Growth of large-sized Nd:NY(WO_4)_2 crystal and its spectral properties

摘要

This paper reports the growth of Nd~(3+) :NY(WO_4)_2 crystal with high optical quality and large size. Nd~(3+) :NY(WO_4)_2 crystal with the dimension Φ 30 x 75 mm~2 and optical homogeneity 4 x 10~(-5) was grown by Czhchoralski method: the seed used was [100] orientation, the pulling rate and rotating rate were 0.5-1.25 mm/h and 15 rpm, respectively. The growing processes and characteristics of Nd~(3+) :NY(WO_4)_2 crystal was discussed. Its unpolarized absorption spectra and emission spectra were measured. The absorption cross-section and emission cross-section were presented. Based on the Judd-Ofelt theory, we obtained the three intensity parameters: Ω_2 = 5.8 x 10~(-20), Ω_4 = 5.74 x 10~(-20), and Ω_6 = 4.32 x 10~(-20) cm~2. The radiative probabilities, radiative lifetimes, branch ratios and quantum efficiency of Nd~(3+):NY(WO_4)_2 were calculated too.