Spectroscopy and lasing of yb-doped NaY(WO4)2:: Tunable and femtosecond mode-locked laser operation

Tetragonal (space group I (4) over bar) single crystals of NaY(WO4)(2) doped with Yb to a density of 4.52 x 10(20) cm(-3) have been employed as laser active materials for the 1-mu m spectral range, operating at room temperature. Using Ti:sapphire laser pumping, slope efficiencies as high as 74.6% were achieved without special cooling for the pi-polarization. The Yb-laser was continuously tunable from 1003.7 to 1073.0 nm with a birefringent filter. Pulses as short as 53 fs were obtained at 1035 nm by SESAM passive mode-locking with intracavity dispersion compensation and additional extracavity pulse compression using analogous prism pairs. Experimental data on the spectroscopic properties of Yb3+ in the 5-300 K temperature range and the room temperature optical properties of this novel Yb-host is also presented.