JPH0325956B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a gas laser oscillation device of a type that forcibly circulates a gas laser medium excited by discharge of a main electrode.

(Prior Art) In a gas laser device such as a CO ₂ laser or an excimer laser, a gas laser medium is forced to circulate in a closed container in which a pair of main electrodes are arranged facing each other at a distance. There are devices that allow excitation using electrodes to be repeated at high speed.

According to this configuration, most of the discharge products generated by the discharge are removed from the discharge space between the pair of main electrodes along with the flow of the gas laser medium, but some of the discharge products are removed from the main electrodes. Remaining near the surface of the electrode is unavoidable. Therefore, if the discharge is repeated at high speed, the discharge products remaining in the discharge space will gradually increase, which causes the discharge between the pair of main electrodes to transition to arc discharge, and the laser beam oscillation becomes impossible. In other words, the pulse repetition of laser light cannot be performed at high speed.

In addition, if the discharge is repeated at high speed, the shock wave generated by the discharge remains in the discharge space before the next discharge, so the shock wave makes the discharge unstable and the discharge is repeated at a high speed. There are some things that cannot be done.

(Problem to be Solved by the Invention) As described above, in the conventional gas laser oscillation device, it was not possible to quickly remove discharge products and shock waves generated by discharge from the discharge space. It happened that it was not possible to do it at high speed.

This invention was made based on the above circumstances, and its purpose is to quickly remove discharge products and shock waves generated in the discharge space from the discharge space. An object of the present invention is to provide a gas laser oscillation device.

[Structure of the invention]

(Means and Effects for Solving the Problems) In order to solve the above problems, the present invention includes a closed container in which a gas laser medium is sealed, and at least a pair of main electrodes disposed facing each other in a spaced manner in the closed container. and one of the main electrodes includes a rotating body that is rotationally driven, a plurality of electrode pieces provided at predetermined intervals in the circumferential direction on the outer circumferential surface of the rotating body, and one of the main electrodes, Each of the electrode pieces is protruded between the electrode pieces, and one electrode piece and the other main electrode face each other across the discharge space to separate the discharge space from other parts of the space in the sealed container, and at the same time, during the rotation. and a vane material that circulates the gas laser medium in the discharge space by rotating with the body. By rotating the rotating body in time with the ignition of the main discharge, discharge products and shock waves generated in the discharge space due to the discharge are removed from the discharge space by the blade member. did.

(Example) An example of the present invention will be described below with reference to FIG. The gas laser oscillation device shown in the drawings includes a closed container 1 in which a gas laser medium is sealed. An opening 2 is formed in the peripheral wall of this closed container 1, and this opening 2 is closed by a mounting plate 3. A cathode 4 is attached to the lower surface of the mounting plate 3 facing into the closed container 1. This cathode 4 is formed into a hollow shape by a wire mesh 5, and a preliminary ionization electrode 6 is arranged inside the cathode 4.

An anode 7 is disposed within the sealed container 1 at a portion facing the cathode 4 . The anode 7 includes a columnar rotating body 8 with an octagonal cross section, electrode pieces 9 each having a semicircular cross section fixed to every other side of the rotating body 8, and electrode pieces 9 of the rotating body 8. The blade member 11 has one end fixed to the side surface to which the blade member 11 is not attached, and protrudes outward in the radial direction.

In a state where one electrode piece 9 faces the cathode 4, the space between them, that is, the discharge space 12, is created by a pair of blade members 11 located on both sides of the one electrode piece 9. separated from the rest of the Note that wall members 13 are disposed on both sides of the cathode 4 to face the tips of the blade members 11 with a slight gap therebetween, thereby improving the separation of the discharge space 12 by the pair of blade members 11. is being measured.

A heat exchanger 14 for cooling the gas laser medium removed from the discharge space 12 is provided in the sealed container 1, as will be described later. Further, one axial end of the rotating body 8 is airtightly protruded from one end surface of the closed container 1 to the outside, and a drive motor (not shown) is connected to the protruding end. The rotating body 8 is rotationally driven by its drive motor.

The cathode 4 is connected to the negative side of a high voltage power supply 15 via a peaking capacitor 16.
The rotating body 8 of the anode 7 is connected to the positive side of the high voltage power supply 15. Further, the pre-ionization electrode 6 is connected to the positive side of the high voltage power supply 15 via a corona capacitor 17.

Note that the positive side of the high voltage power supply 13 is grounded.

Next, the operation of the gas laser oscillation device having the above configuration will be explained. First, the high-voltage power supply 15 is turned on, and a drive motor (not shown) is operated to rotate the rotating body 8 of the anode 7 in the direction of the arrow. When the high-voltage power supply 15 is turned on, corona discharge occurs between the pre-ionization electrode 6 and the cathode 4, whereby the discharge space 12 between the cathode 4 and the anode 7 is pre-ionized.

In this way, when the preliminary ionization of the discharge space 12 is sufficiently performed and the cathode 4 and one of the plurality of electrode pieces 9 of the anode 7 face each other, a main discharge is ignited between them. The gas laser medium in the discharge space 12 is excited. The laser beam generated thereby is amplified by a total reflection mirror and a partial reflection mirror (not shown) disposed on both axial end faces of the sealed container 1,
The light is oscillated from the partial reflecting mirror.

When the main discharge is ignited between the cathode 4 and one electrode piece 9 of the anode 7 in this way, discharge products and shock waves are generated in the discharge space 12. The discharge space 12
is separated from the rest of the space inside the closed container 1 by a pair of blade members 11 and a wall member 13.
Therefore, as the main discharge is ignited while the anode 7 rotates, the gas laser medium containing discharge products and shock waves in the discharge space 12 is transferred to the blade member 11 that separated the discharge space 12 during the main discharge. At the same time, it is removed from the discharge space 12. At the same time, the gas laser medium in the closed container 1, which does not contain discharge products or shock waves, is sent into the discharge space 11 by another blade member 11, and the next main discharge is ignited.

Therefore, discharge products and shock waves generated in the discharge space 12 can be quickly and reliably removed by the blade member 11, and fresh gas laser medium can be supplied to the discharge space 12 by the other blade member 11. Therefore, it is possible to speed up the repetitive operation of the main discharge.

It should be noted that the discharge products removed from the discharge space 12 are captured by a filter (not shown) provided in the heat exchanger 14, and therefore hardly ever flow into the discharge space 12 again.

FIG. 2 shows the relationship between the number of main discharge repetitions and the laser output in the conventional method and the present invention. In the figure, the curve A shows the conventional method, and the curve B shows the present invention. As is clear from this figure, according to the present invention, the main discharge can be repeated at a rate more than twice that of the conventional method, thereby making it possible to obtain a high laser output.

Although the cathode is provided with four electrode pieces in the above embodiment, the number is not limited, and the larger the number, the higher the number of repetitions of the main discharge can be.

Further, although the anode is set to a ground potential, it goes without saying that the cathode side may be grounded.

〔Effect of the invention〕

As described above, the present invention includes a rotating body in which one of a pair of main electrodes is rotationally driven, a plurality of electrode pieces provided at predetermined intervals in the circumferential direction of this rotating body, and protrusions between these electrode pieces. one of the electrode pieces and the other main electrode face each other with a discharge space in between, separating the discharge space from other parts of the space in the sealed container, and rotating together with the rotating body. It is composed of a vane member that circulates the gas laser medium in the discharge space. Therefore, the discharge products and shock waves generated by the main discharge between the pair of main electrodes are forcibly removed from the discharge space by the rotating blade member of one main electrode, and the other Since fresh gas laser medium is supplied by the vane member, discharge can be repeated at high speed without transitioning to arc discharge.

[Brief explanation of drawings]

FIG. 1 is a schematic block diagram of the entire apparatus showing an embodiment of the present invention, and FIG. 2 is an explanatory diagram of the relationship between the number of discharge repetitions and the laser output between the conventional apparatus and the present invention. 1... Airtight container, 4... Cathode, 7... Anode, 8
... Rotating body, 9 ... Electrode piece, 11 ... Vane member,
12...discharge space.

Claims (1)

[Claims] 1 Comprising a closed container in which a gas laser medium is sealed, and at least a pair of main electrodes arranged in a spaced-apart manner and facing each other in the closed container, one of the main electrodes is connected to a rotating body that is driven to rotate, a plurality of electrode pieces provided on the outer peripheral surface of the rotating body at predetermined intervals in the circumferential direction; one electrode piece protruding between each of the electrode pieces on the outer peripheral surface of the rotating body and the other main electrode; A vane member that faces each other with a discharge space in between, separates the discharge space from other parts of the space in the sealed container, and rotates together with the rotating body to circulate the gas laser medium in the discharge space. A gas laser oscillation device characterized by: