Abstract

The use of ultrashort pulsed lasers in the field of material processing has been widely studied and its ability of micro-machining any kind of material by direct processing with a high degree of accuracy has been demonstrated. Femtosecond laser processing is especially relevant since its spatial accuracy is closely related to its "deterministic" character, meaning that damage/ablation will occur systematically on regions where the local fluence on the material (depending on the intensity distribution of the laser beam) exceeds a very precise threshold fluence. This characteristic must be seen in opposition to the stochastic character of damage threshold observed for "long" pulses (typically > 10 ps), for which damage appearance is known to be probabilistic. This property, combined with the reduced thermal diffusion, makes possible the ablation of materials with sub-micrometer precision, opening the way towards nano-machining applications.

© 2009 IEEE