JPS5848484A - Sealed type carbon dioxide gas laser tube - Google Patents

Abstract

PURPOSE:To obtain a sealing type carbon dioxide gas laser tube characterized by high laser output power and a long life, by using platinum nickel alloy for cathode. CONSTITUTION:By adding nickel, which can resist sputtering, to platinum, it is recognized that the sputtering can be suppressed to a considerable extent without extremely imparing oxidizing catalytic action of the platinum. As a result of using the platinum nickel alloy as the cathode 5 of the sealing type carbon dioxide laser tube, the long life of the sealing type carbond dioxide gas laser tube can be realized, even though the laser output power is reduced to some extent in comparison with the case the platinum is used as the cathode. The laser output power and the life of the sealed type carbon dioxide gas laser tube depend on the quantity of addition of the nickel, but they are contrary matters to each other. Therefore it is recommended that the quantity of the nickel addition is selected so as to meet the purpose. As for the electrode shape, a circular cylinder shaped electrode is usually employed. However, effect is not impaired even in a circular column shape or in the other shapes.

Description

[Detailed description of the invention] The present invention relates to a sealed carbon dioxide laser tube.

Conventionally, platinum has been mainly used as an electrode material for sealed carbon dioxide laser tubes. The reason for this is that platinum exhibits an extremely excellent oxidation catalytic effect, so by using platinum in the electrode, it is possible to suppress the dissociation of carbon dioxide gas in the laser tube due to discharge, and it is possible to improve the laser output. However, platinum has the disadvantage of being prone to sputtering. Therefore, when platinum is used as a cathode, sputtering occurs violently, and a large amount of sputtering products adheres to the inner wall of the laser. Generally, sputtering products are Platinum is no exception, especially carbonic acid 2.

Compared to other gases commonly used in carbon dioxide lasers, such as nitrogen gas and helium gas, the gas has the property of being adsorbed by sputtering products much more easily, so when platinum is used as the cathode, However, it has been extremely difficult to extend the life of sealed carbon dioxide laser tubes. Incidentally, since splattering does not occur at the anode, the above-mentioned problem does not occur even if platinum is used for the anode.

Next, a conventional example will be explained based on the drawings.

As the first conventional example, the laser tube is as shown in Figure 1.
It has a double structure made of glass and has a cooling section 3. The discharge section 2 is a cylindrical tube with an inner diameter of 10 cm, and both ends are sealed with optical windows 1 made of zinc selenide (ZnSe).

The anode 4 is a cylindrical platinum electrode with a diameter of 2. The cathode 6 is a platinum cylindrical electrode with an outer diameter of 1ofi and a wall thickness of 0.11III.
+, and the effective discharge length is 400 gourds. 'In this laser tube, the mixing ratio is 11%Co2°20%N2? a e
After enclosing a mixed gas with fa He at a total pressure of 30 Toxr, it was installed in a laser resonator with mirror spacing of 600 m+a, and while the cooling part 3 was cooled with tap water, laser oscillation was performed with a discharge current of 20 mA DC. The operating time vs. laser output characteristic at that time is shown by the broken line a in Figure 2, and the initial laser output is 1
6W, and the time for the output to decay to % of the initial value was 110 hours.

As a second conventional example, lensizer oscillation was performed under exactly the same conditions as in the conventional example 1, except that a nickel cylindrical electrode was used as the anode 4 and a nickel cylindrical electrode was used as the cathode 6.

The operating time vs. laser output characteristics at that time are already shown in broken lines in FIG. 2, and the initial laser output was 3 W, and the time for the output to decay to the initial value of H was 3,290 hours.

2.° or more, when platinum is used for the electrode, the laser output is high, but the life is short, and when the electrode is made of nickel, which is resistant to sputtering, the life is short. However, since nickel does not have oxidation catalytic ability, it has the disadvantage of low laser output. ,
2. The present invention has been made in view of these points, and provides an enclosed carbon dioxide laser tube with high laser output and long life.

The enclosed carbon dioxide laser tube of the present invention is characterized in that a platinum-nickel alloy is used for the cathode. That is, the present inventors have confirmed that by adding nickel, which is resistant to sputtering, to platinum, sputtering can be suppressed to a considerable extent without significantly impairing the oxidation catalytic action of platinum.

Therefore, as a result of using a platinum-nickel alloy for the cathode of an encapsulated carbon dioxide laser tube, although the laser output is reduced to some extent compared to when platinum is used for the cathode, it is possible to extend the life of the encapsulated carbon dioxide laser tube. became. Note that the laser output and the life of the sealed carbon dioxide laser tube depend on the amount of nickel added, and since these are contradictory matters, the amount of nickel added may be selected depending on the purpose. Further, although a cylindrical electrode shape is normally used, the effects of the present invention will not be impaired in any way even if the electrode shape is cylindrical or other shapes.

Next, embodiments according to the present invention will be described based on the drawings.
)・<Example 1> Laser oscillation was carried out under exactly the same conditions as in Conventional Example 1, except that an inner cylindrical electrode made of NiPt3 (triplatinum-Nila-6-Beh-Mickel alloy) was used as the cathode 4 in FIG. Operating time at that time -
The laser output characteristics are shown by the solid line A in Figure 2.The initial laser output is 16W, and when the output decays to % of the initial value, r5 is 420 hours. Ta. Output is approximately 6% compared to conventional example 1
Although it has decreased slightly, life expectancy has increased by about 4 years.

<Example 2> Conventional example 1 except that a NiPt cylindrical electrode was used for the cathode 4
Laser oscillation was performed under exactly the same conditions. The operating time vs. laser output characteristic at that time is shown by the solid line B in FIG. 2, where the initial laser output was 13 W and the time it took for the output to decay to % of the initial value was 1,770 hours. Compared to Conventional Example 1, the output decreased by about 19 inches, but the life span increased by about 16 inches.

<Example 3>

Laser oscillation was performed under exactly the same conditions as in Conventional Example 1, except that an inner cylindrical electrode made of N 13P was used for the cathode 4. The operating time vs. laser output characteristic at that time is shown by solid line C in FIG. 2, where the initial laser output was 1 oe and the time for the output to decay to % of the initial value was 2,820 hours. Compared to Conventional Example 1, the output was reduced by about 38 cm, but the life span was increased by about 26 cm. Also, compared to conventional example 2, the life span was reduced by about 14%, but
Output has improved by about 3 times.

As described above, the present invention provides a carbon dioxide sealed laser tube with high laser output and long life by using a platinum-nickel alloy as the cathode material, and its industrial value is extremely high. It is a big thing.
.

[Brief explanation of the drawing]

FIG. 1 is a side view showing a sealed carbon dioxide laser tube, and FIG. 2 is a diagram showing operating time versus laser output characteristics of the present invention and a conventional sealed carbon dioxide laser tube. 1...Optical window, 2...Discharge section, 3...
...Cooling section, 4...Anode, 6...
cathode.

Claims (1)

[Claims] An encapsulated carbon dioxide laser tube characterized by using a platinum-nickel alloy for the cathode.