Optical limiting in fullerenes, colloidal metal solutions, and semiconductors in the field of pico-and nanosecond pulses of an Nd:YAG laser

Optical limiting of pico-and nanosecond pulsed radiation of a Nd:YAG laser (λ=1064 and 532 nm) is studied in solutions of fullerenes (C 60 and C 70 ), semiconductor crystals and films (GaAs, As 2 S 3 , As 20 S 80 , 2As 2 S 3 /As 2 Se 3 , and 3As 2 S 3 /As 2 Se 3 ), and colloidal solutions of metals (Au, Ag, Pt, and Cu). The effect of the particle aggregation in silver solutions on the optical limiting is considered. Optical limiting mechanisms, specifically, reverse saturable absorption, two-photon absorption, and self-action effects, are discussed. Nonlinear absorption coefficients of the studied materials are measured.