Crystal growth and spectroscopic characterization of Dy3+ :Na2La4 (WO4)7 - A potential yellow laser material

A Dy3+ :Na2La4(WO4)(7) crystal was grown successfully by the Czochraski method, its spectroscopic properties were investigated in detail. The radiative transition probabilities, fluorescence branching ratios, and radiative lifetime of Dy3+ ions were obtained based on the Judd-Ofelt theory. The absorption cross sections at 454 nm are 1.1 x 10(-21) cm(2) and 0.75 x 10(-21) cm(2) for sigma-polarization and pi-polarization, respectively. The stimulated emission cross sections at 574 nm is 1.64 x 10(-20) cm(2) for pi-polarization, and 1.79 x 10(-20) cm(2) for sigma-polarization. The fluorescence lifetime of the F-4(9/2) energy level is 218 mu s. The results show that Dy3+ :Na2La4(WO4)(7) crystal is very suitable for commercial 450 nm blue laser diodes pumping, and is a promising yellow laser material.