Ultrafast dynamics of periodic nanostructure formation on diamondlike carbon films irradiated with femtosecond laser pulses

摘要

Using a pump-probe technique the authors have measured reflectivity of diamondlike carbon (DLC) film irradiated with femtosecond laser pulses to understand dynamic processes responsible for periodic nanostructure formation. The results have shown that characteristic reflectivity change observed as a function of superimposed laser shots is closely associated with the nanostructure formation and the bonding structure change to induce surface swelling, leading to a conclusion that the nanostructure formation on the DLC surface is certainly preceded by the bonding structure change. The nanoscale ablation to produce the nanostructure is discussed based on the local field generation on the surface.