JPS63202980A - Gas laser equipment - Google Patents

Abstract

PURPOSE:To obtain the stable output of laser light, by preventing the impulsive wave generating between a first main electrode and a second main electrodes from travelling in the inverse direction to gas flow, and attenuating rapidly the impulsive wave. CONSTITUTION:A main electrode is constituted of a first main electrode 25 and a pair of second main electrodes 26. By the first and the second main electrodes 25 and 26, a flow path is formed which makes the gas flowing from a space between the second main electrodes 26 into a space between the first and the second main electrodes 25 and 26, flow along the direction of the width of the first main electrode 25. Therefore, an impulsive wave can be prevented form travelling in the inverse direction to the gas flow, by a discharge between the first main electrode 25 and a pair of the second main electrodes 26. Thereby, the impulsive wave can be extinguished from the space between the first and the second electrodes in a short time, so that the output of a laser light is stabilized.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a gas laser device that outputs laser light by exciting gas as a laser medium with discharge energy.

(Prior Art) It is known that gas laser devices include atmospheric pressure or high pressure transverse discharge excitation type TEACO2 lasers and excimer lasers.

Conventionally, there is a gas laser device having such a structure as shown in FIG. That is, in the figure, 1 is a discharge space, and gas as a laser medium is forced to circulate in this discharge space 1 in the direction shown by arrow a. Further, a pair of main electrodes 2.3 facing each other and spaced apart in the vertical direction are arranged in the discharge space 1 along a direction perpendicular to the gas flow direction. These pair of main electrodes 2.3
A first resistor 4 and a first capacitor 5 are connected to the capacitor 5 and the second main electrode 3.
A switch 6 is provided between the two. Further, one end of a second resistor 7 is connected between the capacitor 5 and the switch 6, and a high voltage power supply 8 is connected to the other end of the second resistor 7. Further, pre-ionization electrodes 11 are connected to the first main electrode 2 via a pair of second capacitors 9, respectively. These pre-ionization electrodes 11 are arranged near the second main electrode 3.

In such a structure, when the switch 6 is closed,
The voltage charged in the first capacitor 5 is applied to the pair of main electrodes 2
．． 3 is applied in a pulsed manner, and the second capacitor 9 is charged with a current flowing by the discharge generated between the pre-ionization type ti11 and the second main electrode 3. The discharge space 1 is ionized by ultraviolet rays generated by the discharge between the pre-ionization electrode 11 and the second main electrode 3, and the pair of main electrodes 2.
A main discharge between 3 and 3 is induced.

By the way, when a main discharge occurs in the pair of main electrodes 2.3M, energy is rapidly injected into the discharge space 1, resulting in a loud sound, that is, a shock wave. The shock wave propagates both in the same direction and in the opposite direction to the gas flow direction a, as shown by arrow C in FIG. Since the shock wave propagating in the direction indicated by the arrow is the same as the gas flow direction a, it is quickly extinguished from between the pair of main electrodes 2.3 due to the gas flow. However, the shock wave propagating in the direction shown by arrow C is directed against the flow of gas, so
It is difficult to disappear from between the pair of main electrodes 2.3, and remains stagnant for a long time, forming compression waves. As a result, the stability of the area between the pair of main electrodes 2 and 3 of the discharge space 1 is impaired, making it difficult to generate a uniform discharge, and the laser light emitted from the discharge space 1 may also become unstable. Ta. In particular, when the laser beam is repeatedly oscillated with high pulses, if the discharge space 1 is difficult to stabilize as described above, the oscillation operation may become impossible.

(Problems to be Solved by the Invention) This invention was made based on the above circumstances, and its purpose is to quickly eliminate the shock waves generated by discharge between the main electrodes, and to achieve stable output. An object of the present invention is to provide a gas laser device that can obtain laser light of

[Structure of the Invention] (Means and Effects for Solving the Problems) In order to solve the above problems, the present invention provides a discharge space in which gas circulates, and a discharge space in which the discharge space intersects with the flow direction of the gas. a wide first main electrode disposed along the direction of a pair of second main electrodes that are narrower than the first main electrodes, and these first and second main electrodes allow the first and second main electrodes to be A flow path is formed in which the gas flowing between the main electrodes flows along the width direction of the first main electrode. Further, the direction of the shock wave generated between the first main electrode and the second main electrode was made not to be in the opposite direction to the gas flow.

(Embodiment) An embodiment of the present invention will be described below with reference to FIGS. 1 to 3. The gas laser device shown in FIG. 2 has a discharge space 23 formed in an annular shape by a cylindrical outer cylinder 21 and an inner cylinder 22. This discharge space 23 contains a laser gas mixed with CO2, N2, He, etc. as a laser medium, and a gas for excimer use, and the gas is forced by a cross-flow fan 24 in the direction shown by arrow a in the figure. It is designed so that it can be circulated. Further, a first main electrode 25 and a pair of second main electrodes 26 are arranged in the discharge space 23 as described later, and these main electrodes 2
5.26 Heat exchanger 2 for cooling the gas passed between
7 are arranged.

The first main electrode 25 has a strip shape with a width slightly smaller than the height of the discharge space 2 shown in FIG. 1, and its longitudinal direction is perpendicular to the gas flow direction a. and one plate surface thereof is arranged perpendicularly to the gas flow direction a. The pair of second main electrodes 26 are spaced apart in the height direction of the discharge space 23 and are disposed on the downstream side of the first main electrode 25. That is, the second main electrode 26 has a substantially triangular cross section, and its side faces are fixedly bonded to the member 28a, which are made of an insulating material and are provided at both ends of the discharge space 23 in the height direction. . Therefore, the gas circulated in the discharge space 23 by the cross-flow fan 24 flows between the pair of second main electrodes 26 and between the first main electrode 25 and second main electrode 26, and then flows into the first main electrode 25 and second main electrode 26. The water collides with one side of the main electrode 25 and branches in the vertical direction of that side, and flows from both widthwise ends of the first main electrode 25 to the other side. That is, the first and second main electrodes 25 and 26 form a flow path 30 through which the gas flows in this manner.

Further, a high voltage power source 28 is connected to the first and second main electrodes 25 and 26, and a pre-ionization electrode 31 is connected to the first main electrode 25 through a pair of capacitors 29, respectively. . These pre-ionization electrodes 31 are arranged near the second main electrode 26, respectively.

A pair of total reflection mirrors 32 are disposed at one end of the opposing interval between the first main electrode 25 and the pair of second main electrodes 26, and a pair of output mirrors 33 are disposed at the other end. Laser light is oscillated from each of these output mirrors 33.

In such a structure, when the high voltage power supply 28 is activated, a discharge occurs between the pre-ionization electrode 31 and the second main electrode 26, and the ultraviolet rays generated thereby cause the first main electrode 25 to
A main discharge is induced between the main electrode 26 and the second main electrode 26 . This main discharge generates a shock wave in the direction shown by arrow d in FIG. 1 between the first main electrode 25 and the pair of second main electrodes 26.

However, the generation direction d of this shock wave is perpendicular to the gas flow direction a, not in the opposite direction, and is along the gas flow direction. Therefore, since the shock wave generated between the pair of main electrodes 25 and 26 disappears in a short time, it is possible to oscillate laser light with stable output, and even if the oscillation is repeated at high speed, the output will not become unstable. It's hard to be.

Furthermore, since discharge occurs at two locations between the first main electrode 25 and one of the second main N-poles 26 and between the first main electrode 25 and the other second main electrode 26, two laser beams are generated. It can oscillate light. If the two laser beams are alternately oscillated, the shock waves generated by each discharge can be prevented from interfering with each other, and the discharge space 23 can be stabilized in a short time, and the oscillation frequency of the laser beam can be can be doubled. Further, by causing a pair of discharges to occur simultaneously and amplifying one laser beam by introducing it into the discharge portion where the other laser beam is oscillated, a high-output laser beam can be obtained.

[Effects of the Invention] As described above, the present invention forms the main electrode of a gas laser device from a first main electrode and a pair of second main electrodes,
These first and second main electrodes form a flow path through which gas flowing between the pair of second main electrodes and between the first and second main electrodes flows along the width direction of the first main electrodes. Formed. Therefore, the direction of the shock wave is prevented from becoming opposite to the gas flow direction due to the discharge between the first main electrode and the pair of second main electrodes, and the shock wave is transferred between the first and second main electrodes. This has the advantage that not only the output of the laser beam is stabilized, but also the pulse operation can be repeated at a high speed in a stable state.

[Brief explanation of the drawing]

FIG. 1 is an enlarged sectional view of the main part of a gas laser device showing an embodiment of the present invention, FIG. 2 is a schematic configuration diagram, and FIG. M3 is a perspective view of the arrangement of the first and M2 main electrodes. Fourth
The figure is a schematic explanatory diagram of a conventional gas laser device. 23...Discharge space, 25...First main electrode, 26.
...Second main electrode, 30...Flow path. Applicant's agent Patent attorney Takehiko Suzue Figure 1 Figure 3 21 'l, □ 7me 1-\

Claims (1)

[Claims] a discharge space in which gas circulates; a wide first main electrode disposed in the discharge space along a direction intersecting the flow direction of the gas; and a first main electrode in the discharge space. A pair of second main electrodes narrower than the first main electrode are provided on the upstream side of the first main electrode and spaced apart from each other in the width direction of the first main electrode. A flow path is formed by the second main electrode to allow gas flowing between the pair of second main electrodes and between the first and second main electrodes to flow along the width direction of the first main electrode. A gas laser device featuring: