Optical recording media using laser-induced size reduction of Au nanoparticles

Silica-gel films containing Au nanoparticles were fabricated by a photoredu ction method, which functioned as a medium for high-density optical recordi ng. On irradiation of 532 nm laser light, which corresponds to the surface plasmon resonance absorption of Au particles, the absorption spectrum of th e film showed a blueshift. Using this property, a hologram was recorded on the film. Transmitting electron microscopy supported that the change in abs orption spectrum was due to size reduction of embedded particles caused by laser irradiation. For recording the hologram, a threshold of laser fluence existed which corresponded to the heat of vaporization of Au particles. (C ) 2001 American Institute of Physics.