Femtosecond nonlinear optical response of metallophthalocyanine films

The third-order nonlinear optical properties of copper phthalocyanine (CuPc ) and magnesium phthalocyanine (MgPc) films were investigated by femtosecon d optical Kerr effect (OKE) and pump-probe techniques. For both CuPc and Mg Pc, the third-order nonlinear optical susceptibility was enhanced at least by one order of magnitude in comparison with that of the metal-free Pc, and the enhancement effect arises from different mechanisms for both films. Fr om pump-probe measurement, quite different transmittance and decay behavior between CuPc and MgPc films were observed. The CuPc films show an ultrafas t decay, while the decay behavior of MgPc him is complicated with several t emporal components, which could be explained by the relaxation of singlet e xcited state. (C) 2001 Published by Elsevier Science Ltd.