Nonlinear processes in organic molecules under high-power laser excitation

The nonlinear processes in organic molecules (phthalocyanines and naphthalocyanines, porphyrins, fullerenes, luminescent polymers, stilbenes) under high-power pulsed laser excitation (at wavelengths of 308 and 532 nm with power densities in the range 1-400 MW/cm/sup 2/) was studied for the development of optical radiation limiters. The theoretical and experimental investigations suggest that the mechanism of optical radiation limitation for the organic molecules with dyes is associated with the process of return saturated absorption (RSA). The mechanism of radiation attenuation by these molecules was also studied.