Growth, spectroscopy and laser operation of Yb:KGd(PO3) 4 single crystals

Identifier:  imarina:6385407

Handle: https://hdl.handle.net/20.500.11797/imarina6385407

Authors:  Parreu, I; Pujol, M C; Aguilo, M; Diaz, F; Mateos, X; Petrov, V

Abstract:
Macrodefect-free single crystals of Yb-doped KGd(PO3) 4, a noncentrosymmetric laser host which possesses second-order nonlinear susceptibility, were grown using the top seeded solution growth slow-cooling (TSSG-SC) technique, reaching a maximum ytterbium concentration in the crystal of ≈3.2×1020 at/cm3. In order to evaluate the potential for self-frequency doubling, the dispersion of the refractive indices of KGd(PO3)4 was studied and Sellmeier equations were constructed which are valid in the visible and near-infrared. The Stark splitting of the two electronic states of ytterbium was determined from absorption and emission measurements at room and low temperatures, and this allowed to compute the emission cross sections at room temperature. The fluorescence decay time is quite long, 1.22±0.01 ms. Laser generation in the 1 μm range is demonstrated with this new Yb host for the first time. Although the maximum output power achieved, of the order of 100 mW, was limited by the available crystal size and doping level, the more than 55% slope efficiency obtained with this first sample is rather promising for the future. © 2007 Optical Society of America.