Erbium doped fluoride glass–ceramics waveguides fabricated by PVD

Transparent amorphous and glass-ceramics waveguides in the system ZrF4-LaF3-ErF3-AlF3 (ZELA) have been fabricated by physical vapor deposition (PVD). The ceramming process was studied by means of Xray diffraction and transmission electron microscopy for different deposition temperatures. With increasing deposition temperature, formation of LaxEr1-xF3 nanocrystals with x similar to 0.3 was observed. The decay curves of the 4I(13/2) level in the glass-ceramics with 14.5 mol% Er3+ gave evidence of the presence of erbium both in the amorphous matrix (tau = 8.6 ms) and in the crystal phase (tau = 2.2 ms). The decrease of lifetime was due to clustering of erbium incorporated in LaF3 crystal lattice. No significant increase of attenuation loss was detected after waveguide cerammization (1.3 dB/cm at 1304 nm)