Photoinduced micron scale maskless etching in transparent glasses

In this work we present the results of a new micron-scale maskless photoetching process which is applicable to a large variety of silica-based transparent glasses. The technique uses multiphoton absorption at 532 nm from a mode-locked Q-switched Nd:YAG laser to write the patterns directly onto the glass. The glass was exposed, to a solid Gaussian beam focused to about 70 μm at the glass surface, resulting in intensities of few GW/cm², for periods of several tens of seconds and then etched in a 12% HF solution for fifteen minutes. The glasses were studied using contact atomic force microscopy (AFM) to determine the topography of the selectively etched patterns