<title>Space-selective precipitation and control of metal nanoparticles inside glasses</title>

We report on precipitation, control and erasure of Au nanoparticles inside transparent glasses. Au3+-doped glass is first irradiated by an 800-nm femtosecond laser at room temperature and then annealed at various temperatures. Transmission electron microscopy shows Au nanoparticles precipitates near the focal point of the laser beam after the irradiation and successive annealing at temperatures above 450°C. We suggest that multiphoton ionization leads to reduction of Au ions, and subsequent nucleation from a high-temperature annealing results in precipitation of Au nanoparticles. We show that the size of the Au nanoparticles could be controlled by the irradiation conditions, and demonstrate that the precipitated Au nanoparticles could be broken by the second irradiation of the femtosecond laser. The similar phenomena have also been observed in Ag+-doped glasses. The observed phenomenon has promising applications for the fabrication of 3-dimensional multi-colored images inside transparent materials, rewriteable optical memory and for integrated micro-optical switches.© (2004) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.