JPS63228772A - Highly repetitive pulsed laser electrode - Google Patents

Abstract

PURPOSE:To stabilize pre-ionization and laser oscillation characteristics by forming a plurality of grooves orthogonal in the direction of discharge to the creeping surface of an insulator between counter electrodes for a pre-ionizing electrode. CONSTITUTION:Groove sections 6C orthogonal in the direction of discharge are shaped at two positions in the direction of discharge of an insulator 6. Since the breakdown voltage of space is acquired in the groove sections 6C at two positions while creeping surfaces except the groove sections 6C are exposed to the discharge of the groove sections 6C on pre-ionization, voltage is hardly obtained. Consequently, the breakdown voltage of the groove sections 6C is determined by the discharge distances of the groove sections 6C, and is not fluctuated by discharge. Accordingly, pre-ionization is conducted by stable breakdown voltage at all times regardless of the number of repetition and repeating frequency of discharge, thus acquiring stable laser oscillation characteristics.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to a high repetition pulse laser electrode used in a high repetition pulse laser device, and in particular to a pre-ionization electrode that performs preliminary discharge. It relates to a high repetition pulse laser electrode with improved parts.

(Prior art) In recent years, with the remarkable progress in the technology of various high repetition pulse laser devices such as CO2 radar and excimer laser,
There is a demand for smaller layers and higher performance of these various high repetition pulse laser devices.

As such a high repetition pulse laser device, for example,
As shown in Fig. 3, there is an acceptable proposal of ζ of Utility Model Application No. 55-65875.

In FIG. 3, within the laser cavity 1, main discharge electrodes 2 and 3 are arranged facing each other, and a preliminary ionization electrode 4 is arranged at a position close to the side of the main discharge electrodes 4JJ2 and 3. The pre-ionization electrode 4 consists of electrode members 4A and 4B that are connected in series to beaking condensers 1 and 5 that are arranged side by side in the main ionizing electrodes)*2 and 3, and an insulator such as a relamic chip that is arranged between them. It is composed of object 6. The pulse voltage is supplied from the pulse power supply device to the discharge section via the power supply conductor 7. Furthermore, an output mirror 8 and a total reflection mirror 9 are disposed on the wall surface of the laser cutter V bit 1 at both ends of the main discharge electrodes 2 and 3 in the longitudinal direction. When this occurs, the excited laser gas is photographed together and the laser is released.
Laser light is emitted in the direction indicated by 0.

By the way, in a high repetition pulse laser device, preliminary ionization is performed in advance to generate a stable glow discharge between the main discharge electrodes 2 and 3, or pre-ionization is performed in the high repetition pulse laser device in FIG. Ionization is carried out using the preliminary ionization electrode 4.
This is carried out by generating ultraviolet light by discharging the creeping surface of the insulator 6 disposed between the 4TI members 4A and 48. Incidentally, FIG. 4 is a perspective view showing the pre-ionization electrode 4 of the apparatus shown in FIG. 3.

However, when the creeping surface of the insulator 6 is discharged in this way, the creeping surface is contaminated by the discharge and electrode sputtering.
When the creeping discharge characteristics change, the discharge starting voltage of the pre-ionization electrode 4 changes, making it impossible to obtain stable ultraviolet light. If the pre-ionization conditions are unstable in this way, the laser oscillation characteristics will not be stable, and the operation will become extremely unstable, especially when the number of repetitions is large or the number of cycles is high. .

In general, in the pre-ionization electrode 4 of the type that causes discharge to occur along the creeping surface of an insulator, in addition to the simple shape shown in FIG. There is also a device that has a groove portion 6A along the discharge direction along the creeping surface and performs discharge at this portion 6A.

In this way, when discharging is carried out in the grooves 6A of the insulator 6, the advantage is that the ultraviolet light becomes stronger in each case. This increases the number of scratches and promotes the instability of pre-W1 ionization as described above.

(Problems to be Solved by the Invention) As mentioned above, conventionally, the creeping surface of an insulator is discharged to generate a preliminary
In the i@ type high repetition pulse laser device, there is a problem in that the firing voltage changes due to discharge and electrode sputtering, and as a result, pre-ionization under stable conditions is impossible.

The present invention was proposed in order to solve the problems of the prior art, and its purpose is to maintain a stable reserve at all times by ensuring that the discharge starting voltage does not change due to discharge or electrode sputtering. An object of the present invention is to provide an excellent high repetition pulse laser electrode that can perform ionization and obtain stable laser oscillation characteristics.

[Structure of the Invention] (Means for Solving the Problems) The high repetition pulse laser electrode according to the present invention has a plurality of insulators disposed between the opposing electrodes of the pre-ionization electrode, along which a plurality of A feature of the composition is that it can explain the grooves.

(Function) In the present invention having the above configuration, while the dielectric breakdown voltage of the space can be reduced by 1q in the groove, almost no dielectric breakdown voltage can be obtained in other creeping areas exposed to the discharge in the groove. The firing voltage of the discharge becomes approximately equal to the total of the firing voltages of the plurality of grooves. In this case, the discharge starting voltage of the groove is determined by the distance of the groove in the discharge direction, so the discharge characteristics do not change even if the discharge or electrode sputtering occurs. Therefore, stable pre-ionization can always be performed. ,
Stable ray light (1q of dragon characteristics).

(Example) An example of the high repetition pulse laser apparatus pole according to the present invention as described above will be described below. In addition, Figures 3 to 5
Is the same part the same as the conventional technology shown in N? ”] and the explanation will be omitted.

In the embodiment shown in FIG. 1, grooves 6C are provided at two locations in the discharge direction of the insulator 6, which are perpendicular to the discharge direction. In this embodiment, during pre-ionization, a spatial breakdown voltage is obtained at the two grooves 6C, while the creeping surface of the insulator 6 other than the grooves 6C is exposed to the discharge of the vortex 6C. Almost no voltage is applied. Therefore, in the same embodiment, the discharge starting voltage of the preliminary discharge is at the two groove portions 6C.
is approximately equal to the total discharge starting voltage. In this case, the firing voltage of the groove 6C is determined by the distance in the discharge direction of the groove 6C, so there is no problem that the firing voltage of the insulator 6 changes due to discharge or N-pole sputtering as in the prior art. Therefore, in this example, a stable discharge starting voltage can always be obtained regardless of the number of discharge repetitions or the height of the repetition frequency, so stable pre-ionization can always be performed, and stable laser emission (film characteristics can be obtained). It will be done.

The embodiment shown in FIG. 2 is an insulator 6 having a groove 6A in the discharge direction.
The present invention is applied to the groove portion 6A of the insulator 6 in the discharge direction, and groove portions 6B that are orthogonal to the discharge direction are provided at two locations in the discharge direction. In this embodiment as well, the same effects as in the embodiment shown in FIG. 1 can be obtained.

Note that the present invention is not limited to the above embodiments,
For example, grooves in the direction orthogonal to the discharge direction may be installed at three or more locations (
It is also possible to Furthermore, the present invention is capable of either a configuration in which an insulator is disposed between all of the pre-layer lit electrodes, or a configuration in which an insulator is disposed only between some pre-ionization electrodes. Furthermore, since the present invention relates to an improvement in the shape of the insulator of the pre-ionization electrode portion, other configurations,
That is, the shape of the main power source (~, peaking capacitor, etc.),
The arrangement and configuration can be selected as appropriate.

[Effects of the Invention] - As explained above, the present invention solves the conventional problem by providing a simple structure in which a groove section perpendicular to the discharge direction is provided in the insulator disposed between the pre-ionization electrodes. This is an excellent high-repetition pulse laser that can obtain stable laser oscillation characteristics because it is almost unaffected by dirt on the creeping surface of the insulator over time and can always obtain a stable firing voltage due to the space discharge in the groove. Can provide electrodes.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing one embodiment of a high repetition pulse laser electrode according to the present invention, Fig. 2 is a perspective view showing another embodiment of the invention, and Fig. 3 is a perspective view showing a conventional high repetition pulse laser oscillation device. The perspective views shown, FIGS. 4 and 5, are respectively perspective views showing different conventional pulsed laser electrodes. 1... Laser cavity, 2, 3... Main discharge electrode,
4...Preliminary ionization electrode, 4A, 4B... Electrode member, 5
...Peaking capacitor, 6...Insulator, 6A~
6C... Insulator, 7... Power supply conductor, 8... Output mirror, 9... Total reflection mirror, 10... Laser light.

Claims (2)

[Claims] (1) A high-pressure high-voltage device is equipped with a pre-ionization electrode on the side of the main discharge electrode arranged oppositely to perform a preliminary discharge prior to the discharge of the main discharge electrode, and an insulator is arranged between the counter electrode of the pre-ionization electrode. A high repetition pulse laser electrode, characterized in that a plurality of grooves perpendicular to the discharge direction are provided along the creeping surface of the insulator. (2) The high repetition pulse laser electrode according to claim 1, wherein the insulator has a groove in the discharge direction.