JPS63114284A - Metal-vapor laser tube - Google Patents

Abstract

PURPOSE:To prevent decrease in optical output due to shortage of metal, by providing a metal feedback member, which connects a low temperature region and a high temperature region in a discharge tube, feeds back the deposited metal in the low temperature region to the high temperature region, end vaporizes the metal again. CONSTITUTION:A metal material is mounted on the central part of the inside of a discharge part 1. In this state, discharging is performed between electrodes 5a and 5b. A metal feedback member 12a is arranged so as to connect a region A, where the metal reaches a temperature sufficient to start evaporation, and a region B at a temperature for starting deposition of the metal as liquid. The metal feedback member 12a is formed by bending heat resisting metal such as molybdenum or tantalum, in which grooves are machined on one surface, so that the grooves 13 face inward. The deposited metal in the low temperature region B is captured in the metal feedback member. Thereafter, the metal reaches the high temperature region A through the grooves 13 with a capillary phenomenon. The metal reaching the high temperature region A is evaporated again and takes part in oscillation of metal vapor laser. Thus decrease in optical output due to shortage of metal evaporation is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to metal vapor laser tubes. More specifically,
The present invention relates to a novel metal laser tube having a novel configuration, and particularly capable of holding vaporized metal for a longer period of time.

Conventional technology A small amount of Cd5 in a buffer gas such as He5Ne or Ar.
Zn.

A method in which a so-called mixed gas discharge in which metal vapor such as 5eSCu is diffused is used as a laser medium and light emitted from metal ions or atoms excited by the discharge plasma is extracted as a laser is called a metal vapor laser. Metal vapor lasers are characterized by wavelengths distributed over a wide range of ultraviolet, visible, and infrared wavelengths.

Devices that oscillate such metal vapor lasers are generally
A discharge tube such as a ceramic tube is held in a vacuum envelope equipped with a water jacket via a heat insulating material, and within this vacuum envelope, a pair of electrodes provided at both ends of the discharge tube are used to control the inside of the discharge path. The device is configured to perform discharge at .

A small amount of metal is sealed inside the vacuum envelope along with a buffer gas such as neon gas or helium gas, and the metal is evaporated by bringing the inside of the ceramic tube into a discharge state and raising the temperature of the ceramic tube.

Problems to be Solved by the Invention By the way, an operating discharge path has a temperature gradient between the temperature at which the metal begins to melt and the temperature at which the metal begins to evaporate.

However, in conventional metal vapor laser tubes, the metal is simply sealed inside the ceramic tube, so the metal vapor precipitates at both ends of the discharge path where the temperature is low, and the metal vapor reaches the high temperature area in a relatively short period of time. It has been known to disappear completely.

It goes without saying that when there is no metal in the high-temperature part, the metal vapor serving as the laser medium cannot be obtained, and therefore no optical output can be obtained, and this is the end of the life of the metal vapor laser tube.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a novel metal laser tube with a long life by solving the problems of the prior art and making more effective use of the metal sealed inside the laser tube. .

Means for solving the problem, that is, according to the present invention, comprises at least a discharge path housed in a vacuum envelope filled with a buffer gas, and a pair of electrodes disposed at both ends of the discharge path. , a metal vapor laser tube that performs metal vapor laser oscillation by evaporating the enclosed metal by electric discharge in the discharge path, wherein the discharge path includes an internal section extending from a low temperature part to a high temperature part of the discharge path. A metal vapor laser tube is provided, characterized in that it is provided with a cylindrical metal return member made of a heat-resistant metal, which is in contact with the metal return member and is provided with a groove for guiding molten metal inside the metal return member.

Operation The main feature of the metal vapor laser according to the present invention is that it includes a metal return member in its discharge path.

That is, as described above, in the conventional metal vapor laser tube, the temperature at both ends of the discharge path is low, and metal particles precipitate in these regions. Furthermore, in conventional metal vapor laser tubes, precipitated metal accumulates in this region over time, eventually resulting in the loss of metal vapor within the discharge tube.

In contrast, the metal vapor laser tube according to the invention includes a metal return member grooved on its inner surface in its discharge path. That is, in the metal vapor laser tube according to the present invention, the metal deposited in the low-temperature part is captured by the metal return member and travels through the groove formed on the inner surface of the metal return member by capillary reduction.
It moves again to the high temperature part within the discharge path. The molten metal that has reached the high temperature section evaporates again and functions as a laser medium.

Considering these functions, the installation position of the metal return member is
It is essential that there is a temperature gradient region formed in the discharge path from the temperature at which the metal begins to melt to the temperature at which the metal begins to evaporate.

Incidentally, as a material for the metal return member, molybdenum, tantalum, or the like can be cited as an advantageous material mainly considering heat resistance.

Thus, according to the present invention, a long-life metal vapor laser tube is provided that can maintain the light output metal in the high temperature portion of the ceramic tube for a long time.

The present invention will be described in more detail with reference to the accompanying drawings, but the following is only one example of the present invention, and does not limit the technical scope of the present invention in any way. isn't it.

FIG. 2 is a sectional view schematically showing the structure of a metal vapor laser tube to which the present invention can be applied.

As shown in the figure, a ceramic discharge tube 1 has a heat insulating material 2
The heat insulating material 2 is housed inside a vacuum envelope 4 via a glass tube 3 that supports it. A pair of electrodes 5a and 5b are arranged at both ends of the discharge path 10 inside the vacuum envelope 4. Therefore, a discharge region is formed inside the discharge tube 1 between the electrodes 5a and 5b.

Furthermore, a pair of bricoaster windows 9 are provided at both ends of the vacuum envelope 40.
A, 9b and a buffer gas supply port 10 and discharge port 11 for the vacuum envelope 4 are provided.

Further, the vacuum envelope is provided with a water jacket 6 for controlling the temperature of the laser tube, and a cooling water supply lower and an outlet 8 for the water jacket are respectively provided.

When this metal vapor laser tube is in operation, the inside of the vacuum envelope 4 is filled with He gas from the buffer gas supply port 10, and a metal material is placed in the center of the discharge path 1. In this state, the electrodes 5a, 5b performs discharge. Discharge path 1 due to discharge
When the temperature of the discharge tube 1 rises, the metal melts and then evaporates, causing the discharge tube 1
Metal vapor diffuses inside. In this way, the metal vapor laser begins to oscillate, but as described above, the temperature near both ends of the discharge path 1 is relatively low, and the metal precipitates as a liquid.

That is, the range shown as region A in FIG. 2 is the region where the temperature has reached sufficient for the metal to start evaporating, and the region B is the region where the temperature is such that the metal starts to precipitate as a liquid.

Therefore, a metal return member 12, which will be described later, is provided so as to connect this area.

FIGS. 2(a) and 2(b) show the configuration and attachment of a metal return member provided in a metal vapor laser tube according to the present invention.

The metal return members 12a and 12b are made by bending a heat-resistant metal such as molybdenum or tantalum with grooves on one side so that the grooves 13 become the inner surface. As shown in FIGS. 1(a) and 1(b), the overall shape is a cylindrical shape that is inscribed in substantially close contact with the inner surface of the discharge path 4, and its length is at least the same as area A in FIG. It reaches both area B and area B.

Furthermore, the groove 13 may be linear in the axial direction of the metal return member 12 as shown in FIG.
As shown in , it may be spiral. That is, as long as the groove is continuous from the low temperature region B to the high temperature region A, the desired function can be achieved.

In the metal vapor laser tube equipped with the metal return member 12a or 12b, the metal deposited in the low temperature region B is captured by the metal return member 12, and then trapped in the groove 12 by capillarity.
and reaches the high temperature area A. The metal that reaches the high temperature region A evaporates again and contributes to the oscillation of the metal vapor laser.

In this manner, in the metal vapor laser tube according to the present invention, the metal deposited in the low temperature region of the discharge path 1 is vaporized again in the high temperature region A, thereby preventing a decrease in optical output due to a lack of metal vapor.

Effects of the Invention As detailed above, the metal vapor laser tube according to the present invention has a metal return member that connects the low-temperature region and the high-temperature region of the discharge path, and returns the metal precipitated in the low-temperature region to the high-temperature region and vaporizes it again. It is equipped with

Therefore, in the conventional metal vapor laser tube, it is possible to effectively utilize the metal that has been precipitated and accumulated in the low-temperature region, thereby preventing a decrease in optical output due to a lack of metal.

Therefore, it becomes possible to obtain laser light output over a long period of time.

[Brief explanation of the drawing]

FIGS. 1(a) and 1(a) are diagrams showing mutually different aspects and attachment states of the metal return member included in the metal vapor laser tube according to the present invention. FIG. 2 is a sectional view schematically showing the structure of a metal vapor laser tube to which the present invention can be applied. (Main reference numbers) 1...Ceramic discharge path, 2...Insulating material, 3...Heat-resistant glass tube, 4...Vacuum envelope, 5a, 5b...Electrode, 6...Water jacket, 7・・Cooling water supply port, 8・・Cooling water discharge port, 9a, 9b
...Brewster window, 10.Buffer gas supply port, 11.Buffer gas discharge port, 12a, 12b..Metal return member, 13..Groove. Patent applicant: NEC Corporation Representative: Masahiko Arai, patent attorney Figure 1 (a) Figure 1 (b) 1...Ceramic discharge paths 12a, 12b...Metal return member 13...
・Sacrilege

Claims (1)

[Claims] The method includes at least a discharge path housed in a vacuum envelope filled with a buffer gas, and a pair of electrodes disposed at both ends of the discharge path, and the encapsulated metal is removed by discharge in the discharge path. A metal vapor laser tube that performs metal vapor laser oscillation by evaporation, the cylinder having a groove inscribed in the discharge path from a low-temperature part to a high-temperature part of the discharge path and guiding molten metal into the inside thereof. A metal vapor laser tube comprising a metal return member made of a heat-resistant metal.