Fabrication of Rare Earth-Doped Transparent Glass Ceramic Optical Fibers by Modified Chemical Vapor Deposition

TL;DR

This paper reports on the fabrication of rare earth-doped transparent glass ceramic optical fibers using a modified chemical vapor deposition process, analyzing how different magnesium concentrations affect nanoparticle formation, optical loss, and erbium ion properties.

Contribution

It introduces a novel fabrication method for RE-doped TGC fibers via MCVD without post-ceramming and studies the effects of alkaline earth doping on nanoparticle characteristics and optical properties.

Findings

Low Mg content yields small nanoparticles with low scattering loss.

High Mg content leads to larger particles and increased optical loss.

Spectroscopic properties of erbium ions are altered by Mg doping levels.

Abstract

Rare earth (RE) doped silica-based optical fibers with transparent glass ceramic (TGC) core was fabricated through the well-known modified chemical vapor deposition (MCVD) process without going through the commonly used stage of post-ceramming. The main characteristics of the RE-doped oxyde nanoparticles namely, their density and mean diameter in the fibers are dictated by the concentration of alkaline earth element used as phase separating agent. Magnesium and erbium co-doped fibers were fabricated. Optical transmission in term of loss due to scattering as well as some spectroscopic characteristics of the erbium ions was studied. For low Mg content, nano-scale particles could be grown with and relatively low scattering losses were obtained, whereas large Mg-content causes the growth of larger particles resulting in much higher loss. However in the latter case, certain interesting alteration of the spectroscopic properties of the erbium ions were observed. These initial studies should be useful in incorporating new doped materials in order to realize active optical fibers for constructing lasers and amplifiers.