Properties and Stability of Nanosecond Optical Limiting of Gold Nanoclusters

Optical limitation (OL) performances of the gold nanoclusters protected by C₆₀-tpy have been investigated with 8-ns pulses at 532 nm. The experimental results show that the nanocomposite possesses the OL effects superior to C₆₀ in toluene. The main mechanism of OL is attributed to the nonlinear absorption and subsequently induced nonlinear scattering during excitation of the pulse. Ageing of the nanocomposite chloroform solution in air lowers the OL performances by a factor of 2.4, which can be due to the formation of aggregates of large gold particles.