On the operation of a long-pulse KrCl excimer laser

摘要: High-power lasers pumped by a gas discharge are extensively used in industrial applications. Of particular importance an electric excimer mixtures because this allows the generation of powerful ultraviolet radiation (UV), with wavelengths below 350 nm. Due to short wavelength, these offer unique possibility structure materials on sub-micron scale, when focused or mask techniques. Also, absorption UV is strong many materials, which improved control ablation depth. Also larger structures be fabricated, can advantage, e.g. for hole drilling too brittle mechanic processing, such as ceramics. The predominantly so far XeCl and KrF but show important limitations. Although operated high spatial beam quality, close fundamental limit diffraction, comparatively long wavelength (308 nm) often leads undesirably deep penetration radiation, problems quality machining. emit at shorter (248 nm), reduces However, rather poor. This limitation arises because, with decreasing discharges known become spatially inhomogeneous through instabilities leading filamentation, within typically only ten a few tens nanoseconds after ignition discharge. excludes buildup unperturbed, high-quality sufficiently roundtrips laser resonator. High-precision processing may still done low beams, filtering masks diaphragms. But strongly efficiency small fraction reaches work piece. What actually required laser, emits diffraction-limited, much than that lasers, possibly even lasers.