INDUCED ABSORPTION IN FULLERENE-DOPED SOLID XEROGEL MATRICES

In this paper measurements of induced absorption and its dynamics in C -60-doped solid xerogel matrices are presented. The measurements are p erformed in a pump-test geometry using picosecond pulses generated fro m a frequency doubled modelocked Nd:YAG laser. An induced absorption l eading to optical limiting was observed. Outstanding optical limiting qualities for single shot excitation were found. Furthermore, limiting dynamics are studied. A decrease of the initial laser-induced absorpt ion with a time constant of 150 picoseconds was observed. This is attr ibuted to a transition from excited singlet to tripler electronic stat es in the C-60 molecule. A long-living component due to the resulting triplet state population was also observed. (C) 1998 Elsevier Science Ltd. All rights reserved.