JPS6396980A - Lser resonator - Google Patents

Abstract

PURPOSE:To bring the temperature of a thermal medium in coincident with a room temperature thereby to simply maintain the temperature of all supporting members constant by circulating the medium in the connecting holes of the members of a laser resonator. CONSTITUTION:A high-frequency voltage is applied to generate a glow discharge in the interior 1c of a laser tube 1, CO2 molecules are excited by passing laser gas through the interior 1c, the irradiated light of predetermined wavelength is reflected to be resonated by reflecting mirrors 2, 4 at both sides of the tube 1, and the reflected lights are partly obtained as a laser output from the mirror 4. In this case, connecting holes 61a-61d are respectively formed longitudinally in the members 6a-6d of the resonator, a circulating water is fed to the holes 61, the heat of the circulating water is exchanged by a radiator 8 and a feed pipe 9 to bring in coincidence with a room temperature. Accordingly, the temperature difference between the upper and lower parts of the tube 1 is absorbed to bring the temperatures of the members 6 in coincidence.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a laser resonator, and in particular, to a laser resonator located in parallel to each other.
The present invention relates to a laser resonator that obtains a laser output by mutually reflecting light within a laser tube using two reflecting mirrors.

[Conventional technology]

FIG. 3 is a diagram for explaining the problems of the conventional laser resonator.

As shown in FIG. 3, a conventional laser resonator for generating a gas laser such as carbon dioxide gas includes a laser tube 101, a reflecting mirror 102, a holding member 103,
, 105, and support members 106a to 106d.

The laser tube 101 applies, for example, a high-frequency voltage to generate a glow discharge inside the laser tube, and a laser gas (for example, COI+Nt) is supplied to the inside of the laser tube 101 that is generating the glow discharge.

By passing a mixed gas of He, carbon dioxide molecules in the laser gas are excited. When the excited carbon dioxide molecules transition to a low-level molecular vibrational state, they emit light of a predetermined wavelength, and the laser resonator uses the emitted light. Two reflecting mirrors 1 installed on both sides of the laser tube 1010
02 and 104 to cause resonance, and a portion of the reflected light is taken out from the reflecting mirror 104, which is a half mirror, thereby obtaining a laser output. Reflector 1 mentioned above
02 and 104 are holding members 103 and 1, respectively.
05, and the holding members 103 and 105 are fixedly supported by four supporting members 106a to 106d.

By the way, unless the reflecting mirrors 102 and 104 are accurately parallel, the light emitted within the laser tube 101 cannot be reflected many times by the two reflecting mirrors 102 and 104 and resonated. That is, two reflecting mirrors 102 and 1
If the angle with 04 deviates even slightly from the exact parallel state,
The path of the light reflected by these two reflecting mirrors 102 and 104 gradually becomes larger, and the path of the reflected light ends up proceeding toward the outside of the reflecting mirrors. The difference in angle between the temperature TI at the top of the laser tube 101 and the temperature T! at the bottom of the laser tube 101 is caused mainly by the heat radiated from the laser tube 101. A temperature difference is generated between the support member 106a (106b)
This is caused by the difference in length change due to thermal expansion between the support member 106c (106d) and the support member 106c (106d). Therefore,
The material of the support members 106a to 106d is Invar (I), such as Fe-Ni alloy, which has an extremely small coefficient of thermal expansion.
nvar) is used.

Furthermore, conventionally, the support member 10 can be removed by eliminating the influence of the temperature difference between the temperature T at the upper part of the laser tube 101 and the temperature Tt at the lower part.
6a (106b) and support member 106c (10
6d), the support member 106a
Communication holes are formed in the longitudinal axis direction of the support members 106d to 106d, and water at a constant temperature is allowed to flow through the communication holes of each support member.

[Problem that the invention seeks to solve]

As mentioned above, a conventional laser resonator includes a laser tube 10
1, the supporting members 106a to 106d are made of a material such as Invar, which has an extremely small coefficient of thermal expansion.
A to 106d were prevented from expanding and contracting due to heat.

However, this method has the disadvantage that materials with extremely small thermal expansion coefficients, such as Invar, are expensive.

In addition, the temperature T1 at the top of the laser tube 101 and the temperature T at the bottom
, the support member 106a (1
In order to match the temperature of the support member 106C (106d) with the temperature of the support member 106C (106d), water at a constant temperature is allowed to flow through the communication hole of each support member. However, in order to flow water at a constant temperature into the communication holes of each support member, a chiller is required that includes a constant temperature chamber to keep the temperature of the water constant and a pump to circulate the constant temperature water. It was. Not only is this chiller required to be large, but if there is a difference between the temperature set by the thermostat and the room temperature, for example, the temperature set by the thermostat is considerably lower than the room temperature. As a result, condensation or the like will occur on the support members 106a-106d, and the temperature of the water sent from the chiller must be made to match the room temperature.However, since the room temperature varies depending on the season, daily weather, etc. For example, the temperature of the constant-temperature water sent out from the chiller had to be frequently set manually. As described above, the laser resonator that uses a chiller to circulate constant-temperature water through the communication holes of the support members 106a to 106d has problems not only in the cost required for the chiller but also in the time and effort required to set the temperature.

An object of the present invention is to solve the above-mentioned problems in the conventional laser resonator, and to form a communication hole inside a supporting member that fixedly supports a pair of holding members each having a reflecting mirror attached thereto. By circulating a heat medium through the communication holes of each support member by means of a heat exchange means, and by making the temperature of this heat medium match the room temperature by means of a simply configured heat exchange means, a heat medium having the same temperature as room temperature is transferred to each support member. It is an object of the present invention to provide a simple and low-cost laser resonator that can keep the temperature of all supporting members constant by circulating through a communication hole.

[Means for solving problems]

According to the present invention, a laser tube, a pair of reflecting mirrors provided in parallel on both sides of the laser tube, a pair of holding members to which the six reflecting mirrors are respectively attached, and the holding members are fixed to each other. a plurality of support members each having a communication hole formed therein; a heat medium that circulates through the communication holes of each of the support members to bring the temperature of each of the support members to the same temperature; A laser resonator is provided that includes a circulation means for circulating the heat medium through communication holes in each support member, and a heat exchange means for bringing the temperature of the heat medium to room temperature.

[For production]

According to the laser resonator of the present invention having the above-described configuration,
A pair of holding members each having a pair of reflecting mirrors provided in parallel on both sides of the laser tube are fixedly supported by a plurality of supporting members each having a communication hole formed therein. Further, the heat medium is circulated through the communication holes of each support member by the circulation means.

Then, since the temperature of the heat medium is made to match the room temperature by the heat exchange means, the temperature of all the support members becomes the same as the room temperature, and thereby the upper support member and the lower support member of the laser tube There will be no temperature difference between the two reflecting mirrors and the two reflecting mirrors will always maintain a parallel relationship.

〔Example〕

Hereinafter, one embodiment of a laser resonator according to the present invention will be described with reference to the drawings.

FIG. 1 is a diagram schematically showing an embodiment of the laser resonator according to the present invention, and FIG. 2 is a diagram showing the laser resonator of FIG.
FIG. 3 is a cross-sectional view taken along a line.

As shown in FIG. 1, the laser resonator generally includes a laser tube 1, a reflector @2, 4, a holding member 3.5, and support members 68-6d.

The laser tube 1 applies a high frequency voltage of, for example, about 2 MHz to generate a glow discharge in the interior 1c of the laser tube 1 (see Figure 2), and also injects laser gas into the interior 1c of the laser tube where the glow discharge is occurring. (For example, CO□*N,,H
CO*,
It is designed to excite molecules. Then, two laser beams installed on both sides of the laser tube 1 emit light of a predetermined wavelength that is emitted when the excited COx molecules in a high-level molecular vibration state transition to a low-level molecular vibration state. The light is reflected by the reflecting mirrors 2 and 4 and resonates. A part of the reflected light is extracted as a laser output from a reflecting mirror 4 which is a half mirror. The above-mentioned reflecting mirrors 2 and 4 are attached to holding members 3 and 5, respectively, so that their inclinations can be adjusted.
They are mutually fixedly supported by 06a to 106d.

In other words, unless the reflecting mirrors 2 and 4 are exactly parallel, the light generated in the laser tube 1 cannot be reflected many times by the two reflecting mirrors 2 and 4 and resonated. The connection between a12 and the holding member 3 and the connection between the reflecting mirror 4 and the holding member 5 are performed via bellows 2a and 4a, respectively, and the attachment of the two reflecting mirrors 2 and 4 and the holding members 3 and 5 is made by A fine adjustment mechanism is provided at this location to ensure that the two reflecting mirrors 2 and 4 are accurately parallel to each other.

This fine adjustment mechanism compensates for deviations from the parallel state of the two holding members 3 and 5, and
The two reflecting mirrors 2 and 4 can be made completely parallel in a state where the lengths of the mirrors 6d do not change individually. In addition, the laser tube 1 and the holding members 3 and 5
Bellows 1a and 1b are also provided at the connection points with
This is designed to accommodate changes in the length of the laser tube 1 due to heat generation.

As is clear from FIGS. 1 and 2, the support member 6a
-6d are formed with communication holes 61a-61d in the longitudinal axis direction, and each communication hole 61a-61d is provided with circulating water for keeping the temperature of each supporting member 6a-6d constant. is being washed away. The amount of circulating water flowing through the communication holes 61a to 61d of this support member is, for example, about 101/min per communication hole of one support member. It absorbs the temperature difference between the upper part and the lower part, and all supporting members 6a
Temperatures of ~6d can be matched.

The circulating water flowing through the communication holes 61a to 61d of the support members 6a to 6d described above is sent out by the pump 7, and as shown by the arrow in FIG. It is configured to be returned to the pump 7 via communication holes 61a to 61d. Here, the temperature of the circulating water is exchanged by passing through the air-cooled radiator 8 and the transfer pipe 9 to match the room temperature of the place where the high-frequency excitation laser is installed. Therefore, even when the room temperature changes due to the season or daily weather, there is no need for special equipment such as a thermostat (the temperature of the circulating water can always be kept consistent with the room temperature. The temperature of the circulating water changes with changes in room temperature due to seasons, daily weather, etc. Therefore, the temperature of all the supporting members 63 to 6d changes to match the room temperature. The temperature of the support members 6a to 6d will change depending on the room temperature, but this temperature change applies to all of the support members 6a to 6d, and there is always no temperature difference between the support members, so there is no difference in temperature between the pair of support members. The parallel relationship between the two reflecting mirrors 2 and 3 attached to the holding members 3 and 5 is always maintained.

In the above embodiment, the circulating water sent out by the pump 7 is configured to exchange heat with the room temperature through the air-cooled radiator 8, but even without this air-cooled radiator 8, the pump 7 and the Heat exchange with room temperature can be performed by the transfer pipe 9 that connects the communication holes 61a to 61d of the member. When heat exchange is performed using only the transfer pipe 9 without providing the air-cooled radiator 8, the transfer pipe 9 is preferably formed of a material with high thermal conductivity, such as a metal pipe.

〔Effect of the invention〕

As detailed above, the laser resonator according to the present invention includes:
A communication hole is formed inside a support member that fixedly supports a pair of holding members each having a reflecting mirror attached thereto, and a heat medium is circulated through the communication hole of each support member by a circulation means. By matching the temperature of this heat medium with room temperature using a heat exchange means, a heat medium with the same temperature as room temperature is circulated through the communication holes of each support member, making it possible to keep the temperature of all support members constant. A low-cost laser resonator can be provided.

[Brief explanation of the drawing]

FIG. 1 is a diagram schematically showing an embodiment of a laser resonator according to the present invention, FIG. 2 is a cross-sectional view of the laser resonator in FIG. 1 taken along line A-A, and FIG. FIG. 2 is a diagram for explaining problems with a conventional laser resonator. (Explanation of symbols) 1... Laser tube, 2.4... Reflecting mirror, 3.5... Holding member, 63-6d... Supporting member, 61a-61d... Communication hole, 7. ...Pump, 8.Air-cooled radiator, 9.Transfer pipe.

Claims (1)

[Claims] 1. A laser tube, a pair of reflecting mirrors provided in parallel on both sides of the laser tube, a pair of holding members to which the respective reflecting mirrors are attached, and the holding members are mutually attached. a plurality of support members fixedly supported by the support member and having communication holes formed therein; a heat medium that circulates through the communication holes of each of the support members to bring the temperature of each support member to the same temperature; and the heat medium. A laser resonator comprising: a circulation means for circulating the heat medium through communication holes of each of the support members; and a heat exchange means for bringing the temperature of the heat medium to room temperature. 2. The laser resonator according to claim 1, wherein the heat medium is water. 3. The laser resonator according to claim 1, wherein the circulation means is constituted by a pump. 4. The laser resonator according to claim 1, wherein the heat exchange means is constituted by an air-cooled radiator. 5. The laser resonator according to claim 1, wherein the heat exchange means is constituted by a transfer pipe that transfers the heat medium.