JPS60219783A - Gas laser tube - Google Patents

Abstract

PURPOSE:To obtain the titled tube of low cost and high quality by a method wherein a discharge path fine tube forming a discharge path is made of silicon nitride. CONSTITUTION:The fine tube made of silicon nitride forms a discharge path between the cathode 11 and the anode 5 connected via encapsulating trays 2 and 3 respectively. Heat dissipating fins 6 are bonded to the outer periphery of the tube 1, and the heat evolving in the encapsulating trays 2, 3, and 7 and the anode 5 is dissipated via fins 6 by the air fed in from a fan not illustrated. A cathode valve 4 includes the cathode 11 and contains argon gas. Besides, a return path 9 for the argon gas connects the valve 4 with an anode valve 8.

Description

DETAILED DESCRIPTION OF THE INVENTION (1) Field to which the invention pertains The present invention relates to helium-neon, argon, krypton,
The present invention relates to a gas laser tube that produces laser oscillation using excitation by discharge of a gas such as carbon dioxide gas.

(Prior art in general) A gas laser tube is a discharge path thin tube (hereinafter referred to as a thin tube) made of glass or ceramic that forms a discharge path.
It is a cylindrical sealed tube whose main components include a pair of windows located at both ends, an anode, and a cathode, and helium-neon, argon, krypton, carbon dioxide gas, etc. are sealed inside the tube.

Incidentally, in order to increase the output of the gas laser tube, it is necessary to increase the density of the discharge current, but in this case, energy loss due to collision of the discharge gas on the thin tube wall increases. For this reason.

The temperature of the tube wall of the capillary increases significantly, causing destruction of the capillary and a decrease in oscillation efficiency.

For these reasons, in the case of high-power lasers such as carbon dioxide lasers and argon lasers, heat dissipation in the gas laser tube, especially in the thin tube section, becomes an extremely important issue.

Therefore, when the output is relatively large, a conductive perforated disk made of a high-melting point metal such as tungsten or graphite is placed inside a quartz glass tube with excellent heat resistance and thermal shock resistance via an insulating spacer. There are generally two types of gas laser tubes: a gas laser tube with a laminated thin tube section and a gas laser tube that uses a thin tube made of beryllia ceramic, which has excellent thermal conductivity and airtightness, and also serves as an envelope. In both cases, the envelope is immersed in cooling water.

In addition, when the output is relatively small, the VC is generally a gas laser tube with heat dissipation fins provided on the outer wall of a thin beryllia ceramic tube, which is air-cooled by a fan.

Among these, beryllia ceramic capillary tubes have various advantages, but have extremely serious drawbacks in manufacturing.

Firstly, beryllia ceramic is a legally regulated substance and must be processed and handled with great care.Secondly, it is extremely expensive and cannot be obtained in long pieces or in the required shape. The third difficulty is that the mechanical strength is weaker than that of alumina ceramics and the like, making it impossible to reduce the weight. In addition, there are many manufacturing problems derived from these drawbacks, and there have been attempts to switch from beryllia ceramic to other materials.

(3) Purpose of the Invention The present invention replaces beryllia ceramic with silicon nitride in order to solve the drawbacks of the conventional gas laser tube using beryllium ceramic thin tubes.

The objective is to provide a relatively inexpensive, high-quality gas laser tube with no legal restrictions.

The present invention will be explained in detail below.

(4) Structure and operation of the invention FIG. 1 shows a cross section of an argon gas laser tube according to an embodiment of the invention. In FIG. 1, 1 is a thin tube made of silicon nitride with a length of 55 mm, an outer diameter of 10 mm, and an inner diameter of 1.02 mm. form a road.

A radiation fin 6 is joined to the outer periphery of the thin tube 1. Enclosure dish 2.3, 7. Heat generated at the anode 5 is dissipated through the heat radiation fins 6 by air blown in by a fan (not shown).

Cathode bulb 4L contains a cathode 11 and stores argon gas. In addition, the argon gas return path 9 is
A cathode bulb 4 and an anode bulb 8 are connected. So-called pre-acitor windows 10 forming a breaster angle with respect to the central axis of the discharge path are connected to both ends of the discharge path.

Next, a method for manufacturing an argon laser tube having the above structure will be described.

Silicon nitride has a low coefficient of thermal expansion and excellent high-temperature strength and mechanical strength, making it suitable as a material to replace beryllia ceramic. but.

Conventionally, silicon nitride cannot be metallized because it does not contain oxides, making joining by brazing difficult. It was confirmed that direct brazing can be performed without any treatment.

Therefore, the enclosure dish 2 shown in FIG. Anode 5. Enclosure dish 3. Braze the capillary tube l, the enclosure plate 2 and the radiation fin 6 with l'48T.
Using 1-482r-4Be, brazing temperature 1030°
Vacuum brazing was performed at C. Thereafter, the argon laser tube 20 was completed by performing glass processing using a conventional known method.

Although this example describes an air-cooled argon laser tube,
Since the water-cooled argon laser tube has the same brazing structure, it can be easily manufactured using the above manufacturing method.

Furthermore, it goes without saying that vacuum brazing of silicon nitride is possible even if pure titanium is used in place of 48Ti-48Zr-4Be.

In this way, we were able to vacuum-braze a thin tube made of silicon nitride and a metal part using a titanium brazing filler metal, and fabricate an argon laser tube with excellent airtightness and thermal shock resistance.

(5) Description of Effects As stated above, the present invention has advantages over beryllia ceramics, which have been conventionally used as thin tubes.

(b) There are no restrictions on handling, (b) metallization treatment that requires complicated processes on the tube surface can be omitted, (c) various machining processes can be performed, and (←) high mechanical strength and thermal shock resistance. .

(e) A high quality gas laser tube can be provided using inexpensive silicon nitride.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of a gas laser tube for explaining the present invention in detail. 1... Thin tube using silicon nitride, 2,3.7.
... Enclosure dish, 4 ... Cathode pulp, 5 ...
...Anode, 6...Radiation fin, 8...
・・Anode pulp, 9・・Return path, 10・
...Brewster window, 11 ... cathode. 20...Gas laser tube.

Claims (1)

[Claims] 1. A gas laser tube having a thin tube forming a discharge path between an anode and a cathode, characterized in that the thin tube is made of silicon nitride.