Fabrication of Low-Threshold 3D Void Structures inside a Polymer Matrix Doped with Gold Nanorods

We report on a low-threshold three-dimensional (3D) void generation inside a polyvinyl-alcohol (PVA) polymer matrix doped with gold nanorods (NRs) by near infra red femtosecond laser pulses. By matching the laser wavelength to the surface plasmon resonance band of the embedded gold NRs, the void generation threshold could be reduced by one order of magnitude lower than undoped matrix. We discuss physical mechanisms involved in the void generation, where distinction between the decomposition of gold NR or PVA is drawn in single pulse and multiple pulse irradiations. We also demonstrate 3D void recording for applications in 3D optical data storage.