Optical limiting of a covalently bonded gold nanoparticle/polylysine hybrid material.

The optical limiting performance of a covalently bonded gold nanoparticle (approximately 2 nm)/polylysine hybrid material (AuNP-PLL) was investigated using 4.1 ns laser pulses at 532 nm. The hybrid material exhibits enhanced optical limiting in comparison to individual nanoparticles, presumably due to the interparticle electromagnetic interactions between particles in close proximity. Reverse saturable absorption and/or free carrier absorption were found to be the dominant contributor(s) to the optical limiting of the hybrid material.