OPTICAL NONLINEARITY IN PHTHALOCYANINES AND CLUSTERS

摘要

The third order nonlinear optical properties of a set of μ-oxo dimeric iron (III) phthalocyanine compounds and another group of mixed metal, mixed chalcogen clusters have been investigated by Degenerate Four Wave Mixing (DFWM), Z-Scan and Optical Limiting at 532 nm using 35 ps and 6 ns pulses. The measured cubic hyperpolarizability and Figure of Merit values of the iron phthalocyanines are found to be some of the best reported so far among metallo-Pc systems. Time evolution studies of the DFWM signal in these samples indicate the presence of at least two different timescales involved in the decay of the signal. In the case of the clusters efficient optical limiting has been observed, and the effective values of their nonlinear absorption coefficient (β_(eff)) and nonlinear refraction coefficient (γ_(eff)) have been calculated from Z-Scan measurements.