Anisotropic and enhanced absorptive nonlinearities in a macroscopic film induced by aligned gold nanorods

Anisotropic and enhanced nonlinear absorption (NLA) has been observed from aligned gold nanorods (GNRs) embedded in a poly(vinyl alcohol) film, which was realized by a stretched-film method. Open-aperture Z-scan experiments revealed that the stretch process enhanced the NLA coefficient by approximately nine times and increased the anisotropic factor of NLA to similar to 20. The enhancement in the NLA coefficient reached as high as similar to 91 times after increasing the concentration of GNRs by four times and this is attributed to the plasmonic interaction between densely packed GNRs. (C) 2010 American Institute of Physics. [doi: 10.1063/1.3458693]