JPH0316293Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an internal mirror type gas laser oscillator, and particularly to a holding mechanism for its resonant mirror.

A so-called internal mirror type gas laser oscillator has a resonant mirror facing into the tube held at both ends of an excitation tube filled with laser gas, which applies excitation energy to the laser gas and reflects it between the resonant mirrors. By doing this, laser light can be obtained. When this gas laser reaches high output, the resonant mirror is affected by the heat generated and its performance deteriorates. Due to the nature of high voltage generated by discharge excitation, the mirror was usually cooled by installing a metal cooling ring that allowed a cooling medium to flow through an insulating material. FIG. 1 shows a conventional example.

In the figure, 10 is an excitation tube, and 20 is a resonant mirror holding mechanism supported at the end of this excitation tube via a support mechanism 11. Support mechanism 11
The annular plate spring 12 is fixed to the excitation tube holding frame 14 with a fixing screw 13 and to the annular support plate 21 of the holding mechanism 20 with a fixing screw 15, and a support screw 16 screwed into the support plate 21.
The tip thereof is brought into contact with the excitation tube holding frame 14. At least three fixing screws 13, fixing screws 15, and support screws 16 are each provided in the circumferential direction.

A metal water cooling ring 23 having a water flow path 22 is attached to the shaft portion of the support plate 21, and an insulating ring 2 made of an insulating material is installed inside the metal water cooling ring 23.
4 is fitted. And this insulating ring 24
A metal mirror holding ring 26 is further fixed inside with a presser nut 25, and an O-ring 27 and a mirror holding ring 28 are attached to this metal mirror holding ring 26.
A resonant mirror 29 facing into the excitation tube 10 is held.

However, in this conventional resonant mirror holding mechanism, the position of the resonant mirror 29 changes significantly due to thermal expansion and contraction of each member due to changes in the temperature of the cooling water flowing through the water flow path 22, and as a result, the resonator length between the resonant mirrors on both sides changes. There was a problem that the stability of the laser output was impaired due to changes in the laser output. In addition, the cooling efficiency is not very good due to the large number of parts, and the metal water cooling ring 23 requires processing such as welding, which is disadvantageous because it is difficult to manufacture and expensive.

The present invention was developed based on this awareness of the problem.It increases the cooling efficiency of the resonator mirror by reducing the number of parts, and also prevents the position of the resonator mirror from changing due to the structure even when the temperature of the cooling water changes. The purpose is to provide a holding structure that is unlikely to cause this.

In order to achieve this objective, the present invention uses the end face of the excitation tube as a mounting reference surface, and provides an annular support plate supported at both ends of the excitation tube via this mounting reference surface, and provides a mounting reference for this annular support plate. A contact surface of an insulating ring fixed to the shaft portion of the annular support plate is brought into surface contact with the surface, and a mirror contact surface contacting the excitation tube side end surface of the resonant mirror is further provided on the inner circumferential step of the insulating ring. The mirror abutment surface of this insulating ring and
It is characterized in that the attachment reference surface of the annular support plate and the abutting surface are located on substantially the same plane.

The invention will now be described with reference to the illustrated embodiments. In FIG. 2, an excitation tube 10, a support mechanism 1
1. The excitation tube holding frame 14 is the same component as the conventional example shown in FIG. 1, and the mirror holding mechanism of the present invention is indicated by the reference numeral 30. The structure of the support mechanism 11 is different from the conventional example, in which a tension spring 32 whose both ends are fixed to an annular support plate 31 and an excitation tube holding frame 14 pulls the annular support plate 31 toward the excitation tube holding frame 14, and this tensile force is applied. Support rod 33 that resists
is supported by an excitation tube holding frame 14. At least three tension springs 32 and support rods 33 are provided in the circumferential direction. Annular support plate 31
The end surface on the excitation tube 10 side is the mounting reference surface 31
It constitutes a.

A step portion 34 is formed on the shaft portion of the annular support plate 31, and an insulating ring 35 made of an insulating material and fitted onto the shaft portion of the annular support plate 31 is connected to the step portion 34 by O-rings 36, 37. A water flow path 38 is formed in. The water flow path 38 communicates with a water inlet 39 and a water outlet 40 provided in the annular support plate 31, respectively. 41 is a hose connection port.

The insulating ring 35 has a flange 42 , the outer surface of which constitutes a support plate abutment surface 43 that makes surface contact with the mounting reference surface 31 a of the annular support plate 31 , and is fixed to the support plate 31 with bolts 44 . Further, the diameter of the inner peripheral portion of this insulating ring 35 decreases in a stepwise manner from the outside, and the stepped portion reaching the smallest diameter portion constitutes the mirror abutting surface 45. The important point is that the support plate abutting surface 43 and the mirror abutting surface 45 are located on the same plane. The outer periphery of the end of the resonant mirror 446 on the excitation tube 10 side is the mirror abutment surface 45.
O-ring 47 and mirror retaining ring 48
Fixed by

According to this mirror holding mechanism configured as described above, thermal expansion and contraction occurs in the annular support plate 31 and the insulating ring 35 due to changes in the temperature of the cooling water flowing through the water inlet 39, the water flow path 38, and the water outlet 40. Also resonant mirror 46
The position of the mirror abutting surface 45, that is, the position of the mirror abutting surface 45 rarely changes. Because the annular support plate 3
1 and the insulating ring 35, the expansion and contraction always occurs with reference to the mounting reference surface 31a (support plate contact surface 43), and the position of this mounting reference surface 31a is thermally separated from the mounting reference surface 31a. This is because the support rod 33 is insulated. Therefore, the annular support plate 31 and the insulating ring 35
Even if it expands and contracts due to heat, this mounting reference surface 31a (support plate abutting surface 43) does not move, and this support plate abutting surface 43
The mirror abutting surface 45, that is, the resonant mirror 46, which is in the same plane as the mirror 46, does not move either. Since the support rod 33 allows fine adjustment of the position of the annular support plate 31, it is preferable that the axial position of the support rod 33 is adjustable.

Although the support plate abutment surface 43 and the mirror abutment surface 45 of the insulating ring 35 are positioned on the same plane as described above, it is clear that they do not need to be on the same geometric plane, and the above effect can be achieved. The surface may be approximately the same as much as possible. Furthermore, although the above embodiment shows the case where the insulating ring 35 is water-cooled, cooling by air cooling, a large-capacity heat sink, etc. is also possible, and the present invention is not limited to any cooling method.

As described above, in the mirror holding mechanism of the present invention, even if the resonant mirror or its surroundings are heated, the mirror is unlikely to move due to its structure, and changes in the position of the mirror surface can be minimized. Therefore, changes in output due to movement of the resonant mirror are reduced, and stable output can be obtained. Furthermore, since the number of parts is reduced compared to conventional devices, the heat transfer efficiency up to the mirror is improved and a large cooling effect can be obtained. Furthermore, since there is no metal cooling ring that is difficult to process, costs are reduced, which is advantageous in terms of manufacturing.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing a conventional resonant mirror holding mechanism, and FIG. 2 is a longitudinal sectional view similar to FIG. 1 showing an embodiment of the present invention. 10...excitation tube, 11...support mechanism, 1
4...Excitation tube holding frame, 31...Annular support plate, 31a...Mounting reference surface, 32...Tension spring,
33...Support rod, 35...Insulating ring, 38...Water flow path, 39...Water inlet, 40...Water outlet, 43
...Support plate abutting surface (abutting surface), 45...Mirror abutting surface, 46...Resonance mirror, 48...Mirror holding ring.

Claims (1)

[Claims for Utility Model Registration] (1) In a resonant mirror holding mechanism in which a resonant mirror facing into the excitation tube is attached to both ends of an excitation tube filled with laser gas, the end face on the side of the excitation tube is used as a mounting reference surface, and this an annular support plate supported at both ends of the excitation tube via a mounting reference surface; a contact surface that makes surface contact with the mounting reference surface of the annular support plate; and fixed to the shaft of the annular support plate; an insulating ring; a mirror abutting surface formed on the inner stepped portion of the insulating ring; a resonant mirror, the outer periphery of the excitation tube side end surface of which is in contact with the mirror abutting surface; 1. A resonant mirror holding mechanism for a laser oscillator, characterized in that a mirror holding ring is provided to fix the mirror to the insulating ring, and the abutting surface of the insulating ring and the mirror abutting surface are located on substantially the same plane. (2) In claim 1 of the utility model registration claim, the annular support plate is biased toward the excitation tube by a spring means, and from the excitation tube side, the annular support plate abuts against the mounting reference surface of the annular support plate and is applied. A resonant mirror holding mechanism for a laser oscillator in which three or more support rods are protruded to determine the position of an annular support plate. (3) In claim 1 or 2 of the utility model registration claim, there is provided a resonant mirror holding mechanism for a laser oscillator, in which the annular support plate is provided with a series of cooling medium inlets, cooling channels, and exhaust ports. .