JPH04356982A - Gas-laser tube device - Google Patents

Abstract

PURPOSE:To provide a gas.laser tube device which can accurately stabilize a laser output and an radiating direction of a laser beam. CONSTITUTION:An inclination of a horizontal direction of either a highly reflecting mirror 21 or an output mirror 22 is moved to a position for obtaining a maximum laser output by driving X-axis regulating motors 25, 27, and an inclination of a vertical direction of the mirror is then so moved to a position for obtaining a maximum laser output by driving Y-axis regulating motors 26, 28. Then, both the reflecting mirror and the output mirror are simultaneously or alternately moved by the same amount in the same direction by rotatably driving the X-axis regulating motors to decide the position where the laser outputs exhibit a maximum value, and, similarly, simultaneously or alternately moved by the same amount in the same direction by rotatably driving the Y-axis regulating motors to decide the position where the laser outputs exhibit a maximum value.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas laser tube device, and more particularly to an improvement in a mirror adjustment mechanism thereof.

0002

[Prior Art] A gas laser tube device includes a gas laser tube provided with a discharge path, a resonator frame with resonator mirrors mounted on both sides of the discharge path of the laser tube, and a power supply device. There is. In order to stabilize the laser output, a laser tube device is also known that includes a control device that splits a part of the output laser light with a beam splitter, receives it with a sensor, and feeds it back to the power supply device.

0003

During operation, heat generated from the laser tube causes the resonator frame to expand, contract, or otherwise deform in an axisymmetric manner. This causes a shift in the optical parallelism of both mirrors, resulting in a decrease in laser output or a shift in the laser beam emission direction. Further, at the initial stage of laser oscillation, it takes a certain amount of time for the resonator frame to become thermally stable, so it may take several minutes to several hours for the laser output and beam radiation direction to become stable. Note that in the case of a method in which the power supply device is controlled by receiving the laser output with a sensor, it is possible to stabilize the laser output, but fluctuations in the beam radiation direction cannot be corrected, and a decrease in efficiency is also unavoidable.

SUMMARY OF THE INVENTION An object of the present invention is to provide a gas laser tube device that can eliminate the above-mentioned disadvantages and stabilize the laser output and the radiation direction of the laser beam with high precision.

[0005]

[Means for Solving the Problems] The present invention provides for horizontal direction adjustment of either a high reflection mirror placed on one side across the discharge path of a gas laser tube and an output side mirror placed on the other side. Move the tilt to the position where the maximum laser output is obtained by driving the X-axis adjustment motor, and then move the vertical tilt of this same mirror to the position where the maximum laser output is obtained by driving the Y-axis adjustment motor. Then, both the high reflection mirror and the output mirror are moved by the same amount in the same direction simultaneously or alternately by the rotational drive of each X-axis adjustment motor to determine the position where the laser output shows the maximum value, Next, both the high reflection mirror and the output mirror are configured to be moved by the same amount in the same direction simultaneously or alternately by the rotational drive of each Y-axis adjustment motor to determine the position where the laser output reaches its maximum value. This is a gas laser tube device.

[0006]

[Operation] According to the present invention, even if the temperature inside or around the laser tube device changes, the optical parallelism of the resonator mirrors placed on both sides of the discharge path can be maintained in an optimal state with high precision. can be controlled and therefore the laser power and laser
Operation characteristics with extremely stable beam radiation direction can be obtained.

[0007]

Embodiments Hereinafter, embodiments will be described with reference to the drawings. Note that the same parts are represented by the same symbols.

The gas laser tube apparatus shown in FIGS. 1 to 4 has the following configuration. A laser tube 11 having a gas discharge path inside has an extension tube 12 with Brewster windows on both sides,
13 and assembled on the support base 14.
Fixed. Fixing plates 16 and 17 are installed vertically on both sides of the resonator frame 15, and a plurality of leaf springs 18 are attached to the fixed plates 16 and 17.
The movable plates 19 and 20 are respectively held via the movable plates 19 and 20. A high reflection mirror 21 is fixed to the center of one movable plate 19, and an output mirror 22 is fixed to the center of the other movable plate 20. Furthermore, motor support plates 23 and 24 are fixed to the support base 14, and two pulse motors 25 and 26, and two pulse motors 27 and 28 are respectively attached to these.
is installed. Pulse motors 25 and 26 connected to one movable plate 19 are an X-axis adjustment motor and a Y-axis adjustment motor that move the high reflection mirror 21 in the X-axis and Y-axis directions. Further, pulse motors 27 and 28 connected to the other movable plate 20 move the output mirror 22 to
These are an X-axis adjustment motor that moves in the axial and Y-axis directions, and a Y-axis adjustment motor. Rotation shaft 25 of each pulse motor
a, 26a, and 27a, 28a are mirror tilt coarse adjustment screws 25b, 26b, and 27b, 28b, respectively.
It is connected to the movable plate 19,20 via. In front of the output mirror, there is a beam splitter 29 and a photo-optical
A laser output detector 30 consisting of a cell for detecting laser light output power is provided. The laser output detector 30 includes an amplification converter 31 that amplifies the output electrical signal and converts it from an analog signal to a digital signal, and a laser output increase/decrease determination device 32 that determines the tendency of increase/decrease in the laser output power. A drive control device 33 that adjusts and drives each pulse motor in response to an output electric signal from this discrimination device is connected, and these are electrically connected to drive and control each pulse motor. Although not shown, a power supply device for applying an operating voltage to the cathode and anode of the laser tube is provided and electrically connected to the cathode and anode of the laser tube.

Each movable plate 19, 20 is provided with pivots 19a, 20a so that one of the four corners at the bottom in the figure serves as a fixed reference point. As shown in FIG. 4, the high reflection mirror 21 is connected to the
5, the inclination in the horizontal direction (X-X) is finely adjusted about the pivot 20a. Also, by rotation of the Y-axis adjustment pulse motor 26, the pivot 20a
The inclination in the vertical direction (Y-Y) is finely adjusted using the reference axis. Similarly, the output mirror 22 is
By the rotation of the axis adjustment pulse motor 27, the pivot 1
The inclination in the horizontal direction (X-X) is finely adjusted using 9a as the reference axis. Further, by the rotation of the Y-axis adjustment pulse motor 28, the vertical direction (Y-Y
) is finely adjusted. In addition, each mirror has the above-mentioned mirror tilt coarse adjustment screws 25b, 26b, and 27b,
28b performs coarse adjustment.

[0010] Each mirror exhibits a maximum laser output value when each part of the gas laser tube device is thermally stable;
In addition, adjustment is made by the coarse tilt adjustment screw of each mirror and each pulse motor so that the radiation direction of the output laser beam matches the specified direction, and this becomes the reference position. Note that when the radiation direction of the laser beam matches the specified direction, the laser output detector 30 displays the maximum laser beam.
When the laser power is incident and the beam emission direction is shifted, the laser power incident on the detector is reduced accordingly.

Therefore, if for some reason one or both of the mirrors deviates from the optimal reference position, that is, the position where the resonator mirrors are optically parallel, automatic adjustment is performed according to the following operation program. is configured to be That is, first, the horizontal tilt of either the high reflection mirror or the output mirror is repeatedly moved to a position where the maximum power is obtained from the laser output detector 30 by driving the X-axis adjustment pulse motor. Depending on the degree of inclination of the mirror, the laser power detected by the detector 30 changes as shown in FIG. , and in response to the output signals thereof, a control signal is given from the drive control device 33 to the pulse motor to continue rotating in the same rotational direction. When the laser output exceeds the maximum value and tends to decrease, the laser output increase/decrease determination device and its output signal are received, and the drive control device gives a control signal to the pulse motor to reverse the rotation direction, and this is repeated until the optimum rotation direction is reached. It is fixed at position O. Next, the vertical inclination of the same mirror is adjusted to the optimum position by movement control of the Y-axis adjustment pulse motor using the same control program as above. Next, both the high reflection mirror and the output mirror are repeatedly moved by the same amount in the same direction simultaneously or alternately by rotational driving of each X-axis adjustment pulse motor. Thereby, similarly to the above case, the position where the laser output shows the maximum value is determined. Next, both the high reflection mirror and the output mirror are repeatedly moved by the same amount in the same direction simultaneously or alternately by the rotational drive of each Y-axis adjustment pulse motor to determine the position where the laser output reaches its maximum value. . This allows both resonator mirrors to be returned to optical parallelism, maximum laser power, and defined laser beam emission direction.

[0012] If a program is set to repeat the above operations two or more times, for example, several times, the optimum state can be set with even higher precision. Considering the numerical calculation and control speed of modern computers, the time required for this can be several seconds or less. If a program is set to automatically repeat this mirror fine adjustment control in a fixed cycle, the laser output and laser beam radiation direction can be stabilized from the beginning of the laser tube device's oscillation startup. .

[0013]

As described above, according to the present invention, it is possible to obtain a gas laser tube device having extremely stable operating characteristics in terms of laser output and laser beam radiation direction.

[Brief explanation of drawings]

FIG. 1 is a schematic side view showing an embodiment of the invention.

FIG. 2 is a top view of the same.

FIG. 3 is a left side view of FIG. 1.

FIG. 4 is a right side view of FIG. 1.

FIG. 5 is a characteristic diagram showing the relationship between mirror inclination and laser output.

[Explanation of symbols]

11... Gas laser tube, 21... High reflection mirror, 22... Output mirror, 25, 27... X-axis adjustment motor, 26, 2
8...Y-axis adjustment motor, 30...sensor, 31...amplification converter, 32...laser output increase/decrease discrimination device, 33...motor drive control device.

Claims (1)

[Claims] [Claim 1] A high-reflection mirror placed on one side of the discharge path of the gas laser tube and an output side mirror placed on the other side, and an X for adjusting the horizontal inclination of each of these mirrors.
An axis adjustment motor, a Y-axis adjustment motor that adjusts the vertical inclination of each mirror, a laser output detector that detects laser light output, and receives electrical signals from this detector to determine trends in increases and decreases in the laser output. a laser output increase/decrease discrimination device, a drive control device that adjusts and drives the X-axis adjustment motor and the Y-axis adjustment motor in response to electric signals from the discrimination device, and is connected to supply energizing power to the laser tube. In the gas laser tube apparatus, the horizontal tilt of either the high reflection mirror or the output mirror is controlled by driving an X-axis adjustment motor to obtain the maximum laser output. Then move the same vertical tilt of this mirror to the position where the maximum laser output is obtained by driving the Y-axis adjustment motor, and then move both the high reflection mirror and the output mirror, By rotationally driving each X-axis adjustment motor, move the same amount in the same direction simultaneously or alternately to determine the position where the laser output reaches the maximum value, and then similarly move both the high reflection mirror and the output mirror to each Y A gas laser tube device characterized in that it is configured to move simultaneously or alternately by the same amount in the same direction by the rotational drive of a shaft adjustment motor to determine the position where the laser output shows the maximum value.