JPH0249484A - Metal vapor laser device - Google Patents

Abstract

PURPOSE:To obtain a metal vapor laser device of high efficiency whose output loss is small by a method wherein clean buffer gas is jetted against the inner face of a laser window from a buffer gas auxiliary inlet and exhausted through an outlet so as to prevent the laser window from decreasing in transmissivity. CONSTITUTION:A laser window 2 and a laser window fitting flanges 3 are provided to both sides of a laser main body 1 respectively in a solid structure. A buffer gas primary inlet 4 and an outlet 5 are provided penetrating through the wall faces of the flanges 3. A buffer gas auxiliary inlet 6 spouts out a buffer gas against the inner face of the window 2. A clean buffer gas is jetted against the inner face of the window 2. The laser windows 2 where a laser beam pass are always cleaned with a clean gas. In result, the contamination of the laser windows 2 due to metal vapor or other impurities can be prevented. By this setup, a metal vapor laser device of high efficiency, whose output loss is small, can be obtained.

Description

[Detailed Description of the Invention] [Objective of the Invention] (Industrial Application Field) The present invention relates to a metal vapor laser device, and in particular to a method for preventing dirt on the inner surface of a window through which laser light passes and reducing loss of laser output. The present invention relates to a metal vapor laser device that can operate continuously for a long period of time.

(Prior Art) Laser devices are used in a wide range of fields such as material cutting, optical communications, medical technology, and the nuclear industry.

In particular, in the nuclear power industry, it plays an important role in uranium enrichment technology using a laser method that selectively excites and separates a specific isotope from a mixture of multiple uranium isotopes. As a laser device for uranium enrichment, high output,
Performance such as long life is required.

As a metal vapor laser device used for enriching uranium isotopes, a steel vapor laser device is generally used because it is highly efficient and can provide the highest output laser beam.

A conventional metal vapor laser device will be described with reference to FIG.

Reference numeral 1 in FIG. 5 denotes a laser main body, and laser windows 2 are attached to both ends of the laser main body 1 via laser window mounting flanges 3. A buffer gas inlet 4 is provided on the mounting flange 3 on the left side of 5 in the figure.

An exhaust port 5 is formed and protrudes from the right side mounting flange 3.

A discharge vessel 7 is provided within the laser body 1, and spaced apart Ir! 8 and a negative electrode 9 are attached. The inside of the discharge vessel 7 forms a discharge space 10, and the metal vapor W111 is accommodated in the discharge space 10. A heat insulating layer 12 and a protective tube 13 are interposed between the discharge vessel 7 and the laser main body 1. An insulating tube 14 is interposed between the laser main body 1 and the cathode 9. The buffer gas inlet 4 is connected to a buffer gas supply device 15 via a gas inlet pipe 15a. The exhaust port 5 provided in the laser main body 1 and the exhaust port 5 provided in the laser window mounting flange 3 are connected to an exhaust device 18 via exhaust pipes 18a and 18b. In addition, the reference numeral 16 in the figure is a high-voltage pulse power supply circuit, which applies a high voltage to the laser body 1 and the cathode, gives discharge energy, vaporizes the metal vapor source 11, generates plasma to serve as a laser medium, and generates plasma in the space 8. spread to. Further, 17 indicates a laser beam resonator.

(Problem to be solved by the invention Wi) In the conventional device, the buffer gas containing a relatively large amount of impurities or metal vapor generated from the discharge vessel 7 or the heat insulating layer 12 comes into contact with the laser window 2. Impurities or metals are deposited on the inner surface of the window 2, reducing the transmittance of the window 2. This causes a decrease in laser power and
For this reason, regular maintenance (every several tens of hours) is required, which limits the continuous operation time.

SUMMARY OF THE INVENTION An object of the present invention is to provide a metal vapor laser device that can operate continuously for a longer period of time with high efficiency by reducing loss of laser output and eliminating window maintenance.

[Structure of the invention]

(Means for Solving the Problems) The present invention provides a laser main body, a laser window attached to both ends of the laser main body, and a plasma that becomes a laser medium by applying discharge energy to a metal provided in the laser main body. a pair of electrodes that generate a high voltage discharge within the discharge vessel; a power supply circuit that applies a high voltage between the electrodes; and a laser medium that generates an initial discharge within the discharge vessel and after the discharge. a buffer gas supply device for relaxing the gas to the ground level, a buffer gas auxiliary inlet for injecting the gas toward the inner surface of the laser window, and an exhaust device for adjusting the pressure inside the discharge vessel and removing impurities. It is characterized by the following:

(Function) A clean buffer is injected onto the inner surface of the laser window from the buffer gas auxiliary inlet and follows the flow path where it is exhausted from the exhaust port. Therefore, since the inner surface of the laser window is always exposed to clean buffer gas, it is possible to prevent the transmittance of the laser window from decreasing due to deposition of impurities or metals.

In addition, since a decrease in transmittance of the laser window can be prevented, maintenance of the laser window can be omitted and continuous operation can be achieved. Furthermore, since there is no need to remove the laser window each time, the laser window and its mounting flange can be integrated, and the structure can be simplified.

(Example) An example of a metal vapor laser device according to the present invention will be explained.

FIG. 1 is a partially block sectional view of a metal vapor laser device according to the present invention. The metal vapor laser device according to the present invention is characterized by the structure of the buffer gas auxiliary inlet 6, the laser window 2, and the laser window mounting flange 3, and other parts are similar to the conventional example shown in FIG. Since the components are the same as those shown in FIG.

The metal vapor laser device of this embodiment shown in FIG. In addition to forming a buffer gas main inlet 4 and an exhaust port 5, a buffer gas auxiliary inlet 6 for injecting buffer gas toward the inner surface of the laser window 2 is provided. It is a gas supply device 15. It is connected via gas pipes 19,20.

One buffer gas auxiliary inlet may be provided for each laser window 2, or a plurality of buffer gas auxiliary inlets may be arranged symmetrically.

Further, the buffer gas auxiliary inlet 6 is installed so that the buffer gas 21 is blown perpendicularly to the center of the laser window 2, as shown in a partially enlarged view of FIG. Alternatively, as illustrated in FIG. 3, it is also possible to install the buffer gas 21 so that it flows along the surface of the laser window 2.

FIG. 4 shows another embodiment of the present invention, which differs from FIG. 1 in that the main inlet 4 and the auxiliary inlet 6 are constructed on the buffer gas introduction side.

The rest of the configuration is the same as that in FIG. 1, so a detailed explanation thereof will be omitted.

Thus, in the metal vapor laser apparatus shown in FIGS. 1 and 4, clean buffer gas is injected onto the inner surfaces of laser windows attached to both ends of the laser body. The laser window through which the laser light passes is constantly flushed with clean gas. As a result, contamination of the laser window by metal vapor or other impurities can be prevented.

〔Effect of the invention〕

According to the present invention, it is possible to prevent the laser window from becoming dirty due to deposition of metal vapor and impurities, thereby providing a highly efficient metal vapor laser device with less output loss due to the laser window.

Furthermore, since maintenance of the laser window can be omitted, it is possible to provide a metal vapor laser device that allows continuous operation for a longer period of time and a simplified structure due to the integration of the laser window.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of a metal vapor laser device according to the present invention, and FIGS. 2 and 3 are longitudinal cross-sectional views showing an enlarged buffer gas auxiliary inlet portion of the laser device in FIG. 1. 4 is a block diagram showing another embodiment of the metal vapor laser device according to the present invention, and FIG. 5 is a block diagram showing a conventional metal vapor laser device. 1...Laser device main body 3...Laser window mounting flange 5...Exhaust port 6...Buffer gas auxiliary inlet 8...Anode electrode 10...Discharge space 12...Insulating layer 14... ... Insulation tube 16 ... High voltage pulse power supply circuit 18 ... Exhaust device 21 ... Buffer gas flow 2 ... Laser window 4 ... Buffer gas main inlet a ... Discharge vessel 9 ... Shade Electrode 11... Metal vapor source 13... Protection tube 15... Buffer gas supply device 17... Laser resonator 19.20... Gas piping

Claims (1)

[Claims] A laser main body, laser windows attached to both ends of the laser main body, a discharge vessel that applies discharge energy to metal provided in the laser main body to generate plasma as a laser medium, and a discharge vessel that generates plasma as a laser medium; A pair of electrodes that perform high voltage discharge, a power supply circuit that applies high voltage between the electrodes, and a buffer gas that performs initial discharge within the discharge vessel and relaxes the laser medium to the ground level after discharge. A metal vapor laser device comprising a supply device, an auxiliary buffer gas inlet for injecting buffer gas toward the inner surface of the laser window, and an exhaust device for adjusting the pressure in the discharge vessel and removing impurities.