JPS63239881A - Metal vapor laser oscillator - Google Patents

Abstract

PURPOSE:To shorten a time from the start of discharge to a laser oscillation by composing an electrode section of an electrode connected to the end of a discharge tube, a plate secured through a thermal insulator having heat resistance, and a conductive member for electrically connecting the electrode to the plate. CONSTITUTION:Electrode sections 21a, 21b are composed of an electrode 22 engaged with the end of a discharge tube 2, a plate 24 secured through a thermal insulator 23 having heat resistance to the electrode 22, and a thin plate 25 made of high melting point V, Mo as a conductive member for electrically connecting the electrode 22 to the plate 24. Thus, the escape of the heat of the tube 2 through the sections 21a, 21b can be suppressed, and the heating time of the tube 2 from the start of discharge to the laser oscillation can be shortened. The heat escaping from the tube 2 is increased at the ratio of radially radiating, the temperature distribution of the tube 2 in the lengthwise direction becomes substantially uniform, and the whole exciting region is allowed to gain access to the optimal temperature of the laser oscillation, thereby increasing laser output.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a metal vapor laser oscillation device, and more particularly, to a metal vapor laser oscillation device in which an electrode portion is improved.

(Prior Art) Conventionally, as a metal vapor laser oscillation device, one shown in FIG. 3, for example, is known.

1 in the figure is the main body of the laser device. The device main body 1 is provided with a discharge tube 2 made of high temperature resistant ceramics, etc., and flanged electrodes 3, 4 made of high melting point tungsten or molybdenum are provided at both ends of the discharge tube 2. Further, at a predetermined position of the apparatus main body 1, a gas supply device 5. A vacuum pump 6 is connected. Furthermore, O-rings 7.7 are provided at both longitudinal ends of the device main body 1. '8.9 are provided respectively. On the straight line passing through these windows 8 and 9, that is, on the oscillation optical path of the laser beam,
High reflective mirror 10. An output mirror 11 is provided.

An electric wire 'a12 is provided between the electrodes 3 and 4. Further, between the outer circumference of the discharge tube 2 and the outer tube 1a of the device main body 1, there is a cylindrical thermal insulator 13, a part of which is connected to the electrode 3.
It is set up to surround.

A ring-shaped high voltage insulator 14 is connected to a thermal insulator 13 between the end of one of the electrodes 3 and the outer wall 1a via an O-ring 15.
It is set up to surround a part of the

Furthermore, near the electrode 4.5 on the outer periphery of the device main body 1,
A cooling pipe 16 is provided to cool down the device main body 1 which has reached a high temperature.

In a device having such a structure, for example, an equivalent metal laser medium 17 is placed inside the discharge tube 2. Then, when the inside of the discharge tube 2 is filled with Ne gas of, for example, 10 to 20 Torr and discharged, the discharge tube 2 is heated by the energy of the discharge, and its temperature reaches several hundred degrees. At this time, the vapor in the medium 17 reaches a predetermined pressure, the metal vapor is excited by discharge, and laser oscillation occurs.

By the way, the lifetime of the upper energy level of the oscillation line of a metal vapor laser is very short, and therefore the discharge for excitation must rise quickly. Therefore, the discharge tube 2 and the outer tube 1a of the laser device must have a coaxial structure and the inductance must be made as small as possible. Therefore,
Conventionally, as shown in Fig. 3, the structure was such that the electrode 3.4 also served as a flange for sealing the discharge tube 2 and the outer tube 1a, and the area around the 7 lange was cooled to protect the 0 ring 7. be done.

However, according to the conventional device, since the electrodes 3 and 4 are made of tungsten, which has a relatively high thermal conductivity and has a melting point, the heat of the discharge tube 2 escapes to the outside through the electrodes 3 and 4, and the discharge starts. The time from when the discharge tube 2 is heated to the temperature required to generate metal vapor until laser oscillation occurs is usually 0.5 to 1.5 hours, which is very long compared to other lasers. It has the problem of being long.

(Problems to be Solved by the Invention) The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a metal laser oscillation device that can shorten the time from the start of discharge to laser oscillation.

[Structure of the Invention] (Means for Solving the Problems) The present invention provides a method for disposing a metal laser medium inside a discharge tube having a pair of electrode portions at both ends, and bringing the inside of the discharge tube into a high temperature state by electric discharge. In a metal vapor laser oscillation device that vaporizes a medium and performs laser oscillation, the electrode portion is connected to an electrode connected to an end of a discharge tube, and a heat insulator having heat resistance is connected to this electrode. The gist is that it is composed of a fixed plate and a conductive member that electrically connects the electrode and the plate.

(Function) According to the present invention, (a) Since a thin plate made of vanadium or the like with low thermal conductivity is used to connect the electrode and the plate, which are part of the electrode part, the heat of the discharge tube is transferred to the outside through the electrode part. It is possible to prevent people from escaping.

Therefore, a certain amount of heat remains in the discharge tube at the start of discharge, and the heating time of the discharge tube from the start of discharge until laser oscillation becomes possible is shortened.

(b) Since the heat escaping from both ends of the discharge tube is reduced, a larger proportion of the heat escaping from the discharge tube is radiated in the radial direction, and the concentration distribution in the direction of the discharge tube is more uniform than in conventional devices. Become.

(c) Generally, in the case of a metal vapor laser, its oscillation output largely depends on the temperature of the medium atmosphere. Therefore, in the case of the present invention, the temperature distribution within the discharge tube becomes nearly uniform, so that the entire excitation region can be brought close to the optimum temperature for laser oscillation, and the laser output can be increased.

(Example) Hereinafter, an example of the present invention will be described with reference to FIG. 1 and the second factor. Here, FIG. 1 is a sectional view showing the entire metal vapor laser oscillation device according to the present invention, and FIG. 2 is a perspective view in which each member of the electrode section of the device is cut away. However, since this device has the same structure as the conventional device (FIG. 3) except for the electrode section, the same members will be given the same reference numerals and explanations will be omitted.

21a and 21b in the figure are electrode parts attached to both ends of the discharge tube 2, respectively. This electrode portion 21a.

21b includes an electrode 22 fitted to the end of the discharge tube 2, a plate 24 fixed to the electrode 22 via a heat insulating material 23 having heat resistance, and a structure in which the electrode 22 and the plate 24 are connected to each other. It is composed of a thin plate 25 as a conductive member for electrical connection. Here, the thermal insulator 23 is, for example, an annular ceramic plate. The plate body 24 is made of a metal member such as SUS, for example, the plate body 24 of one electrode part 21a is connected to the high voltage side of the high voltage N source, and the plate body 24 of the other electrode part 21b is connected to the low voltage side of the high voltage power source. connected to the side. The thin plate 25 has a U-shaped annular shape and is made of a highly heat-resistant material such as vanadium or molybdenum. Further, the electrode 22 and the fixing screw (not shown) are each made of molybdenum.

Here, the electrode 22 and the thermal insulator 23. The heat insulator 23 and the plate 24 are fixed using separate screws, so that heat does not escape through the screws.

According to the above embodiment, the electrode parts 21-a and 21b each include an electrode 22 fitted to the end of the discharge tube 2, and a plate fixed to the electrode 22 via a heat-resistant thermal insulator 23. body 2
4 and a thin plate 25 made of molybdenum with a high melting point as a conductive member that electrically connects the electrode 22 and the plate 24, so that it has the following effects. .

(a) Since the thin plate 25 made of vanadium or the like having low thermal conductivity is used to connect the electrode 22 and the plate 24, it is possible to suppress heat from the discharge tube 2 from escaping to the outside through the electrode parts 21a and 21b. Therefore, a certain amount of heat remains in the discharge tube 2 at the start of discharge, and the heating time of the discharge tube 3 from the start of discharge to the time when laser excavation becomes possible is shortened.

(b) Since the heat escaping from both ends of the discharge tube 2 is reduced, a larger proportion of the heat escaping from the discharge tube 2 is due to radiation in the radial direction, and the temperature distribution in the length direction of the discharge tube 2 is more uniform than in conventional devices. become closer to you.

(c) Generally, in the case of a metal vapor laser, its oscillation output largely depends on the temperature of the medium atmosphere. Therefore, in the case of the present invention, the temperature distribution within the discharge tube becomes nearly uniform, so that the entire excitation region can be brought close to the optimum temperature for laser oscillation, and the laser output can be increased.

In the above embodiment, a case was described in which a U-shaped ring-shaped thin plate made of vanadium or the like was used as the conductive member, but the present invention is not limited to this. A thin plate or radial wire may also be used. However, the material is the same as in the example.

[Effects of the Invention] As detailed above, according to the present invention, the time from the start of discharge to laser oscillation can be shortened, the temperature distribution in the length direction of the discharge tube can be made uniform, and the laser output can be increased. A metal laser oscillation device can be provided.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a metal vapor laser oscillation device according to an embodiment of the present invention, FIG. 2 is a perspective view of an electrode section of the same device, and FIG. 3 is a sectional view of a conventional metal vapor laser oscillation device. . DESCRIPTION OF SYMBOLS 1... Laser device main body, 1a... Outer tube, 2... Discharge tube, 5... Gas supply device, 6... Vacuum pump, 7
... Output mirror, 8, 9... Window, 10... High reflection mirror, 11... Output mirror, 12... Power supply, 13
...Thermal insulator, 14...High voltage insulator, 17...
Cooling pipe, 21a. 21b... Electrode portion, 22... Electrode, 23... Conductive member, 24... Plate body, 25... Thin plate.

Claims (2)

[Claims] (1) A metal vapor laser oscillation device in which a metal laser medium is disposed inside a discharge tube having a pair of electrode portions at both ends, and the inside of the discharge tube is brought into a high temperature state by discharge to vaporize the medium and perform laser oscillation, The electrode part includes an electrode connected to an end of the discharge tube, a plate fixed to the electrode via a heat-resistant thermal insulator, and a conductive member that electrically connects the electrode and the plate. A metal vapor laser oscillation device comprising: (2) The metal vapor laser oscillation device according to claim 1, wherein the conductive member is a thin plate or a radial wire.