JPH03262181A - Baking of gas laser oscillator - Google Patents

Abstract

PURPOSE:To enable air and moisture attached inside an oscillator tank to be rapidly removed by a method wherein a cooling means provided inside the oscillator tank is lessened in cooling capacity and a baking current is made small at the rise time of a gas laser oscillator. CONSTITUTION:Laser gas 11 rising in temperature due to the discharge in a discharge section 1 is cooled down by a heat exchanger 10 which serves as a cooling means and recirculated. At this point, the heat exchanger 10 provided inside an oscillator tank 3 as a cooling means is set lower than usual in cooling capacity. The heat exchanger 10 is lessened in cooling capacity through such a way that cooling water sent into the heat exchanger 10 is lessened in volume by an adequate quantity. Therefore, the laser gas 11 increased in temperature due to the discharge occurring inside the discharge section 1 does not fall so much in temperature even after it passes the heat exchanger 10. The laser gas 11 is made to circulate inside the oscillator tank 3 and returns again to the discharge section 1 keeping high in temperature. Therefore, laser gas can be kept high in temperature at a B section without making a large current flow, so that air, moisture, and the like attached inside the oscillator tank 3 can be efficiently removed independently of parts where they are attached.

Description

[Detailed Description of the Invention] [Purpose of the Invention (Industrial Application Field) The present invention relates to a gas laser oscillator, and in particular, when assembling the gas laser oscillator or inspecting the inside thereof, after the oscillator tank is exposed to the atmosphere. The present invention relates to a baking method for a gas laser oscillator.

(Prior Art) A gas laser oscillator that has been used conventionally has a discharge section, a heat exchanger as a cooling means, and a blower arranged in an oscillator tank, and the blower circulates laser gas to the discharge section, and the discharge causes the laser gas to flow through the discharge section. After exciting the laser gas and generating laser light, the laser gas whose temperature has increased due to discharge is cooled by the heat exchanger and reused.

In such gas laser oscillators, in order to remove air and moisture adhering to the oscillator tank, it is desirable to raise the temperature of the entire tank and evacuate it. However, in high-output gas laser oscillators, the equipment Due to its large size, it is very difficult to heat the entire tank externally. Therefore, in high-output gas laser oscillators,
As shown in FIG. 3, a baking method is used in which the laser gas 2 whose temperature has been raised by the discharge in the discharge section 1 is circulated to warm the entire oscillator tank 3, and then the laser gas is exhausted.

Note that if air and moisture are present inside the oscillator tank 3, the degree of vacuum inside the oscillator tank 3 will be reduced and the components of the laser gas 2 will change, resulting in a significant decrease in the oscillation efficiency of the gas laser oscillator. It was. Also,
In the discharge section 1, normal discharge cannot be performed,
There were cases where arcing occurred and the oscillator had to be stopped.

(Problems to be Solved by the Invention) However, the conventional baking method for a gas laser oscillator as described above has the following problems to be solved. That is, in the gas laser oscillator, the laser gas 2 whose temperature has increased due to discharge in the discharge section 1 is cooled by the heat exchanger 4, which is a cooling means, and recirculated. Although the temperature of the laser gas 2 is at a high level in the section A from the heat exchanger 1 to the heat exchanger 4, the temperature of the laser gas 2 is at a low level in the section B from the heat exchanger 4 to the discharge section 1. Therefore, it was very difficult to remove air and moisture adhering to part B.

Conventionally, a small current was applied to discharge the laser gas 2 to raise its temperature to a certain extent, thereby releasing the air and moisture that had settled in the tank (=J), and then exhausting the tank and gradually increasing the current. However, baking methods were used because the cycle of discharging and evacuation could not be repeated.However, with this baking method, discharging and evacuation had to be repeated, making the work process very complicated. , which was inefficient.

The present invention has been made in order to solve the problems mentioned above, and its purpose is to provide a baking method for a gas laser oscillator that can quickly remove air and moisture adhering to the oscillator tank. Our goal is to provide the following.

[Structure of the Invention] (Means for Solving the Problems) The present invention includes forming a discharge section by arranging one or more pairs of discharge electrodes in an oscillator tank, and discharging the laser medium while flowing the laser medium in the discharge section. In a baking method for a gas laser oscillator, the method includes applying a high frequency voltage between electrodes to generate a high frequency discharge, exciting the laser medium to generate a laser, and cooling the laser gas heated by the discharge by a cooling means for reuse. , the cooling capacity of the cooling means is reduced to reduce the baking current during startup of the gas laser oscillator.

(Function) According to the baking method for a gas laser oscillator of the present invention,
By reducing the cooling capacity of the cooling means installed in the oscillator tank, the temperature of the laser gas heated in the discharge section can be maintained at a high level, and by circulating the laser gas within the oscillator tank, the gas laser Even if the baking current at startup of the oscillator is small, air, moisture, etc. attached to the oscillator tank can be efficiently removed.

(Example) Hereinafter, an example of the present invention will be specifically described based on FIGS. 1 and 2. Incidentally, the same members as those of the conventional type shown in FIG. 3 are given the same reference numerals, and the description thereof will be omitted.

In this embodiment, as shown in FIG. 1, the cooling capacity of the heat exchanger 10 disposed within the oscillator tank 3 as a cooling means is maintained at a level lower than the normal cooling capacity. . In addition, as a means for this, a method of reducing the amount of cooling water sent to the heat exchanger 10 by an appropriate amount, etc. is used.

In the baking method for the gas laser oscillator of this embodiment configured as described above, air and moisture deposits in the oscillator tank are removed as described below. That is,
Since the cooling capacity of the heat exchanger 10 is reduced, the laser gas 11 whose temperature has increased due to the discharge in the discharge section 1
Even after passing through the heat exchanger 10, its temperature does not drop much (see Figure 2). Then, while maintaining the high temperature, it circulates within the oscillator tank 3 and returns to the discharge section 1 again. Therefore, even without passing a large current, a temperature distribution as shown in Fig. 2 can be obtained, and the laser gas temperature in section B can be maintained at a high level. It can be efficiently removed regardless of where it is attached. Furthermore, compared to the conventional method in which evacuation is repeated while gradually increasing the current, the number of evacuations can be significantly reduced.

In this way, according to this embodiment, by reducing the cooling capacity of the cooling means, the temperature of the laser gas in the oscillator tank can be maintained at a high level by simply passing a small current, and as a result, the temperature of the laser gas in the oscillator tank can be maintained at a high level. Even if the baking current at startup is small, it is possible to efficiently remove air, moisture, and other deposits that have adhered to the inside of the oscillator tank.

It should be noted that the present invention is not limited to the above-mentioned embodiments, and among the various members arranged in the oscillator tank, a temperature sensor or the like is attached to a member whose performance deteriorates in response to high temperatures. It may be configured to monitor temperature changes and adjust the discharge current value and the cooling capacity of the cooling means as appropriate so that the temperature can be maintained at a limit temperature that does not cause performance deterioration. In this case, a gas laser oscillator that can provide a more stable laser output can be obtained.

[Effects of the Invention] As described above, according to the present invention, the cooling capacity of the cooling means disposed in the oscillator tank is reduced to reduce the baking current at startup of the gas laser oscillator. Accordingly, it is possible to provide a baking method for a gas laser oscillator that can quickly remove air and moisture attached to the oscillator tank.

[Brief explanation of drawings]

Fig. 1 is a schematic diagram showing an embodiment of the baking method for a gas laser oscillator of the present invention, Fig. 2 is a diagram showing the temperature distribution of the laser gas in the embodiment shown in Fig. 1, and Fig. 3 is a diagram showing a conventional gas laser oscillator. FIG. 4 is a diagram showing the temperature distribution of the laser gas in the conventional type shown in FIG. 3. DESCRIPTION OF SYMBOLS 1... Discharge part, 2... Laser gas, 3... Oscillator tank, 4... Heat exchanger, 10... Heat exchanger with reduced cooling capacity, 11... Laser gas with high temperature level .

Claims (1)

[Claims] A discharge section is formed by disposing one or more pairs of discharge electrodes facing each other in an oscillator tank, and a high-frequency voltage is applied between the electrodes while a laser medium is flowing through the discharge section to generate a high-frequency discharge. A method for baking a gas laser oscillator, in which the laser gas heated by the discharge is cooled by a cooling means and reused, the laser gas being heated by the discharge being cooled by a cooling means, the cooling capacity of the cooling means being reduced; A method for baking a gas laser oscillator characterized by reducing a baking current at startup of the gas laser oscillator.