Photoluminescence of Tm-doped Ta2O5 waveguides

Photoluminescence is observed from tantalum pentoxide thin film waveguides, doped with 3 wt% of Tm
₂
O
₃
(Tm:Ta
₂
O
₅
), in the wavelength range of 1.6 to 2.1 μm. Maximum emission was obtained using a pump wavelength of 795 nm, which corresponds to the excitation of thulium ions to the
³
H4 manifold. The effect of post-deposition annealing temperature and duration on the photoluminescence lifetime and intensity was investigated. This is the first report of photoluminescence around 1.8 μm and lifetime measurements of Tm:Ta
₂
O
₅
films with potential for gain in a planar platform.