Femtosecond Laser Filamentation in Gaseous Ethylene: Formation of Hydrogenated Amorphous Carbon

Photochemical reactions of gaseous ethylene in femtosecond laser filaments are studied. It is shown that hydrogenated amorphous carbon (a-C:H) films and nanoparticles are produced by the strong interactions with the intense laser fields (~1013 W/cm2). The laser field intensity is found to be an important parameter to determine the sp2/sp3 carbon ratio of the films and the size and number of nanoparticles.