Excited State Absorption and 1.5 µm Laser Oscillation of Er3+ in KY(WO4)2

The fluorescence dynamics from excited states of Er3+ in KY(WO4)2 are compared with Judd-Ofelt theory calculations and spectroscopic parameters of the promising laser transitions from the 4I13/2, 4I11/2 and 4S3/2 levels are detennined. The cw excited state absorption spectra of Er3+-doped KYW are measured with a pump and probe technique and analysed in the spectral range from 500 nm to 1800 nm. Energy transfer between Yb3+ and Er3+ ions in co-doped KY(WO4)2 is investigated. Laser action near 1.54 µm under Ti-sapphire and diode laser pumping is obtained in Er,Yb :KY(WO4)2.