JPS63217685A - Pulse laser device - Google Patents

Abstract

PURPOSE:To conduct pulse discharge, rise of which is fast, by charging first and second capacitors connected to a main electrode in parallel, discharging the first capacitor through a pre-discharge gap and pre-ionizing the first capacitor while inversion-charging the first capacitor. CONSTITUTION:High Voltage is applied to the node of capacitors C1, C2 connected to main electrodes 1, 2, the capacitors C1, C2 are charged in parallel, and one capacitor C1 is discharged through a pre-discharge gap and pre-ionized. Voltage of twice as high as charging voltage is applied between the main electrodes 1, 2 by inversion-charging, and pulse discharge is performed. Accordingly, pulses, rise of which is fast, can be applied while automatic pre-ionizing can be conducted.

Description

[Detailed description of the invention] [Object of the invention] (Industrial application field) The present invention provides a pulse laser device that performs pulse discharge excitation in a laser gas, such as a TEACO2 laser, an excimer laser, a gold FsM gas laser, and a halogen gas laser. Regarding.

(Prior Art) Laser devices that excite laser gas to perform pulsed laser oscillation include TEACO2 lasers, excimer lasers, metal vapor lasers, and halogen gas lasers. these are,
Except for high-output electron beam excitation, discharge excitation is common. FIG. 3 shows an example of a circuit diagram of a conventional discharge-excited pulsed laser. This is designed to perform pulsed discharge by applying a pulsed voltage to two main electrodes placed oppositely in a laser gas. In order to stably perform this pulse discharge, it is common to perform preliminary discharge in advance. In FIG. 3, this preliminary discharge is performed using a separate pulse circuit. The timing of the preliminary discharge and the main discharge is such that the main discharge is delayed from the preliminary discharge by several tens to hundreds of ns. Figure 4 shows this preliminary discharge and main discharge,
This is done in one circuit and is called an automatic pre-ionization type. Briefly explaining this operation, by short-circuiting the trigger gap (switching element) 10, a current flows through the pre-discharge gap 7.8 between the capacitor 3 and the capacitor 9, which is charged in advance. At this time, when preliminary ionization is performed and the capacitor 9 is sufficiently charged, discharge occurs between the two main electrodes 1.2, and laser oscillation is performed.

In order to perform this laser oscillation efficiently, it is necessary to apply a pulse with a fast rise of 9. It has also been found that adding a pulse with a fast rise time is effective for stabilizing the discharge. However, in the conventional circuit, the rise time determined by the external voltage C is several tens of n3, and it is almost impossible to apply a pulse with a faster rise time. In addition, conventional circuits that generate pulses with a fast rise time include the so-called inverge run circuit and the Blumlein circuit, but pre-ionization must be performed using a separate pulse power source, making each circuit complex. It had the disadvantage of being expensive.

(Problems to be Solved by the Invention) As described above, with the circuit of the conventional pulse laser device, it is not possible to obtain a pulse with a fast rise, the laser oscillation efficiency is low, and the discharge is unstable. It was common.

An object of the present invention is to employ a simple discharge circuit that can apply a pulse with a fast rise and at the same time perform automatic pre-ionization.

The object of the present invention is to provide a pulse laser device that solves the above-mentioned problems.

[Structure of the invention]

(Means for Solving the Problems) The pulse laser device according to the present invention charges the first and second capacitors CI'+02 connected to the main electrode 1.2 in parallel, and charges one of the capacitors @ The capacitor CI of 1 is discharged through a pre-discharge gap to perform pre-ionization, and at the same time, by reverse charging, a voltage twice the charging voltage is applied between the main electrodes 1 and 2, and a pulse with a fast rise is generated. It is characterized by discharging.

(Function) A high voltage is applied to the connection point of the capacitor ClIC2 connected to the main electrode 1.2, the capacitors C1 and C2 are charged in parallel, and one of the capacitors fC1 is discharged through the pre-discharge gap. A circuit was adopted in which preliminary ionization was performed and further reverse charging was performed to apply a voltage twice the charging voltage between the main electrodes 1 and 2 to perform pulse discharge. Using this circuit, it is possible to create an automatic pre-ionization type pulse laser device that has a quick start-up time.

(Example) FIG. 1 shows an example of the present invention. The operation of the circuit will be explained below. Apply a high voltage to the connection point of two sets of capacitors CI*02 connected to the main electrode 1.2, charge the capacitors CI and C2 in parallel through the charging resistor R1, and apply a trigger pulse to the gap switch 1°. and connect one of the capacitors CI to the pre-discharge gap 7
．． 8 to perform preliminary ionization, and further reversely charge the capacitor C1, so that a voltage twice the charging voltage is applied between the main electrodes and a main discharge occurs. The rise time of the bending at this time is C1=CI=C/2, and if the inductance of the circuit is L, then LC/2. Resistance R
2 is C] a charging resistor. Also, the third capacitor C
3 is a peaking capacitor, and adding this will make the rise even faster. At this time, %C3≦CI must be satisfied. FIG. 2 is also an embodiment of the present invention, and is a circuit diagram in which pulse circuits are provided on both sides of the electrode. This operation is also the same as in the case of FIG. 1, but the start-up time is LC/22, which is faster than in the case of FIG. 1. The present invention can be applied to a pulsed laser device such as a halogen gas laser, and can be an automatic pre-ionization type pulsed laser device with a fast discharge rise time.

In the above embodiment, a gap was used for switching, but
A switching element such as a thyratron or a semiconductor element may also be used. The peaking capacitor C3 may or may not be present. The compact invention can be implemented with various modifications without departing from the spirit thereof.

〔Effect of the invention〕

As described above, in the pulse laser device according to the present invention,
As the start-up can apply a fast pulse,
By employing a simple discharge circuit that can perform automatic pre-ionization, an inexpensive pulsed laser device that is stable and has high oscillation efficiency can be realized.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing a main part of a pulse laser device according to an embodiment of the present invention, and FIG. 2 is a circuit diagram showing a main part of a pulse laser device according to an embodiment of the present invention, in which a pulse circuit is provided on both sides of the electrode. The circuit diagram shown in Fig. 3 is. FIG. 4 is a circuit diagram showing the main parts of a conventional automatic pre-ionization type pulse laser apparatus. 1.2... Main electrode* C1-C2... Main capacitor, 7.8... Pre-ionization electrode %C3... Peaking capacitor, 10... Switching element, 11.
R2...Charging resistance. Figure 1 Figure 2

Claims (6)

[Claims] (1) First and second disposed facing each other in the laser gas
In a pulse laser device comprising a main electrode and a pre-ionization electrode disposed near the main electrode, on the surface of the main electrode, or on the back side of the main electrode, the first and second capacitors connected in series are connected to the main electrode. The first and second capacitors are connected in parallel to both main electrodes, and the first and second capacitors are close to ground potential at least during charging, and a high voltage is applied to the connection side of the first and second capacitors. can be supplied to charge the first and second capacitors, and the pre-ionization electrode and the switching element connected in series are connected in parallel to the first capacitor. Pulsed laser equipment. (2) The pulse laser device according to claim 1, wherein the capacitances of the first and second capacitors are approximately equal. (3) The pulse laser device according to claim 1, wherein an arc gap for generating ultraviolet rays is used as the pre-ionization electrode. (4) The pulse laser device according to claim 1, wherein a corona electrode is used as the pre-ionization electrode. (5) The pulse laser device according to claim 1, wherein a creeping discharge electrode is used as the pre-ionization electrode. (6) The pulse laser device according to claim 1, wherein a third capacitor is connected in parallel to both of the main electrodes, and the capacitance of the third capacitor is smaller than the capacitance of the first and second capacitors.