JPS62152190A - Laser oscillator - Google Patents

Abstract

PURPOSE:To eliminate the change of the position of a mirror due to the temperature difference of a supporter and to obtain a stable laser output, by composing the supporter of external and internal members having the same quality of material and an intermediate member, which has a linear expansion coefficient of approximately double as large as the members on the operation of laser oscillation, and making a pair of the mirrors supported by the end sections of the external and internal members in a laser oscillator. CONSTITUTION:The end sections of external and internal members 12, 14 consisting of steel are displaced in the opposite directions, the member 14 is extended from one end of the member 12, and the other end of the member 12 is extended to the other end of the member 14. An intermediate member 13 composed of steel is joined on the insides of the steel members 12, 14. These members are supported in a displaceable manner in the direction of an optical axis 5 by a bearing 15. Even when the steel members 12, 14 are thermally expanded, the steel member 13 follows up to displacement, and support plates 4a, 4b for mirrors 1a, 1b are not displaced. Accordingly, stable laser beams can be oscillated along the optical axis.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a laser oscillation device, and more particularly to a laser oscillation device in which support means for a pair of mirrors constituting a laser resonator are improved.

[Technical background of the invention and its problems]

FIG. 4 shows an example of a conventional laser oscillation device.

This laser oscillation device is an internal mirror type laser oscillation device, and includes a pair of mirrors (la) constituting a laser resonator,
(lb) are attached to both ends of the oscillator main body (3) by bellows (2) so that the alignment can be adjusted, and the optical axis (5) of the oscillator is connected via the support plates (4a) and (4b). Multiple lines extending along, for example 3~
It is integrally supported by four supports (6). This support (6) is usually made of Invar, which has a small coefficient of thermal expansion.

However, when the laser oscillation device is configured as described above, the temperature rises because the support body (6) is located close to the oscillation device main body (3), which is one heat source.
) creates a temperature difference between For example, in a high-output gas laser oscillation device, a temperature difference of several degrees may occur between the support rods (6). If a temperature difference occurs between the supports (6) in this way, the length of the supports (6) will change, and the angles and positions of the pair of mirrors (la) and (lb) that have been aligned will be incorrect. , change the laser output, direction, etc.

Conventional methods to prevent this have been to wrap a heat insulating material around the support (6), or to construct the support rod (6) with a pipe through which temperature-controlled cooling water is passed. . However, even if you wrap the heat insulating material around it or run temperature-controlled cooling water, it is not possible to completely eliminate the effects of temperature differences, and a pair of mirrors (la
), (lb) had angular deviations and positional deviations.

[Purpose of the invention]

The present invention is directed to configuring a laser oscillation device so that even if a temperature difference occurs in a support body that integrally supports a pair of mirrors constituting a laser resonator, the positional relationship of the mirrors does not change.

[Summary of the invention]

The present invention provides a laser oscillation device in which a pair of mirrors constituting a laser resonator is integrally supported by a support body.
The support body is composed of outer and inner members made of the same material and an intermediate member having a coefficient of linear expansion approximately twice that of these members during laser oscillation, and a pair of mirrors are arranged opposite to the outer member and the inner member, respectively. By supporting the mirror at the side ends, the position of the mirror does not change even if a temperature difference occurs in the support.

[Embodiments of the invention]

Hereinafter, the present invention will be described based on embodiments with reference to the drawings.

FIG. 1 shows a laser oscillation device which is an embodiment of the present invention. This laser oscillation device is an internal mirror type gas laser oscillation device, and the gas discharge section (10
) a pair of mirrors (la) forming a laser resonator via bellows (2).

(1b) is attached so that alignment can be adjusted.

Further, the pair of mirrors (la) and (lb) are integrally supported by the following support body (11) via support plates (4a) and (4b), respectively.

The support body (11) is a rod-shaped member (1 set of three pieces).
2) to (14), and a plurality of sets are arranged around the gas discharge section (10) along the optical axis (5) of this laser oscillation device.

A set of three rod-shaped members (12) to (14) are outer members (12) disposed parallel to each other along the optical axis (5).
), an inner member (14) disposed inside it, and an intermediate member (13) interposed between these members (12) and (14). This outer and inner member (12
) and (13) have respective ends shifted in opposite directions, such that one end of the inner member (12) is offset from the inner member (13).
One end of the outer member (12) projects in the direction of extension thereof, and the other end of the outer member (12) also projects in the direction of extension relative to the other end of the inner member (14). In contrast to the outer and inner members (12) and (14), the intermediate member (13) has two ends that are respectively the outer and inner members (12),
(14) and is joined to one end of the outer member (12) and the other end of the inner member (14). In addition, compared to the outer and inner members (12) and (13) formed of members made of the same material (same coefficient of linear expansion), the intermediate member (13) has a linear expansion that is approximately twice that during laser oscillation. has a coefficient. For example, the outer and inner members (12) and (14) are made of steel (linear expansion coefficient 6).
．． 8 x 10-'), and the intermediate member (13) is made of copper (linear expansion coefficient: 13.8 x 10''').

Furthermore, the outer and inner members (12) and (14)
A linear motion bearing (15) is installed between both ends of the
is inserted to support the radial load applied to the support (11) and to prevent displacement in the thrust direction (direction of the optical axis (5)) of the outer and inner members (12) and (14) caused by thermal expansion. It is supported so that it can be relatively displaced.

To this support (11) a pair of mirrors (la).

(1b) has one mirror attached to one end of the inner member (14) via the support (4a), and the other mirror (lb)
is supported by the other end of the outer member (12) via the support (4b).

Now, when the support body (11) is constructed as described above, as shown by the dashed line in FIG.
, (14) cause thermal expansion due to temperature changes, the intermediate member (13), which has a coefficient of linear expansion twice that of these members (12) and (14), will expand the outer and inner members (14).
12), (14), each mirror (
support plates (4a), (4
b) Do not displace the fixed end. Hence mirror (la).

(1b) is not displaced. The function of the support body (11) made up of a set of three is performed regardless of its temperature, so there is a temperature difference between the multiple sets of support bodies (11) that support the mirrors (la) and (lb). Even if this occurs, the pair of mirrors (la) and (lb) will support this without changing their positional relationship.

Therefore, when a laser oscillation device is constructed using such a support (11), the positional relationship between the pair of mirrors (la) and (lb), which have been aligned once, does not change, and the alignment is maintained along the optical axis (5). It is possible to oscillate stable laser light.

Next, other embodiments will be described.

In the above embodiment, the support body is formed of a rod-shaped member at the center, but this support body can also be formed of other members having different cross-sectional shapes, such as a pipe.

Further, in the above embodiment, a pair of mirrors is supported using multiple sets of three supports, but this support is made by coaxially combining three cylindrical members, and the inner cylindrical member The oscillation device main body may be disposed within the mirror, and a pair of mirrors may be supported by a set of supports.

Further, in the above embodiment, a linear motion bearing was arranged between the ends of the outer member and the inner member that constitute the support body, but this bearing supports the radial load applied to the support body, and Any other support may be used as long as it supports the support so that it can be displaced in the thrust direction.

Furthermore, in the above embodiments, the outer and inner members of the support are assembled in such a way that the ends of the outer member and the inner member are shifted so as to protrude in opposite directions,
A support plate supporting a pair of mirrors was attached to the inside of the plurality of support bodies, and as shown in FIG. 3, the inner member (14)
Make only one end protrude.

The other ends of the outer and inner members (12), (14) are aligned, and a support plate (4a) is placed on the outside of these both members (12), (14).

(4b) may be attached. Note that the other parts of this embodiment are given the same numbers as those of the previous embodiment, and the explanation thereof will be omitted.

Although the above embodiments have been described with respect to an internal mirror type gas laser oscillation device, the present invention can also be applied to an external mirror type gas laser oscillation device, and can also be applied to other laser oscillation devices such as a solid state laser oscillation device having a similar resonator. It can also be applied to

〔Effect of the invention〕

A support body that integrally supports a pair of mirrors constituting a laser resonator is arranged between an outer member made of the same material having the same coefficient of linear expansion, an inner member disposed inside the outer member, and these two members. and an intermediate member having a coefficient of linear expansion approximately twice that of Since the pair of mirrors is supported, the positional relationship between the pair of mirrors does not change and the laser oscillation device can have a stable output.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the configuration of an internal mirror type gas laser oscillation device that is an embodiment of the present invention, and FIG. 2 is an explanatory diagram of the operation of a support body that supports a pair of mirrors constituting the laser resonator.
FIG. 3 is a diagram showing the configuration of another embodiment, and FIG. 4 is a diagram showing the configuration of a conventional laser oscillation device.

Claims (1)

[Claims] In a laser oscillation device in which a pair of mirrors constituting a laser resonator are integrally supported by a support body, the support body includes an outer member disposed along an optical axis of the laser oscillation device;
An inner member made of the same material is disposed along and inside the outer member, and has a coefficient of linear expansion approximately twice that of these outer and inner members during laser oscillation operation, and one end of the outer member and an intermediate member having both ends joined to the other end of the inner member, and an intermediate member disposed between both ends of the outer member and the inner member, so that these two members can be relatively displaced in the direction of the optical axis. 1. A laser oscillation device comprising: a bearing supported by the pair of mirrors, one of the pair of mirrors supported by the other end of the outer member, and the other mirror supported by one end of the inner member.