JPH0444283A - Laser oscillator - Google Patents

Abstract

PURPOSE:To prevent a decrease in a laser output and to obtain a stable laser output by providing a folding mirror section in which an optical axis is folded by a folding mirror and at least one laser gas bypass provided in parallel with the section in a multiple folding type high speed axial flow laser oscillator. CONSTITUTION:A folding mirror section 1 is an optical path formed from a folding mirror 3 to a folding mirror 4, and a laser light 5 in a resonator is bent by the folding mirrors 3, 4 of a folding mirror section 2. On the other hand, a bypass 15 is provided in parallel with the section 2, and has an opening end 16 between a gas inlet 10 and the mirror 3, and an opening end 17 between a gas inlet 11 and the mirror 4. Since the diameter of the bypass 15 is set larger than the diameter of the section 2, the blast resistance is extremely smaller than that of the section 2. Therefore, even if a differential pressure is generated between laser gas pressures in resonators according to the diameter of a tube for circulating laser gas and the length of the path, the flow of the gas generated by the differential pressure is fed through the bypass 15, but not fed through the section 2. Thus, the gas pressures in the resonators are made uniform, thereby reducing the flows of the gases in the sections.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a laser oscillation device that is a multi-folded high-speed axial flow laser, and more particularly to a laser oscillation device having a mechanism for stabilizing the output and preventing a decrease in the output.

[Conventional technology]

2. Description of the Related Art Conventionally, a multi-folding type high-speed axial flow type laser oscillation device is known in which the optical axis is folded in multiple stages using a folding mirror in addition to a total reflection mirror and an output coupling mirror.

FIG. 2 is a diagram showing the configuration of a resonator of this conventional laser oscillation device. In the figure, the laser beam 21 is reflected by a total reflection mirror 22.
and is output through the output coupling mirror 23. Laser tube 24
The laser beam 25 inside is bent by folding mirrors 26 and 27.

The laser gas flows through the gas inlet 28.2 as shown by the arrow.
9. Gas flows into the laser tube 24 through gas outlets 32 and 31 and flows out through gas outlets 32 and 33.

When the laser gas pressure in the laser tube 24 is kept uniform, the laser gas pressure in the path (folding mirror section) 34 extending from folding mirrors 26 to 27 is also kept uniform, and no laser gas flows through this folding mirror section 34. .

[Problem to be solved by the invention]

However, in the conventional laser oscillation device, there is a difference in tube diameter and path length within each blowing system through which the laser gas circulates, so a pressure difference occurs in the laser gas pressure within the laser tube 24. For this reason,
For example, the portion 3 in front of the folding mirror 26 in the laser tube 24
5 and the immediate rear portion 36 of the folding mirror 27. Therefore, a flow of laser gas is generated in the folding mirror section 34, which is originally an optical path.

On the other hand, the laser gas contains dust, oil mist, etc. from the mechanical part when circulating in the ventilation system.

In addition, there was a problem in that the optical components (folding mirrors 26 and 27) were exposed to the laser gas, and the surfaces were contaminated, resulting in a decrease in laser output.

The present invention has been made in view of these points, and it is an object of the present invention to provide a laser oscillation device that can prevent a decrease in laser output and provide stable laser output.

[Means to solve the problem]

In order to solve the above-mentioned problems, the present invention provides a laser oscillation device that is a multi-folding type high-speed axial flow laser in which the optical axis is folded in multiple stages using a folding mirror in addition to a total reflection mirror and an output coupling mirror. Provided is a laser oscillation device, comprising: a folding mirror portion for folding back the optical axis; and at least one laser gas nozzle provided in parallel with the folding mirror portion. be done.

[Effect]

Since the laser gas nozzle is provided in parallel with the folding mirror section, the laser gas pressure within the laser tube is made uniform, and the flow of the laser gas through the folding mirror section is reduced. Therefore, the optical component is not exposed to the flow of laser gas and the surface is not contaminated. Therefore, a decrease in laser output can be prevented.

〔Example〕

Hereinafter, one embodiment of the present invention will be described based on the drawings.

FIG. 1 is a diagram showing the configuration of a resonator of a laser oscillation device according to the present invention.

The resonator is of the multiple folded high speed axial flow type.

Two sets of two discharge tubes 1 in series are arranged in parallel. These two sets of discharge tubes 1 arranged in parallel are connected by a folding mirror section 2.

The folding mirror section 2 is an optical path formed across the folding mirrors 3 and 4, and the laser beam 5 within the resonator is bent by the folding mirrors 3 and 4 of the folding mirror section 2.

When a high frequency voltage is applied from a laser power source (not shown), the laser gas inside the discharge tube 1 generates a discharge and is excited. The total reflection mirror 6 and the output coupling mirror 7 provide energy emitted from the excited laser gas molecules, oscillate and amplify the laser beam 5, and output a part of it to the outside as a laser beam 8 from the output coupling mirror 7. do.

The laser gas flows through the gas inlet 9. as shown by the arrow in the figure.
10. Gas flows into the discharge tube 1 through gas outlets 11 and 12, and flows out through gas outlets 13 and 14. The gas velocity within the discharge tube 1 is approximately 200 m/sec.

The bypass 15 is provided in parallel with the folding mirror section 2 and has open ends at 16 between the gas inlet 10 and the folding mirror 3 and between 17 between the gas inlet 11 and the folding mirror 4, respectively. The diameter of the bypass 15 (for example, 20φ) is set larger than the diameter of the folding mirror portion 2 (for example, 12φ). Therefore, the air blowing resistance of the bypass 15 is extremely small compared to the air blowing resistance of the folding mirror section 2.

For this reason, even if a difference in pipe diameter or path length in each ventilation system (not shown) through which the laser gas circulates causes a difference in laser gas pressure within the resonator, as a result, a pressure difference occurs between the open end sides 16 of the bypass 15 and the Even if a pressure difference occurs also in 17, the flow of laser gas generated by this pressure difference passes through the bypass 15 and does not pass through the folding mirror section 2.

Therefore, the folding mirrors 3 and 4 of the folding mirror unit 2 are not exposed to the laser gas, and their surfaces are contaminated by dust, oil mist, etc. from the mechanical parts contained in the laser gas when the laser gas circulates in the V transmission system. Not done.

Therefore, it is possible to prevent the laser gas output from decreasing, which conventionally occurs due to contamination of the surfaces of the folding mirrors 3 and 4, and to stably obtain the laser gas output. Furthermore, since the maintenance period for optical components such as the folding mirrors 3 and 4 in the resonator is extended, the reliability of the laser oscillation device can be improved.

In this embodiment, the maintenance period was 2000 hours in the conventional technology, but it was 4600 hours, which is about 2.3 hours.
It was attempted to be twice as long.

In the above explanation, the bypass is provided on the folding mirror side, but it can also be provided on the total reflection mirror and output coupling mirror side.

Further, the number of discharge tubes and the shape of their coupling can be increased depending on the purpose of the laser oscillation device.

〔Effect of the invention〕

As described above, in the present invention, since the laser gas bypass is provided in parallel with the folding mirror section, the laser gas pressure within the resonator is made uniform, and the flow of the laser gas through the folding iron section is reduced. Therefore, the optical component is not exposed to the flow of laser gas and the surface is not contaminated. Therefore, it is possible to prevent the laser output from decreasing and to stably obtain the laser output.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the configuration of a resonator of a laser oscillation device of the present invention, and FIG. 2 is a diagram showing the configuration of a resonator of a conventional laser oscillation device. 2. 3.4 9.10. 13.14 Folding mirror unit Folding mirror Total reflection mirror Output coupling mirror 11.12 Gas outlet bypass Gas inlet

Claims (3)

[Claims] (1) In a laser oscillation device that is a multi-folding type high-speed axial flow laser in which the optical axis is folded in multiple stages using a folding mirror in addition to a total reflection mirror and an output coupling mirror, folding in which the optical axis is folded back by the folding mirror A laser oscillation device comprising: a mirror; and at least one laser gas bypass provided in parallel with the folding mirror. (2) The laser oscillation device according to claim 1, wherein the laser gas bypass is provided immediately before the folding mirror. (3) The laser oscillation device according to claim 1, wherein the laser gas bypass has extremely small air blowing resistance compared to the folding mirror.