5 nm structures produced by direct laser writing.

Here we present a new approach to overcome the optical diffraction limit by using novel materials. In the paper, we report experimental results obtained by high-resolution transmission electron microscopy (HRTEM) and optical absorption spectroscopy, for a fluorescent photosensitive glass-ceramic containing rare-earth ions such as samarium (Sm). Using a home built dynamic tester, with a low power laser, we recorded nanostructures having 5 nm line widths. In the line structure, measurements reveal the presence of silver nanocrystals with few nanometre sizes. HRTEM shows that there is a random orientation of the nanocrystals. A writing mechanism with three steps is proposed.