Ultrashort pulse nanomachining

A wavelength in the ultraviolet spectral range enables the irradiation of surfaces with an optical resolution of the order of 100 nm. In many materials like polymers or glasses this optical resolution can be converted into a structural resolution of the material ablation. However, in the case of materials with high thermal diffusivity, the laser pulse duration plays an important role with respect to the achievable resolution. In the case of a nanosecond pulse, the absorbed energy dissipates into a comparatively large area. To reduce this thermal diffusion length for metals to the order of the optical resolution, ultrashort laser pulses (picosecond or femtosecond) are required. Consequently, a UV-femtosecond laser system offers the best prerequisites for high definition direct laser patterning of metals.

Cu nanowires	Relief grating in stainless steel

Further information:

J. Ihlemann, J.-H. Klein-Wiele, J. Békési and P. Simon
UV Ultrafast Laser Processing Using Phase Masks
Journal of Physics: Conference Series 59, 449 (2007)

B. Borchers, J. Békési, P. Simon, J. Ihlemann
Sub micron surface patterning by laser ablation with short UV pulses using a proximity phase mask setup
Journal of Applied Physics 107, 063106 (2010)