Nano material processing with lasers in combination with near-field technology

Recent research work has shown, that 'focusing' of laser radiation down to a few nanometer can be obtained y using lasers in combination with nearfield technology (known from scanning tunneling microscope 'STM' or atomic force microscope 'AFM'). Lateral external illumination of STM- or AFM-probe tips with laser radiation can cause tremendous intensity enhancement in the nearfield underneath the tip. This effect can be explained by various electrostatic as well as electrodynamic effects known from surface enhanced raman spectroscopy. This effect was utilized to concentrate laser radiation with high intensity between a tip and a substrate in the nearfield. FOLANT-technique (focusing of laser radiation in the nearfield of a tip) enables intensity enhancement up to 106 in a narrow localized zone underneath the tip. The interaction area with nanometer scale can be applied for material processing even down to atomic dimensions. Using STM- laser-combination, hillocks, pits and grooves with lateral dimensions down to 10 nm have been obtained on gold substrates. AFM- laser-combination enabled nanostructures down to 20 nm on dielectric materials as for example polycarbonate.