Competition of Third‐ and Fifth‐Order Non‐linear Optical Processes in C<sub>60</sub>Thin Film
Annotatsiya
Abstract The non‐linear refractive processes due to the third‐ and fifth‐order non‐linearities in fullerene thin films were investigated using the Z‐scan technique (λ=532 nm, t=55 ps). The analysis of the simultaneous influence of the third‐order non‐linear refraction causing the self‐focusing and fifth‐order nonlinear refraction causing the self‐defocusing was carried out. It is shown that at low intensities (up to 5×108 W cm−2) the non‐linear refraction process was determined by the only third‐order process, while at intensity increase both influence of the third‐ and the fifth‐order processes was observed. The origin of observed non‐linearities was analyzed.