Patterned graphene ablation and two-photon functionalization by picosecond laser pulses in ambient conditions

Direct laser writing is a technology with excellent prospects for mask-less processing of carbon-based nanomaterials, because of the wide range of photoinduced reactions that can be performed on large surfaces with submicron resolution. In this paper, we demonstrate the use of picoseconds laser pulses for one-step ablation and functionalization of graphene. Varying the parameters of power, pulse frequency, and speed, we demonstrated the ablation down to 2 mu m width and up to mm-long lines as well as functionalization with spatial resolution less than 1 mu m with linear speeds in the range of 1m/s. Raman and atomic-force microscopy studies were used to indicate the difference in modified graphene states and correlation to the changes in optical properties. (C) 2015 AIP Publishing LLC.