of the flange portions 46, 46. The exhaust pipe 21a is provided at two locations on the outer peripheral surface of the circular tubular member 48 facing the axis 42.
And an exhaust pipe 21b (not shown) are connected. That is, in the present embodiment, the exhaust pipe 21a and the like are formed on the outer peripheral surface of the circular tubular member 48 attached to the upper edge portions of the ring plate-shaped flange portions 46, 46. The hollow heat insulating layer 5 is divided into two hollow heat insulating layers 5a and 5b with an exhaust pipe 21a and an exhaust pipe 21b (not shown) as boundaries.

A ring plate-shaped flange portion 47 is formed at one end of one of the divided cathode outer tubes 1b, and a ring plate-shaped flange portion 49 is formed at one end of the anode outer tube 1d. The insulating outer tube 1c is formed between the flange portion 47 and the flange portion 49 by the ring plate-shaped flange portions 50, 50.
Attached through.

According to the configuration of this embodiment, the protective tube 2 and the cathode outer tube 1b are composed of two circular tubular portions, and the exhaust pipe 21a and the like are attached to the ring plate-shaped flange portions 46, 46. Since the connection is made on the outer peripheral surface of the circular tubular member 48, when the exhaust pipe 21a and the like are constructed, the axis line 42
It is possible to assemble the protection tubes 2a, 2b and the cathode outer tubes 1b, 1b, etc. in series along one another. As a result, the exhaust pipe 21a and the like can be formed extremely easily as compared with the case where the protective tube 2 and the cathode outer tube 1b are integrally formed.

Next, FIG. 9 shows another embodiment.
In the embodiment shown in FIG. 9, only one side cross section which is axisymmetric with respect to the axis 42 is shown as in the case shown in FIG. In this embodiment, the exhaust pipe 21a is formed by utilizing the connecting portion of the insulating outer pipe 1c, the cathode outer pipe 1b, and the anode outer pipe 1d. The position of the insulating outer tube 1c is located in the central portion of the outer tube 1 so that the exhaust tube 21a is located in the central portion of the outer tube 1 as compared with the case of FIG.

Ring plate-shaped flanges 52, 52 are formed at the ends of the protective tubes 2a, 2b.
Is hermetically connected between lower portions of the flange portion 47 and the flange portion 49 via an O-ring or the like. Flange part 4
Between the upper portion of 7 and the flange portion 49, a circular tubular insulating outer tube 1c having a shape symmetrical with respect to the axis 42 is attached. On the outer peripheral surface of the insulating outer tube 1c, the axis 42
An exhaust pipe 21a and an exhaust pipe 21b (not shown) are connected at positions facing each other.

According to the configuration of this embodiment, the exhaust pipe 21
a is an insulating outer tube 1c, a cathode outer tube 1b, and an anode outer tube 1
The exhaust pipe 21a can be formed with a simple structure because the exhaust pipe 21a is formed by utilizing the connecting portion with d.

Next, another embodiment will be described with reference to FIGS. In the embodiment shown in FIGS. 10 and 11, the exhaust pipes 21a and 21b are connected to the outer peripheral surface of the protective pipe 2 so as to project at positions facing the axis 42. The insulating outer tube 1c is composed of several insulating rods 25, and each insulating rod 25 is arranged at equal intervals on the circumference with the axis 42 as the center line between the flange portion 47 and the flange portion 49. It is set up. Further, in the present embodiment example, the hollow heat insulating layer 5 is not airtight.

According to the configuration of this embodiment, the insulating outer tube 1
Since c is composed of the insulating rods 25 and the exhaust pipes 21a and 21b are projected from between the arranged insulating rods 25 and 25, the exhaust pipes 21a and 21b can be formed with a simple structure. it can.

Next, still another embodiment will be described with reference to FIG. FIG. 12 shows an example in which exhaust pipes 21a and 21b are formed at the connection portion of a tandem type vertical excitation copper vapor laser device. In the tandem-type copper vapor laser device shown in FIG. 12, the two laser tubes 55 and 56 are the anode outer tube 1e.
Are shared and connected in series. Laser tubes 55, 5
6 is substantially the same as the laser tube shown in FIG. 1 except for the anode part. Buffer gas is supplied from gas introduction pipes 10a and 10b provided near the windows 3a and 3b,
The air is exhausted from exhaust pipes 21a and 21b provided in the central porcelain insulator for the anode part.

In this way, the flow of the buffer gas in the direction away from the windows 3a, 3b is formed, and the laser medium metal particles and other impurity particles are transferred to the windows 3a, 3b.
To prevent it from adhering to 3b.

Next, still another embodiment will be described with reference to FIG. So far, an example in which the present invention is applied to a longitudinally pumped copper vapor laser device has been described.
Is an example in which the present invention is applied to a laterally pumped copper vapor laser.
FIG. 13 is a schematic sectional view, in which the outer tube 1 is a cathode part outer tube 1a,
1b, an insulating outer tube 1c, and an anode outer tube 1d, 1e. The cathode outer tube 1a, 1b and the anode outer tube 1d, 1e are made of a conductive material, and the cathode outer tube 1a and the anode part are formed. Gas introduction ports 10a and 10b are connected to the outer pipe 1e, respectively. Both ends of a protective tube 2 provided coaxially inside the outer tube 1 are airtightly connected to the outer tube 1.

A hollow heat insulating layer 5 is formed in the space between the outer tube 1 and the protective tube 2. Brewster windows 3a and 3b are attached to both ends of the outer tube 1, whereby both open ends of the outer tube 1 are closed and the inside of the protective tube 2 is in an airtight state. An exhaust pipe 21 is connected to the central portion of the protective pipe 2, that is, the intermediate portion between the windows at both ends. An inner tube 6 is provided on the inner surface of the axially intermediate portion of the heat insulating material layer 4 provided on the inner surface of the protective tube 2. Vent holes 22 a and 22 b are provided in the inner pipe 6 at positions corresponding to the exhaust pipe 21.

Plate-shaped cathode 7 and anode 8 which are long in the axial direction of the inner tube
Are installed in the inner pipe 6. The electrodes 7 and 8 are connected to the cathode outer tube 1b and the anode outer tube 1d by the lead wires 7a and 8a, respectively.
It is connected to the.

Between the plate-shaped anode 7 and cathode 8 which are long in the axial direction,
A wide discharge plasma is formed. The feature of this discharge is that the discharge is maintained at a high pressure of 1 atm or more and the discharge current is large. It is necessary for the electrode surface to have no irregularities in order to maintain a stable discharge.

In the embodiment shown in FIG. 13, when exchanging the buffer gas, the gas is introduced from the vicinity of the window and exhausted at the central portion of the inner pipe, so that the flow of the buffer gas from both ends to the central portion is formed. To be done. As a result, the impurities and the metal of the laser medium do not flow out to both ends and are deposited on the ends of the electrode at a low temperature, and the instability of discharge is not caused. Particularly, in the laterally pumped copper vapor laser device, the buffer gas pressure is higher than the atmospheric pressure, the copper vapor density is high, and the density of impurities and metal particles carried along with the flow toward the window is high. The effect of improving the laser oscillation output is great.

Some metal vapor lasers use, for example, copper halide such as copper bromide or copper chloride. When the present invention is applied to these, the effects described above can be obtained. Needless to say.

Further, as shown in FIG. 1, a metal is installed in the inner tube, and a gaseous halogen compound such as hydrogen bromide is mixed in the buffer gas to first generate a metal halide and then discharge to discharge the halide. There is also the one that dissociates and excites a metal atom. For example, it is known that copper is used as a metal and neon containing hydrogen bromide as a buffer gas of several% is used. When the present invention is applied to this metal vapor laser, effects other than those described above also appear. The effect will be explained by taking a laser using a chemical reaction between hydrogen bromide and metallic copper as an example. Hydrogen bromide mixed with the buffer gas and introduced into the oscillation tube flows in the inner tube together with the flow of the buffer gas, but it is considered that the hydrogen bromide concentration decreases in the downstream compared to upstream due to reaction with copper and dissociation due to discharge. To be
Copper atoms that contribute to laser oscillation are supplied by dissociation of copper bromide generated by the reaction of copper and hydrogen bromide. Therefore, if the concentration of hydrogen bromide is lowered, the copper bromide produced, and consequently the copper atom density produced, is also reduced. FIG.
In the conventional example shown in (1), the concentration of hydrogen bromide on the downstream side of the anode decreases, and the amount of copper atoms generated on the anode side decreases. However, by applying the present invention, a sufficient concentration of hydrogen bromide can be supplemented from the anode and a sufficient amount of copper atoms can be supplied also to the anode side to increase the output.

[0056]

As described above, according to the structure of the present invention, the contamination of the window can be prevented, the light loss due to the window can be reduced, and the abnormal discharge due to the adhesion of the laser medium metal on the discharge electrode can be eliminated. It is possible to realize a high-efficiency and high-power metal vapor laser device.

[Brief description of drawings]

FIG. 1 is a schematic vertical sectional view showing an embodiment of a metal vapor laser device of the present invention.

FIG. 2 is a perspective view showing an example of holes formed in an inner pipe in another embodiment of the present invention.

3 is a schematic cross-sectional view showing an example of an embodiment using the inner pipe shown in FIG.

FIG. 4 is a schematic cross-sectional view showing another embodiment example of the present invention.

FIG. 5 is a schematic vertical sectional view showing still another embodiment of the present invention.

FIG. 6 is a schematic cross-sectional view showing another embodiment example of the present invention.

FIG. 7 is a schematic vertical sectional view showing still another embodiment of the present invention.

FIG. 8 is a schematic one-sided longitudinal sectional view of another embodiment of the present invention, which is axially symmetric with respect to the axis.

FIG. 9 is a schematic one-sided vertical sectional view of yet another embodiment of the present invention, which is axially symmetric with respect to the axis.

FIG. 10 is a schematic one-sided vertical sectional view of another embodiment of the present invention, which is axially symmetric with respect to the axis.

11 is a schematic cross-sectional view showing the position of the exhaust pipe of the embodiment example shown in FIG.

FIG. 12 is a schematic cross-sectional view showing an embodiment example in which the present invention is applied to a tandem type copper vapor laser device.

FIG. 13 is a schematic cross-sectional view showing an embodiment example in which the present invention is applied to a longitudinally pumped copper vapor laser device.

FIG. 14 is a schematic sectional view showing a conventional longitudinally pumped copper vapor laser device.

[Explanation of symbols]

 1 Outer Tube 1a Cathode Outer Tube 1b Insulated Outer Tube 1c Anode Outer Tube 2 Protective Tube 4 Heat Insulating Material Layer 5 Hollow Heat Insulating Layer 6 Inner Tube 7 Cathode 8 Anode 9 Laser Medium Metal Particles 10a Gas Inlet 10b Gas Inlet 21, 21a, 21b Exhaust pipe

Claims (2)

[Claims] 1. A gas is introduced from a gas introducing pipe connected to an airtight container and exhausted from a gas exhausting pipe connected to the airtight container, and a laser medium metal is placed in the airtight container to form the airtight container. In a metal vapor laser device that discharges in the airtight container through a discharge electrode arranged in the container and outputs the oscillated laser light to the outside through a window attached in the vicinity of both ends of the airtight container, The gas exhaust pipe is connected to the airtight container at a position farther from the window than the position at which the gas introduction pipe is connected to the airtight container. 2. A gas is introduced from a gas introduction pipe connected to an airtight container and exhausted from a gas exhaust pipe connected to the airtight container, and a laser medium metal is placed in the airtight container to form the airtight container. In a metal vapor laser device that discharges in the airtight container through a discharge electrode arranged in the container and outputs the oscillated laser light to the outside through a window attached in the vicinity of both ends of the airtight container, The gas exhaust pipe is connected to the airtight container at a position farther from the discharge electrode than the position at which the gas introduction pipe is connected to the airtight container.