JPH0582858A - Gas laser tube - Google Patents

Abstract

PURPOSE:To offer a gas laser tube hard to generate a scrape on the wall surface of an insulating fine tube made of beryllia ceramics for a long time while suppressing lowering of laser output. CONSTITUTION:In a gas laser tube, an insulating fine tube 12 made of berryllia ceramics composing a gas discharge path 11 is constituted of a raw material where the size of void holes being scattered in the inside thereof has the maximum diameter not exceeding 10mum in average.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas laser tube, and more particularly to improvement of the material of its insulating thin tube.

[0002]

2. Description of the Related Art For example, an argon gas laser tube is
The gas discharge passage is made of beryllia ceramics to ensure electrical insulation and to efficiently dissipate the heat generated in the discharge passage to the outside. In the manufacturing process of this beryllia ceramics, evaporative components are put together with fine powder of beryllia and sintered, so that it is unavoidable that voids are scattered inside.

[0003]

By the way, the laser output may decrease during operation. In many cases, the output decrease occurs in the region A of the discharge passage, particularly in the region A close to the cathode side opening, as shown in FIG. 4 and FIG. Partially enlarged and reduced. That is, the gas discharge passage
A region A in which the inner wall is corrugated is formed in the vicinity of the opening of the beryllia ceramic insulating thin tube 12 which constitutes 11. This is due to the fact that the inner wall of the discharge passage of the insulating thin tube was partially shaved by plasma discharge, and conversely, the fine particle was deposited and thinned (the portion of arrow B in FIG. 5). .. As a result, the outer peripheral portion of the laser beam is shaved and the output is reduced.

It is an object of the present invention to eliminate the above-mentioned inconveniences, to provide a gas laser tube in which the inner wall of an insulating thin tube made of beryllia ceramics is unlikely to be scraped for a long period of time, and a decrease in laser output is suppressed. And

[0005]

According to the present invention, an insulating thin tube made of beryllia ceramics that constitutes a gas discharge passage has pores scattered inside the material with a maximum average diameter of 10 micrometers or less. It is a gas laser tube.

[0006]

According to the present invention, since the holes in the inner peripheral wall of the beryllia ceramics forming the discharge passage are small,
Ceramic materials are rarely scraped by plasma,
Therefore, the reduction of the laser output is suppressed.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. The same parts are denoted by the same reference numerals. FIG. 1 shows the overall configuration of an argon gas laser tube.
In the figure, reference numeral 11 is a small-diameter discharge passage, 12 is an insulating thin tube made of beryllia ceramics, 13 is a cathode, 14 is a vacuum vessel, 15
Is an anode, 16 is a radiation fin, 17 is a gas return pipe,
18 and 19 are resonator mirrors, and 20 is a mirror parallelism adjuster.

Therefore, in the beryllia ceramics forming the insulating thin tube 12, as shown in FIG. 2, at least the material of the inner peripheral wall portion thereof has voids scattered inside the material (small holes scattered in the photograph in the figure). (Parts that are visually recognized as depressions or small holes)
Has a major axis (maximum diameter) of 10 micrometers or less on average. In addition, more preferably, it has a long diameter (maximum diameter) of 7 micrometers or less on average. Furthermore, for non-spherical holes, the average is 5
It has a short diameter of less than a micrometer. This can be manufactured by applying a high pressure to the material during the sintering of beryllia ceramics.

A generally commercially available discharge tube made of beryllia ceramics, which is used for a conventional gas laser tube, is as shown in FIG.
The pores are made of a material that is several times larger than that of the present invention (FIG. 2). This is because the inner wall surface is easily abraded by the plasma, and the phenomenon as shown in FIGS. On the other hand, according to the discharge thin tube of the present invention, the inner wall surface of the discharge thin tube is less likely to be scraped by the plasma, and the decrease in the laser output is small.

[0010]

As described above, according to the present invention,
Since the holes in the material of the beryllia ceramics forming the discharge capillaries are smaller than those of conventional ones, the inner wall surface of the discharge passage is less likely to be scraped by plasma, and therefore the reduction in laser output is suppressed. Thus, it has stable operation performance for a long time.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing an embodiment of the present invention.

FIG. 2 is a micrograph showing a crystal structure of a material of the insulating thin tube of FIG.

FIG. 3 is a micrograph showing a crystal structure of a material of a conventional insulating thin tube.

FIG. 4 is a micrograph showing a crystal structure of a material cross section of an insulating thin tube obtained by operating a conventional laser tube for a predetermined time.

5 is a micrograph showing a crystal structure of the insulating thin tube of FIG.

[Explanation of symbols]

11 ... Discharge passage, 12 ... Discharge capillary (beryria ceramics), 13 ... Cathode, 15 ... Anode.

Claims (1)

[Claims] 1. A gas laser tube using beryllia ceramics having a gas discharge passage formed in a longitudinal direction as an insulating thin tube, wherein the insulating thin tube is at least a region of the beryllia ceramic forming the gas discharge passage. A gas laser tube characterized in that the pores scattered inside the material have an average maximum diameter of 10 micrometers or less.