ABSTRACT
We report on the fabrication and optical assessment of an all-solid tellurite-glass photonic bandgap fiber. The manufacturing process via a preform drawing approach and the fiber characterization procedures are described and discussed. The fiber exhibits some minor morphological deformations that do not prevent the observation of optical confinement within the fiber by bandgap effects. The experimental fiber attenuation spectrum displays clear bandgap confinement regions whose positions are confirmed by modeling the guiding properties of the ideal geometry using a plane-wave expansion method. The model identifies the bound modes of the structure and provides confirmation of experimentally observed mode field profiles.
ABSTRACT
We present a microstructured fiber whose 9 µm diameter core consists in three concentric rings made of three active glasses having different rare earth oxide dopants, Yb3+/Er3+, Yb3+/Tm3+ and Yb3+/Pr3+, respectively. Morphological and optical characterization of the optical fiber are presented. The photoluminescence spectrum is investigated for different pumping conditions using a commercial 980 nm laser diode. Tuning of the RGB (or white light) emission is demonstrated not only by adjusting the pump power but also by using an optical iris as spatial filter which, thanks to the microstructured core, also acts as a spectral filter.