JP3064099B2 - Optical resonator of orthogonal gas laser oscillator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in an optical resonator of an orthogonal gas laser oscillation device.

[0002]

2. Description of the Related Art A folded optical path in an optical resonator of an orthogonal gas laser oscillation device is provided on a plane parallel to a gas flow because a discharge gap is generally narrow as shown in FIG. When a high-frequency discharge is used to excite the laser beam, a relatively stable discharge can be obtained even if the discharge gap is widened.
Some are provided on a plane inclined at 5 degrees.

In the case where the folded optical path is provided on a plane parallel to the gas flow, the output is large, but the transverse mode pattern of the laser beam (hereinafter simply referred to as mode pattern) is shown in FIG.
It becomes asymmetric as shown in FIG. When the folded optical path is provided on a plane perpendicular to the gas flow, the mode pattern is relatively symmetric but the output is small.

[0004]

As described above, when the folded optical path is provided on a plane parallel to the gas flow, the mode pattern becomes asymmetric. One of the reasons is that the temperature of the gas flow is reduced. However, as shown in FIG. 4 (c), the discharge increases from the entrance to the exit of the discharge part due to the discharge, the refractive index of light changes, and the phase of light passing through this part changes according to the distance from the entrance. It seems to be. When the folded optical path is provided on a plane perpendicular to the gas flow, the mode pattern is relatively symmetrical because the distances from the entrance of the discharge unit are equal. The present invention has been made in view of such a point, and an optical resonator of an orthogonal gas laser oscillation device capable of reducing the asymmetry of the mode pattern by rotating the optical axis of the folded optical path by a fixed angle. It is intended to provide.

[0005]

According to a first aspect of the present invention, there is provided a gas laser oscillating apparatus in which a gas flow direction of a laser gas and a longitudinal direction of an optical resonator are orthogonal to each other. The rear mirror and the plurality of folded mirrors provided at the end of the first plane forming the predetermined angle α with the gas flow including the folded optical path of the above, and the end of the second plane parallel to the first plane including the plurality of folded optical paths. The output mirror provided and the plurality of return mirrors are provided, and a third plane perpendicular to the longitudinal direction of the optical resonator, the optical path direction of which is provided at an end on the same side of the first plane and the second plane. The mirror comprises a first optical path plane changing mirror that changes 45 degrees with respect to the first plane and the second plane, and a second optical path plane changing mirror.

According to a second aspect of the present invention, there is provided a gas laser oscillating device in which a gas flow direction of a laser gas and a longitudinal direction of an optical resonator are orthogonal to each other. A rear mirror and two folded mirrors provided at the ends of the four planes, and an output mirror and two folded mirrors provided at the end of the fifth plane including a U-shaped folded optical path and intersecting at right angles to the fourth plane In the sixth plane perpendicular to the longitudinal direction of the optical resonator, the optical path direction is provided on the same side end of the fourth plane and the fifth plane with respect to the fourth plane and the fifth plane, respectively. The mirror comprises a fourth optical path plane changing mirror for changing the angle by 45 degrees and a fifth optical path plane changing mirror.

[0007]

According to the structure described above, the optical axis of the first aspect of the present invention is rotated by 90 degrees by the mirror for changing the optical path plane, and the second aspect of the present invention is further rotated by 180 degrees by the folded mirror in the U-shape arrangement. Therefore, the asymmetry of the mode pattern based on the difference between the upstream and downstream distances of the gas flow is reduced, and the mode becomes lower. In addition, since the gas flow is used effectively, the laser output increases.

[0008]

Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1A shows the first embodiment in which the first plane and the second plane form a gas flow at a predetermined angle α of 90 degrees. As shown, the rear mirror Mr, the first folded mirror Mb1, and the second folded mirror Mb are provided at the end of the first plane S1.
2 and a first optical path changing mirror Mp1 are arranged, and the optical path is Z-shaped. Further, a second optical path surface changing mirror Mp2, a third folded mirror Mb3, a fourth folded mirror Mb4, and an output mirror Mo are arranged at the end of the second plane S2, and the optical path is similarly Z-shaped.

The first optical path changing mirror Mp1 and the second optical path changing mirror Mp2 have a first plane S1 and a second plane S, respectively.
2 is a third plane S perpendicular to the longitudinal direction of the optical resonator.
Within 3, the first plane S 1 and the second plane S 2 are respectively changed by 45 degrees, guided to the mating plane, and the optical paths of both planes are respectively rotated by 45 degrees about the optical axis.

FIG. 2B shows a fourth plane S4 according to the second aspect of the present invention.
, The case where the predetermined angle β formed by the fifth plane S5 and the gas flow is 45 degrees. As shown, a rear mirror Mr, a fifth folded mirror Mb5, a sixth folded mirror Mb6, and a third optical path surface changing mirror Mp3 are arranged at the end of the fourth plane S4, and the optical path has a U-shape. I have. Further, a fourth optical path surface changing mirror Mp4 and a seventh folded mirror M are provided at the end of the fifth plane S5.
b7, an eighth turn mirror Mb8, and an output mirror Mo are arranged, and the optical path is also U-shaped.

The third optical path changing mirror Mp3 and the fourth optical path changing mirror Mp4 are respectively composed of a fourth plane S4 and a fifth plane S4.
5 is the sixth plane S perpendicular to the longitudinal direction of the optical resonator.
In FIG. 6, the fourth plane S4 and the fifth plane S5 are each changed by 45 degrees with respect to the other plane, and the optical paths of both planes are rotated by 45 degrees about the optical axis.

FIG. 2 shows the first embodiment of the present invention.
This is an embodiment in the case where the predetermined angle α that the plane makes the gas flow is 0 degrees, that is, parallel. FIG. 2 shows FIG.
Since it is rotated by 0 degrees, the description of the mirror of each part is omitted.

FIG. 3 shows the rotation of the optical axis of the optical path of each plane in the three embodiments in the direction of the arrow. FIG. 1A is a cross section of the optical path shown in FIG. 1A. In a Z-shaped optical path (hereinafter, referred to as a Z path) on the first plane, the optical axis does not rotate relatively, so the arrows are directed in the same direction, for example, the horizontal right direction. However, since the optical axis is rotated by 90 degrees when moving to the Z path on the second plane, both the arrows are vertically upward in the Z path on the second plane. FIG. 2B is a cross-sectional view of the optical path of FIG. 2, and similarly to the above, the horizontal rightward arrow attached to the optical axis of the Z path on the first plane is rotated by 90 degrees in the Z path on the second plane. It goes vertically upward. FIG. 1C is a cross-sectional view of the optical path of FIG. 1B. The vertical downward arrow attached to the rear mirror Mr on the fourth plane changes the third optical path surface by a U-shaped path (optical path) on the same plane. The mirror Mp3 goes vertically upward, goes to the fifth plane, goes to the horizontal left direction at the fourth optical path surface changing mirror Mp4, and goes to the horizontal right direction at the output mirror Mo by the U-shaped path on the same plane, and makes one rotation. .

As described above, when the optical axis is rotated, the symmetry of the mode pattern is improved, and a low-order mode is easily generated. The laser light output from these resonators is 45
This is a linear deflection in degrees and can easily be changed to a circular deflection.

[0015]

As will be understood from the above description, the present invention has the structure described in the claims.
A mode pattern with good symmetry can be obtained. In addition, a low-order mode can be obtained. Further, the laser output is increased because the gas flow is effectively used. Therefore, the processing accuracy can be improved in the cutting processing or the like.

[Brief description of the drawings]

FIG. 1 (a) is an explanatory view of an embodiment according to claim 1 of the present invention. FIG. 1B is an explanatory view of a second embodiment of the present invention.

FIG. 2 is an explanatory diagram of another embodiment of claim 1 of the present invention.

FIG. 3 is an explanatory view showing rotation of an optical axis of an optical path on each plane according to the embodiment of the present invention.

FIG. 4 is an explanatory diagram of modes of an optical resonator of a conventional orthogonal gas laser oscillation device.

[Explanation of symbols]

 Mo Output Mira Mr Reamilla Mb1 to Mb8 Folded Mira Mp1 to Mp4 Optical Path Change Mira

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H01S 3/08

Claims (2)

(57) [Claims] In a gas laser oscillation device in which a gas flow direction of a laser gas and a longitudinal direction of an optical resonator are orthogonal to each other, the gas laser oscillation device is provided at an end of a first plane including a plurality of folded optical paths and forming a predetermined angle α with the gas flow. A rear mirror, a plurality of folded mirrors, an output mirror and a plurality of folded mirrors provided at ends of a second plane parallel to the first plane and including a plurality of folded optical paths, and the same side of the first plane and the second plane. A first optical path plane changing mirror provided at each end of the first optical path plane and changing the optical path direction by 45 degrees with respect to the first plane and the second plane in a third plane perpendicular to the longitudinal direction of the optical resonator; An optical resonator of an orthogonal gas laser oscillation device comprising a second optical path plane changing mirror. 2. A gas laser oscillating device in which a gas flow direction of a laser gas and a longitudinal direction of an optical resonator are orthogonal to each other, provided at an end of a fourth plane including a U-shaped folded optical path and forming a predetermined angle β with the gas flow. A rear mirror and two folded mirrors, an output mirror and two folded mirrors provided at an end of a fifth plane including a U-shaped folded optical path and intersecting at right angles to the fourth plane; Fourth optical paths respectively provided at the same side end of the fifth plane and changing the optical path direction by 45 degrees with respect to the fourth plane and the fifth plane in a sixth plane perpendicular to the longitudinal direction of the optical resonator. An optical resonator of an orthogonal gas laser oscillation device comprising a plane changing mirror and a fifth optical path plane changing mirror.