JPS61284984A - Gas laser - Google Patents

Abstract

PURPOSE:To obtain a laser beam of homogeneous and stable mode by constructing the components of the flow of gas of the direction perpendicular to an optical axis of the components of the flow of the gas reversely at least two positions on an optical axis. CONSTITUTION:A high frequency high voltage is applied by a high frequency high voltage source 6 between metal electrodes 2 and 3. Since glasses 4, 5 are coated on the electrodes 2, 3, a voiceless discharge 7 is generated between the electrodes. A housing 1 is partitioned by a partition plate 16 to the right and left sides, the gas is passed by a blower 88 through a discharge space beforehand perpendicular to the paper shown by 12 in the right section, and passed by a blower 8 in a discharge space in the depthwise direction perpendicular to the paper shown by 11 in the left section. In other words, the gas flows are reverse in the right and left sides. While the gas is circulated, it is cooled by a heat exchanger 10, uniform exciting space of the light is obtained to provided a stable and homogeneous laser beam.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a gas laser device, particularly to improving the quality of its laser beam mode.

[Conventional technology]

Figure 7 (a) is a cross-sectional configuration diagram showing a conventional silent discharge type gas laser device, and @T figure (b) is a
- It is an arrow view from the B line.

In the figure, (1) is a housing, inside of which laser gas is filled. +21 +31 are opposing metal electrodes.

+41, (51 is metal polarization (2), (31 is each coated glass, (6) is a high frequency high voltage power supply, (7) is a silent discharge generated between the electrodes, (8) is a blower, ( 9) is a plate with holes for installing the blower, (II
is a heat exchanger, αυ is a symbol indicating the direction of gas flow generated by the blower (8), (13 is a partial reflection mirror, (4) is a total reflection mirror, and α9 is a laser beam.

(150) is the optical axis of the laser beam.

Next, the operation will be explained. A high frequency high voltage is applied between the metal electrode (2) and the metal electrode (3) from a high frequency high voltage power source (6). Since the metal electrode +21, (3) is coated with glass (41, (5)), a silent discharge (7) occurs between the electrodes.The gas is supplied by a blower (
8) into the discharge space (7), and the heat exchanger 0
1 and then sent into the discharge space (7) again. The resonator consists of a total reflection mirror I and a zero partial reflection mirror αj,
The light is amplified by going back and forth in the silent discharge excited by the laser, and when it exceeds a certain value, the laser beam a! 9 and taken out to the outside.

[Problem that the invention seeks to solve]

The conventional gas laser device is configured as described above.

(1) The temperature rise of the gas caused by the discharge causes a temperature distribution in the direction of the gas flow within the resonator space, which results in a non-uniform refractive index distribution in the space.

(2) The laser-excited gas is caused to flow by the gas flow, resulting in a gain distribution such that the amplification factor, ie, the gain, of the laser beam is maximum near the downstream side.

Due to the above two reasons, anisotropy occurs in the gas flow direction within the resonator space, resulting in a problem that a homogeneous laser beam cannot be obtained.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a gas laser device that produces a homogeneous and stable laser beam mode.

[Means for solving problems]

The gas laser device according to the present invention is configured such that among the gas flow components, flow components in a direction perpendicular to the optical axis are in opposite directions at at least two locations on the optical axis.

[Effect]

The gas flow in this invention is as follows when viewed from the optical axis direction:
Since there are multiple gas flows in opposite directions, the temperature distribution and gain distribution caused by the gas flows cancel each other out.

[Embodiments of the invention]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 (al is a cross-sectional configuration diagram showing a silent discharge gas laser device according to an embodiment of the present invention, and FIG. 1 (bl is a view taken from line B-B in FIG. 1 (81), Figure 1 (
El is a view taken from the O-0 line in FIG. 1(a). In the figure, the same reference numerals as in FIG. 7 indicate the same or corresponding parts. (88) is a blower whose rotation direction is different from that of blower (8);
al is the flow direction of gas generated by the blower (8).

(I7J is the flow direction of the gases generated by the blower (88), and the flow direction of these gases (lH3 is the direction of the optical axis (15
The flow components in the direction orthogonal to 0) are in opposite directions. (1e is a partition board.

Next, the operation will be explained. Metal electrode f21, (3
1, a high frequency high voltage is applied from a high frequency high voltage power supply (6). Metal electrode +21, (Glass (4) on 31.

(5) is coated, a silent discharge (7) occurs between the electrodes. The inside of the casing (1) is divided into left and right parts by a partition plate αe, and in the right part in FIG. It passes through the inside.

In the left part, the gas is passed through the discharge space by the blower (8) in a direction perpendicular to the plane of the paper shown at αυ. In other words, the gas flow directions are opposite to each other on the left and right sides. Each gas is cooled by a heat exchanger system during circulation.

The resonator consists of a partial reflection mirror αj and a total reflection mirror α4.

The light traveling back and forth between both reflecting mirrors is amplified by the gas excited by the silent discharge. in the direction of gas flow.

There is a temperature distribution and a gain distribution in the resonator space.

Because the direction of gas flow differs between the left and right discharge parts, the temperature distribution changes for the light that travels back and forth within the resonator.

It feels like there is no gain distribution, and it is amplified homogeneously,
Laser beam a! 9 and taken out to the outside.

In the above embodiment, as shown in FIG. 1(e), the gas flow system circulates in the order of discharge space → heat exchanger → blower → discharge space in the left part, and in the right part. In the above, we have shown the system that circulates in the order of discharge space → blower → heat exchanger → discharge space, but as shown in Figure 2 or Figure 3, the circulation path is the same in the right and left parts. A blower and a heat exchanger may be placed in the area, or the electrodes may be divided to correspond to areas where the gas flow direction is different, as shown in Figure 4, or the discharge may be limited to the central area using the same electrode. . By doing this, the opposite gas flow direction (Iυ
, (The instability of discharge caused by stagnation due to I'IJ can be reduced.

Further, as shown in FIG. 5, the electrodes may be divided and arranged so that the vicinity of the downstream side of the discharge is on the optical axis (150), or the discharge surface may be limited by the same electrode. in general.

Since the amplification factor is maximum near the downstream side of the gas, a high-power laser beam can be extracted by arranging the optical axis near this point.

As an effect similar to that shown in Fig. 5 above.

As shown in FIG. 6, the electrodes may be arranged diagonally. Also, in the above embodiment, silent discharge was used.
The same effects as in the above-mentioned embodiments can also be achieved with a gas laser device that uses discharge by ordinary DC glow discharge, microwave discharge, or any combination thereof.

A gas laser device using a highly repetitive pulsed discharge also produces the same effect as the above embodiment without changing the situation in which temperature distribution occurs in the discharge direction.

〔Effect of the invention〕

As described above, according to the present invention, among the components of the gas flow, the component of the flow in the direction perpendicular to the optical axis.

Since the excitation space is small on the optical axis (both directions are opposite to each other at two locations), a homogeneous excitation space can be obtained for zero elements, and a stable and homogeneous laser beam can be obtained.

[Brief explanation of drawings]

FIG. 1 (aHbl(e)) is a cross-sectional configuration diagram showing a gas laser device according to an embodiment of the present invention, and FIG.
) is a view taken from the low B line and the O-0 line; FIG. 2 is a view taken from the a-O line showing a laser device according to another embodiment of the present invention; FIG. ) are a cross-sectional configuration diagram showing a gas laser device according to another embodiment of the present invention, and a third
FIG. 4 is an arrow view taken from line BB in figure (a). 5 and 6 are views taken along the C-O line, respectively, showing gas laser apparatuses according to other embodiments of the present invention. FIGS. 7(a) and 7(b) are a cross-sectional configuration diagram showing a conventional gas laser device and a view taken along the line BB of FIG. 1), respectively. In the figure, (2+(3) is the electrode, (6) is the high frequency high voltage power supply s (7) I! Silent radio 1i, (8) (88
) C blower, (II is the heat exchanger, t1υQ2 is the gas flow direction, aS is the laser beam, (150) is the optical axis, and Qe is the diaphragm plate. In Figure 9, the same symbols are the same or equivalent parts. O indicating

Claims (5)

[Claims] (1) In a device that flows gas between opposing electrodes and applies a high voltage between the electrodes to generate a discharge between the electrodes and excite the laser, the components of the gas flow that correspond to the optical axis A gas laser device characterized in that flow components in orthogonal directions are in opposite directions at at least two locations on the optical axis. (2) The gas flow system consists of a discharge space formed between the electrodes;
2. The gas laser device according to claim 1, wherein the gas laser device comprises a blower and a heat exchanger, and the gas flows in mutually opposite directions flow through the discharge space, the blower, and the heat exchanger in the same order. (3) Corresponding to areas where gas flow directions are different from each other,
3. The gas laser device according to claim 1, wherein the electrode is divided into at least two parts. (4) The gas laser device according to any one of claims 1 to 3, wherein the electrode is arranged so that the vicinity of the gas downstream of the discharge is on the optical axis. (5) The gas laser device according to any one of claims 1 to 4, wherein the electrode is arranged obliquely to the optical axis.