JPH0582867A - Laser oscillator - Google Patents

Abstract

PURPOSE:To obtain a laser oscillator in which the pointing of laser light is stabilized. CONSTITUTION:The angle adjusting mechanism of total reflection mirror 7 is provided with an adjusting plate 22 to adjust the angle of the mirror 7 and an optical board 20 for vacuum shielding through fitting the plate 22, and a point of support 32 and an adjusting screw 23 are both fitted on the plate 20. Therefore, since both the point 32 and screw 23 are dependent on the same outside air temperature, the temperature difference between the point 32 and screw 23 may not occur. As a result, the expansion amount of the point 32 due to thermal expansion approximates to that of the screw 23 and the angle of the plate 22 does not change any more, resulting in stabilizing the pointing of laser light.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser oscillator in which the positional accuracy (pointing) of laser light is always stable.

[0002]

2. Description of the Related Art FIG. 7 shows, for example, Japanese Patent Laid-Open No. 60-254684.
FIG. 8 is a perspective view showing an example of a conventional laser oscillator disclosed in the publication, and FIG. 8 is a schematic view showing an example of a resonance optical path of the laser oscillator shown in FIG. In the figure, 1 is a housing in which a medium gas is enclosed, 2 and 2 are a pair of discharge electrodes that are arranged opposite to each other for exciting the laser medium gas, 3 is a blower for circulating the laser medium gas, and 4 is a laser medium. It is a heat exchanger that cools gas. Reference numeral 5 is a partial reflection mirror, and 6, 7 and 8 are total reflection mirrors.
Are slightly tilted upward, and are respectively arranged in the longitudinal direction of the housing 1 to form resonator mirrors that determine the resonator optical path. 9 is a first including a partial reflection mirror 5 and a total reflection mirror 7.
The laser light reflecting means 10 is a second laser light reflecting means including a total reflection mirror 8 and a total reflection mirror 6. 11 is a laser beam,
Reference numerals 12, 13 and 14 denote a first optical axis, a second optical axis and a third optical axis, respectively.

FIG. 9 is a vertical sectional view of the laser beam reflecting means 9 shown in FIGS. Reference numerals 15 and 16 denote apertures provided immediately before the partial reflection mirror 5 and the total reflection mirror 7, respectively. Reference numeral 17 is a first optical base for holding the first laser light reflecting means 9, and 18 is a first optical base 17 and a second optical base.
Connecting rod for connecting a second optical base (not shown) holding the laser light reflecting means 10 of the above, and 19 is attached so as to hold the housing 1 and the first optical base 17 in a vacuum-tight manner. The bellows 20 is an optical substrate attached to the first optical base 17. Reference numerals 21 and 22 are adjusting plates to which the partial reflecting mirror 5 and the total reflecting mirror 7 are attached, and adjust the angles of the reflecting mirrors 5 and 7.

FIG. 10 and FIG. 11 are an enlarged sectional view and a front view of the main part of FIG. 23 is an iron adjustment screw,
Two optical boards 20 are attached in a diagonal direction to adjust the angle of the adjusting plate 22. Reference numeral 24 is a screw portion to which the adjusting screw 23 is screwed. Reference numeral 25 is an O-ring for vacuum-sealing between the optical substrate 20 and the adjusting screw 23.
Rotates while being evacuated with an O-ring. Reference numeral 26 is an iron fulcrum attached to the adjusting plate 22. Reference numeral 27 is a screw portion with which the fulcrum 26 is screwed. Reference numeral 28 denotes a receiving portion provided on the adjusting plate 22, and the tip portion 23a of the adjusting screw 23 is in contact therewith. Reference numeral 29 denotes a receiving portion provided on the optical substrate 20, and the tip end portion 26a of the fulcrum 26 is in contact therewith. 30 is an adjusting plate 22
Are two springs that attract the light toward the optical substrate 20. Incidentally, 31 is cooling water flowing in the adjusting plate 22.

Next, the operation of the conventional laser oscillator shown in FIGS. 7 to 9 will be described. First, when a voltage is applied from the power supply between the discharge electrodes 2 and 2, a discharge is generated between the discharge electrodes 2 and 2. This discharge excites the laser medium gas between the discharge electrodes 2 and 2 to generate laser light. This laser light is resonated as three resonance optical paths that draw a Z shape between the partial reflection mirror 5, the total reflection mirrors 6, 7 and 8, and the laser light 11
And is taken out of the laser oscillator. That is, the laser light reflected by the total reflection mirror 6 has the first optical axis 12
To reach the total reflection mirror 7. Since the total reflection mirror 7 is tilted slightly downward, the laser light is emitted from the first optical axis 12 to the second position.
It reaches the total reflection mirror 8 through the optical axis 13 of. Since the total reflection mirror 8 is tilted slightly upward, the laser light passes through the third optical axis 14 parallel to the first optical axis 12 and the partial reflection mirror 5
Reach A part of the laser light reaching the partial reflection mirror 5 is output to the outside as it is, and the rest returns to the total reflection mirror 6 through a route opposite to the above, and the above process is repeated. The laser light is amplified while repeatedly passing through the excitation region and output from the partial reflecting mirror 5 to the outside.

On the other hand, the laser medium gas excited between the discharge electrodes 2 and 2 is carried by the blower 3 from between the discharge electrodes 2 and 2 toward the heat exchanger 4 and, after being cooled there, further toward the A direction. It is circulated and excited again between the discharge electrodes 2, 2.

Next, the total reflection mirror 7 shown in FIGS.
The operation of the angle adjusting mechanism will be described. The tilt of the total reflection mirror 7 is adjusted by changing the angle of the adjusting plate 22. Since the adjusting plate 22 is attracted toward the optical substrate 20 by the spring 30 and is pressed in the opposite direction by the fulcrum 26 and the two adjusting screws 23, the length of the fulcrum 26 and the adjusting screw 23 protruding from the optical substrate 20. The angle of the adjusting plate 22 is determined by the relative relationship with the length. Therefore, the adjusting screw 23 is rotated to change the protrusion length from the optical substrate 20, and the angle of the adjusting plate 22 is adjusted vertically and horizontally.

[0008]

Since the total reflection mirror 7 has a constant absorptance with respect to the laser light, it generates heat when the laser light hits it. The heat generated by the total reflection mirror 7 is cooled by the cooling water 31. Therefore, the temperature of the adjusting plate 22 depends on the temperature of the cooling water 31, and the temperature of the optical substrate 20 depends on the outside air temperature.
Therefore, the temperature of the fulcrum 26 attached to the adjusting plate 22 and the temperature of the adjusting screw 23 attached to the optical substrate 20 also depend on the temperature of the cooling water 31 and the outside air temperature, respectively. If there is a temperature difference between the cooling water temperature and the outside air temperature, the fulcrum 26 and the adjusting screw 2
There is also a temperature difference between the fulcrum 26 and the adjustment screw 23, and the expansion amount between the fulcrum 26 and the adjustment screw 23 due to thermal expansion differs, and the angle of the adjustment plate 22 changes. When the angle of the adjusting plate 22 changes, the total reflection mirrors 7, 8
Changes, the optical axis of the laser light in the resonator is deviated, and the position of the laser light becomes unstable.

Incidentally, a mirror angle adjusting device for a laser oscillator in which a fulcrum pin is attached to an optical substrate to reduce a change in laser beam mode due to vibration (Actual No. 63-89371).
(Japanese Laid-Open Patent Publication No. 60-172353), and an invention of a reflecting mirror angle adjusting mechanism (Japanese Laid-Open Utility Model Publication No. 60-172353) in which the angle of the reflecting mirror of the mirror holder is adjusted by two screws on the support side. However, these inventions also do not sufficiently solve the above problems.

The present invention has been made to solve the above problems, and an object of the present invention is to obtain a laser oscillator with stable position accuracy (pointing) of laser light.

[0011]

A laser oscillator according to the present invention is constructed such that a fulcrum of an adjusting plate arranged in a vacuum and an adjusting screw for an angle are attached to an optical substrate side.

Further, in the laser oscillator according to the present invention, the material of the fulcrum of the adjusting plate arranged in vacuum and the adjusting screw for the angle is made of Invar.

Further, the laser oscillator according to the present invention is
The material of the fulcrum of the adjusting plate arranged in vacuum and the adjusting screw for the angle is made of a material whose main component is carbon fiber.

[0014]

The fulcrum of the adjusting plate and the angle adjusting screw attached to the optical board both depend on the same outside temperature, and there is no temperature difference between the fulcrum of the adjusting plate and the adjusting screw. Therefore, the fulcrum caused by thermal expansion and the amount of expansion of the adjusting screw are close to each other, and the angle of the adjusting plate does not change.

Also, the fulcrum of the adjusting plate made of Invar and the adjusting screw for the angle have a very small change in length even if the temperature changes.

Further, the fulcrum and the angle adjusting screw of the adjusting plate made of a material containing carbon fiber as a main component have a very small change in length even if the temperature changes.

[0017]

EXAMPLES Example 1. 1 and 2 are a sectional view and a front view showing a main part of a first embodiment of the present invention. It should be noted that the same or corresponding parts as those of the conventional example shown in FIGS. 32 is a fulcrum attached to the optical substrate 20, 32a is a screw portion for screwing the fulcrum 32 to the optical substrate 20, 33 is a receiving portion provided on the adjusting plate 22, and the tip 32b of the fulcrum 32 is in contact with the receiving portion. There is.

Next, the operation of this embodiment constructed as described above will be described. The tilt of the total reflection mirror 7 is adjusted by the adjusting plate 2 as described above.
Adjust by changing the angle of 2. The adjusting plate 22 is the spring 3
0 is attracted to the optical substrate 20 and is pressed in the opposite direction by the fulcrum 32 and the two adjusting screws 23. Therefore, depending on the relative relationship between the length of the fulcrum 32 and the protruding length of the adjusting screw 23 from the optical substrate 20. The angle of the adjusting plate 22 is determined. Therefore, by rotating the adjusting screw 23, the adjusting screw 2
The projection length of the optical plate 20 from the optical substrate 20 is changed to adjust the adjustment plate 2
Adjust the angle of 2 vertically and horizontally. By the way, since both the fulcrum 32 and the adjusting screw 23 are attached to the optical substrate 20, both depend on the outside temperature. Therefore, even if there is a difference between the temperature of the cooling water 31 and the temperature of the outside air, there is no difference in temperature between the fulcrum 32 and the adjusting screw 23, and the expansion amount of the fulcrum 32 and the adjusting screw 23 due to thermal expansion is similar. The angle of the adjusting plate 22 does not change. Therefore, total reflection mirror 7
Since the angle of 8 or 8 does not change and the optical axis of the laser light in the resonator does not change, the position of the laser light is stabilized.

Example 2. 3 and 4 are a sectional view and a front view showing a main part of a second embodiment of the present invention. In addition,
The same or corresponding parts as those in the first embodiment (FIGS. 1 and 2) are designated by the same reference numerals, and the description thereof will be omitted. 34 is the optical substrate 20
The fulcrum 35 attached to the optical board 20 is provided on the optical board 20.
It is a hole into which the protrusion 34b behind the fulcrum 34 fits.
Reference numeral 36 denotes a receiving portion provided on the adjusting plate 22, and the tip end portion 34a of the fulcrum 34 is in contact therewith.

The operation of the present embodiment configured as described above is the same as that in the case of the first embodiment, and the description thereof will be omitted.

Example 3. FIG. 5 is a vertical cross-sectional view showing the main part of the third embodiment of the present invention. The same or corresponding parts as those in the first embodiment (FIG. 1) are designated by the same reference numerals and the description thereof will be omitted. Reference numeral 230 is an adjusting screw, and two adjusting screws are attached in a diagonal direction of the optical substrate 20 for adjusting the angle of the adjusting plate 22. 37 is a fulcrum attached to the adjusting plate 22, 3
Reference numeral 8 denotes a screw portion with which a fulcrum 37 is screwed onto the adjusting plate 22. Three
Reference numeral 9 denotes a receiving portion provided on the optical substrate 20, and the tip portion 37a of the fulcrum 37 is in contact therewith. The fulcrum 37 and the adjusting screw 230 are made of Invar. Invar is a nickel (Ni) alloy whose main component is iron and has a linear expansion coefficient of 1.5.
It is about 10 ^-5 and very small.

According to the present embodiment configured as described above,
The adjusting plate 22 depends on the temperature of the cooling water 31,
Depends on the outside temperature. Therefore, the fulcrum 37 attached to the adjustment plate 22 and the adjustment screw 2 attached to the optical substrate 20
Each 30 also depends on the temperature of the cooling water 31 and the outside air temperature. If there is a temperature difference between the temperature of the cooling water 31 and the outside air temperature, a temperature difference also occurs between the fulcrum 37 and the adjusting screw 230. However, there is almost no difference in the amount of expansion due to thermal expansion between the fulcrum 37 and the adjusting screw 230, and the angle of the adjusting plate 22 does not change.

Example 4. FIG. 6 is a sectional view showing a main part of the fourth embodiment of the present invention. The third embodiment (FIG. 5)
The same or corresponding parts are designated by the same reference numerals, and the description thereof will be omitted. Two adjustment screws 231 are attached in a diagonal direction of the optical substrate 20 for adjusting the angle of the adjustment plate 22. Reference numeral 40 is a fulcrum attached to the adjusting plate 22, and 41 is a screw portion with which the fulcrum 40 is screwed into the adjusting plate 22. A receiving portion 42 is provided on the optical substrate 20, and the tip end portion 40a of the fulcrum 40 is in contact therewith. The fulcrum 40 and the adjusting screw 23
The material of No. 1 has carbon fiber as a main component. The expansion coefficient of the material containing carbon fiber as a main component can be made very small by changing the mixed material, its ratio, the knitting method of the fiber, and the like.

The operation of this embodiment having the above-described structure is the same as that of the second embodiment, and the description thereof will be omitted.

The first and second embodiments (FIGS. 1 and 3)
However, unlike the third and fourth embodiments (FIGS. 5 and 6), the fulcrums 32 and 34 of the adjusting plate 22 and the adjusting screw 23 arranged in a vacuum are both attached to the optical substrate 20. Even in this state, the fulcrums 32 and 34 and the angle adjusting screw 23 may be made of a material such as Invar or a material containing carbon fiber as a main component.

[0026]

As is apparent from the above description, according to the present invention, the fulcrum of the adjusting plate arranged in vacuum and the adjusting screw for the angle are attached to the optical substrate, so that the laser beam with stable position accuracy of the laser beam is provided. An oscillator is obtained. Moreover, since the material of the fulcrum of the adjusting plate and the angle adjusting screw which are arranged in a vacuum is made of Invar, a laser oscillator in which the positional accuracy of the laser light is stable can be obtained. Further, since the material of the fulcrum of the adjusting plate arranged in vacuum and the adjusting screw for the angle is made of a material whose main component is carbon fiber, a laser oscillator with stable laser light position accuracy can be obtained.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a first embodiment of the present invention.

FIG. 2 is a front view of FIG.

FIG. 3 is a sectional view showing a second embodiment of the present invention.

FIG. 4 is a front view of FIG.

FIG. 5 is a sectional view showing a third embodiment of the present invention.

FIG. 6 is a sectional view showing a fourth embodiment of the present invention.

FIG. 7 is a perspective view showing an example of a conventional laser oscillator.

8 is a schematic diagram showing an example of a resonant optical path of the laser oscillator shown in FIG.

9 is a cross-sectional view of the laser light reflecting means shown in FIG.

10 is an enlarged cross-sectional view of a main part of FIG.

11 is a front view of FIG.

[Explanation of symbols]

 1 Case 2 Discharge Electrode 3 Blower 4 Heat Exchanger 5 Partial Reflecting Mirror 6, 7, 8 Total Reflecting Mirror 9 First Laser Light Reflecting Means 10 Second Laser Light Reflecting Means 11 Laser Light 12 First Optical Axis 13 Second optical axis 14 Third optical axis 15, 16 Aperture 17 First optical base 18 Connecting rod 19 Bellows 20 Optical substrate 22 Adjusting plate 23, 230, 231 Adjusting screw 24 Screw part 25 O-ring 28, 33, 36, 39, 42 Receiving part 30 Spring 31 Cooling water 32, 34, 37, 40 Support point 28, 33, 36, 39, 42 Receiving part 35 Hole

Claims (3)

[Claims] 1. A laser oscillator that excites a laser medium and outputs laser light by its stimulated emission, the laser oscillator including a resonator mirror including a partial reflection mirror and a total reflection mirror that determine a resonator optical path. At least one of the resonator mirrors is arranged in a vacuum, and an adjusting plate for adjusting the angle of the resonator mirror arranged in the vacuum and the adjusting plate are attached to interrupt the vacuum. A laser oscillator in which an adjusting screw for adjusting a fulcrum and an angle of the adjusting plate arranged in a vacuum is attached to the optical substrate. 2. A laser oscillator that excites a laser medium and outputs laser light by stimulated emission of the laser medium, the laser oscillator including a resonator mirror including a partial reflection mirror and a total reflection mirror that determine a resonator optical path. At least one of the resonator mirrors is arranged in a vacuum, and an adjusting plate for adjusting the angle of the resonator mirror arranged in the vacuum and the adjusting plate are attached to interrupt the vacuum. A laser oscillator characterized in that the material of the fulcrum of the adjusting plate arranged in vacuum and the adjusting screw for the angle is Invar. 3. A laser oscillator that excites a laser medium and outputs laser light by stimulated emission of the laser medium, the laser oscillator having a resonator mirror including a partial reflection mirror and a total reflection mirror that determine a resonator optical path. At least one of the resonator mirrors is arranged in a vacuum, and an adjusting plate for adjusting the angle of the resonator mirror arranged in the vacuum and the adjusting plate are attached to interrupt the vacuum. A laser oscillator characterized in that the material of the fulcrum of the adjusting plate arranged in a vacuum and the adjusting screw for the angle is a material containing carbon fiber as a main component.