Spectral and laser properties of Yb3+ doped aluminium fluorophosphate glasses

The absorption and fluorescence spectra of Yb3+ doped aluminium fluorophosphate (AFP) glasses were studied. The effective line width of Yb3+ (Deltalambda(eff) > 55nm) and the lifetime of F-2(5/2) (tau(max) = 2ms) were measured and their variations with Yb3+ doping concentration are discussed. The emission cross section (0.66823 pm(2)) of Yb3+ was calculated based on reciprocity theory, and the laser gain coefficient tau(f) x sigma(emi) is estimated to be 1.289 ms(.)pm(2). The laser properties of Yb3+ in AFP glasses was evaluated, which indicate that AFP glass has a promising value in excited state minimum populations (0.15), pump saturation intensity (8.3 kW/cm(2)), minimum pump intensity(1.245 kW/cm(2)) and good thermal stability. Yb3+ doped AFP glasses can be a good candidate for high power, ultra short pulses, tunable laser gain media.