Gold nanoparticle-doped silica fiber for a new generation of optical amplifiers

Owing to their plasmonic properties as efficient scatterers or absorbers of light in the visible and near-infrared (NIR) range, noble metal nanoparticles (NPs) have been widely investigated in recent years for a variety of... [ view full abstract ]

Owing to their plasmonic properties as efficient scatterers or absorbers of light in the visible and near-infrared (NIR) range, noble metal nanoparticles (NPs) have been widely investigated in recent years for a variety of applications in different fields such as sensing, nonlinear optics and fluorescence enhancement. Indeed, Maurizio et al. show that gold nanoparticles can act as very efficient nanoantennae for the luminescent enhancement of photoemitting systems like Er ions [1]. Erbium Doped Fiber Amplifiers (EDFAs) are clearly a key technology in present optical communication systems because of their high gain, low noise and high-speed response. Many research efforts are being made in these years to increase the small cross-section for Er excitation and enhance the Er3+ luminescent emission at 1.54 mm to improve the efficiency of EDFAs.

The aim of our ANR project AMPEROR was to realize silica fibers co-doped with gold nanoparticles (Au-NPs) and Er ions for a new generation of EDFAs. The preparation of optical fibers required high temperature process (> 1800°C for pure silica fibers, elaborated by Modified Chemical Vapor Deposition process(MCVD)). This temperature is higher than the gold nanoparticle melting point (300°C). A technological obstacle is to maintain the gold nanoparticles in the manufacturing process. In this project, we developed a new doping concept involving a zirconia sol co-doped with gold nanoparticles and Er ions in a MCVD-compatible process. Preservation of Au-NPs all along the fiber manufacturing process is demonstrated. Surface Plasmon Resonance (SPR) is clearly observed at 500 nm and remain unchanged during the process fabrication (fig. 1). First attenuation value measurement by conventional cut-back technique is about 120 dB/m showing a high incorporation of Au-Nps into the glass fiber.

This promising method for the manufacture of gold nanoparticle-doped fibers was also used for the realization of an EDFA incorporating erbium to the doping solution. The characterization of the co-doped fiber is under progress.

[1] C. Maurizio, E. Trave, G. Perotto, V. Bello, D. Pasqualini, P. Mazzoldi, G. Battaglin, T. Cesca, C. Scian and G. Mattei, Phys. Rev. B: Condens. Matter Mater. Phys., 2011, 83, 195430.