Nano- and Microstructuring of SiO2 and Sapphire with Fs-laser Induced Selective Etching

Sub wavelength ripples perpendicular to the polarisation of the laser radiation are obtained by scanning a tightly focused beam (~1m) of femtosecond laser radiation over the surface and through the volume of various materials. The ripple patterns extend coherently over many overlapping laser pulses and scanning tracks. The cross-sections and the surface of the ripples and in volume nanoplanes are investigated using electron microscopy. By using microscope objectives with higher Numerical Apertures micro-channels can be fabricated with a technique called In Volume Selective Laser Etching (ISLE).