JPS63110683A - Gas laser oscillator - Google Patents

Abstract

PURPOSE:To obtain a stable laser output by causing a folded part of an optical axis to be made of a folded block having a passage of a gas flow rate that is equal to that of an electric discharge part as well as a folded reflecting mirror. CONSTITUTION:A gas inflow block 2a of folded reflecting mirror sides 7 and 7a as well as a folded mirror block 8 are incorporated into a folded block 14. The folded block 14 is equipped with the folded reflecting mirrors 7 and 7a that make up a folded part of an optical axis 4; besides, it is provided by a folded passage 13 (shadowed part) so that a gas can flow at a flow rate that is equal to that in a discharge tube 1. Laser beams are amplified along the optical axis 4 but the inside is free of stagnation of the gas because the whole inside is a flow route of a circulating gas. Thus, there is no possibility that the gas is heated by the laser beams and output characteristics of the laser beams can be maintained constant, regardless of time and then a stable laser output is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a gas laser oscillator that can provide stable laser output.

[Conventional technology] FIG. 2 is a schematic diagram of a conventional gas laser oscillator.

In the figure, reference numeral 1 denotes a discharge tube installed between gas inflow blocks 2, 2a on both sides and a gas outflow block 3 in the center, and is installed so as to form two parallel optical axes 4. A total reflection mirror 5 and a partial reflection mirror 6 are attached to the outer end of one gas inflow block 2 corresponding to each optical axis 4, and the outer end of the other gas inflow block 2a is attached to a A folding mirror block 8 having folding reflectors 7, 7a is attached to form a section.

Reference numeral 9 denotes a blower for gas circulation, which is equipped with a heat exchanger 310.10a on the inlet and outlet sides, and gas inlet pipes 11.11, respectively.
It is connected to the gas inlet blocks 2 and 2a through the gas inflow pipe 12, and to the gas outflow block 3 through the gas outflow pipe 12.

Next, the operation will be explained.

The laser gas flows in the direction of arrow a by the circulation blower 9,
After exiting the heat exchanger 10, the gas passes through the gas inflow pipes 11° and 11a, enters each discharge tube 1 through the gas inflow blocks 2 and 2a on both sides, and then exits the discharge tube 1 and flows out from the gas outflow block 3 in the center. It reaches the circulation blower 9 via the pipe 12 and the heat exchanger 10a and makes a complete circuit. During this gas circulation flow, the excited gas molecules are subjected to a discharge action in the discharge tube 1 and undergo stimulated emission by the total reflection mirror 5, folding reflection mirrors 7 and 7a, and partial reflection mirror 6, generating laser light 15. .

[Problems to be Solved by the Invention] Since the conventional gas laser oscillator is configured as described above, the folding reflector 7. "7a side gas inflow block 2
At point a, the laser gas flows in the direction of arrow a, so the passage 13 in the folding mirror block 8 (the shaded part in the figure)
No gas flows through.

Since the laser light is amplified in the direction of the optical axis 4, the gas in the passage 13 is heated by the laser light. Therefore, the temperature of the gas increases, and the self-absorption rate by gas molecules increases, resulting in a decrease in the amplification factor in the passage 13. the result,
As shown by line B in FIG. 3, there was a problem in that the laser output decreased with time.

The present invention has been made to solve these problems, and an object of the present invention is to provide a laser oscillator that can provide stable output.

[Means for Solving the Problems] The gas laser oscillator according to the present invention causes gas to flow in the direction along the optical axis to excite gas molecules in the discharge section, and furthermore, the optical axis is folded at one end of the discharge section. The optical axis folding section is characterized in that the folding section of the optical axis is constituted by a passage having a gas flow rate equivalent to that of the discharge section and a folding block that holds a folding reflector.

[Function] In the present invention, the optical axis is reflected by the folding reflector of the folding block at the folding part of the optical axis, and the gas is made to flow at the same flow rate as the discharge part, so that absorption by the gas is reduced. The effect is suppressed and the laser output is stabilized.

[Example] Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

FIGS. 1(a) and 1(b) are schematic configuration diagrams of an embodiment of the present invention, with FIG. 1(a) being a plan view and FIG. 1(b) being a side view. Note that the same or equivalent parts as shown in FIG. 2 are denoted by the same reference numerals, and the explanation thereof will be omitted.

In this embodiment, the gas inflow block 2a on the side of the folding reflector 7.degree. 7a shown in FIG. 2 and the folding mirror block 8 are integrated into a folding block 14. A folding reflector 7.7'a constituting a folding part of the optical axis 4 is attached to the folding block 14, and a folding passage 13 (the shaded part shown in the figure) is attached to the folding block 14 so that the gas flows at the same flow rate as in the discharge tube 1. ) is provided.

Next, the operation will be explained.

When the laser gas exits the heat exchanger 10 by the circulation blower 9, it flows into two parts, to the gas inflow block 2 and the folding block 14, each passing through the discharge tube 1 to the gas outflow block 3.
It is cooled by the heat exchanger 10a and returned. The operation in the discharge tube 1 is similar to that shown in FIG.

By the way, since the passage 13 in the folding block 14 is a part of the circulation flow path by the circulation blower 9, the gas flows in the same manner as in the discharge tube 1.

The laser beam is amplified along the optical axis 4, but unlike the conventional one, the entire optical axis is a circulating gas flow path, so there is no stagnant part of the gas, and therefore the gas is heated by the laser beam. Never. Therefore, the output characteristic of the laser is kept constant regardless of time, as shown by line A in FIG.

[Effects of the Invention] As described above, according to the present invention, the folding block of the conventional gas inflow block and the folding mirror block is used to configure the folding part of the optical axis as part of the gas circulation path. Since the gas stagnation part is eliminated, the gas is not heated by the laser light, and therefore stable laser output can be obtained.

[Brief explanation of the drawing]

FIGS. 1(a) and 1(b) are schematic configuration diagrams of an embodiment of the present invention, with FIG. 1(a) being a plan view and FIG. 1(b) being a side view. FIG. 2 is a schematic configuration diagram of a conventional example, and FIG. 3 is a diagram showing the output characteristics of the laser. 1...Discharge tube 2.2a...Gas inflow block 3...Gas outflow block 4...Optical axis 5...Total reflection mirror 6...Partial reflection mirror 7.7a...Folded reflection Mirror 8... Turning mirror block 9... Circulation blower 13... Turning passage 14... Turning block In the drawings, the same reference numerals indicate the same or corresponding parts. Agent Patent Attorney Souji Sasaki Figure 2 B Tankai

Claims (1)

[Claims] In a device in which gas is made to flow in the direction along the optical axis to excite gas molecules in a discharge part, and an optical axis folding part is provided at one end of the discharge part, the optical axis folding part is connected to the discharge part. 1. A gas laser oscillator comprising a folding block having a passage with a gas flow rate equivalent to that of , and a folding reflector.