JPH0240979A - Gas laser oscillator - Google Patents

Abstract

PURPOSE:To ensure the stability of discharge by arranging a pair of semicylindrical insulators holding a metallic elecrode between the insulator and a discharge tube, winding and fixing a coil on the outer circumferences of the insulators and connecting the coil to the metallic electrode as a resonance circuit element for impedance matching. CONSTITUTION:A pair of semicylindrical insularors 16 holding metallic electrode 2, 3 between the insulators 16 and a discharge tube 1 are disposed on the outer circumference of the discharge tube 1. Coils 17 are wound and fastened onto the outer circumferences of the insulators 16. The coils 17 function as resonance circuit elements for impedance matching between the electodes 2, 3 and a high- frequency power supply 4, and the connected to the power supply 4 by short- sized wirings. According to the constitution, the wirings between the high-frequency power supply 4 and the resonance circuits can be reduced largely, and the electrodes 2, 3 are not pooled by the heat generation of the discharge tube 1. Consequently, stable discharge is acquired by simple constitution, thus obtaining a gas laser device displaying the excellent performance of laser beam machining.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a gas laser oscillation device in which the axial force direction of a discharge tube and the optical axis direction match, and in particular, the present invention relates to a gas laser oscillation device that achieves high efficiency of laser oscillation. This invention relates to a gas laser oscillation device.

[Conventional technology]

Conventionally, as this type of gas laser oscillation device, for example, a second
As shown in Fig. 3 and Fig. 3, a pair of metal electrodes (2) (3) are placed at a predetermined interval on two positions on both sides of the tube axis on the outer peripheral surface of a cylindrical discharge tube (1) made of a dielectric material such as glass. ) are arranged in close contact with each other in a state facing each other, and the pair of metal electrodes (2) and (3) are connected to a high frequency AC power source (4),
For example, 13.56Ml1z, 2k for both electrodes (2) and (3)
While applying a high frequency high voltage of V, both metal electrodes (2) (
3) A total reflection mirror (6) and a partial reflection mirror (7) are arranged at fixed positions at both ends of the discharge space (5) in the discharge tube m sandwiched between them, and these total reflection mirrors (6) and a partially reflecting mirror (7) constitute an optical resonator, and the discharge tube (1)
An air pipe (8) is provided in communication with the center between both electrodes (2) and (3) of the discharge tube (1), and both ends of the discharge tube (1) and the air pipe (
Connect a pair of branch pipes (9) (to) between the other ends of both pipes (1
) (8) to form a pair of circulation passages branching in two directions from the center of the discharge tube (1). ), and a heat exchanger is provided in the air pipe (8) on both sides of the blower (ll) to cool down the laser gas that has been heated due to discharge in the discharge space (5) and driving of the blower (11). (12)(
A so-called axial flow type gas laser oscillation device is known, in which a so-called axial flow type gas laser oscillation device is provided.

In addition, as the blower (H), it is recommended to use a blower having a blowing ability capable of obtaining a gas flow having a flow velocity of about 100 m/see in the discharge space (5).

In the conventional device having the configuration described above, first, a pair of metal electrodes (2
)(3) is applied with a high frequency and high voltage from the island's electrified device 1 (4) to generate a glow-like discharge in the discharge space (5), the laser gas passing through this discharge space (5) absorbs the discharge energy. At the same time, the optical resonator formed by the total reflection mirror (6) and the partial reflection mirror (7) becomes resonant, and the laser beam (B) is output from the partial reflection mirror (7). This laser beam (B
) will be used for purposes such as laser processing.

By the way, when obtaining a laser beam (B) by applying a high frequency and high voltage between the metal electrodes (2) and (3) as described in 1.1-, the impedance between the metal electrodes (2 and 3) causes damage inside the discharge tube. In order to keep this impedance constant, for example, metal electrodes (2) and (3) were placed on the outer peripheral surface of the discharge tube (+) with an adhesive (14).
) etc., and in order to achieve impedance matching between the high frequency power source (4) and the metal electrodes (2) and (3), a resonant circuit (I5) was interposed between them.

[Problem to be solved by the invention]

However, in the gas laser oscillator having the conventional structure described above, the adhesive (14) deteriorates due to heat generation of the discharge tube (1), so the impedance between the metal electrodes (2) and (3) changes, and the resonant circuit (15 ) and metal electrodes (2) (3
Stray capacitance is generated from the connecting wires between the two, causing variations in matching conditions, making the discharge unstable and causing the problem that the laser beam cannot be extracted efficiently.

The present invention has been made in order to solve the conventional problems as described in 1., and aims to improve the reliability of the device by ensuring the stability of the discharge in the discharge space within the discharge tube. The purpose is to

[Means to solve the problem]

In order to achieve the above object in item 1, the present invention allows a laser gas to flow in the optical axis direction inside a discharge tube made of a dielectric material, and metal electrodes are provided on the outer circumferential surface of the discharge tube to face each other in the tube diameter direction. In a gas laser oscillator device that generates a discharge in the discharge tube by applying a high frequency voltage between the two, and uses this discharge as a laser excitation source to generate a laser beat in the tube axis direction of the discharge tube, the metal electrode is connected to the discharge tube. A set of two semi-cylindrical insulators is placed between them, and a coil is wound around the outer periphery of the semi-cylindrical insulators. E, and the coil is connected between the metal electrodes as a resonant circuit element for impedance matching.

[For production]

This invention! - According to the configuration described above, the resonant circuit element for impedance matching between metal electrodes is constituted by a coil, and this coil also serves as the nine stages of fixed plates of semi-cylindrical insulators, so the structure is simplified. Moreover, there is no need to separately provide a resonant circuit element, and as a result, the length of the connection wiring between the resonant circuit and the metal electrode can be reduced. Therefore, the generation of stray capacitance due to connection wiring can be suppressed as much as possible, making it possible to stabilize the impedance between the metal electrodes.Also, variations in impedance matching between the metal electrode and the high-frequency power source are suppressed, ensuring stability of discharge. can do.

Furthermore, since the metal electrode is always held in a compressed state on the outer periphery of the discharge tube by the coil via the insulator, it is possible to prevent the metal electrode from peeling off due to heat generation of the discharge tube.

〔Example〕

Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

This embodiment device has the same basic configuration as the conventional example described above, so parts with common configurations and functions will be given the same reference numerals, and their explanation will be omitted to avoid misunderstandings. do.

In FIG. 1, in the gas laser oscillation device according to this embodiment, the discharge tube (1) is attached to the outer periphery of the discharge tube (1).
A semi-cylindrical insulator (]B) made of two pieces of string is arranged between which the metal electrodes (2) and (3) are sandwiched, and a coil (17 ), and this coil (I7) connects the same insulator (1B) to the discharge tube (1).
The structure is such that it is fixed on the outer peripheral surface of the

Further, the coil (17) acts as a resonant circuit element for impedance matching between the metal electrodes (2) (3) and the Takaoka 7t [source (4), and is connected to both ends of the high frequency power source (4). connected via a short wire. By making the coil (17) double as the resonant circuit element in this way, the wiring between the resonant circuit and the high-frequency power source (4) can be significantly reduced, and the metal electrodes (2) and (3) 1
7), the discharge tube (
+) peeling due to heat generation can be prevented.

〔Effect of the invention〕

As explained above, according to the present invention, a set of two semicircular T5-shaped insulators are provided to sandwich the metal electrode between the discharge tube, and this semi-cylindrical insulator is wrapped around the outer periphery. The coil is fixed on the outer peripheral surface of the discharge tube by a coil, and the coil is connected between the metal electrodes as a resonant circuit element for impedance matching. The resonant circuit element is constituted by a coil, and this coil also serves as a fixing means for the semi-cylindrical insulator to integrate the metal electrode and the resonant circuit, so there is no need to provide a separate resonant circuit element. can be simplified.

Further, since this allows the connection wiring between the resonant circuit and the metal electrode to be of a short length, the generation of stray capacitance due to the connection wiring can be suppressed as much as possible. Therefore, the impedance between the metal electrodes can be stabilized, and variations in impedance matching between the metal electrodes and the high-frequency power source can be suppressed, so that stability of discharge can be ensured.

Historically, the metal electrode has always been held in a compressed state on the outer periphery of the discharge tube via an insulator by a fill, so that it is possible to prevent the metal electrode from peeling off due to heat generation of the discharge tube.

As described above, according to the present invention, it has been possible to provide a gas laser oscillation device that can be constructed relatively easily, has high reliability, and exhibits excellent laser performance.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a discharge tube showing one embodiment of the present invention, and FIG.
The figure is a longitudinal sectional front view of a conventional example, and FIG. 3 is a longitudinal sectional side view of a conventional discharge tube. (1)...discharge tube, (2)(3)...metal electrode, (
l[i)...Semi-cylindrical insulator, (17)...Coil. Figure 1 1f: Coil

Claims (1)

[Claims] A laser gas is caused to flow in the optical axis direction within a discharge tube made of a dielectric material, and a high-frequency voltage is applied between metal electrodes provided on the outer peripheral surface of the discharge tube facing each other in the tube diameter direction to generate a discharge within the discharge tube. In a gas laser oscillation device that generates a laser beam in the tube axis direction of the discharge tube using this discharge as a laser excitation source, a set of two semi-cylindrical insulators sandwiching the metal electrode and the discharge tube is provided. a resonant circuit for winding a coil around the outer periphery of the semi-cylindrical insulator to fix the semi-cylindrical insulator on the outer peripheral surface of the discharge tube and for impedance matching the coil; A gas laser oscillation device which is connected between the metal electrodes as an element.