JPS62101093A - Metal vapor laser apparatus - Google Patents

Abstract

PURPOSE:To obtain a long-life metal vapor laser apparatus which provides high output steadily by composing a discharge tube of a multilayer tube. CONSTITUTION:The discharge tube 20 of a metal vapor laser apparatus is composed of a ceramic inner tube 20A, a ceramic intermediate tube 20B and a high melting pint metal outer tube 20C. When discharge is induced in the discharge part 2 in the inner tube 20A, discharge plasma is induced inside auxiliary electrodes 21a and 21b. As the inner tube 20A is supported by ceramic spacers 22 only, the temperature distribution in the tube is nearly uniform. Gas gaps 5A and 6A are provided between the outside circumferences of the tip parts of anodes 5 and 6 and the inside circumference of the intermediate tube 20B so that even if the tubes are heated to the high temperature, the two open ends of the intermediate tube 20B are not influenced by the heat. As the outer tube 20C is closely contacted with the outside of the intermediate tube 20B, the temperature in the intermediate tube 20B can be kept uniform in the portion corresponding to the length of the outer tube 20C. With this constitution, the output can be elevated significantly.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a metal vapor laser device using metal vapor as a laser medium, and particularly to a metal vapor laser device that is an improved group Ti tube containing metal particles. Regarding.

[Technical background of the invention]

Conventionally, this type of metal vapor laser device is constructed as shown in FIG. 3, and the discharge tube is a ceramic tube 1 with poor heat resistance.

The ceramic tube 1 receives HC! from the gas supply system 3 to the discharge section 2 inside it. , Ne, and the like are supplied and exhausted by a rotary pump 4, and an anode 5 and a cathode 6 are disposed facing each other at both ends.

A pulsed high voltage from a pulsed high voltage power source 7 is applied between the anode 5 and the cathode 6, and a pulsed bipolar discharge '1'u is performed to generate discharge plasma. This pulsed high voltage has a voltage of several kV to several tens of kV, and a repetition frequency of several kilovolts.
~10 k l - I z.

A plurality of metal particles 8 are arranged in the ceramic tube 1,
When the metal particles 8 come into contact with the discharge plasma, the lamic tube 1 is heated to an extremely high temperature 1111 and the metal particles 8 evaporate, thereby generating metal vapor which becomes the laser medium.

The metal vapor is 1014 to 1016n in the ceramic tube 1.
The casing 9 is uniformly distributed with a density of / cd, and when excited by the free electrons in the discharge plasma, emits light with a wavelength specific to the metal of A, and this light is emitted by the outer shell 9.
Through the window 9a, the laser beam is amplified while reciprocating through an optical resonator consisting of an output mirror 10 and a total reflection mirror 11 placed on both sides of the ceramic tube 1, and is output as a laser beam from the output mirror 10 side. Ru.

In addition, on the outer periphery of the lamic tube 1, a plurality of shielding plates 1 made of high melting point metals such as tungsten, tantalum J3, and molybdenum are provided.
A vacuum insulation chamber 13 is provided to house the ceramic tubes 1 while coaxially stacking them to keep the ceramic tubes 1 warm. The vacuum insulation chamber 13 is hermetically sealed by a ceramic tube 1 which is telescopically connected via a bellows 14, and the room is evacuated by a rotary pump 15.

Further, in FIG. 3, reference numeral 16 is a water-cooled 7JI pipe that is wound around the outer periphery of the casing 9 to cool it.

[Problems with background technology]

However, such conventional metal vapor laser devices have the following problems.

That is, in order to shift the laser light output upward, when the pressure of the discharge buffer gas is increased and the input power is increased, 1/i Lightning starts and the tips of both electrodes 5.6 become locally heated. Furthermore, since the outer circumferential surfaces of the tips of both electrodes 5.6 are in contact with the inner circumferential surface of the ceramic tube 1, the ceramic tube 1 is locally overheated at this contact portion.

Due to this overheating, the life of the ceramic tube 1 is extremely shortened, and in the worst case, cracks may occur.

Furthermore, since the ceramic tube 1 that vacuum-seals the vacuum insulation chamber 13 is provided with an O-ring 17 and a σ bellows 14, both ends of the ceramic tube 1 where these are located are cooled. For this reason, a temperature gradient was created in which the axially intermediate portion of the ceramic tube 1 was at a high temperature and the opposite ends thereof were at a low temperature.

As a result, the following problems occurred.

First, if the metal vapor source is copper, for example, the temperature range of the ceramic tube 1 in which the maximum light output is obtained is 14
Since the temperature range was 50 to 1,500°C, which was quite unique, the gain range as a +7 device was unique.

Second, evaporated metal such as copper condenses on the lower parts of both ends of the ceramic tube 1, blocking the laser optical path and forming one of the causes of output reduction.

Thirdly, the high-pitched portion in the center of the ceramic tube 1 softens and bends due to the high temperature, which blocks the laser output port and prevents the laser light output from decreasing.

(Object of the Invention) The present invention was made in consideration of the above circumstances, and its purpose is to expand a high-density and uniform plasma region by 1h (high electron temperature) α, and to stabilize metal alcohol. The object of the present invention is to provide a long-life metal vapor sea 11 device that can stably produce high output by generating -C.

[Summary of the invention]

In order to achieve the above-mentioned [1], the present invention supplies a 5U buffer gas to a discharge tube containing metal particles to reduce the discharge, and provides a vacuum insulation chamber around the outer periphery of the 11I electric discharge tube. J5 is installed in the laser device, and the discharge tube is housed in an inner tube containing the metal particles and having a pair of auxiliary electrodes disposed therein so as to be slidable in the axial direction through a space. An intermediate tube that airtightly seals the vacuum insulation chamber, and a high melting point gold J11 that is tightly attached to the outer periphery of the intermediate tube.
′! The feature is that it is configured into a multiple tube with the outer tube of the IJ.

[Embodiments of the invention]

Embodiments of the present invention will be described below with reference to FIGS. 1 and 2. In addition, in the figure, the same reference numerals are omitted for the parts that pass through Figure 3 and J (explanation of the overlapping parts [
, 1 omitted.

FIG. 1 shows the overall configuration of an embodiment of the present invention, in which a discharge tube 20 is housed coaxially in the center of a casing 9, which is an outer envelope.

The detonator 20 is configured as a three-tube tube that sequentially accommodates an inner tube 2OA, an intermediate tube 20B, and an outer tube 20G in a coaxial manner, as shown in the enlarged vertical cross-sectional view of the principal part in FIG.

The inner tube 20△ is made of heat-resistant f1 ceramics that can be used up to the boiling point temperature of the metal particles 8, and is formed into a circular tube shape. A pair of short-axis cylindrical auxiliary electrodes 21a and 21b are provided in the part.
It is fitted tightly inside. A pair of auxiliary electrodes 21a, 2
The members 1b are made of a high melting point metal such as tungsten, tantalum, or molybdenum, and are arranged to face each other left and right with a required interval in the discharge section 2 within the inner tube 20Δ. Each auxiliary electrode 21a, 21b is heated by the discharge plasma generated in the discharge FIs2, and the heat is transferred to the inner tube 20△
Heat is transferred to both open ends of the inner tube 2OA, thereby making the temperature distribution of the inner tube 2OA uniform.

On the outside of the inner tube 20A, a cylindrical anode 5J'3 and a cathode 6 having substantially the same diameter as the inner tube 20Δ are disposed opposite to the inner tube 20Δ at a required distance in the axial direction. Inner tube 20
△ is housed in the intermediate tube 20B of the highly heat-resistant Hiramix device with a larger diameter and longer axis in the axial direction [moveable and coaxially] through a plurality of ring-shaped spacers 22, and the inner tube 2
Thermal expansion and contraction in the axial direction of the OA is freed. Spacer 2
2 is made of ceramics with low thermal conductivity, and the inner tube is 20△
A certain degree of heat insulation is provided between the intermediate pipe 20B and the intermediate pipe 20B.

Each front end of the intermediate tube 20B extends to the outer periphery of the tip of the anode 5 and the cathode 6, respectively, and there is an annular gap between the two, that is, a gas gear V-tube 5Δ, 6A to prevent the 11i electric buffer gas from intervening. It is set. Also, intermediate pipe 2
An outer ring 23 is further fitted on the outer periphery of the O-ring 17 that is placed on the outer periphery of each opening end of 0B, and the outer ring 23 is telescopically connected to the partition wall that partitions the vacuum insulation v23 via the bellows 14. has been done. As a result, the intermediate pipe 20B
The central part of the vacuum insulation chamber 13 is hermetically sealed.

An outer tube 20 having substantially the same length as the inner tube 20A is tightly fitted onto the outer periphery of the axially intermediate portion of the intermediate tube 20B. The outer tube 20C is made of a high melting point metal such as tungsten, tantalum, or molybdenum and is formed into a circular tube shape to prevent thermal deformation such as bending of the intermediate tube 20B during discharging in the discharge section 2, and has high thermal conductivity. This aims to make the temperature distribution of the intermediate tube 20B uniform.

Next, the operation of this embodiment will be described.

First, the discharge section 2 and the vacuum insulation chamber 13 are evacuated using the rotary pumps 4 and 15, respectively. Next, gas supply system 3
/Jl r etc. A discharge buffer gas such as Ne is supplied into the inner tube 2OA, and a pulsed high voltage from a pulsed high voltage power source 7 is applied to the anode 5 and cathode 6, and the ceramic inner tube 2OA is
Discharge is performed in the discharge section 2 in A. The inner tube 20Δ is heated by the discharge plasma generated during this discharge, and for example, in the case of the copper vapor beam 11, the axially intermediate portion of the inner tube 20Δ is heated to 1/I 50 to 1500'C, which is optimal for laser oscillation. .

At this point, the inner tube 20△ is supported only by the spacer 22 made of ceramics with poor thermal conductivity.
The temperature distribution inside the tube is uniform because the negative heat from the discharge plasma is constant.

In addition, since both opening ends of the inner tube 20Δ are open, they are somewhat cooled by fIi radiation cooling, but the inner tube 2OA is Since the heat inside is transferred to both open ends and heated, the degree of stagnation F within the inner tube 20Δ becomes uniform. As a result, the gain range as a laser device becomes extremely wide.
It is possible to achieve a significant increase in output.

Further, when the cathode 6 and the anode 5 are discharging, the auxiliary electrodes 21a and 21b function as indoor electrodes inside the inner tube 2OA. In other words, discharge plasma is generated inside the pair of left and right auxiliary electrodes 21a and 21b.

Is the inner tube 2OA 7t? Although the IL5 undergoes thermal expansion η, since a sufficient distance is set between the pair of electrodes 5 and 6 in the axial direction, the IL5 will not be damaged by hitting the electrodes 5 and 6.

Moreover, since the inner tube 20Δ is freely supported by the base 122, the inner tube 20Δ can freely expand and contract in the axial direction.

The outer periphery of the tip of the anode 5 and the negative J46 and the inner periphery of the intermediate tube 20B are provided with gas hooks 11, 5△, 6A, respectively.
Even if the tips of the 1i poles 5 and 6 are heated to a high temperature, both open ends of the intermediate tube 20B are not thermally affected, and the intermediate tube 20
[3] Long life can be achieved.

The outer periphery of the intermediate tube 20B is made of an outer T made of Pl melting point metal.
Since the outer tube 20C has a heat conduction of 120C, the length of the outer tube 20C is the same as that of the intermediate tube 20.
[The temperature within 3 can be maintained uniformly. Further, even if the inner tube 2OA softens at high temperatures, it is supported by the outer tube 20C, so bending can be prevented.

Note that the present invention is not limited to the above-mentioned embodiments,
For example, the inner tube 2OA may have a divided structure, or a circular ceramic tube may be further fitted around the outer circumference of the outer tube 20C.

(Effects of the Invention) As explained above, the present invention provides a discharge tube containing metal particles with a tube for use in the IIi electric current bar. After supplying gas, a vacuum insulation chamber was installed around the outer periphery of the discharge tube.
In the F device, the detonator is housed in an inner tube in which the metal particles are built in and a pair of auxiliary electrodes are disposed facing each other inside, and the inner tube is accommodated in a slidable manner in the -C axis direction via a sub-V. A multi-tube structure was constructed with an intermediate tube that airtightly sealed the double insulation constriction, and an outer tube made of a high-melting point metal that was tightly fitted around the outer periphery of the intermediate tube.

Therefore, according to the present invention, it is possible to make the temperature distribution of the inner tube containing metal particles and forming the discharge part uniform over the entire length, so that the high-temperature and high-density plasma region can be transferred to the inner tube. can be distributed almost uniformly over almost the entire length.

Thereby, it is possible to significantly increase the laser light output and improve stability.

Furthermore, since the intermediate tube can be prevented from being bent and its integrity can be maintained, the life of the discharge tube can be extended, and reliability and operating efficiency can be improved.

[Brief explanation of drawings]

Fig. 1 is a partial cross-sectional view of the entire structure of an embodiment of a metal vapor laser device according to the present invention; Fig. 2 is an enlarged cross-sectional view of the main parts shown in Fig. 1; The figure is a partial cross-sectional view of the overall configuration of a conventional metal vapor sear 11 device. 1.20...Discharge tube, 2...Discharge part, 3...Gas supply IM, 4,15...Rotary pump, 5...Anode, 6...Cathode, 8...Metal Particles, 13... Vacuum insulation chamber, 20A... Inner tube, 20B... Intermediate tube, 20C
... Outer tube, 21a, 21b... Auxiliary electrode.

Claims (1)

[Scope of Claims] 1. A metal vapor laser device in which a discharge buffer gas is supplied to a discharge tube containing metal particles for discharge, and a vacuum insulation chamber is provided around the outer periphery of the discharge tube. an inner tube that contains metal particles and has a pair of auxiliary electrodes disposed therein facing each other; an intermediate tube that accommodates the inner tube so as to be slidable in the axial direction via a spacer and airtightly seals the vacuum insulation chamber; A metal vapor laser device characterized in that the intermediate tube is configured with a multi-tube structure including an outer tube made of a high melting point metal that is tightly fitted around the outer periphery of the intermediate tube. 2. The metal vapor laser device according to claim 1, wherein the inner tube, intermediate tube, and spacer are made of ceramics.