Lasers, Gas

Abstract

This article reviews the characteristics of gas lasers that are important as both scientific and industrial tools. The basic principles common to the operation of all gas lasers and a few of their general properties are discussed. The lasers are categorized according to the pumping mechanisms of the upper laser level: electron impact excitation (copper and gold lasers and argon‐ and krypton‐ion lasers), excitation transfer (He–Ne laser, He–Cd laser, and CO 2 laser), reactive collision lasers (excimer lasers: ArF, KrF, XeCl, and XeF), chemical lasers (HF and iodine laser), and other lasers in the far‐infrared (IR), ultraviolet, and X‐ray regions. Selected applications of pulsed and continuous gas lasers are presented in material processing, marking and laser evaporation, microlithography, photochemical processing, stereolithography, and medicine.