Vacuum ultraviolet (VUV) –ultraviolet (UV) multiwavelength excitation process for high-quality ablation of fused silica, in which VUV laser beam with low laser fluence and UV laser beam with relatively high fluence are simultaneously irradiated, is reviewed. Ablation mechanism is explained as absorption of the UV laser by excited-states formed by the VUV laser irradiation (excited-state absorption: ESA). A coaxial irradiation system of F₂ (157 nm) and KrF excimer (248 nm) lasers has been developed for this process. This system performs well-defined micropatterning of not only fused silica but also other advanced materials including sapphire and GaN with little thermal influence and little damage. The discussion includes characterization of optimum experimental conditions and the detailed mechanism of multiwavelength excitation process.

Date Published: 9 May 2013
PDF: 9 pages
Proc. SPIE 8777, Damage to VUV, EUV, and X-ray Optics IV; and EUV and X-ray Optics: Synergy between Laboratory and Space III, 877704 (9 May 2013); doi: 10.1117/12.2019720

Published in SPIE Proceedings Vol. 8777:
Damage to VUV, EUV, and X-ray Optics IV; and EUV and X-ray Optics: Synergy between Laboratory and Space III
Libor Juha; René Hudec; Ladislav Pina; Saša Bajt; Richard London, Editor(s)