Dispersion studies of non-linear absorption in C60 using Z-scan

We present our experimental and theoretical results on the dispersion studies of non-linear absorption in C60 solution. Open-aperture Z-scans are performed over the visible region (440–660 nm) using an ns OPO. Our results are interpreted using a 5-level model taking into account both the excited state absorption and two-photon absorption processes. Results indicate that the excited state absorption dominates in the shorter-wavelength region (440–560 nm) whereas the two-photon absorption dominates in the longer-wavelength region (580–660 nm).