JPS62145788A - Ion laser tube - Google Patents

Abstract

PURPOSE:To readily obtain cooling medium like city water by forming a part between an anode and a cathode of a ceramic material, and providing cylindrical connection members alternately connected hermetically between a plurality of disclike members including through holes for a discharge path and a gas return path. CONSTITUTION:Through holes 2 for forming discharge paths are opened at a plurality of disclike members 1, and a plurality of through holes 3 for a gas return path are opened at the periphery. The members 1 may use aluminum nitride ceramics having nonconductivity, excellent heat resistance and excellent relatively thermal conductivity. Connection members 4 disposed between the disclike members are cylindrical members having inner diameter capable of containing the holes 2 and 3 in the bore of the inner hole thereof, and a laser tube can be cooled by directly feeding cooling medium to the members 1 and 4. The medium is not particularly limited, and may use city water.

Description

[Detailed description of the invention] Application fields in industrial application fields The present invention relates to an ion laser tube.

More specifically, the present invention relates to a novel structure of a discharge path of an ion laser tube.

Conventional technology Ion laser tubes ionize gases such as argon and krypton and generate laser oscillations by the energy transition.
In order to achieve high output, it is necessary to increase the ion density, and for this purpose, the discharge path is configured so that a large current exceeding the IOA flows through a narrow discharge path with an inner diameter of 1 to 4 mm.

However, gas lasers generally have poor oscillation efficiency and most of the supplied power turns into heat, so the vicinity of the discharge path is exposed to extremely high temperatures. Therefore, the members constituting the discharge path of the laser tube are required to have excellent heat resistance.

Moreover, this heat causes thermal deformation of the laser tube, which deteriorates the optical quality of the output laser and, in extreme cases, even causes thermal damage to the laser tube itself. Therefore, in practice, it is common to actively cool the laser tube when it is in operation, and for this reason, the materials that make up the discharge path have not only heat resistance but also excellent thermal conductivity. is also required.

Prior Art i+Ii; (I Warning) Various structures have been proposed in order to achieve high heat resistance and thermal conductivity against the heat generated by the laser tube as described above.

A typical example that is actually used is the one disclosed in U.S. Pat. There is a structure in which the device is operated while being housed in a glass envelope, and is cooled by flowing cooling water outside the envelope.

However, graphite has a high melting point, and repeated heating and cooling will turn it into powder and dissipate, which will expand the inner diameter of the discharge path and significantly impede the quality of the output laser light. It adheres to the star window and impairs the function of the laser tube itself, ultimately shortening the life of the laser tube.

In order to solve this problem, a structure using a metal discharge path forming member is also disclosed in U.S. Pat. are housed in an envelope made of alumina ceramics via copper supporting members, and the through holes are used as discharge paths.

In this structure, the durability of the discharge path members is excellent, and since each member has high thermal conductivity, the cooling performance is also good, but the structure often does not match the characteristics of the materials used. That is, it is very difficult to mold the ceramic material used for the envelope with precise dimensions, and it is difficult to make the inner diameter and straightness of the envelope uniform. On the other hand, with this structure, it is necessary to precisely arrange the holes with a diameter of 1 to 4 mm drilled in the center of the tungsten disk coaxially, so the mounting position of the tungsten disk can be adjusted by using a support member. This requires a labor-intensive manufacturing method in which brazing is performed at the same time. Furthermore, in order to braze the inner surface of the alumina ceramic envelope without macerating it, a special brazing material must be used, which makes manufacturing even more troublesome. Furthermore, tungsten is a metal;
If the thickness of the disk is increased, the area heated by the plasma generated by the discharge will increase, and this will cause the surface of the tungsten member to spatter.
This has the disadvantage that it has to be made into a thin disk shape, which reduces the effective length of the discharge path, resulting in a drop in oscillation efficiency of about 30% compared to a laser tube with a conventional structure.

Furthermore, with recent advances in ceramic manufacturing technology, it has been proposed to use ceramic materials with excellent heat resistance to form discharge paths.

In addition to heat resistance, the discharge path is formed using beryllia ceramics, which is a typical ceramic material with excellent thermal conductivity. It has a structure that cools directly with a cooling medium, achieving extremely excellent durability and cooling performance.

However, it is difficult to precisely mold ceramic materials, including beryllia ceramics, and it is extremely difficult to mold long tubes with an inner diameter of 1 to 4 mm, such as the discharge path of a laser tube, while maintaining precision and straightness. be.

Therefore, as disclosed in U.S. Pat. No. 3,760,213, a structure in which a through hole for a discharge path is bored in the center of a relatively thick beryllia disk and a plurality of through holes are airtightly connected to form a discharge path. has already been proposed.

However, in the gas laser tube, gas pressure imbalance occurs between the cathode side and the anode side of the discharge path due to the gas pumping phenomenon in the discharge path, so it is necessary to provide a gas return path that communicates the two. Therefore, the above
A through hole for the gas return path is drilled in the disc-shaped member made by J IJT, separate from that for the discharge path, and when connecting the disc-shaped member, the gas return path is aligned at the same time as the discharge path to ensure communication. It is necessary to ensure that Therefore, when the above-described structure is adopted, extremely complicated operations are required during manufacturing, especially when connecting the disc-shaped members, which still makes manufacturing the gas laser tube difficult.

Furthermore, since beryllia ceramics are toxic to the human body, the supply of their raw materials is limited, and despite their high thermal conductivity, their casual use should be discouraged.

The inventors of the present invention have carefully examined the advantages and disadvantages of each of the above-mentioned conventional techniques, and have made multiple efforts to utilize the advantages while solving the above-mentioned problems. This led to the present invention.

That is, according to the present invention, at least a portion between the anode and the cathode is formed of a non-conductive and highly thermally conductive ceramic material, and has a plurality of through holes for the discharge path and the gas return path. An ion laser tube comprising a disc-shaped member and a cylindrical connecting member having an inner diameter capable of enclosing the through hole and connected alternately and airtightly between the disc-shaped members. is provided.

In the ion laser tube according to the present invention, the discharge path is formed of a ceramic material that is difficult to precisely process. However, according to the present invention, the discharge path is formed by stacking disc-shaped members having through holes, so that the discharge path is formed in a disc-shaped manner. Each of the members can be easily machined, and by connecting the discharge path through holes drilled in each disc-shaped member so that they are coaxially arranged, it is easy to create a discharge path of a desired length. can be obtained.

In addition, the connection is made through a cylindrical connecting member, and continuity of the gas return path can be maintained without special consideration during assembly.

Furthermore, since these members are airtightly connected, the external surfaces of these members can be brought into direct contact with the cooling medium for cooling during operation of the laser tube, and the materials are not limited by processability as described above. By selecting a non-conductive material, the cooling medium can be easily available, such as tap water.

EXAMPLE The structure of a laser tube according to the present invention will be explained in more detail below with reference to the accompanying drawings. However, what is described below is only one example of the present invention, and does not exceed the technical scope of the present invention. There is no restriction in any way.

FIG. 1 is a sectional view showing the structure of one embodiment of a laser tube according to the present invention.

Each of the plurality of disc-shaped members 1 is provided with a through hole 2 for forming a discharge path, and a plurality of through holes 3 for a gas return path are provided around the through hole 2. This disc-shaped member 1
It is possible to use aluminum nitride ceramics, etc., which are non-conductive and have excellent heat resistance, and also have relatively excellent thermal conductivity.

The connecting member 4 located between the disk-shaped members is a cylindrical member having an inner diameter that allows the through-hole 2 for the discharge path and the through-hole 3 for the gas return path to be accommodated within the diameter of the inner hole,
The requirements for heat resistance are milder than for disc-shaped members, and in addition to ceramic materials such as aluminum nitride ceramics,
Glass or the like can also be used.

The disc-shaped member 1 and the connecting member 4 can be hermetically connected to each other by a low-melting-point sealing glass or the like, and there is no need to form an envelope further outside the discharge path formed by the above-mentioned members.

In addition, the laser tube is cooled by the disk-shaped member 1 and the connecting member 4.
This can be achieved by flowing a cooling medium directly onto the surface. Since all of the above members are non-conductive, there are no particular restrictions on the cooling medium, and tap water or the like may be used.

Further, in this embodiment, the disc-shaped member 1 and the connecting member 4 are formed with the same diameter, but by making the diameter of the disc-shaped member 1 larger than the diameter of the connecting member 4, It is also possible to further increase the cooling efficiency of the laser tube by increasing the contact area between the member 1 and the external cooling medium, and by cutting fins in this area.

Incidentally, at both ends of the discharge path formed in this way, there is a terminal member 6 for supplying power to the anode 5 on one side, and a metal tube 7 for carrying out evacuation and filling of gas in the laser tube.
A metal member 8 having a terminal member 8 and a metal member 11 having a terminal member 10 at the other end for supplying power to the cathode 9 are respectively attached in an airtight manner. Further, these end metal members 8 and 11 are each provided with a Brewster window 12 made of quartz glass, and are configured to function as a laser tube.

Effects of the Invention As detailed above, the discharge path of the ion laser tube according to the present invention is formed by laminating disc-shaped members having through holes, so it has favorable characteristics but is difficult to process. Precise discharge paths can be easily formed using ceramic materials.

In addition, since the connection of the disk-shaped members is through the cylindrical connecting member, when assembling the discharge path, it is only necessary to pay attention to the axis alignment of the through-hole for the discharge path, and the gas return path is well-conducted. It does not require any effort.

Furthermore, by employing the above configuration, the members forming the discharge path can be directly cooled during operation of the laser tube, resulting in extremely high cooling efficiency. Therefore, there is no need to rely on the high thermal conductivity of the material to cool the laser, and sufficient cooling capacity can be achieved without using toxic materials such as beryllia ceramics.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing the structure of one embodiment of a laser tube according to the present invention. (Main reference numbers) ■...Disk-shaped member, 2...Through hole for discharge path, 3...Through hole for gas return path, 4...Tubular connection Components, 5. . . . Anode, 6. IO... Terminal member, 7... Ventilation pipe, 8.11... End metal member, 9... Cathode,

Claims (1)

[Claims] At least a portion between the anode and the cathode is formed of a non-conductive and highly thermally conductive ceramic material,
A plurality of disc-shaped members each having a through-hole for a discharge path and a through-hole for a gas return path, each having an inner diameter capable of containing the through-hole, and connected alternately and airtight between the disc-shaped members. An ion laser tube comprising: a cylindrical connecting member;