Two- and three-dimensional periodic structures produced by nano-pulsed laser irradiation in Ag-doped glass

Abstract

Direct laser recording of two-dimensional and three-dimensional periodic structures in a glass containing nanocrystalline Ag clusters is demonstrated. The Ag-doped glasses were irradiated by the third harmonic of a Nd:YAG laser (354 nm) with pulse duration of 7 ns and 10 Hz repetition rate, and fluences which varied from 0.2 fto 1.2 J/cm 2 . Four intersecting beams of equal intensity were used to create an intensity-modulated pattern at the glass surface and the fifth beam was used to obtain intensity modulation in the bulk. The resultant gratings written in the glass as well as the kinetics of the laser-induced evolution of the Ag clusters were studied by AFM and optical microscopy. Under illumination the nanocrystals move rapidly toward the surface and towards one another, agglomerate and coalesce. The mechanisms and kinetics of light induced mass transfer occurring during recording are analyzed. The kinetics of cluster motion is estimated.