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Mechanisms of nonlinear optical limiting by fullerenes and fullerene-like nanostructures in solutions, suspensions theoretically and experimentally investigated in wide spectral range 0.3-1.1 µm.An essential contribution of photoinduced scattering to nonlinear optical limiting was demonstrated in fullerene solutions and in suspensions of fullerene-like nanostructures. It is shown than suspensions based on fullerene-like nanostructures are the most perspective for devices design with nonlinear optical protection from laser radiation (speed less than 1 ns, dynamic range 10 3 -10 4 , limiting threshold 5×10 -6 J/cm 2 , spectral range 0.3-1.1 µm, color-comfortable vision through it, i.e. the absence of limiter color.) Devices with nonlinear optical limiters are demonstrated.The computer simulation of femtosecond range optical switchers, based on fullerene containing media was performed. Fabri-Perot interferometers, containing film of fullerene film, produced by vacuum deposition and film of fullerene-polymer solid solution were investigated. Fullerene polarization nonlinearity leads to light-induced refractive index change. The probability of interferometer reflection and transmission control by low intensity signal is demonstrated. Study of temporal and relaxational processes in nonlinear-optical media, containing fullerenes, fullerene-like and carbon nanostructures in nanosecond range of pulse durations IntroductionNonlinear optical limiting in fullerene-containing media (solutions, microporous matrices, and polymer films) was thoroughly investigated by our team in nanosecond range of laser pulse durations [1]. It was shown that fullerene-containing solutions (C 60 -toluene, C 60 -CCl 4 et al.) have the maximum dynamic range of optical limiting. There are two basic mechanisms of optical limiting in these media -RSA (reverse saturable absorption) and stimulated scattering (SS) by light-induced fine-scale refractive index inhomogeneities. The last one mechanism takes place only in liquid media. It was shown that for such systems limiting threshold value is 10 -2 J, dynamic range is more 100 times. The main disadvantage of nonlinear-optical systems, based on fullerene solutions is their coloring. Therefore the suspensions of carbon nanostructures (carbon black suspensions -CBS), and Astralene suspensions in water and alcohol [2] were investigated for development of laser radiation nonlinear-optical filters. These suspensions have no coloring. For carbon nanostructures suspensions the mechanism of nonlinear optical limiting is nonlinear light scattering by vapour shell, formed around carbon nanostructure, heated up (by laser radiation) to the temperature of surrounding liquid boiling [3]. For Astralene suspension along with nonlinear scattering by vapour shell, RSA takes place because Astralenes as fullerene-like clusters have π-conjugated electron shell. Therefore the dynamic range for Astralene suspensions is increased approximately two times [2].The theoretical and experimental investigation of nonlinear optical pro...

The results of theoretical and experimental studies on photodynamics and mechanism of nonlinear optical processes, responsible for optical limiting of power radiation in the wavelength range from 0.3 to 1.3 microns, are presented. Peculiarities in the mechanisms of optical limiting for different fullerene-containing matrices, including solutions, solid-state and polymer systems, are shown.