JPS60257189A - Laser - Google Patents

Abstract

PURPOSE:To enable to facilitate the adjustment of the resonator mirror by a method wherein a wedge plate is rotatably fixed on the base plate, which is provided on the end part of the resonator, and a supporting plate, a rotatable wedge plate and holder for the resonator mirror are fixed by superposing. CONSTITUTION:A laser discharge tube 20 is airtightly fixed to a base plate 18 through O-rings and a terminal member 19. Bearings 17 are fitted in the end parts of the base plate 18 and the outer periphery of the base plate 18 is fixed with a retainer 16. The central aperture of a wedge plate 15, one end face of which is being obliquely performed a processing, is fitted in the retainer 16 and the wedge plate 15 is rotatably and airtightly fixed. Subsequently, a supporting plate 14 being provided an aperture on the center thereof, bearings 13, a retainer 12, a wedge plate 11 in the same structure as that of the wedge 15 and a holder 10 for a resonator mirror 3 are fixed by superposing airtightly in order. The inclination angles theta (angles of aperture theta1 and theta2 of the vertical line by coma motion) of the wedge plates are chosen smaller, the set sensitivity is raised and the wedge plates are rotated, thereby enabling to easily hold the surface of the resonator mirror vertically to an optical axis L.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a laser device, and more particularly to a mechanism for adjusting and fixing a resonator mirror or closing window of a laser resonator.

As is well known, a laser resonator consists of a laser medium and a pair of resonator mirrors that face each other with the laser medium in between. Extremely high precision is required for the perpendicularity of the mirror reflecting surface to the optical axis. Maintaining the accuracy of the reflecting mirror over a long period of time is an extremely important issue for the reliability of the laser device.

FIG. 1 is an explanatory diagram showing a conventional resonator mirror adjustment method. As shown in the figure, the conventional method uses a plurality of adjustment screws 1 arranged parallel to the optical axis and a return spring 2 to adjust the tilt of the mirror 3 in a predetermined direction. Ta. However, this method had the following drawbacks.

1) Play may occur between the mirror holder 4 and the adjustment screw 1, causing misalignment.

2) Since the mirror holder 4 is supported by only a few pieces, the mirror holder 4 is deformed by external forces and the mirror holder's own weight, causing misalignment.

3) When adjusting the mirror, the angle of inclination of the mirror caused by the rotation of the adjustment screw 1 is proportional to the pinch of the adjustment tool. Therefore, in order to increase the adjustment sensitivity, screws with a special pitch must be prepared.

4) Fatigue of the return spring 2 causes looseness in the adjustment screw, causing alignment to go out of order.

5) When automating mirror adjustment, a motor for driving the adjustment screw must be installed. However, it is difficult to install the motor in that case.

The present invention has been made in view of the above-mentioned drawbacks of the conventional apparatus, and an object of the present invention is to provide a laser apparatus that can easily adjust the mirror and maintain a stable optical system.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

FIG. 2 is an explanatory diagram showing one embodiment of the present invention. In the same figure, for all examples of internal mirror type gas laser resonators,
Only one of the mirror adjustment mechanisms will be explained.

In the figure, 20 indicates a laser discharge tube, 19 an end block, and 18 a base plate. 17th nin 1 in the figure, 1st
16 is the first retainer, 15 is the first wenge plate, and 14 is the sabot I plate.

Further, in FIG. 1, 31 shows a second bearing, 12 shows a second retainer, 11 shows a second wedge plate, and 10 shows a mirror holder. In the figure, 3 shows a resonator mirror.

As shown in the figure, the laser discharge tube 20 is hermetically fixed to the end block 19 via the O-') 7 pin 17. The end block 19 is hermetically fixed to the base plate 18 via an O-ring.

An inner circumferential portion of a bearing 17 is fixed to an end of the base plate 18, and a first retainer 16 is fixed to an outer circumferential portion of the bearing 17. A first wedge play 1, 15 having an opening in the center and having one end sliced diagonally is fixed to the retainer 16.

Therefore, the wedge plays 1 and 15 are rotated around the optical axis. As described above, the first rotation mechanism is configured. Note that an O-ring is interposed between the joint surface of the base plate 18 and the wedge plate 15 to maintain airtightness.

On the first wedge plate 15 described above is a support plate having an opening in the center!・One end of 14 is airtightly fixed via an O-ring.

The inner peripheral portion of the second bearing 13 is fixed to the other end of the support plate 1/14. A second retainer 12 is fixed to the outer periphery of the bearing 13. the retainer
A second wedge plate 11 having the same structure as the wedge plate 15 is fixed to the wedge plate 12 .

Therefore, wedge plate】1 is Zaport plate 1
Rotated on 4. With the above, the second rotation mechanism is configured. Incidentally, an O-ring is interposed between the joint surface of the support plate 14 and the second wedge plate 11.
Needless to say, airtightness is maintained.

A mirror holder 10 is airtightly fixed onto the second wedge play i.11 via an O-ring. The holder 1
0, a resonator mirror 3 is fixed. Therefore, the mirror 3 is rotated together with the wedge plays 1 and 11.

Next, the adjustment principle of the present invention will be explained based on FIG. The present invention aims to enable the mirror to be adjusted to a specific inclination angle with respect to the axis.

In the figure, wedge plate 15 of the first rotation mechanism
If the perpendicular direction vector on the L axis on the upper surface is taken as 1, πl performs a complete coma movement with respect to the L axis due to rotation. The opening angle θ1 of the top movement is equal to the inclination angle of the wedge plate of the first rotation mechanism.

Furthermore, the upper surface of the wedge plate 11 of the second rotation mechanism (
If R2 is the perpendicular direction vector of the R1 axis (equal to the mirror surface), then R2 makes a coma movement with respect to the R1 axis by rotation, and the opening angle θ2 of the coma movement is the wedge play 1 of the second rotation mechanism. is equal to the inclination angle of

When the first and second rotation mechanisms rotate independently, the inclination angle of R2 with respect to the L axis is 1θ1−θ21≦θ≦1θ1+θ21.

By the way, in a laser resonator, the mirror surface is aligned with the optical axis (L
axis). Therefore, if the vertical deviation angle of 2" to the Z axis due to the structure existing from the base plate 18 to the mirror surface is θ', θ' is corrected by the adjustment mechanism to maintain the mirror surface perpendicular to the optical axis. Must.

In order for θ' to be correctable, 1θ1-θ21≦θ'≦01+θ2 When the accuracy of each component is good and θ'≧0, θ1-θ2≧
If it is 0, there are no problems. That is, θ1≧θ2.

Therefore, the resonator mirror 3 can be adjusted to any inclination angle only when the inclination angles of the two wedge plates are equal.

As detailed above, the present invention has two wedge plates, each of which can be rotated independently.The mirror has two degrees of freedom and can be adjusted in any direction. It is characterized by

In the apparatus configured as follows, the effects listed below are achieved.

1) The first and second rotating mechanisms 1d2 and the wedge play I, which is a rotating part, are each supported by bearings and maintained in rotational capacity. Therefore, the inclination angle of the mirror is maintained by the surface contact between the wedge plate and the bearing, and play is less likely to occur. Therefore, the alignment of the mirror is kept stable.

2) Wedge play 1. Change the angle θ around 1.

The adjustment range of the tilt angle of the mirror surface can be changed. Therefore, by selecting a small value θ, it is easy to increase the adjustment sensitivity.

3) When automating the angle adjustment of the optical system, it is necessary to install a power source such as a pulse motor to transmit power, but in this case, when adjusting the angle by transmitting power to the adjustment point / It has better reproducibility and is more compact than 1'.

In this embodiment, the present invention is coupled to the mirror adjustment mechanism of an internal mirror type laser resonator, but if a cavity placed at Brewster's angle is provided instead of the resonator mirror,
The present invention can also be used as a mechanism for adjusting the closing window of an external mirror resonator.

Next, another embodiment of the present invention will be described based on FIG. 4. The motor shown in the figure is the same as that of the first embodiment in which two pulse motors 21 and 25 are added.

In the figure, the first pulse motor 21 has a base plate 18
Fixed. On the other hand, the outer periphery of the first retainer 16 has chipped teeth, which mesh with the worm gear 23. The worm gear 23 is connected to a drive shaft 22 of a pulse motor 21 via a belt 24.

Therefore, by driving the first pulse motor 21, the worm gear 23 rotates 7, and the rotation is converted into the rotation of the wedge plays 1 and 15.

Similarly, a second pulse motor 25 is fixed to the support plate 14. Helical teeth are cut on the outer periphery of the second retainer 13 and mesh with the worm gear 27. The core worm gear 27 is connected to the pulse motor 25 via a belt 28.
is connected to the drive shaft 26 of.

Therefore, by driving the second pulse motor 25, the worm gear 26 rotates, and the rotation causes the wedge play 1 to rotate.
・Converted to 11 rotations, 1'.

Therefore, by appropriately driving the first and second pulse motors, it is possible to set the resonator mirror to any inclination angle.

As described in detail above, this embodiment is characterized in that the angle adjustment of the resonator mirror is driven and controlled by a pulse motor. Therefore, in addition to the effects of the first embodiment,
It becomes possible to achieve angle adjustment of the mirror by remote control. Therefore, there is no need to inadvertently touch the laser beam during mirror adjustment, and there is no risk of electric shock.

Next, still another embodiment of the present invention will be described based on FIG. This embodiment shows a case where mirror adjustment is automated. In the figure, the same numbers as in the first and second practical examples indicate the same structures.

As shown in the figure, four pulse motors 21 , 25 , 21', and 25' arranged at both ends of the discharge tube 2o are driven by a pulse motor driver 30. The driver 30 is controlled by a microcomputer 33.

On the other hand't 1. A portion 41 of the light 40 is reflected by the mirror 31 and enters the power meter 32 .

The signal from the power meter 32 is transmitted to the microcomputer 3
Manually powered to 3.

In the stem, the microcomputer 33 independently controls each pulse motor based on the laser output signal from the power meter 32 to adjust the mirror to the optimum angle.

When controlling the conopuitor, if the initial state of the optical system is not adjusted at all and the laser does not oscillate, send one pulse to each pulse motor independently and monitor and memorize the power for each case. Return to optimal conditions at the time of memorization.

1, the optical system has been adjusted to some extent, and the pulse motor is driven in a direction that increases the 01 output in a situation where the laser oscillates to some extent.

As described in detail above, this embodiment is characterized in that the output laser beam is detected, the J: repulse motor is driven under computer control, and the resonator mirror is set in the optimum state. Therefore, if you apply the example 2, you can do it without any human intervention.
Adjustment of the resonator mirror can be performed automatically. Therefore, it becomes possible to adjust the mirror at night when the laser device is not in use, and the operating rate of the laser device can be greatly improved. Great, there is no need for any maintenance on the resonator mirror.

[Brief explanation of drawings]

Figure 1 is an explanatory diagram of the mirror adjustment mechanism of a conventional laser device.
Figure 2 is an explanatory diagram of the mirror adjustment mechanism of the present invention, Figure 3d,
FIG. 4 is an explanatory diagram of the adjustment principle of the present invention. FIG. 5 is an explanatory diagram of another embodiment of the present invention.
Show a clear diagram. , tz diagram

Claims (2)

[Claims] (1) A first wedge plate rotatably fixed to the base plate at the end of the laser resonator, a support plate fixed to the wedge plate 2, and a first wedge plate rotatably fixed on the support plate. What is claimed is: 1. A laser device comprising: a second wedge plate; and a mirror holder fixed on the second wedge plate and holding a resonator mirror. (2) In the apparatus according to item 1, a first wedge plate is driven by a first motor means fixed to the base plate, and a second wedge plate fixed to the support plate is driven by a first motor means fixed to the base plate.
A laser device characterized in that the second wedge plate is driven by motor means.