Femtosecond laser near field ablation

The high field strength of femtosecond laser Pulses leads to nonlinear effects during the interaction with condensed matter. One Such effect is the ablation process, which can be initiated below the threshold of common thermal ablation if the excitation pulses are sufficiently short. This effect leads to structure formation, which is anisotropic because of the polarization properties of the near field and can result in pattern sizes below the resolution limit of light. These effects are explored by temporally resolved scattering methods and by post-mortem analysis to show the non-thermal and anisotropic nature of this process. The near-field distribution of plasmon modes can be tailored to a large extent in order to obtain control of the pattern formation.