JPS5915087Y2 - High power gas laser tube - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a high power gas laser tube that requires a water-cooled double tube structure.

In high-output gas laser tubes with a double-tube structure that has a glass thin tube and a water-cooled outer cylinder with electrodes arranged coaxially on both ends, the thin tube and electrodes are conventionally placed in isolated positions.
Moreover, the inner diameter of the electrode was larger than the inner diameter of the capillary so as not to limit the laser mode volume.

However, when the laser output exceeds 200 W, the scattered or diffracted light from the laser inside the resonator hits the end corner of the capillary, locally heating this part to a high temperature, which causes cracks in the capillary. This has the disadvantage that the corner portion may soften and curl into the inside of the tube, resulting in unstable discharge.

An object of the present invention is to provide a high-output gas laser tube that is capable of stable, high-output continuous operation for a long period of time by preventing local temperature increases at the ends of the thin tube.

That is, the present invention has a structure in which the outer surface of the cylindrical electrode is closely attached or sealed to the inner wall of the terminal end of the capillary, and the terminal end of the capillary and the end of the cylindrical electrode are aligned with substantially the same end surface. , the tube ends are not glass tubes like conventional ones,
Since it is a metal cylindrical electrode, even if the laser beam hits the end of this metal cylindrical electrode, the generated heat will be diffused throughout the electrode and will be spread over a wide area closely or
Since the heat is transmitted to the sealed water-cooled thin tube and is cooled, unlike the conventional glass thin tube, not only the thin tube but also the cylindrical electrode hardly deteriorates.

Next, the present invention will be explained in detail with reference to the drawings.

As shown in FIG. 1, a conventional water-cooled high-power gas laser tube has an outer tube 1 coaxially arranged on the outside of a thin glass tube 2, and an inlet 3 and an outlet port are arranged between the inner tube and the outer tube. It has a double-tube structure in which cooling water flows through 4 to cool the inner thin tube 2, which becomes hot.

The electrode structure is such that an anode 5 is provided in the center of the thin tube 2, and a cylinder having an inner diameter larger than the outer diameter of the thin tube 2 is provided at both ends of the thin tube 2 so as not to obstruct the laser mode volume. A shaped cathode 6 is provided so as to wrap around the end of the thin tube.

Of course, the outer tube in the area where the cathode 6 is provided is shaped in an enlarged manner, and a cymbal 8 with a resonant mirror 7 attached thereto is placed at the open end of the tube with an O-ring (not shown) interposed therebetween. It is kept airtight.

In such a conventional high-power laser tube, when the laser output exceeds 200 W, the scattered or diffracted light of the laser in the resonator hits the corner of the end of the thin tube 2, causing There were disadvantages in that the tube was locally heated to a high temperature, which caused cracks to occur in the tube and caused it to break, and that the edge corners softened and curled inside the tube, making the discharge unstable.

FIG. 3 is an enlarged view of the main part of the embodiment of the present invention. Unlike the conventional glass thin tubes in which both ends of the thin tube 2 are terminated, the cylindrical cathode 6 is tightly attached to the inside of both ends of the thin tube 2. Alternatively, the capillary tube 2 is sealed so that the terminal end of the capillary tube 2 and the end of the cylindrical cathode 6 are substantially aligned with the same end surface, so that both ends of the capillary tube 2 are terminated with the cylindrical cathode 7.

In this way, according to the present invention, both ends of the thin tube are metal cylindrical cathodes, so compared to conventional thin tubes that are terminated with glass, they can be easily cut off by laser beams. The heat generated by the electrode 6 is quickly diffused throughout the electrode 6 and is cooled by the cooling water on the outside of the thin tube, which is in close contact with the electrode 6. Therefore, there is almost no deterioration at the end of the thin tube, and the life of the laser tube is improved.

As a result of the experiment, we compared the lifespan of a gas laser tube with a structure similar to that shown in Figure 2 and the conventional gas laser tube shown in Figure 1, and found that the lifespan of the conventional gas laser tube was several times shorter than that of the conventional gas laser tube when operating at a continuous output of 300 W. The lifespan of the gas laser tube with the structure of the present invention was more than 1,000 hours, compared to 10 hours.

As can be seen from the above examples, the life of the gas laser tube according to the present invention is one order of magnitude longer than the conventional gas laser tube as a high output gas laser tube of 200W or more, and it can be said that the effect is remarkable. .

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a conventional high-power gas laser tube, and FIG. 2 is a cross-sectional view of a main part of the high-power gas laser tube of the present invention. 1... Outer tube, 2... Thin tube, 3...
... Water supply port, 4 ... Drain port, 5 ... Anode pin, 6 ... Cathode, 7 ... Resonance mirror 8 ... cymbal mount.

Claims (1)

[Scope of utility model registration request] In a high-power gas laser tube with a water-cooled double tube structure, a cylindrical tube is installed inside the terminal end of the water-cooled thin tube so that the outer cylindrical surface is in close contact or sealed with the inner wall of the front thin tube, and the end surface is almost the same as the thin tube end. A high-power gas laser tube characterized by having a shaped electrode.