JPH01220489A - Metal vapor laser apparatus - Google Patents

Abstract

PURPOSE:To prevent abnormal discharge and to make laser oscillation efficient, by constituting each electrode supporting flange by a planar part having an electrode inserting hole and a cylinder part which protrudes into the planar part, and forming the corner part of the electrode inserting hole as a chamfered curved surface. CONSTITUTION:Stable pulse discharge is performed between two electrodes, i.e., an anode 4 and a cathode 5. For this purpose, a high voltage is applied to electrode supporting flanges 20. The high voltage passes through a curved surface 24 which is the smooth curved surface on the side of a ceramic tube 2. The high voltage is applied to a cylinder part 23 which supports the anode 4 and the cathode 5 and introduces electricity to the anode 4 and the cathode 5. The high voltage is moved to the anode 4 and the cathode 5 from the cylinder part 23 having the broad contact part with the anode 4 and the cathode 5 with small resistance. Stable discharge is performed only between the anode 4 and the cathode 5. Since the corner part of an electrode inserting hole 21 of the electrode supporting flange 20 is made to be a smooth curved structure, abnormal discharge is prevented, and stable discharge is performed.

Description

[Detailed Description of the Invention] [Purpose of the Invention (Industrial Application Field) The present invention relates to a metal vapor laser device, and in particular, to a metal vapor laser device, which uses metal vapor as a laser medium, and improves the discharge state of the laser to improve laser oscillation output, efficiency, etc. This invention relates to a metal vapor laser device with improved performance.

(Prior Art) The structure and operation of a conventional metal vapor laser device will be explained with reference to FIG.

That is, an anode 4 and a cathode 5 are connected to both ends of a ceramic tube 2 in which a metal vapor source 1 is disposed via a joining member 2a, thereby forming a discharge tube. The anode 4 and cathode 5 in this discharge tube each have an electrode flange 6.
is provided.

The electrode flange 6 is fixedly attached to a body 9 for surrounding the discharge tube, an electrode support flange 7 interposed between an insulating tube 10 and a Brewster tube 11. ceramic tube 2
The outer peripheral surfaces of the anode 4 and the cathode 5 are surrounded by a heat insulating material 13, and the outside of the heat insulating material 13 is covered with the body 9 and an insulating tube 10 having an insulating tube flange 19. A pair of Brewster tubes 11 are connected to each electrode support flange 7, a window 12 is attached to each opening of the Brewster tube 11, and a pair of mirrors 14 are arranged outside of these windows 12. to form a resonator.

For example, neon (N
e) A gas supply pipe 3 for supplying gas is connected, and a gas exhaust pipe 8 is connected to the Brewster pipe 11 on the right side. A high DC voltage is applied between the left electrode support flange 7 and the insulating tube flange 19. In the figure, reference numeral 15 is a charging capacitor C+, and 16 is an intermediate capacitor C2, 17.
and resistor R118 indicate a thyratron, respectively.

In the metal vapor laser device having such a configuration, laser oscillation is performed as follows.

First, a discharge buffer gas such as neon gas is supplied from a gas supply tube 3 into a ceramic tube 2 serving as a discharge tube in which a metal vapor source 1 is disposed. Next, a high voltage is applied between the anode 4 and cathode 5 provided at both ends of the ceramic tube 2 to form discharge plasma. Anode 4 and cathode 5
The electrode is connected to the electrode support flange 7 via the electrode flange 6.
is fixed. The ceramic tube 2 is heated to a high temperature by this discharge plasma, and the metal vapor source 1 generates vaporized metal particles (metal vapor) that become a laser medium. Furthermore, this metal vapor diffuses into the ceramic tube 2,
It is excited by free electrons in the discharge plasma within the ceramic tube 2. Laser light is emitted when this excited metal vapor transitions to a lower energy level.

To generate metal vapor, which becomes the laser medium, a pulsed high voltage source is activated to cause a discharge between the picture electrodes 4.5, and the energy of this pulsed bipolar discharge is applied to the ceramic tube 2 to heat the shellac tube 2. This is done by doing. For example, when copper is used as the metal vapor source 1, the ceramic tube is always heated up to 1500°C.

(Problems to be Solved by the Invention) As mentioned above, in the conventional metal vapor laser device, it is necessary to start a pulsed high voltage source to generate a discharge between the picture electrodes 4 and 5 to generate stable plasma in the ceramic tube 2. There is.

By the way, the picture electrode 4.5 is made of molybdenum, which has high heat resistance.
A metal such as tungsten is used, and the electrode support flange 7, which is the electricity introduction part, is made of a metal such as copper or aluminum.The electrode support flange 7, which is the electricity introduction part, is made of a metal such as copper or aluminum. There is. Therefore, the structure of the electrode portion is complicated, and corners and metals such as copper and aluminum are used, which can cause abnormal discharge. Abnormal discharge hinders plasma generation necessary for laser oscillation and causes a decrease in laser oscillation output.

The present invention has been made in consideration of the above facts, and an object of the present invention is to provide a laser oscillation device that prevents abnormal discharge and efficiently performs laser oscillation.

[Structure of the Invention] (Means for Solving the Problems) The present invention provides a discharge tube in which a metal vapor source that generates metal is disposed, a heat insulating material provided around the outer periphery of the discharge tube,
The discharge tube includes a pair of electrodes connected to both ends, an electrode flange supporting the pair of electrodes, and a Brewster tube connected to the flange having the electrodes, and the electrode support flange has an electrode insertion hole. The electrode insertion hole has a flat plate portion and a cylindrical portion protruding from the flat plate portion, and the corner portion of the electrode insertion hole has a chamfered curvature surface.

(Function) The inside of the ceramic tube is evacuated and buffer gas such as neon gas is supplied from the gas supply system. Next, a pulsed high voltage source is activated to generate plasma within the ceramic tube and the metal vapor source is heated to a temperature at which metal vapor can be generated, thereby uniformly distributing the metal vapor within the ceramic tube.

Free electrons in the plasma collide with this metal vapor to excite the metal vapor, creating a state of population inversion inside the ceramic tube. Laser light is generated in this state.

The laser beam passes through the window, increases its amplitude while being reflected by the output mirror and the total reflection mirror, and eventually oscillates from the mirror side. Here, a stable pulsed bipolar discharge is generated between the anode and the cathode, and free electrons collide with the metal vapor at high energy to oscillate laser light. The high voltage applied to the electrode support flange passes through the flat plate part from the electrode insertion hole on the ceramic tube side, is applied to the cylindrical part, and is transferred to the anode and cathode, causing stable discharge only between the anode and cathode, and preventing abnormal discharge. prevent.

(Example) An example of the present invention will be described with reference to FIGS. 1 and 2.

In FIG. 1, the same reference numerals and names are used for the same parts as in FIG. 3, which are explained with reference to the conventional metal vapor laser device. That is, in FIG. 1, a metal vapor laser device is provided with a ceramic tube 2 as a discharge tube, and an anode 4 and a cathode 5 are connected to opposite ends of the ceramic tube 2 via a connecting member 2a. Ru. These electrodes 4.5
A pulsed bipolar discharge occurs between the two. Furthermore, inside the ceramic tube 2, there is a metal vapor source 1 that can generate metal vapor.
is placed.

A heat insulating material 13 is arranged around the outer periphery of the ceramic tube 2, and a metal body 9 is arranged around the outer periphery.

An insulating tube 10 is connected to the left end of the body 9 via an insulating tube flange 19. Furthermore, stainless steel electrode support flanges 20 are connected to the right end of the body and the left end of the insulating tube 10, respectively. As shown in an enlarged view in FIG. 2, this electrode support flange 20 consists of a flat plate part 22 having electrode insertion holes 21 into which the anode 4 and cathode 5 are inserted and supported, and a cylindrical part 23 protruding from the flat plate part 22. It has become. Further, a corner portion of the electrode insertion hole 21 is formed with a chamfered curved surface 24 . This curvature surface 24 is smoothly curved toward the heat insulating material 13 side. Brewster tubes 11 are connected to the outer surfaces of these electrode support flanges 20.

The Brewster tube 11 on the left side is provided with a gas supply pipe 3 connected to a gas supply system, and the Brewster tube 11 on the right side 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 neon gas into the ceramic tube 2 . Further, the gas exhaust pipe 8 is for discharging buffer gas and the like within the ceramic tube 2 to the outside.

An output mirror and a total reflection mirror are arranged outside the passenger 12 of the Brewster tube 11, respectively, and the output mirror and the total reflection mirror 14 constitute an optical resonator.

The above-mentioned pulsed bipolar discharge is performed by a pulsed high-voltage power supply connected to the electrode support flange 2° that supports the anode 4 and the cathode 5 and allows current to flow therethrough.

This pulsed high-voltage power supply is activated by the electric charge charged in the charging capacitor 15 igniting the thyratron 18.
Generates a discharge current with a rise time of 0-7 seconds or less. Thyratron 18 is a pulse discharge switching element. The generated pulsed high voltage has a voltage of several kilovolts to several tens of kilovolts, and a repetition frequency of several kilohertz to several tens of kilohertz. Symbol A in the figure is an anode terminal, C is a cathode terminal,
G is a trigger signal introduction terminal. A pulsed high voltage from this pulsed high voltage power supply is applied between the anode 4 and the cathode 5 to cause a pulsed bipolar discharge, and discharge plasma is generated within the ceramic tube 2.

Next, the effect will be explained.

First, the exhaust system is activated to exhaust the inside of the ceramic tube 2, and a buffer gas such as neon gas is supplied from the gas supply system. Next, activate the pulse high voltage power supply and
Plasma is generated within the metal vapor source 1, and the plasma raises the temperature of the metal vapor source 1 to a temperature at which metal vapor can be generated. 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 is uniformly distributed within the ceramic tube 2.

Free electrons in the plasma collide with this metal vapor to excite the metal vapor, and eventually the inside of the ceramic tube 2 enters a state of population inversion. In this state, laser light is generated when the excited metal vapor transitions to a lower energy level. The laser beam generated within the ceramic tube 2 passes through the window 12, increases in amplitude while being reflected by the output mirror and the total reflection mirror that constitute the optical resonator, and eventually oscillates from the output mirror side.

In order to oscillate the laser beam, it is necessary to perform a stable pulsed bipolar discharge between the anode 4 and the cathode 5 to cause free electrons to collide with the metal vapor with high energy, and to generate a higher output laser beam. In order to oscillate, even higher energy plasma generated by pulsed bipolar discharge is required. In order to perform stable pulse bipolar discharge between the anode 4 and the cathode, the high voltage applied to the electrode support flange 20 is applied to the ceramic tube 2 side by a curved surface 24 composed of a smooth curved surface.
passes through the anode 4 and supports the anode 4 and the cathode 5, and conducts electricity to the anode 4.
and the cylindrical part 23 introduced into the cathode 5, and the anode 4
and transfers from the cylindrical part 23 having a wide contact surface with the cathode 5 to the anode 4 and cathode 5 with small resistance.
Stable discharge occurs only during Here, ceramic tube 2
The sides have no corners or other structures where discharge is likely to occur, and have a smooth curved structure, making it possible to prevent abnormal discharge and ensure stable discharge.

[Effects of the Invention] According to the metal vapor laser device according to the present invention, pulsed bipolar discharge can be stably generated, so the laser output can be oscillated stably and efficiently, and the oscillation of a high-output laser can be It also has the effect of making it possible.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram showing an embodiment of a metal vapor laser device according to the present invention, FIG. 2 is a longitudinal sectional view showing an enlarged main part of FIG. 1, and FIG. 3 is a conventional metal vapor laser device. FIG. 2... Ceramic tube 4... Anode 5... Cathode 20... Electrode support flange 21...・・・
..... Electrode insertion hole 22 ..... Flat plate section 23 ..... Cylindrical section 24 ..... Curvature surface Applicant Toshiba Corporation Agent Patent Attorney Suyama Sa - 1==4- ~ Sunguchi =====~- Figure 2

Claims (1)

[Claims] a discharge tube in which a metal vapor source for generating metal vapor is disposed;
A heat insulating material provided around the outer circumference of the discharge tube, a pair of electrodes connected to both ends of the discharge tube, an electrode support flange supporting the pair of electrodes, and a Brewster tube connected to the electrode support flange. The electrode support flange includes a flat plate portion having an electrode insertion hole and a cylindrical portion protruding from the flat plate portion, and the corner portion of the electrode insertion hole has a chamfered curved surface. metal vapor laser equipment.