JPS5848485A - Pulse laser oscillator - Google Patents

Abstract

PURPOSE:To elongate life of electrodes, to simplify a triggering structure, and to prevent the contamination of laser gas due to abraded material of the electrode, by arranging a dielectric electrode covered by a dielectric between a cathode and anode, and by steadily generating an AC discharge as an auxiliary discharge, e.g. silent discharge, between the cathode and anode or between either electrode and the auxiliary electrode. CONSTITUTION:The AC discharge is generated between the cathode 17 and the feeding line 19 and between the anode 1 and the feeding line 19 by the application of a voltage from an AC high voltage power source 21. Said AC discharge has inherent homogenity owing to the presence of the dielectric electrode 18. A low ionized state is steadily yielded in the vicinity of the cathode 17 and over the entire main discharge space. When a main discharge trigger switch 9 is made to be conducting state under the presence of the auxiliary discharge, the charge stored in a main discharge capacity 10 quickly flows between the cathode 17 and the anode 1, and the uniform pulse discharge is obtained over the entire electrode region.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a laterally pumped pulsed laser generator.

Figure 1 shows the main part configuration of a so-called three-axis orthogonal type ■2 laser oscillator, which is a typical example of this hammer's conventional laser oscillator, in which the optical axis discharge and gas flow directions are approximately 1/a [l'i] orthogonal to each other. The vertical cross-sectional view and FIG. 2 are cross-sectional views taken from FIG. 1 1-fl, and the peak is the flat plate 11! pole, (2; is MECUE! pole, C3) is a spark board for ultraviolet light emission, 14) is a discharge stabilizing resistor, (5
1 is a gap switch for ultraviolet light emission, (6) is a capacitor for ultraviolet light emission, (7) is a charging resistor, 18) is a DC high-voltage power supply for charging, (9) is a gap switch for main radiation generation, and uC is a gap switch for generating main radiation. Main discharge co/capacitor, tin is a delay pulse generator, ■ is a trigger generator, a3. is the discharge prevention part, aatiν-zagas, us is the total reflection mirror, ueF
i partial reflecting mirror, @ is the laser optical axis. +11&L between Mt. and Yin [i 121, Cot.

N2. The ultraviolet light emission condenser (6) and the main discharge condenser (I
I? Charged delayed pulse generator Qll i O
When set to N, the gap switch for ultraviolet light emission (5)
becomes conductive, and the charges stored in the ultraviolet light emission capacitor (6) flow all at once to the spark board 13). Due to the generation of a high current density spark discharge, the spark board becomes an emitter of ultraviolet light, and the mixed gas becomes weakly ionized W1 near the cathode (2) and throughout the discharge excitation part α3.
(Electron density @@=lQ@~108-/ll3).

After the trigger pulse is sent to the ultraviolet light emission gap switch (5), several hundred 5 seconds to several seconds*ec, the delayed pulse generator 1111+ generates a second pulse, and the main discharge gap switch is activated. (9) becomes conductive,
The charge stored in the main discharge conductor 7-(II) is immediately transferred to the cathode (2).

Anode-ILrlaK flows and a pulsed discharge is formed.

This pulse discharge occurs because the discharge space is made uniformly weakly ionized by ultraviolet light in advance.

This results in uniform ° discharge.

In the discharge excitation part a3 formed by this discharge.

Population inversion is formed between specific excited levels in the plate mixed gas 141. Total reflection mirrors a are arranged opposite to each other with the discharge excitation part Q3 in between.
A lep beam is emitted from S, the partial reflecting mirror 1151, and the partial reflecting mirror (9).

By the way, in order to increase the total laser output per unit effective discharge volume with this persimmon laser.

(It is common to operate at a pressure higher than atmospheric pressure J, but as the total pressure increases, it becomes difficult to discharge uniformly. As mentioned earlier, ultraviolet light, etc.)
It is necessary to make the entire discharge space into a weakly ionized state beforehand! It is a condition. Various types of electrode structures for emitting ultraviolet light have been devised, and the friend sparkboard type shown above is just one example. However, even in the case of the offset configuration, there is a configuration in which high current density spark discharges are carried out simultaneously at a large number of force points. Also.

This is a place where this woodcutter's pulsed laser will be used industrially.

It is necessary to generate a pulse λ in several ffHy to i,000HF, and a so-called high-speed repetition function is required.
・Do 1'.

However, in the above-mentioned configuration of the conventional one.

(2) High current density spark discharge is used to emit ultraviolet light, but this type of discharge causes severe wear on the electrodes, and if the discharge is repeated at high speed, the life of the electrodes for emitting ultraviolet light will be significantly shortened. (b) Abrasion substances from the ultraviolet light emitting electrode mix into the laser gas, which deteriorates the gas.Ninth, it becomes difficult to operate the laser gas in a sealed state.

To increase the discharge cross-sectional area of the tfi laser, the VC is a mesh electrode; or it is effective to use an anode and apply ultraviolet light to the entire discharge space from the back side.
However, the cathode or anode of meshwork has a small heat capacity and is difficult to cool with water, so during high-speed repetitive operations, the wear is severe and unsuitable.

(2) In order to perform uniform ultraviolet light pre-ionization, ultraviolet light emission was performed, and several hundred
A delay time of several seconds to several seconds is required, which requires a delay pulse generator and the like, making the trigger mechanism complicated. There are drawbacks such as.

This invention attempts to eliminate the above-mentioned drawbacks of the conventional ones, and uses a dielectric electrode covered with a dielectric between the cathode and the anode, and connects this to the cathode, anode, or both.
An alternating current discharge 9, for example, a silent discharge, is constantly generated as an auxiliary discharge between one pole and the other.

The third factor is a vertical sectional view of an embodiment of the G invention, and the fourth factor is the third factor.
In the cross-sectional view taken from the line ff-ff, αη is a flat plate shade;
Pipe-shaped dielectric electrodes made of heat-resistant insulators such as α8σ and IREC λ;
1 is an alternating current (100H) 1 to 100KHy as a preliminary ionization discharge between the power supply IWII■, the cathode Uη, and the anode (1;
) It is a sophisticated AC high-voltage power supply that generates electrical discharge.
' In the above embodiment, the stile, AC high voltage power supply 11! By applying the voltage D, alternating current discharge occurs between the cathode αη and the power supply line α3 and between the anode 11: and the power supply +1i1ull. This alternating current discharge has essentially homogeneity due to the presence of the n-electrode (181), and a steady, even, and low ionization state is realized throughout the main discharge space near the cathode surface. The ionosphere at this time differs depending on the power supplied from AC high voltage power supply 1.

Similar to ionization by an ultraviolet light source, an ionosphere of about 10" can be easily obtained. In the presence of such an auxiliary discharge, when the main discharge trigger switch (9) is made fully conductive, the main discharge capacitor The charges stored in the [phase] flow at once between the cathode [171] and the anode (1), and a uniform pulse discharge is obtained over the entire electrode area.

Here, compared to the conventional ultraviolet photon power supply JIII/c,
Since a flat plate cathode is used in place of the TJ mesh cathode 12), there is no wear and tear, and back cooling is also possible, so there is no longer a problem with life. As for the pre-discharge electrode, $! Since it is used for dielectric electrodes, its lifespan is semi-permanent. In addition, the ν-zagas is not contaminated due to wear of the electrodes, and the sealing operation can be performed for a long time. Furthermore, AC discharge does not require consideration of delay times between pre-ionization discharge and main discharge, which are regularly performed, and the trigger mechanism is simplified, making it particularly suitable for high-speed repetition.

If you want to expand the discharge area, you just need to increase the number of dielectric electrodes along the discharge cross section, and in that sense you have a lot of freedom.

In the above embodiment, near the cathode side [6 electric body electrode Q8
Although the case where one is arranged is shown, the same effect can be obtained even if it is arranged near the * pole mark.

The fifth element is a dielectric electrode (
1g+i A plan view showing only the cathode part when it is carried in a direction perpendicular to the optical axis, and Fig. 6 is a side view of the cathode.The laser discharge length is long and the dielectric electrode is long along the optical axis direction. When I can't install the.

This configuration is valid.

Moreover, FIG. 7 is a plan view of still another embodiment, in which a metal plate with many holes is used as a dielectric electrode.

A plan view of a glass-lined cathode in which only the cathode part is hydrated, and Figure 8 is a side view.

(To) is a flat metal plate with many through holes 129 and to which high AC voltage is applied, and @ is an O electric body that wraps around the flat metal plate.

Similar to the dielectric electrode a8 shown above! l! Waiting for Noh.

This invention is arranged to face each other across the airflow of laser gas, and a pulsed DC high voltage is applied to generate a glow discharge. and a cathode, and the above 1118 is disposed in the laser gas flow and is constantly applied with an AC high voltage.
Equipped with a saidenden # that generates silent discharge between it and the cathode,
t things ÷.

Extends electrode life and simplifies trigger mechanism.

Furthermore, it prevents contamination of the laser gas due to abrasions on the electrodes.
It becomes possible to seal off the laser gas.

From this K, several hundred to several I, which is important in industrial applications,
Q(y) Continuous operation in a high-speed repetition state is possible, and the performance of the device can be improved.

[Brief explanation of the drawing]

Figure 1 is a longitudinal cross-sectional view of a conventional pulsed laser oscillator, and Figure 2
FIG. 1 is a cross-sectional view seen from 1-11. Figure wEa is a vertical #r view of one embodiment of this invention, Figure 4 is a cross-sectional view taken from line 3 IV-IV, and Figure 5 is an enlarged plane INF of main parts of another embodiment of this invention. FIG. 7 is an enlarged plan view of a main part of another embodiment of the present invention, and FIG. 8 is a side view thereof. In the figure, +1) is a flat anode, 12) is a flat anode, and 12) is a flat anode. (4) is a discharge stabilizing resistor, and (8) is a DC high-voltage power supply for charging. (9) is the main discharge gap switch, (121 is the trigger generator, a3 is the discharge excitation part, a# is the laser gas, Q51 is the total reflection z, (
1G+ is a partial reflecting mirror, a71Fi flat plate cathode, and QB+ is a dielectric 'c& pole. a9 is the power supply line, ■ is the cooling water, and a is the AC high voltage power supply. @ is the optical axis, is the metal flat plate, (to) is the dielectric, and the opening is the through hole. It should be noted that the same reference numerals in the figures indicate the same or corresponding parts. Agent Shin Kuzuno (1 other person) Lee 3 Nurvl! ■−

Claims (1)

[Scope of Claims] II+ An anode and a cathode that are arranged to face each other across the laser gas airflow and to which a pulsed DC high voltage is applied to generate a glow discharge; A pulsed laser oscillator equipped with a 4ilt-electronic body to which an AC high voltage is applied to generate a silent discharge between the anode and the cathode. (2) A plurality of rod-shaped I electric body electrodes are arranged in the direction of the laser optical axis or in the direction intersecting with the social axis so as to support the discharge surface of the positive II# or cathode. A pulse laser oscillator according to claim 1. 131 - The pulsed laser oscillator according to claim 1, wherein the electric electrode is formed into a flat plate shape with a plurality of through holes formed therein.