JPH03173485A - Co2 gas laser oscillator - Google Patents

Abstract

PURPOSE:To generate a stable laser beam for a long term, by forming a metal electrode by using sintered metal which is mainly made of titanium nitride. CONSTITUTION:Along the optical axis direction of a discharge tube 1 made of insulator, CO2 gas is made to flow by a blower. A high voltage is applied between metal electrodes 20, 21 arranged on both ends of the discharge tube 1, by a high voltage power supply 4. Thus discharge takes place in the discharge tube 1. By using this discharge as a laser pumping source, a laser beam 8 is generated in the axial direction of the discharge tube. The metal electrodes 20, 21 are formed by using sintered metal mainly made of titanium nitride, and the deterioration of the metal electrode can be restrained for a long term, so that a stable laser beam can be generated.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention is directed to CO2 in which the axial direction of the discharge tube coincides with the optical axis direction.
This invention relates to a gas laser oscillation device.

(Prior Art) FIG. 4 is a configuration diagram showing a conventional CO2 gas laser oscillation device, in which 1 is a discharge tube made of an insulating material such as glass, and 2 and 3 are provided inside the discharge tube 1. 4 is a high voltage power supply connected to the metal electrodes 2 and 3, and applies a voltage of, for example, 30 kV between the metal electrodes 2 and 3. 5 is a discharge space in the discharge tube 1 sandwiched between the metal electrodes 2 and 3, 6 is a total reflection mirror, and 7 is a partial reflection mirror. They are fixedly arranged at both ends to form an optical resonator. Reference numeral 8 denotes a laser beam output from the partial reflecting mirror 7. arrow 9
indicates the flow direction of the laser gas, which circulates inside the axial flow laser device.

10 is an air pipe, 11 and 12 are heat exchangers for lowering the temperature of the laser gas whose temperature has risen due to discharge in the discharge space 5 and operation of a blower to be described later, and 13 is a blower for circulating the laser gas. A gas flow of about 100 m/sac is obtained in the discharge space 5 by this blower 13.

In the figure, first, a high voltage is applied to a pair of metal electrodes 2 and 3 by a high voltage power source 4 to generate a glow-like discharge in a discharge space 5. The laser gas passing through the discharge space 5 is excited by obtaining this discharge energy, and the excited laser gas enters a resonant state in the optical resonator formed by the total reflection mirror 6 and the partial reflection mirror 7, and is emitted from the partial reflection mirror 7. A laser beam 8 is output. This laser beam 8 is used for purposes such as laser processing.

FIG. 5 is a detailed view of the surfaces of the metal electrodes 2 and 3. The materials for the metal electrode 2.3 include tungsten (W) and copper (
Sintered alloys such as Cu) are used. The reason for using this sintered alloy is that due to the difference in the thickness of the oxide films of tungsten (W) and copper (Cu), the discharge is uniformly and selectively dispersed, so even when the discharge energy is increased, the discharge does not arc. This is because stable glow discharge can be obtained without transitioning to .

(Problems to be Solved by the Invention) In the conventional device described above, when the metal electrodes 2 and 3 are used for a long time, as shown in FIG.
4 grows and stacks up, covering the surface of the copper (Cu), deteriorating the electron (-e) emitting surface and making it difficult to discharge, and causing the oxide 14 to scatter, causing damage to the discharge tube 1. There was a problem in that stable glow discharge could not be obtained due to internal contamination.

An object of the present invention is to provide a CO2 gas laser oscillation device that can provide a stable laser beam over a long period of time.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a method for flowing laser gas in the optical axis direction within a discharge tube made of an insulating material using a blower.
In a CO2 gas laser oscillation device, a high voltage is applied between metal electrodes provided at both ends of the discharge tube to generate a discharge within the discharge tube, and the discharge is used as a laser excitation source to generate a laser beam in the axial direction of the discharge tube. , the metal electrode,
It is characterized by being formed from sintered metal mainly consisting of titanium nitride.

(Function) Since the above means is employed, oxidation of the metal electrode is suppressed, a uniform glow discharge is obtained over a long period of time by the metal electrode, and a stable laser beam is generated.

(Example) Embodiments of the present invention will be described below based on the drawings.

FIG. 1 is a configuration diagram showing an embodiment of a CO2 gas laser oscillation device of the present invention, and members corresponding to those explained in FIG. 4 are given the same reference numerals.

The embodiment shown in FIG. 1 differs from the conventional example shown in FIG. 4 in that the metal electrodes 20 and 21 provided inside the discharge tube 1 are
The structure is made of sintered metal mainly made of titanium nitride (TiN).

FIG. 2 is a detailed view of the surface of the metal electrode 20.21 of this example, and the metal electrode 20.21 is formed from titanium nitride (T i N ) particles as described above.

In the figure, CO and gas are dispersed into CO and 02 by discharge. Generally, the surface of the metal electrode 20.21 combines with the 02 to form an oxide, but the surface of the metal electrode 20.21 is titanium nitride (T
iN), oxidation is suppressed for the following three reasons.

First, since titanium nitride (TiN) is a conductive material, it easily emits electrons (-e).

Secondly, the bond between nitrogen and titanium in titanium nitride (TiN) is strong, and there is little dispersion oxidation due to reaction with 02.

Thirdly, the titanium itself, as shown in Figure 2.

Since only a thin oxide film 22 is formed, oxidation progress is not continued and oxide scattering is reduced. Therefore, there is little deterioration of the electron (-e) emitting surface over a long period of time, and the discharge is extremely stable.

FIG. 3 is a characteristic diagram showing the laser output characteristics of the conventional example and the present example. As is clear from FIG. 3, the characteristic line B of the conventional example shows a decrease in output, whereas the characteristic line A of this example is flat and shows no decrease in output over a long period of time. .

(Effects of the Invention) According to the present invention, by using the metal electrode as a sintered alloy made of titanium nitride, deterioration of the metal electrode can be suppressed over a long period of time, a stable laser beam can be generated, and reliability can be improved. A gas laser oscillation device can be provided.

[Brief explanation of the drawing]

Fig. 1 is a configuration diagram showing an embodiment of the CO2 gas laser oscillation device of the present invention, Fig. 2 is a detailed view of the surface of the metal electrode in the embodiment of Fig. 1, and Fig. 3 is a characteristic showing the output characteristics of the laser. figure,
FIG. 4 is a configuration diagram showing a conventional CO2 gas laser oscillation device, and FIG. 5 is a detailed diagram of the surface of a conventional metal electrode. 1...discharge tube, 4...high voltage power supply, 5...
・Discharge space, 6 ... total reflection mirror, 7 partial reflection mirror,
8...Laser beam, 9...Laser gas flow, 10...Air pipe, 11°12...Heat exchanger, 13
...Blower, 20°21...Metal electrode.

Claims (1)

[Claims] Laser gas is flowed by a blower in the optical axis direction within a discharge tube made of an insulating material, and a high voltage is applied between metal electrodes provided at both ends of the discharge tube to generate a discharge within the discharge tube, which is used as a laser excitation source. In a CO_2 gas laser oscillation device that generates a laser beam in the axial direction of a discharge tube,
A CO_2 gas laser oscillation device, characterized in that the metal electrode is formed of a sintered metal mainly made of titanium nitride.