JPS62130576A - Carbon dioxide gas laser oscillator - Google Patents

Abstract

PURPOSE:To improve the stability and the efficiency of a glow discharge by forming a cathode by aligning a plurality of thin plates in parallel, and auxiliarily discharging between the thin plates. CONSTITUTION:When a high DC voltage is applied between a cathode plate 10 and an anode plate 11 disposed via a gas stream of laser gas containing CO2, a glow discharge 12 is generated to emit a laser beam perpendicular to the discharge 12. The cathode plate 10 of thin plate having an emboss 13 for making the gas stream turbulent is disposed in the same plane through a gap to form a cathode, and an auxiliary glow discharge 21 is generated between the plates 10. Discharge power density ratio is raised by the auxiliary discharge, and the stability and the efficiency of the glow discharge of a carbon dioxide gas laser oscillator are improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a carbon dioxide laser oscillator that uses an auxiliary discharge to stabilize the laser and increase its output.

[Technical background of the invention and its problems]

An example of a conventional system configuration of a biaxial orthogonal carbon dioxide laser oscillator is shown in FIG.

In FIG. 5, 1 is a resonator that emits a laser beam by glow discharge, and an anode 5 for generating discharge;
It is composed of a cathode 6, an insulating plate 7, a mixing wall 8 that makes laser gas turbulent in order to increase ionization efficiency, and an optical resonator (not shown), and emits a laser beam in a direction perpendicular to the glow discharge.

2 is a blower, which blows CO through the wind tunnel 3 and the resonator 1.
Circulate the laser gas containing □.

A heat exchanger 4 lowers the temperature of the laser gas sent to the resonator 1 in order to stabilize the generation of glow discharge within the resonator 1.

The conventional resonator 1 described above uses a large number of rod-shaped discharge pins as the cathode 6, and the mixing wall 8 is placed on the upstream side thereof, so the pressure loss against the gas flow increases and the cooling effect of the cathode decreases. , there is a problem of reducing discharge efficiency.

In addition, the discharge is started by lowering the gas pressure to 20 to 25 Torr and applying a high voltage for excitation to cause an initial discharge, and then increasing the gas pressure to 30 to 50 Torr to perform laser oscillation. There are problems in that it requires a high-voltage initial discharge circuit, complicates startup, and increases power loss.

[Purpose of the invention]

In the present invention, the cathode is configured by arranging a plurality of thin plates in parallel,
The object of the present invention is to provide a rational biaxial orthogonal type carbon dioxide laser oscillator that facilitates startup by causing an auxiliary discharge between cathode plates, and improves the stability and efficiency of glow discharge.

[Summary of the invention]

The present invention applies a direct current high voltage between a cathode and an anode that are placed across an airflow of laser gas containing CO□ to generate a glow discharge, and thereby generates a continuous oscillation of a CO□ laser. In this type of carbon dioxide laser oscillator, the cathode and anode are each constructed by a plurality of thin plate electrodes arranged in parallel, and a gap is provided between the cathode plates.
A high-frequency auxiliary power source generates a partial auxiliary glow discharge in the gap between the cathode plates, thereby increasing the stability and efficiency of the glow discharge and eliminating the need for starting excitation with high voltage, making the device smaller and simpler as a whole. This is aimed at increasing efficiency.

[Embodiments of the invention]

An embodiment of the present invention is shown in FIG. 1.6 FIG. 2 is a sectional view of the cathode plate in FIG. 1 viewed from the upstream side of the gas flow.6 In FIG. is an anode plate, by which a glow discharge 12 is created.

Reference numeral 13 denotes an irregularly shaped object such as an emboss provided on each cathode plate, which acts as a mixing wall to make the gas flow turbulent.

14 is a water cooling pipe for anode cooling, 15 is a heat-resistant insulating plate, 16 is an insulating plate, 17 is a wind tunnel frame, 18 is a heat-resistant transparent plate, 19 is a heat-resistant plate, and 20 is a transparent plate.

Each pair of cathode plates 10 are arranged on the same plane with a predetermined discharge gap in between, and are arranged at a predetermined interval as shown in FIG.
A high frequency power source is supplied through a capacitor 25 and a stabilizing resistor 27 provided for each cathode plate to generate an auxiliary glow discharge 21 in each discharge gap.

Furthermore, if a protrusion is provided on the cathode plate 10 facing the discharge gap, an auxiliary glow discharge can be stably generated.

23 is a laser power supply, and a stabilizing resistor 2 is connected at the start of main discharge.
2, a high DC voltage is applied between the cathode plate 10 and the anode plate 11, thereby starting a main discharge and emitting a laser beam. 26 is ground.

FIG. 4 is a characteristic diagram showing an example of the relationship between the gas flow rate and the discharge power density ratio in the case without the conventional auxiliary discharge (characteristic B) and in the case with the auxiliary discharge according to the present invention (characteristic A). If there is, the discharge power density ratio will be improved by about 30 to 50%, and stable glow discharge will be performed even in the high speed range of gas flow.

The 1ktz experimental machine of the present invention used 5US304 with a thickness of 0.3I as the cathode plate and 0.3+ as the anode plate.
60 m+ thick copper plates are arranged in parallel at intervals of 15++ m each.

Molded in one piece with heat-resistant epoxy.

As the laser gas, a mixed gas of Coz-N2-lie was used at a gas pressure of 30 to 60 Torr and a flow rate of 50 to 100 Ill.
/sec.

Further, the frequency of the auxiliary power source was IKHz to 1M11z, and the laser voltage was 3 to 10 kV.

In the above example, the pi electrode plate and the cathode plate are arranged in parallel, but the same characteristics are exhibited even if they are arranged vertically or at an angle. 30
℃ or higher, but with the plate structure according to the present invention, it can be suppressed to 25℃ or lower.

〔Effect of the invention〕

As explained above, according to the present invention, in a biaxial orthogonal carbon dioxide laser oscillator, the electrode is configured by arranging a plurality of thin plates in parallel, and a partial auxiliary discharge is caused in the gap between the cathode plates. This makes it easy to start the main discharge and eliminates the need for starting excitation with high voltage, and also makes it possible to stabilize and improve the efficiency of the discharge, making it possible to realize a small, simple, and efficient carbon dioxide laser oscillator as a whole.

[Brief explanation of drawings]

FIG. 1 is a side sectional view showing an embodiment of the present invention, FIG. 2 is a diagram showing the arrangement of the cathode plate in FIG. 1, FIG. 3 is an electric circuit diagram of the present invention, and FIG. A characteristic diagram showing an example of the effect, and FIG. 5 is a system configuration diagram showing an example of a conventional carbon dioxide laser oscillator. 1...Resonator 2...Blower 3...Wind tunnel 4...Heat exchanger 5...Anode
6... Cathode 7... Insulating plate 8... Mixing wall 10... Cathode plate 11... Anode plate 12.
... Glow discharge 13 ... Emboss 14 ... Water-cooled tube
15.16... Insulating plate 17... Wind tunnel frame
18.20...Transparent plate 21...Auxiliary glow discharge 2
2.27... Stabilizing resistor 23... Laser power supply
24... Auxiliary power supply 25... Capacitor (8733) Agent Patent attorney Yoshiaki Inomata (1 idiot) No. 1 Figure broom 2 Figure Ino 3 Concave〃°°Person flow rate (deposit/5ec) Sheep 4 figure

Claims (3)

[Claims] (1) Biaxially orthogonal carbon dioxide that generates a glow discharge by applying a DC high voltage between the cathode and anode, which are placed across the airflow of laser gas containing CO_2, and thereby continuously oscillates the CO_2 laser. In gas laser oscillators,
The cathode and the anode are each configured by a plurality of thin plate-like electrodes arranged in parallel, and a gap is provided between the cathode plates, and a high-frequency auxiliary power source generates a partial auxiliary glow discharge in the gap between the cathode plates. carbon dioxide laser oscillator. (2) The carbon dioxide laser oscillator according to claim 1, wherein a projection for auxiliary glow discharge is provided on a portion of the cathode plate facing the gap. (3) The carbon dioxide laser oscillator according to claim 1, wherein the cathode plate is formed with an irregular shape such as an emboss for generating turbulence in the airflow of the laser gas.