JPH01117076A - Pulse gas laser device - Google Patents

Abstract

PURPOSE:To obtain a laser output efficiently, and to lengthen the lifetime of a laser gas by burying at least one part of a peaking capacitor into an insulator. CONSTITUTION:An insulator constituting one part of a laser tube 1 and having high halogen resistance its formed in two layer structure composed of an inwall 2 brought into contact with a laser gas and an external wall 3 not brought into contact with the laser gas. Peaking capacitors 4 are buried between the inwall 2 and the external wall 3. Distances among the peaking capacitors 4 and a discharge electrode pair 5 are shortened and floating inductance can be reduced by adopting such structure. Accordingly, electric enregy can be injected during glow discharge conducting laser excitation in a short time, thus inhibiting the generation of arc discharge, then efficiently acquiring a laser output.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a pulsed gas laser device using a capacitive transfer type excitation circuit as an excitation circuit.

(Prior art) A pulsed gas laser device such as an excimer laser, IEA CO, or laser consists of a laser tube that seals laser gas, a pair of discharge electrodes that are installed in the laser tube and generates a discharge for excitation of the laser, and energy that is transferred between the pair of discharge electrodes. It consists of an excitation circuit for injecting . In most of these pulsed gas laser devices, in order to obtain high-output laser light, the laser is excited by glow-discharging the laser gas at a gas pressure equal to or higher than atmospheric pressure. However, when discharging gas at atmospheric pressure or higher, arc discharge is likely to occur, and arc discharge not only reduces the output of the laser but also rapidly deteriorates the laser gas and significantly shortens the life of the gas. Particularly in excimer lasers and the like, it is necessary to reduce the inductance between the peaking capacitor and the discharge electrode pair in order to prevent arc discharge from occurring and to obtain laser output efficiently. Furthermore, since the life of an excimer laser is significantly shortened by impurities in the laser gas, the portion of the laser tube that comes into contact with the laser gas must be made of a material that does not chemically react with the halogen gas contained in the laser gas. Regarding the capacitive transfer type excitation circuit, please refer to the literature "Laser Research", Volume 9,
No. 6, pages 682-687. FIG. 2 shows a schematic cross-sectional view of a pulsed gas laser device using a conventional capacitive transfer type excitation circuit. In the conventional example shown in FIG. 2, a part of the laser tube 1 is made of an insulator 6 having high halogen resistance, and a peaking capacitor 4 is installed outside the insulator 6.

(Problems to be Solved by the Invention) In the conventional pulsed gas laser device, the peaking capacitor 4 is installed outside the insulator 6.

In this structure, from the viewpoint of withstand voltage, it is necessary to make the insulator 6 thick, so the distance between the discharge electrode pair 5 and the peaking capacitor 4 is long, and the stray inductance becomes large. Therefore, the conventional pulsed gas laser device shown in FIG. 2 has the disadvantage that arc discharge is likely to occur between the discharge electrode pair 5, making it difficult to efficiently obtain laser output, and that the arc discharge shortens the life of the laser gas.

The purpose of the present invention is to efficiently obtain laser light,
Another object of the present invention is to provide a pulsed gas laser device using a capacitance transfer type excitation circuit as an excitation circuit in which the life of the laser gas is long.

(Means for Solving Conventional Problems) The pulsed gas laser device of the present invention is a pulsed gas laser device in which at least a portion of the laser tube is made of an insulator, and is equipped with a capacitive transfer type excitation circuit consisting of a charging capacitor and a peaking capacitor. The device is characterized in that at least a portion of the peaking capacitor is embedded within an insulator.

(Function of the invention) By embedding the peaking capacitor in an insulator as in the present invention, the distance between the discharge electrode pair connected in parallel with the peaking capacitor and the peaking capacitor is shortened compared to the conventional pulsed gas laser device. Inductance can be reduced. Therefore, in the pulsed gas laser device of the present invention, most of the electrical energy stored in the peaking capacitor can be injected into the discharge space before the glow discharge that excites the laser between the discharge electrode pair shifts to arc discharge. As a result, the occurrence of arc discharge is suppressed, laser output can be efficiently obtained, and the life of the laser gas is extended.

(Example) Hereinafter, the present invention will be explained in more detail with reference to the drawings.

FIG. 1 is a cross-sectional view schematically showing an embodiment of the present invention.

In the present invention, the insulator with high halogen resistance constituting a part of the laser tube 1 is different from the conventional example shown in FIG. In this embodiment, the insulator has a two-layer structure consisting of an inner wall 2 that is in contact with the laser gas and an outer wall 3 that is not in contact with the laser gas. The peaking capacitor 4 is embedded between the inner wall 2 and the outer wall 3. By adopting such a structure, the distance between the peaking capacitor 4 and the discharge electrode pair 5 can be shortened, and the stray inductance can be reduced.

Therefore, in the embodiment shown in Fig. 1, electrical energy can be injected into the glow discharge that excites the laser within a short time as described in the section of operation, the occurrence of arc discharge can be suppressed, and the laser output can be efficiently output. can be obtained. Furthermore, in this embodiment, the lifetime of the laser gas is extended because the occurrence of arc discharge is suppressed.

In this embodiment, the insulator constituting a part of the laser tube 1 has a two-layer structure, but in the present invention, it is made into a single layer, and a hole is made to embed the peaking capacitor 4, and the peaking capacitor 4 is inserted into the hole. You can also embed it in Further, in the embodiment shown in FIG. 1, the inner wall 2 and the outer wall 3 are made of the same halogen-resistant material, but in the present invention, an insulator with low halogen resistance may be used for the outer wall 3 that does not come into contact with the laser gas. .

(Effects of the Invention) As described above, according to the present invention, it is possible to provide a pulsed gas laser device that can efficiently obtain laser output and can extend the life of the laser gas compared to the conventional apparatus.

[Brief explanation of the drawing]

FIG. 1 is a schematic cross-sectional view of a pulse gas laser device showing an embodiment of the present invention, and FIG. 2 is a schematic cross-sectional view of a conventional pulse gas laser device. DESCRIPTION OF SYMBOLS 1... Laser tube, 2... Inner wall, 3... Outer wall, 4...
...Peaking capacitor, 5...Discharge electrode pair, 6.
... Insulator, 7... Charging capacitor, 8... Switching element.

Claims (1)

[Claims] In the pulsed gas laser device, at least a part of the laser tube is made of an insulator, and includes a capacitance transfer type excitation circuit consisting of a charging capacitor and a peaking capacitor, wherein at least a part of the peaking capacitor is embedded in the insulator. Characteristic pulsed gas laser equipment.