JPH02281772A - Metal vapor laser oscillating tube - Google Patents

Abstract

PURPOSE:To keep the clearance of a heat-insulating material at zero at all times by dividing the heat-insulating material covering the outside into the plural in the axial direction of a tube and installing elastic members deformable in response to thermal expansion in the axial direction of the heat-insulating material near one end sections of the heat-insulating material. CONSTITUTION:Elastic members 20 are disposed at least one end sections in the axial direction of heat-insulating materials 12, and the thermal expansion of the heat-insulating materials 12 is absorbed. One end sections of the heat- insulating materials 12 in which thermal expansion is generated in the axial direction are made to abut against an end plate 19a, elongation is further generated and the end plate 19a is pushed, and springs 20 are compressed and the end plate 19a is moved. Accordingly, the thermal expansion of the heat- insulating materials 12 is compensated by the action of the elastic members 20, a clearance is hardly generated, the efficiency of heat insulation is improved, and a high-temperature region required for laser oscillation is ensured.

Description

[Detailed description of the invention] [Purpose of the invention] (Industrial application field) This invention relates to a metal vapor laser oscillation tube.

(Prior Art) A metal vapor laser oscillation tube generally has a structure as shown in FIG. In FIG. 4, reference numeral 1 denotes a ceramic inner tube with excellent heat resistance, and a discharge buffer gas such as He, Ne, etc. is supplied from a gas supply system 3 to a discharge section 2 inside the tube, and is exhausted by a rotary pump 4. , the voltage applied from the pulse high voltage power supply 7 between the anode 6 and the cathode 5 is from several KV to 10-odd KV, and the repetition frequency is from several KHz to 10-odd KV.
Plasma is generated by pulsed bipolar discharge using a high voltage pulse of Hz. Metal particles 8 are placed inside the ceramic inner tube 1, and the metal particles 8 come into contact with the discharge plasma to heat the inside of the ceramic inner tube 1 to an extremely high temperature, and the metal particles 8 evaporate, forming a laser medium. metal vapor is produced.

This metal vapor is uniformly distributed in the ceramic inner tube 1 at 10 to 10
Output mirrors placed at both ends of the ceramic inner tube 1 emit light with a wavelength specific to the metal by being excited by free electrons in the discharge plasma distributed at a density of 16n/■3. 10 and total reflection mirror 11
The light is amplified by 1J in an optical resonator composed of , and is output as a laser beam from the output mirror 10 side.

A heat insulating material 12 is wrapped around the ceramic inner tube 1 to keep the inside at a high temperature, and these are further inserted into a protective tube 13. Ceramic inner tube 1° heat insulating material 12 and protection tube 13 are supported by outer tube 15 via O-rings 14 at both ends. Further, the space between the outer tube 15 and the protection tube 13 is evacuated by a rotary pump 16 to form a vacuum insulation chamber 17. An insulating tube 18 is disposed in the middle of the outer tube 15 to electrically isolate the anode 5 side and the cathode 6 side.

FIG. 5 shows a prototype of the metal vapor laser oscillation tube as described above, which was manufactured by the present inventors. That is, the heat insulating material 12 wound around the outer circumference of the ceramic inner tube 1 is divided into a plurality of parts in the axial direction, and the positioning plates 19 are attached to both ends of the outer tube 15.
It was placed so that there was a gap between the two.

The reason for this is that the inside of the ceramic inner tube 1 is at a high temperature of approximately 1500°C, and the heat insulating material 12 undergoes thermal expansion in the circumferential direction and axial direction. This is because the structure requires sufficient clearance in the axial direction for safety reasons.

Figures 6 and 7 show the position of the heat insulating material 12 when laser oscillation is repeated several times.
Figure 7 shows a state in which there is an average gap due to the number of axial divisions in Figure 7, and a state in which the gap is concentrated near the center. That is, by repeating expansion and contraction, the heat insulating material 12 moves freely in the axial direction by the amount of the gap.

If laser oscillation is performed with a gap created like this (according to experiments by the inventors, a gap of 30 to 40 degrees was created for a ceramic inner tube of about 2 m), the insulation efficiency will decrease. However, since it is not possible to secure a uniform high temperature area that contributes to discharge, efficient output cannot be obtained.

(Problem to be solved by the invention) As mentioned above, in the metal vapor laser oscillation tube in which the insulation material is divided into multiple parts in the axial direction, the elongation due to the thermal expansion of the insulation material in the axial direction is reduced by the gap (space). ), so if the laser oscillation is repeated several times, the position of the gap will change, and especially if it is concentrated near the center, a uniform high temperature area cannot be secured and efficient output will not be achieved. I couldn't get it.

The present invention is intended to solve the above-mentioned problems, and its purpose is to provide a metal vapor laser oscillation tube that can always keep the gap between the insulation materials at zero and obtain efficient output.

[Structure of the Invention] (Means for Solving the Problems) The metal vapor laser oscillation tube of the present invention has a structure in which an elastic member is disposed at at least one end in the axial direction of the heat insulating material to absorb thermal expansion of the heat insulating material. And so.

(Function) In the metal vapor laser oscillation tube configured in this way, even after repeated laser oscillations, the thermal expansion of the heat insulating material is compensated for by the action of the elastic member, so that almost no gaps occur, and the heat insulation is maintained. Efficiency is improved, the high temperature region necessary for laser oscillation is secured, and metal vapor laser oscillation with high laser output becomes possible.

(Example) Hereinafter, the present invention will be explained in detail based on the illustrated example. Incidentally, the same parts as in the prior art are given the same reference numerals, and redundant explanations will be omitted.

FIG. 1 is a schematic cross-sectional view showing a metal vapor oscillator tube according to the present invention. As shown in this figure, the heat insulating material 12 is divided into a plurality of parts in the axial direction, and end plates 19a and 19b for positioning the heat insulating material 12 are provided at both ends. One end plate 19a is attached to the outer tube 15 by a bolt 21a via a spring 20.
The other end plate 19b is supported by bolts 21b.
It is fixed to the outer tube 15 by.

During laser oscillation, the heat insulating material 12 reaches a high temperature of about 1500"C and causes thermal expansion. Especially in a horizontally excited metal vapor laser oscillation tube that is long in the axial direction, the axial expansion is remarkable.Thermal expansion occurs in the axial direction. The heat insulating material 12 contacts the end plate 19a at one end and further stretches, pushing the end plate 19a, compressing the spring 2o, that is, moving the end plate to the position indicated by the broken line on the lower right side of FIG. 19a moves.Furthermore, when the laser oscillation is stopped, the heat insulating material 12 contracts, and the end plate 19a returns to the initial state shown by the solid line in FIG. 1 due to the elastic restoring force of the spring 20.

The main feature of this embodiment is that the expansion and contraction of the heat insulating material 12 in the axial direction is absorbed by the spring 20 provided in the end plate 19, so that the gap in the axial direction of the heat insulating material 12 is made zero.

Next, FIG. 2 shows a second embodiment of the present invention, which differs from the first embodiment in the structure of the elastic member.

In FIG. 2, one end 19a is divided into two parts, 19a and 19a', respectively.

The end plate 19a is fixed to the outer tube 15 with bolts 21a,
An end plate 19a' divided by a bellows 22 is attached to the fixed end plate 194 so as to be movable in the axial direction.

In this structure, when the heat insulating material 12 extends in the axial direction due to thermal expansion during laser oscillation, the end plate 19
By pressing a', the end plate 19a extends the bellows 22 and moves in the axial direction. (The state shown in Fig. 2) Then, when the laser oscillation is stopped, the heat insulating material 12 contracts, and the end plate 19a'' returns to its initial state due to the restoring force that causes the bellows 22 to return from its extended state to its initial state. .

In this embodiment as well, even when the heat insulating material is thermally expanded, the heat insulating material 12 is always pressed against the other end plate 19b by the elastic force of the bellows 22, so that no gap is created.

FIG. 3 shows a third embodiment of the present invention, which differs from the first and second embodiments in the structure of the elastic member.

In FIG. 3, the end plate 19a itself is constructed of a spring 24. This spring 24 is made by, for example, bending a part of the elastic plate so that the expansion and contraction of the heat insulating material 12 is absorbed by this curved part. It has a so-called diaphragm shape.

Note that the state in which the spring 24 is elastically deformed is shown by a broken line on the lower right side of FIG.

Note that it is also possible to form the spring 24 with a normal leaf spring without forming this curved portion.

In this way, the configuration of the third embodiment also provides the same functions and effects as those of the first and second embodiments, and the end plate 19
Since a itself is formed from the spring 24, the number of parts can also be reduced.

In addition, in the first to third embodiments above, one of the end plates at both ends is equipped with an elastic body or has the function of an elastic body, but it is also possible to implement the elastic body on both end plates. It is.

Further, the present invention is not limited to the above embodiments, and the structure of the elastic body or the structure of other parts can be modified in various ways without departing from the gist thereof.

[Effects of the Invention] As described above in detail based on the embodiments, according to the present invention, the effect of the heat insulating material is improved due to the structure in which the elastic member does not create a gap in the axial direction of the heat insulating material, and the efficiency is improved. It is possible to perform high laser oscillation.

[Brief explanation of drawings]

FIG. 1 is a schematic sectional view showing a metal vapor laser oscillation tube according to the present invention, and FIGS. 4 is a schematic sectional view showing a conventional metal vapor laser oscillation tube; FIG. 5 is a schematic sectional view showing an improved conventional metal vapor laser oscillation tube; Figure 6 and 7
This figure is a schematic sectional view showing a state in which oscillation is repeated in the oscillation tube of FIG. 5. 1...Ceramic inner tube, 3...Gas supply system, 5...
・Anode, 6... Cathode, 7... Pulse high voltage power supply, 8
...Metal particles, 10...Output mirror 11...Total reflection mirror 12-...Insulating material, 15-...Outer tube, 19a
, 19b19b'', 23... end plate, 20... spring (
elastic member), 22... bellows (elastic member), 24.
...Spring (elastic member).

Claims (1)

[Claims] A discharge gas is supplied into a tube in which metal particles are arranged, and a voltage is applied between discharge electrodes provided in the tube to form a discharge plasma to vaporize the metal particles, and the vaporized metal particles are vaporized. In a metal laser oscillation tube that performs laser oscillation by exciting metal particles in the discharge plasma with free electrons in the discharge plasma, a heat insulating material covering the outside of the tube is divided into a plurality of parts in the axial direction of the tube, and at least one of the tubes is A metal vapor laser oscillation tube characterized in that an elastic member that can be deformed according to the thermal expansion in the axial direction of the heat insulating material is provided near the end of the metal vapor laser oscillation tube.