Ti:sapphire femtosecond laser direct micro-cutting and profiling of graphene

Abstract

This paper reports the formation of uniform single layer micro-patterns of graphene on a glass substrate using direct femtosecond laser cutting. The cutting of graphene was achieved in air and argon. By translating the graphene sample with respect to the laser beam, continuous micro-channels were carved. The cutting geometry can be controlled by varying the laser fluence and the scanning path. Also, 1∼2 µm wide graphene micro-ribbons were hatched out. The ablation threshold of graphene was determined to be 0.16∼0.21 J/cm2. With the laser fluence higher than the ablation threshold, graphene was ablated rapidly and removed completely without damaging the glass substrate. Atomic force microscopy (AFM) and Raman spectroscopy have been used to confirm the ablation of graphene. Time domain finite difference modelling was employed to understand the thermal history of the laser ablation process.