The gases are used in the gas lasers for generation of the laser beams. The gas mixture required to run a CO2 laser contains 60-85% helium, 13-55% nitrogen and 1-9% carbon dioxide. The exact composition depends upon the laser type and manufacturer.
Some lasers also require small additions of other gases, such as oxygen, hydrogen or xenon. On the other hand, the gas mixture for для TEA lasers often contains small percentage of CO. CO is toxic and corrosive gas, when it is applied in the system of gas supply it is necessary to install the additional protective devices.
Gas used for excimer lasers contains 0.05-0.3% halogen (fluorine or chlorine hydride), 1-10% Inert Gas (krypton, xenon or argon) и 90-99% buffer gas (helium or neon). For safety reasons halogen is always diluted with helium or neon.
Purity of laser gases
Today the laser manufacturers demand the application of relatively high purity gases. The impurities in the laser gases impede the laser performance due to lowering its power output, disturbing the electrical discharge homogeneity, besides it necessitates frequent maintenance of the laser optics.
The laser gases purity is of high importance for the laser efficiency and operating life. The minimum standard of the laser gases purity is 99.999; the admixtures composition is also very important and shall be known to the laser tool operator. Special requirements regarding the number of the pressure lowering steps, material, tightness, filtration system and regulation of the outgoing flow are applied to the equipment used for the pressure lowering and stabilization of the laser gas flow. The most harmful admixtures are water vapor and hydrocarbon. But the admixtures may enter the gases not only from the cylinders but also when using poorly designed and assembled gas distribution system.
Therefore, the selection of the suitable components of the gas feed system and its efficient installation is essential for provision of a reliable and satisfactory laser performance.
Russian department of Linde Gas offers all types of gas mixtures and pure gases for laser cutting, welding, marking and engraving, excimer mixtures and special gas distribution equipment. Besides it is possible to supply special gas mixtures, made by Linde Gas department in Germany, for foreign laser tools (Rofin and etc.).