Photoluminescence properties of Er(3+)-doped alkaline earth titanium phosphate glasses

Er(3+)-doped alkaline earth titanium phosphate (RTP) glasses with molar composition of 24 (NaPO(3))(6) + 30 KH(2)PO(4) + 25 TiO(2) + 20 RCl(2) + 1 Er(2)O(3) were prepared by melt quenching technique. Judd-Ofelt intensity parameters ([Omega](2,4,6)) were determined from the experimental oscillator strengths (f(exp)) of absorption bands. From these parameters spontaneous emission probabilities (A(R)), luminescence branching ratios (b(R)) and radiative lifetimes (t(R)) have been calculated. Visible and near infrared photoluminescence spectra has been recorded by exciting the samples at 380 and 970 nm respectively. An intense broad emission band at 1.53 km was observed corresponding to (4)I(13/2) -- > (4)I(15/2) transition. McCumber theory has been applied to determine the emission cross-sections ([sigma](e)) of the (4)I(13/2) -- > (4)I(15/2) transition using the absorption cross-sections ([sigma](a)). The lifetimes of (4)S(3/2) level were measured for the glasses by exciting the samples at 540 nm wavelength and the quantum efficiencies were also determined.