JPH03237778A - Metal vapor laser equipment - Google Patents

Abstract

PURPOSE:To keep high temperature over the total length in the axial direction of an inner discharge tube, and realize stable laser oscillation, by installing a temperature fall preventing means to keep the whole temperature of the inner discharge tube higher than the melting point temperature of inserted metal grains. CONSTITUTION:A temperature fall preventing means 15 is constituted as follows: a heat insulating layer 3 surrounding the outer periphery of an inner discharge tube 2 is formed to be longer in the axial direction than the total length of the inner discharge tube 2 containing laser windows 6, 10, and encloses the the whole part of the tube 2; laser leading-out holes 16 are formed so as to be connected with the laser windows 6, 10, in the axial center part of the atmosphere heat insulating layer 3. When the inner discharge tube 2 is heated by pulse discharge between electrodes in an atmosphere of discharge gas 14 in the tube 2, metal grains in the tube 2 are fused and vaporized. Thus metal vapor is generated. At this time, since the outer periphery of the inner discharge tube 2 is completely surrounded by the heat insulating layer 3, the temperature fall at the end portions of the inner discharge tube 2 can be prevented.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a metal vapor laser device for obtaining laser light by melting metal grains such as copper grains with discharge heat and exciting metal vapor, and in particular, measures to prevent temperature drop at least in the electrode portion of the inner discharge tube. The present invention relates to a metal vapor laser device.

[Conventional technology]

FIG. 5 is a sectional view showing a conventional metal vapor laser device, in which 1 is a vacuum jacket made of a metal outer tube;
1a is a vacuum layer formed on the peripheral wall of the vacuum jacket 1 to control heat loss due to radial heat transfer and convection from the inner discharge tube 2, which will be described later; 2 is the vacuum layer 1a formed on the peripheral wall of the vacuum jacket 1;
A discharge inner tube 3 is inserted into the axial center of the inner discharge tube with both ends protruding outward, and is filled between the vacuum jacket 1 and the discharge inner tube 2, and is inserted in the discharge inner tube 2 in the radial direction. an atmospheric insulation layer such as a wool layer to prevent heat transfer to and heat loss due to convection; 4 is metal grains such as copper grains installed in the discharge inner tube 2 to generate metal vapor; 5 is a metal grain such as a copper grain that is installed in the discharge inner tube 2; A cylindrical cathode is connected to one end (left end in FIG. 5) of the inner tube 2, 6 is a laser window provided at the outer end of the cathode 5 for extracting laser light from the cathode side, and 7 is the cathode 5. 9 is a cylindrical anode connected to the other end (right end in FIG. 5) of the discharge inner tube 2, and 10 is an outer end of the anode 9. The provided laser window for extracting laser light on the anode side, 11 is an anode terminal, and this anode terminal 11 connects the vacuum jacket 1 and the connection viI2 that closes the anode side end of the vacuum jacket 1, and the anode 9 side. It is connected to the anode 9 via the electrode flange 13. 1
4 is a discharge gas sealed in the discharge inner tube 2. Next, the operation will be explained. When a pulse voltage is applied between the cathode terminal 7 and the anode terminal 11, a pulse discharge is generated between the cathode 5 and the anode 9 in the atmosphere of the discharge gas 14 in the discharge inner tube 2, thereby causing the above-mentioned discharge. The inside of the inner tube 2 is in a discharge state. The heat generated by the discharge is conducted to the discharge inner tube 2 and radiated from the discharge inner tube 2 in the radial and axial directions. Heat loss due to radiation from the discharge tube 2 is suppressed as much as possible by the atmospheric heat insulating layer 3 surrounding the discharge inner tube 2 and the vacuum layer 1a.
The temperature of the discharge inner tube 2 rises. Due to this temperature rise, the metal particles 4 within the discharge inner tube 2 are melted, and metal vapor necessary for obtaining laser oscillation is generated. Then, this metal vapor is excited by the pulse voltage, causing population inversion. For this reason, the laser windows 6 at both ends of the discharge inner tube 2. Optical resonator (not shown) outside i0
If these windows 6 and 10 are arranged, laser light can be obtained through these laser windows 6 and 10.

[Problem to be solved by the invention]

Since the conventional metal vapor laser device is configured as described above, when the inner discharge tube 2 is heated by the pulse discharge between the electrodes 5 and 9, the metal particles melt in the high temperature part within the inner discharge tube 2. Metal vapor is generated by evaporation, but the temperature of the discharge inner tube 2 decreases particularly at the ends, making the overall temperature distribution uneven.
The metal vapor moves from the high temperature part to the low temperature part, and metal vapor is no longer generated in the low temperature part, so the amount of metal vapor generated becomes insufficient and there is a problem that stable laser oscillation cannot be obtained. This invention was made in order to solve the above-mentioned problems, and it is possible to prevent temperature drop at the ends of the discharge inner tube, etc., and to obtain a good temperature distribution over the entire axial length of the discharge inner tube. It is an object of the present invention to provide a metal vapor laser device that can generate sufficient metal vapor and always perform stable laser oscillation.

[Means to solve the problem]

The metal vapor laser device according to the present invention has a laser window made of a high melting point material, such as sapphire, and is provided with means for keeping the temperature of the entire interior of the discharge tube higher than the melting point of the inserted metal grains. It is.

[For use]

In the metal vapor laser device of the present invention, a temperature drop is prevented in the electrode portion and the window portion of the discharge inner tube where the temperature drop is most likely to occur, so that the melting point of the metal particles inserted over the entire axial length of the discharge inner tube is prevented. The temperature above is obtained, and therefore,
A satisfactory amount of metal vapor generation can be obtained and stable laser oscillation can be performed at all times.

【Example】

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view of a metal vapor laser device according to a first embodiment of the present invention, and the same or corresponding parts as in FIG. 5 are given the same reference numerals and redundant explanation will be omitted. In the figure, I5 is the electrode 5.9 of the discharge inner tube (discharge tube) 2.
This is a temperature drop prevention means that prevents a temperature drop in the laser windows 6 and 10. The temperature drop prevention means 15 of the first embodiment protects the atmospheric heat insulating layer 3 surrounding the outer periphery of the discharge inner tube 2 from the inner discharge tube 2.
It is longer in the axial direction than the entire length including the laser windows 6 and 10, and wraps around the entire discharge inner tube 2 including the laser windows 6 and 10, and the axial center of the atmospheric insulation N3 has the above-mentioned Laser extraction hole 1 leading to each laser window 6°10
The configuration includes 6. Next, the operation of the first embodiment will be explained. Between the electrodes in the atmosphere of the discharge gas 14 in the discharge inner tube 2 (
The inner discharge tube 2 is caused by the pulse discharge between the cathode 5 and the anode 9.
When heated, the metal particles 4 in the discharge inner tube 2 melt and vaporize, generating metal vapor. At this time, since the discharge inner tube 2 and the laser windows 6 and 10 are surrounded by the atmospheric heat insulating layer 3 which extends longer than the entire length of the discharge inner tube 2 in the axial direction, the ends of the discharge inner tube 2 temperature drop is reliably prevented. As a result, a temperature higher than the melting point temperature of the inserted metal can be obtained over the entire length of the discharge inner tube 2 in the axial direction.
Metal vapor is efficiently generated from the entire interior of the discharge inner tube 2, and stable laser oscillation can always be performed from the laser windows 6, 10. FIG. 2 is a sectional view of a metal vapor laser device in which a temperature drop prevention means 15 according to a second embodiment of the present invention is assembled. It consists of a vacuum layer provided at the first laser window 6.10 of the discharge inner tube 2, and second laser windows 6a, 10a are provided at the outer end of this vacuum layer 15. There is. Also in the case of this second embodiment, the first laser window 6,
The entire discharge inner tube 2 including 10 is buried in the atmospheric heat insulating layer 3, and there is a temperature drop prevention device in the first laser window 6° 10 in the atmospheric heat insulating layer 3. By providing the vacuum layer 15 as a means,
The temperature drop at the end of the discharge inner tube 2 is more efficiently prevented, and more stable laser oscillation can be achieved. FIG. 3 is a sectional view of a metal vapor laser device in which a temperature drop prevention means 15 according to a third embodiment of the present invention is assembled;
The figure is an enlarged cross-sectional view of the main part. The temperature drop prevention means 15 of this third embodiment is disposed at the end of the discharge inner tube 2 made of an insulator, and together with the discharge inner tube 2, an atmospheric heat insulation layer 3 is formed. It consists of a cylindrical insulator 15a protruding outward from the electrode flanges 8, 13 inserted into the atmospheric heat insulating layer 3, and a heater 15b wound around the insulator 15a. In this third embodiment, a laser window 6.10 (only one laser window 6 is shown) is provided at the tip of the insulator 15a. Therefore, in the case of the third embodiment, the end portion of the discharge inner tube 2, which is the low temperature portion, is forcibly heated by the heater 15b.
Since the temperature of the entire discharge inner tube 2 becomes higher than the melting point of the metal particles 4, metal vapor can be generated from various parts of the discharge inner tube 2 more efficiently, and stable laser oscillation can be obtained for a long time. .

【Effect of the invention】

As described above, according to the present invention, the temperature drop prevention means for keeping the overall temperature of the inner discharge tube higher than the melting point temperature of the inserted metal particles is provided, so that the temperature drop of the discharge tube is minimized. It is possible to prevent the temperature drop at the electrode and window parts, which is likely to occur, and to maintain the temperature higher than the melting point of the inserted metal over the entire length of the discharge inner tube in the axial direction, so that a satisfactory amount of metal vapor can be generated. This has the advantage that stable laser oscillation can be performed at all times.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a metal vapor laser device according to a first embodiment of the invention, FIG. 2 is a sectional view of a metal vapor laser device according to a second embodiment of the invention, and FIG. 3 is a sectional view of a metal vapor laser device according to a second embodiment of the invention. FIG. 4 is an enlarged sectional view of a main part of FIG. 3, and FIG. 5 is a sectional view of a conventional metal vapor laser device. 2... Discharge inner tube, 3... Atmospheric insulation layer, 4... Metal particles, 5... Cathode (electrode), 9... Anode (electrode), 1
5... Temperature drop prevention means. In addition, in the figures, the same reference numerals indicate the same or equivalent parts. Patent issuer: Mitsubishi Electric Corporation No. 1 Figures 6o, 10o: Lepe Tatsumi Otsuji Figure 8: Electric f ribs ``'')゛゛ 15o: Itiroki Tama 15
b: Heater Fig. 4

Claims (1)

[Claims] In a metal vapor laser device comprising a discharge tube containing metal grains for generating metal vapor and placed between electrodes, and an atmospheric heat insulating layer surrounding the discharge tube, a metal in which the entire inside of the discharge tube is inserted. A metal vapor laser device characterized in that it is provided with means for preventing temperature drop to maintain the temperature above the melting point of the metal vapor laser.