JPH02240979A - Gas laser device - Google Patents

Abstract

PURPOSE:To absorb impacts of impulse waves which are caused by an electric discharge by providing either of a total reflecting mirror or an output mirror at the holding part of a laser tube through an impact absorption member. CONSTITUTION:A totally reflecting mirror 11 is held at the first holding part 21 which is mounted at an axial one end side of a laser tube and an output mirror 12 is held at the second holding part 22 which is mounted at the other end surface. In the first holding part 21, an impact absorption member 26 consisting of impact absorption materials, e. g. rubber and cork, is provided at a recessed part 25 which is formed at one side of a base plate 24 and the total reflecting mirror 11 is joined and fixed onto the impact absorption member 26. Further, in the same way as the case of the first holding part 21, an impact absorption member 31 is provided at the second holding part 22 and then the output mirror 12 is joined and fixed onto the impact absorption member 31. Impacts of impulse waves which are caused by an electric discharge are thus absorbed.

Description

[Detailed description of the invention]

[Object of the Invention] (Industrial Application Field) The present invention relates to a gas laser device that excites a gas laser medium with discharge energy to emit laser light. (Prior Art) Generally, in a gas laser device such as a TEACO2 laser or an excimer laser, a cathode and an anode, which constitute a main electrode, are placed in a laser tube in which a gas laser medium is sealed, separated from each other, and a main discharge is generated between them. By generating the gas, the laser medium gas is excited to emit laser light. Prior to generating the main discharge between the cathode and anode,
The space between the cathode and the anode, that is, the discharge space, is pre-ionized by the Y-ionization means to enable efficient laser oscillation. Figures 4 and 5 are examples of such conventional gas laser devices.
There was one with the structure shown in the figure. In other words, 1 in the figure is a laser tube, and inside this laser tube 1 are CO2, N2, H.
A gas laser medium mixed with a gas such as e is sealed. Further, a pair of holding plates 2 are arranged in the laser tube 1 so as to be spaced apart from each other and facing each other. A cathode 3 and an anode 4 constituting a main electrode are held and fixed on opposing surfaces of each holding plate 2 in an electrically conductive state. These cathode 3 and anode 4
is connected to a high-voltage power source 5, and the anode 4 is grounded. Of the pair of holding plates 2, one holding plate 2 provided with the cathode 3 has a peaking capacitor 6 for waveform shaping.
The upper bottle electrode 6 to which a is connected is on both sides of the cathode 3,
Furthermore, lower pin electrodes 7 are provided at predetermined intervals along the longitudinal direction, and the other holding plate 2 is provided with lower pin electrodes 7 with their tips facing the upper pin electrodes 6. A fan 8 for circulating a gas laser medium in the direction shown by the arrow in FIG. 5 is disposed within the laser tube 1, and a heat exchanger 9 is disposed upstream of the fan 8. Furthermore, a total reflection mirror 12 and an output mirror 13 are held in an airtight state by holders 11 at one end and the other end in the axial direction of the laser tube 1, respectively. In the gas laser device having such a configuration, when the high-voltage power supply 5 is activated and electrical energy is supplied, a discharge occurs between the opposing end surfaces of the upper pin electrode 6 and the lower bottle electrode 7, and UV light (ultraviolet light) is generated. light) is generated. The UV light pre-ionizes the space between the cathode 3 and the anode 4, that is, the discharge space. When pre-ionization progresses in the discharge space and the voltage between the cathode 3 and anode 4 increases, a main discharge occurs between these electrodes 3.4 and laser light is emitted, and the laser light is reflected by the total reflection mirror 11. It is amplified between the output mirror 12 and is oscillated from the output mirror 12. That is, the laser light is oscillated along the longitudinal direction of each electrode 3.4, which is a direction perpendicular to the discharge direction. By the way, in the gas laser device having such a configuration, shock waves are generated in the discharge space due to the discharge generated between the upper bottle electrode 6 and the lower bottle electrode 7 and the main discharge generated between the cathode 3 and the anode 4. is unavoidable. The shock wave is reflected by the cathode 3 and anode 4 and not only travels back and forth between them, but also propagates throughout the discharge space. Therefore, since the flow of the gas laser medium in the discharge space becomes unstable due to the impact of the shock wave, it is inevitable that the laser light emitted from the discharge space also becomes unstable. Furthermore, if the flow of the gas laser medium becomes unstable, it may become impossible to increase the number of repetitions of laser oscillation. (Problem to be solved by the invention) In this way, conventionally, the flow of the gas laser medium becomes unstable due to the impact of the shock wave generated by the discharge, which not only makes the oscillation state of the laser beam unstable, but also causes repeated laser oscillation. There were some things like not being able to raise the numbers. The present invention was made based on the above circumstances, and its object is to provide a laser device capable of absorbing shock waves generated by electric discharge.

[Structure of the invention]

(Means and Effects for Solving the Problems) In order to solve the above problems, the present invention provides a main body consisting of a laser tube in which a gas laser medium is sealed, and a cathode and an anode arranged spaced apart from each other in the laser tube. A high-voltage power supply that applies a voltage between the electrode, the cathode and the anode, and a pre-ionization unit that pre-ionizes the discharge space prior to the main discharge that occurs between the cathode and the anode. 7
8 separating means, a total reflection mirror disposed at one end in the optical axis direction perpendicular to the direction of the main discharge generated between the cathode and the anode, and an output mirror disposed at the other end; At least one of the reflection mirror and the output mirror is held in a holding part provided on the laser tube via a shock absorbing member, so that the discharge generated by the discharge and propagated throughout the discharge space can be prevented. When the shock wave collides with the total reflection mirror or the output mirror, the shock is absorbed by the shock absorbing member. (Embodiment) An embodiment of the present invention will be described below with reference to FIGS. 1 to 3. Note that the same parts as those in the conventional structure shown in FIG. 4 are given the same symbols and their explanations will be omitted. That is, in this invention, the total reflection mirror 11 is connected to the laser tube 1.
The output mirror 12 is held by a first holding part 21 provided at one axial end of the laser tube 1 , and the output mirror 12 is held by a second holding part 22 provided at the other end of the laser tube 1 . The first holding section 21 includes a base plate 24 attached at a position corresponding to a first through hole 23 bored in one end surface of the laser tube 1, as shown in FIG. A four part 25 formed on one side surface opposite to one end face of the laser tube 1, and a sheet-like shock absorbing member 26 made of a shock absorbing material such as rubber or cork provided in this recess 25. It is composed of. The total reflection mirror 11 is bonded and fixed to this shock absorbing member 26. As shown in FIG. 3, the second holding part 22 is a base provided in a portion corresponding to a second through hole 27 bored in the other end surface of the laser tube 1, similar to the first holding part 21. board 28;
A recess 29 is formed on one side of the base plate 28 facing the other end of the laser tube 1, and a sheet-like sheet made of a shock-absorbing material such as rubber or cork is provided in the recess 29. The output mirror 12 is bonded and fixed to the shock absorbing member 31. Note that the base plate 28 and the shock absorbing member 31 are provided with a through hole 28 a s 31 a in a portion corresponding to the second through hole 27 through which the laser beam passes. In the gas laser device having such a configuration, the high voltage power supply 5
When activated, a discharge occurs between the upper bin electrode 6 and the lower bin electrode 7, generating UV light, which flows into the discharge space to pre-ionize the discharge space. When the preliminary ionization of the discharge space progresses sufficiently in this manner, a main discharge occurs between the cathode 3 and the anode 4, and laser light is output in a direction perpendicular to the direction of the discharge. When a discharge for pre-ionizing the discharge space and a main discharge for outputting laser light are generated, shock waves are generated by these discharges, and the shock waves propagate throughout the discharge space. Of the shock waves propagated in the discharge space, the laser light and
Shock waves propagated in the axial direction of the laser tube □1 are transmitted to the base plate 24 via shock absorbing members 26 and 31, respectively.
．． Total reflection mirror 11 and output mirror 1 attached to 28
Collision with 2. Therefore, the impact of the shock wave is absorbed and reduced by the shock absorbing member 26, 31, so that the influence of the shock wave on the gas laser medium in the discharge space can be suppressed in a short time. Therefore, the discharge that is repeatedly performed in the discharge space is less likely to become unstable due to the impact of the shock wave, and moreover, it is possible to increase the number of discharge repetitions. Note that in the above embodiment, both the total reflection mirror and the output mirror are attached via the shock absorbing member, but even if only one of these mirrors is attached via the shock absorbing member, the shock wave can absorb shock. Further, the shock absorbing member may be replaced with a coil spring instead of a rubber material or cork. [Effects of the Invention] As described above, in this invention, at least one of the total reflection mirror and the output mirror is provided in the holding part formed on the laser tube through a shock absorbing member, so that the impact caused by electric discharge can be reduced. When a shock wave collides with the mirror, the impact is absorbed by the shock absorbing member. therefore,
Even if the flow of the gas laser medium in the discharge space is disturbed due to the shock wave caused by the discharge, the disturbance can be corrected in a short time, which not only stabilizes the laser output but also increases the number of repetitions of laser oscillation. .

[Brief explanation of drawings]

FIG. 1 is a sectional view along the optical axis of a laser tube showing an embodiment of the present invention, FIG. 2 is an enlarged sectional view of a total reflection mirror, FIG. 3 is an enlarged sectional view of an output mirror, and FIG. The figure is a cross-sectional view of a conventional gas laser device taken along the optical axis direction, and FIG. 5 is a cross-sectional view taken in a direction perpendicular to the optical axis direction. 1... Laser tube, 3... Cathode, 4... Anode, 5...
...High voltage power supply, 6.. Upper bottle electrode, 7.. Lower pin electrode, 11.. Total reflection mirror 12.. Output mirror 21.. First holding part, 22.. Second 424.28 Base plate, 26.31 Shock absorbing member.

Claims (1)

[Claims] A laser tube in which a gas laser medium is sealed, a main electrode consisting of a cathode and an anode arranged spaced apart and facing each other in the laser tube, a high-voltage power supply that applies a voltage between the cathode and the anode, and the cathode and the anode. Pre-ionization means for pre-ionizing a discharge space prior to the main discharge occurring between the cathode and the anode, and a total reflection mirror disposed at one end in the optical axis direction perpendicular to the direction of the main discharge occurring between the cathode and the anode. and an output mirror disposed on the other end side, and at least one of the total reflection mirror and the output mirror is held by a holding part provided on the laser tube via a shock absorbing member. A gas laser device characterized by: