JPH02194577A - Metal steam laser oscillation tube - Google Patents

Abstract

PURPOSE:To obtain an efficient laser output by mainly using alumina for a heat-insulating material placed at the center of an inner tube, using zirconia for the heat-insulating material placed at both edges of the inner tube, and making temperature within the inner tube to be nearly uniform for effective high-temperature region. CONSTITUTION:A heat-insulating material 4a with alumina (Al2O3) as a main constituent at the central part is placed among an inner tube 1, an anode 2, a cathode 3, and a protection tube 5. A heat-insulating material 4b with zirconia (ZrO2) as a main constituent is placed at both edges. Zirconia has better heat- insulating characteristics than alumina but is inferior in electrical insulating properties.

Description

[Detailed description of the invention] [Purpose of the invention] (Industrial application field) The present invention relates to a metal vapor laser oscillator tube.

(Prior Art) A conventional metal laser oscillation tube is configured as shown in FIG. 2, for example. That is, on both sides of an inner tube 1 made of ceramic with excellent heat resistance, a cylindrical anode 2 and a cathode 3, which are formed to have approximately the same diameter as the inner tube 1 along the axial direction, are arranged.
A protective tube 5 filled with a heat insulating material 4 is disposed along the axial direction on the outer peripheral surfaces of the inner tube 1, anode 2, and cathode 3.

Further, on the outside of the protective tube 5, outer tubes 6a and 6 made of a conductor are provided.
b, and the anode 2, cathode 3, and protective tube 5 are supported at both ends of the outer tubes 5a and 5b. In addition, the outer tube 6a
, 6b is provided with an insulating tube 7 for electrically separating the anode 2 side and the cathode 3 side, and Brewster windows 8a, 8b are attached to both ends of the outer tubes 5a, 5b, respectively. There is. , 9 is a metal particle that is a laser medium (for example, AIJ
, CIJ, etc.).

A conventional metal vapor laser oscillation tube is constructed as described above, and in order to carry out laser excavation, the inside of the inner tube 1 is first evacuated using a rotary pump (not shown) or the like to maintain a high vacuum.
A discharge buffer gas such as He or Ne is supplied into the inner tube 1. Then, by applying a high voltage pulse from a pulsed high voltage power source (not shown) between the anode 2 and the cathode 3 via the outer tubes 6a and 5b, metal vapor in the discharge plasma is introduced between the anode 11i2 and the cathode 3. generate. By exciting this metal vapor with free electrons in the discharge plasma, light with a wavelength unique to the metal is emitted, and the Brewster window 8
The laser beam is amplified by an optical resonator (not shown) disposed outside of the laser beam R, through which the laser beam passes through a and 8b.

By the way, in the conventional metal vapor laser oscillation tube mentioned above,
During laser oscillation, a high voltage is applied between the anode 2 and the cathode 3 to generate plasma discharge, so the inside of the inner tube 1 reaches a high temperature of about 1500°C. At this time, since both ends of the inner tube 1 are open, the heat inside the inner tube 1 escapes from both ends, so that the temperature inside the inner tube 1 becomes lower near both ends than near the center. Therefore, during laser oscillation, h! between the anode 2 and the cathode 3. Since the effective high-temperature region (approximately 1500° C.) that contributes to i-electricity is only near the center of the inner tube 1, the effective high-temperature region becomes narrow, making it impossible to obtain efficient laser output.

For this reason, conventionally, as shown in FIG. 2, by making the thickness near the center of the heat insulating material 4 thinner than near both ends, the escape of heat near the center is increased, and the thickness of the heat insulating material 4 in the axial direction is increased. The temperature inside the inner tube 1 was made uniform by making heat conduction uniform.

(Problem to be Solved by the Invention) However, if the area near the center of the heat insulator 4 is made thinner, a space 10 will be formed in that area. There is a risk that the gas generated from the above may accumulate in the space 10 and cause abnormal discharge.

Furthermore, when the amount of gas accumulated in the inner tube 1 increases, the gas causes convection, which, combined with the thermal conductivity of the gas, impairs the insulation properties, causing the temperature near the center of the inner tube 1 to rise. It becomes impossible to equalize the internal temperature.

The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide a metal vapor laser oscillation tube that can substantially equalize the temperature inside the inner tube, widen the effective high temperature region, and obtain efficient laser output. It is something to do.

[Structure of the Invention] (Means for Solving the Problems) In order to solve the above-mentioned problems, the present invention provides a method in which a heat insulating material is provided along the axial direction on the outer periphery of the inner tube in which the electrodes are disposed inside or on both sides. In a metal vapor laser oscillation tube in which a metal vapor laser oscillation tube is provided, the heat insulating material provided at the center of the inner tube is mainly composed of alumina, and the heat insulating material provided at both ends of the inner tube is zirconia. It is characterized by having as a main component.

(Function) According to the present invention, the heat insulating material mainly composed of zirconia on both end sides has better heat insulating properties than the heat insulating material mainly composed of alumina on the center side. The escape of heat from the inner tube is increased, the temperature rise is suppressed, the temperature in the axial direction within the inner tube becomes approximately equal, and efficient laser output can be obtained.

(Example) Hereinafter, the present invention will be described in detail based on an illustrated example. In addition, the same reference numerals are attached to the same members as in the conventional case for explanation.

FIG. 1 is a schematic sectional view showing a metal vapor laser oscillation tube according to the present invention. As shown in this figure, a cylindrical i-electrode 2 and a cathode 3 are disposed at both ends of an inner tube 1 made of ceramic in which metal particles (for example, Au, Cu, etc.) 9 are arranged. , a protection tube 5 and outer tubes 6a and 6b are arranged approximately concentrically outside the anode 2 and cathode 3. Between the inner tube 1, the anode 2, the cathode 3, and the protection tube 5, a heat insulating material 4a mainly composed of alumina (Aai2o3'''') is provided in the center, and zirconia is provided in both ends. A heat insulating material 4b containing (Zr02) as a main component is provided. Zirconia has better thermal insulation properties than alumina, but is inferior in electrical insulation properties.

Further, the outer tubes 6a and 6b are connected in an insulated manner by an insulating tube 7, and Brewster windows 3a and 8b are attached to both ends of the outer tubes 6a and 6b, respectively.

The metal vapor laser oscillation tube according to the present invention has a vapor-like structure, and when performing laser oscillation, the inside of the inner tube 1 is maintained at a high vacuum by exhausting with a rotary pump (not shown), and He, Ne, etc. The discharge buff 7 gas is supplied. Thereafter, a high voltage pulse is applied between the anode 2 and the cathode 3 from a pulsed high voltage power source (not shown) through the outer tubes 6a and 6b, thereby generating discharge plasma between the anode 2 and the cathode 3, and causing the metal to melt. The particles 8 are vaporized to generate metal vapor that becomes a laser medium. Then, this metal vapor is transferred to anode 2 and cathode 3.
It is excited by free electrons in the discharge plasma generated during this period, is amplified by an optical resonator (not shown) disposed outside the Brewster windows 8a and 8b, and is oscillated as a laser beam.

At this time, the heat insulating material 4b mainly composed of zirconia disposed at both ends of the inner tube 1 has better heat insulating properties than the heat insulating material 4a mainly composed of alumina disposed at the center. Therefore, the escape of heat from the vicinity of the center of the inner tube 1 becomes large, the temperature rise is suppressed t++, and the temperature inside the inner tube 1 becomes approximately equal to -.

Therefore, the effective high-temperature region that contributes to the discharge between the anode 2 and the cathode 3 during laser oscillation extends to the vicinity of both ends of the inner tube 1,
Highly efficient laser oscillation can be performed.

Further, when a pulsed high voltage is applied between the anode 2 and the cathode 3, the electric field is concentrated at the tips of the anode 2 and the cathode 3, and the insulation material 4b
@Although there is a risk of damage, by using zirconia, which is electrically conductive at high temperatures, for the insulation material 4b, the electric field at the tips of the anode 2 and cathode 3 is relaxed, so the field of the insulation material 4b is becomes longer.

Furthermore, since the heat insulating materials 4a and 4b have spaces in which gas accumulates, abnormal tIl electricity will not occur during laser oscillation.

In the above-mentioned embodiment, the metal vapor seam 11 oscillation tube has an anode 2 and a cathode 3 disposed at both ends of the inner tube 1, but an anode 2 and a cathode 3 are disposed inside the inner tube 1. A metal vapor laser oscillation tube may also be used.

[Effects of the Invention] As described above in detail based on the embodiments, according to the present invention, a heat insulating hole mainly composed of alumina is provided on the central part side of the outer periphery of the inner tube, and By arranging a heat insulating material mainly composed of zirconia on the side, the escape of heat from the vicinity of the center of the inner tube is increased, and during laser oscillation, the temperature inside the inner tube is approximately equalized and an effective high temperature area is created. Since it can be made wide, highly efficient and stable laser oscillation can be performed.

[Brief explanation of the drawing]

It is a schematic sectional view showing a swing tube.

Claims (1)

[Claims] In a metal vapor laser oscillation tube in which a heat insulating material is disposed along the axial direction on the outer periphery of an inner tube in which electrodes are disposed inside or on both sides, the heat insulating material is disposed on the center side of the inner tube. A metal vapor laser oscillation tube characterized in that the main component is alumina, and the heat insulating material provided at both ends of the inner tube is mainly zirconia.