Erbium-doped nanoparticles in silica-based optical fibres

Abstract

Developing of new rare-earth (RE)-doped optical fibres for power amplifiers and lasers requires continuous improvements in the fibre spectroscopic properties (like shape and width of the gain curve, optical quantum efficiency, resistance to spectral hole burning and photodarkening,…). Silica glass as a host material for fibres has proved to be very attractive. However some potential applications of RE-doped fibres suffer from limitations in terms of spectroscopic properties resulting from clustering or inappropriate local environment when doped into silica. To this aim, we present a new route to modify some spectroscopic properties of rare-earth ions in silicabased fibers based on the incorporation of erbium ions in amorphous dielectric nanoparticles, grown in-situ in fiber preforms. By adding alkaline earth elements, in low concentration into silica, one can obtain a glass with an immiscibility gap. Then, phase separation occurs under an appropriate heat treatment. We investigated the role of three alkaline-earth elements: magnesium, calcium and strontium. We present the achieved stabilization of nanometric erbium-doped dielectric nanoparticles within the core of silica fibers. We present the nanoparticle dimensional characterization in fiber samples. We also show the spectroscopic characterisation of erbium in preform and fibre samples with different compositions. This new route could have important potentials in improving rare-earth doped fibre amplifiers and laser sources.Keywords: Optical fibres, Erbium, Spectroscopy, Nanoparticles, Phase separation, Silica, Alkaline-earth elements Reference for publisher use only Biographical notes: Wilfried Blanc has worked extensively with rare earth doped materials. He prepared his PhD thesis at the Laboratoire de PhysicoChimie des Matériax Luminescents, University of Lyon (France). The work aims at understanding the energy transfer between the matrix and rare earth ions.

Tailoring of the Local Environment of Active Ions in Rare-Earth- and Transition-Metal-Doped Optical Fibres, and Potential Applications

“…In this section, we discuss a more straightforward and original technique to embed RE ions within in-situ grown oxide nanoparticles in silica-based preforms (Blanc et al, 2009a). The implemented principle is the spontaneous phase separation process (Zarzycki, 1991).…”

Nano-Structured Optical Fibers Made of Glass-Ceramics, and Phase Separated and Metallic Particle-Containing Glasses

“…Nevertheless, due to this thermal treatment, inherent to the MCVD process, nanoparticles can be formed in situ through the phase separation mechanism by introducing, through the doping solution, alkaline earth elements, such as magnesium [185], calcium [186], or scandium and yttrium ions [187], resulting in the particles of nm-range size. Later, phase separation was obtained for Mg and La-doped silicate fibers [188,189]. The small size of the nanoparticles allows one to ensure low scattering losses, and at the same time, a significant broadening of the Er 3+ emission spectrum was observed (Figure 6a).…”

“…The small size of the nanoparticles allows one to ensure low scattering losses, and at the same time, a significant broadening of the Er 3+ emission spectrum was observed (Figure 6a). It is important to note, that the formation of the nanoparticles in these works did not require additional post-heat treatment of the fibers as the nanoparticles formed during the collapsing step of the MCVD process [190]. The particles survive the high-temperature drawing process.…”

“…of the fibers as the nanoparticles formed during the collapsing step of the MCVD process [190]. The particles survive the high-temperature drawing process.…”

Fabrication of Large Core Yb2O3 Doped Phase Separated Yttria-Alumino Silicate Nano-Particles Based Optical Fiber for Use as Fiber Laser

“…However, the incorporation of REs into a suitable nano-crystalline host that are dispersed within the silica rich matrix of optical fiber preform, through MCVD and solution doping process is challenging compared to the fabrication of such type of bulk material by normal crucible melting process. In earlier work, we have reported the synthesis of Er 2 O 3 doped phase-separated amorphorous nano-particles into calcium-germano silicate core glass host by applying the basic principle of phase-separation phenomena (Blanc et al, 2009). This is to improve the spectroscopic properties of Er-doped fiber, mainly the spectral broadening of fluorescence band.…”