JP2905646B2 - Metal vapor laser equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrode structure of a metal vapor laser apparatus which heats a metal by gas discharge, vaporizes and excites the metal, and obtains a laser output.

[0002]

2. Description of the Related Art FIG. 3 is a sectional view showing a conventional metal vapor laser apparatus disclosed in Japanese Patent Application Laid-Open No. Hei 1-220489. In the figure, a metal tube laser device is provided with a ceramic tube 2 as a discharge tube.
The anode 4 and the cathode 5 are connected to each other at both ends via a connecting member 2a, and a pulse bipolar discharge is performed between these electrodes 4 and 5. Further, a metal vapor source 1 that can generate metal vapor is disposed inside the ceramic tube 2. A heat insulating material 13 is arranged on the outer periphery of the ceramic tube 2, and a metal body 9 is arranged on the outer periphery thereof. An insulating tube 10 is connected to the left end of the body 9 via an insulating tube flange 19. A stainless steel electrode support flange 20 is connected to the right end of the body 9 and the left end of the insulating tube 10, respectively. As shown in FIG. 2, the electrode support flange 20 includes a flat plate portion 22 having an electrode insertion hole 21 for inserting and supporting the anode 4 and the cathode 5, and a cylindrical portion 23 protruding from the flat plate portion 22. Has become. A corner 24 of the electrode insertion hole 21 is formed with a chamfered curvature surface 24. The curvature surface 24 is smoothly curved toward the heat insulating material 13. A Brewster tube 11 is connected to the outer surfaces of these electrode support flanges 20. Brewster tube 11 on left side
Is provided with a gas supply pipe 3 connected to a gas supply system, and the right blaster pipe 11 is provided with a gas exhaust pipe 8 connected to a gas exhaust system. The gas supply pipe 3 supplies a discharge buffer gas such as a neon gas into the ceramic pipe 2. The gas exhaust pipe 8 exhausts a buffer gas and the like in the ceramic pipe 2 to the outside. An output mirror 14 and a total reflection mirror 14a are arranged outside the window 12 attached to the Brewster tube 11, respectively. The output mirror 14 and the total reflection mirror 14a constitute an optical resonator.

The above-described pulse bipolar discharge is performed by a high-voltage pulse power supply connected to an electrode support flange 20 that supports the anode 4 and the cathode 5 and allows current to flow. This pulse high voltage power supply has a charge of approximately 10 ⁻⁷ due to the charge charged in the charging capacitor 15 igniting the thyratron 18.
A discharge current is generated with a rise time of less than a second. The thyratron 18 is a pulse discharge switching element. The generated pulse high voltage has a voltage of several kv to several tens kv and a repetition frequency of several kHz to several tens kHz. In the pulse high-voltage power supply of FIG. 3, symbol A is an anode terminal, C is a cathode terminal, and G is a trigger signal introduction terminal. The pulse high voltage of the pulse high voltage power supply is applied between the anode 4 and the cathode 5 to perform pulse bipolar discharge, and discharge plasma is generated in the ceramic tube 2.

Next, the operation of the above device will be described. First, the inside of the ceramic tube 2 is evacuated by operating the exhaust system, and a discharge buffer gas such as neon gas is supplied from the gas supply system. Next, the pulse high-voltage power supply is operated to generate plasma in the ceramic tube 2, and the plasma is heated to a temperature at which the metal vapor source 1 can generate metal vapor.
The temperature required for laser oscillation is, for example, about 1500 ° C. when the metal vapor source 1 is copper. By maintaining this state, the metal vapor in the ceramic tube 2 is uniformly distributed. Free electrons in the plasma collide with the metal vapor to excite the metal vapor, and eventually the inside of the ceramic tube 2 has a population inversion state. In this state, a laser beam is generated when the excited metal vapor transitions to a low energy level. The laser light generated in the ceramic tube 2 passes through the window 12 and its amplitude increases while being reflected between the output mirror 14 and the total reflection mirror 14a constituting the optical resonator, and then oscillates from the output mirror 14 side. I do.

[0005]

The conventional metal vapor laser apparatus is configured as described above, and the fitting portion between the anode 4 or the cathode 5 and the electrode insertion hole 21 of the electrode support flange 20 has a contact surface. Is a current passage, and in order to prevent the optical axis from shifting due to vibration or the like, it is necessary to adopt a structure in which the optical axis is closely fixed. For this reason, in order to accurately project the optical axis of the cathode 5, the ceramic tube 2, and the anode 4, the mounting surface of the metal body 9 and the electrode support flange 20 and the electrode insertion hole 21 of the electrode support flange 20 are removed. Must be manufactured with processing accuracy that meets the requirements of Also, it is difficult to finely adjust the optical axis of the electrode during assembly. Further, when performing maintenance replacement and repair due to aging of both electrodes regularly, it is difficult to remove only the electrodes 4 and 5 due to the above-described structure, and the flange of the metal body 9 together with the electrode support flange 20 is difficult. It is necessary to disassemble and remove at the part, and reproducibility of centering between the two electrodes at the time of reassembly, that is, alignment of the optical axis of laser light is difficult. And the deviation of the axis between both electrodes is
There is a problem in that this causes abnormal discharge and directly affects the reduction in laser oscillation output and the stabilization of the output.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is possible to easily reproduce an optical axis after replacing electrodes, prevent abnormal discharge, and stabilize a laser oscillation output. It is intended to provide a device.

[0007]

In a metal vapor laser device according to the present invention, a conventional cylindrical electrode with a collar is separated into an electrode supporting flange and an electrode holder, and the electrode holder supports an anode or a cathode electrode. And the axis between the two electrodes
And a guide holder to be fixed.

[0008]

In the metal vapor laser apparatus according to the present invention, since the reproducibility of the axial center and the optical axis alignment between the two electrodes after the replacement of the electrodes is easy, the stable discharge is performed between the two electrodes to prevent the abnormal discharge. Further, the reproducibility of the laser oscillation output and the stability of the output are greatly improved.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, the same reference numerals and the same names are used for the same components as those in FIG. 3 described in the conventional metal vapor laser apparatus and FIG. In this embodiment, the electrode part is a conductive electrode holder 23a having a fitting part 25 for inserting and supporting the anode 4a and the cathode 5a (not shown), and the axial center fixing between the anode 4a and the cathode 5a. And a guide holder 26 attached to the electrode holder 23a. These electrode holders 23a are connected to the electrode support flange 20a. A Brewster tube 11a is connected to the outer surface of the electrode support flange 20a.

A high pulse voltage is applied between the anode 4a and the cathode 5a to perform a pulse bipolar discharge, and a discharge plasma is generated in the ceramic tube 2. The temperature of the metal vapor source 1 is raised to a temperature at which the metal vapor source 1 can generate the metal vapor by this plasma, and the metal vapor is uniformly distributed in the ceramic tube 2 by maintaining this state. Here, in order to oscillate the laser light, it is necessary to perform stable pulsed bipolar discharge between the anode 4a and the cathode 5a and cause free electrons to collide with the metal vapor with high energy. In order to oscillate, higher energy plasma is required by pulse bipolar discharge. In order to perform a stable pulse bipolar discharge between the anode 4a and the cathode 5a, the high voltage applied to the electrode flange 20a passes through the electrode holder 23a and passes through the anode 4a and the cathode 5a.
a to the anode 4a and the cathode 5a, and to the anode 4a and the cathode 5a, the contact portion 25 having a large contact area with the anode 4a and the cathode 5a.
a, and a stable discharge is performed between the anode 4a and the cathode 5a.

In the above embodiment, the electrode 4a (5a) and the electrode holder 23a are separated and a part of the electrode 4a (5a) is fitted. Since it is easy to adjust the reproduction of the center axis and the optical axis, stable discharge can be performed between the two electrodes, and abnormal discharge can be prevented. Further, the reproducibility of the laser oscillation output and the stability of the output are greatly improved. Further, since the electrode 4a can be repaired and repaired alone by removing the guide holder 26, the electrode repair work time is reduced and the workability is greatly improved.

[0012]

As described above, according to the present invention , the electrode
Insert the fitting that supports the electrode between the support flange and the electrode.
Providing the formed electrode holder and fixing the axis between both electrodes
And a guide holder for
The electrodes can be easily attached and detached, and the axis center and optical axis between both electrodes
Reproduction adjustment, that is, realization of concentricity is highly accurate and easy
As a result, pulsed diode discharge can be stably generated with high reproducibility, and the laser output can be oscillated stably and efficiently. In addition, the fitting part is tightly fixed as the interference fit with the temperature rise, and when replacing the electrode,
Since the fitting portion is cooled, it can be easily removed.

[Brief description of the drawings]

FIG. 1 is a sectional configuration diagram showing an electrode part of a metal vapor laser device according to an embodiment of the present invention.

FIG. 2 is a cross-sectional configuration diagram showing an electrode section of a conventional metal vapor laser device.

FIG. 3 is a configuration diagram showing a conventional metal vapor laser device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Metal vapor source 2 Ceramic tube 4 Anode 5 Cathode 9 Metal body 11 Brewster tube 12 Window 13 Insulation material 14 Output mirror 20a Electrode support flange 23a Electrode holder 25 Fitting part 26 Guide holder

Claims (1)

(57) [Claims] And 1. A discharge tube arranged metal laser medium therein, and a pair of electrodes connected to both ends of the discharge tube, this
A pair of electrodes provided with a fitting portion for supporting a pair of electrodes
A holder, a guide holder for fixing the axis between the two electrodes,
A pair of electrode support flange for supporting said electrode holder, a high voltage is applied to the electrode support flange, transmitted to the electrode through the electrode holder, performing laser oscillation by vaporizing the laser medium of the discharge tube portion Metal vapor laser device.