Nanostructuring of Laser-Deposited Ti Films by Self-Limited Oxidation

Local laser-induced oxidation of thin titanium films on glass is shown to be self-limiting due to a decrease in the absorptivity during the reaction. Taking advantage of this confinement, stable writing of transparent oxide line structures narrower than the diffraction-limited focused spot of a continuous wave Ar ion laser (500 nm) has been accomplished. The greatest optical contrast (1:10) with the highest resolution down to 165 nm was observed if the film thickness is of the order of the light absorption length in the metal.