Pulse laser processing of nano-carbon film structures

摘要

Special features of the interaction of the powerful pulse laser radiation with films from graphite-like carbon material (layers of oriented carbon nano-tubes and plate-like graphite crystallites with the size of the nanometer order) were studied experimentally. After irradiation with 5-10 laser pulses for 22 ns on the wave-length of 1064 nm at a power density of 10-30 MW/cm~2, the appearance of lengthy structural formations on the rough surface of the carbon film has been observed. The formations have a preferred direction perpendicular to the plane of the linear polarization of laser radiation, which is normal incident on the film surface. It has been shown that the carbon film treatment with circularly polarized laser radiation does not give rise to the appearance of oriented structural formations. The investigation of special features of the diffuse-scattered light from the surfaces of carbon films in the initial state and carbon films irradiated with laser was carried out. It has been established that powerful laser radiation gives rise to the appearance of a significant anisotropy in the indicatrix of the diffuse-scattered light from the surfaces of the irradiated films under study. The model was proposed, which explained the experimental results by anisotropic evaporation of the graphite-like carbon material occurring due to the essential polarization dependence of the absorption and reflection factors of light at large angles of incidence on an absorbing rough surface.