Thermal, and optical features study of Dy:YAlO3 and Dy/Tb:YAlO3 crystals for yellow laser applications

Optical features of Dy3+:YAP and Dy3+/Tb3+:YAP single crystals that were successfully fabricated by the Czochralski method were reported. The thermal behaviors and XRD rocking curves of the grown Dy3+ :YAP crystal were carried out. The identified broad absorption bands of Dy3+:H-6(15/2) -> I-4(15/2) with FWHMs approximately to 11 nm and the moderate absorption cross-sections at 450 nm in both crystals, imply their high suitability to the blue LD pumping. Polarized emission spectra with yellow fluorescence peaks at 572 nm were acquired in both crystals by means of a 450 nm Xenon lamp excitation. As compared with Dy3+ :YAP crystal, the larger emission cross-sections of 7.83 x 10(-21), 9.08 x 10(-21) and 9.01 x 10(-21) cm(2) for E//a, E//b and E//c polarizations respectively, were determined in Dy3+/Tb3+:YAP crystal. Moreover, a slightly reduced lifetime of the upper laser level F-4(9/2) and a much shortened lifetime of the lower laser level H-6(13/2) were obtained in Dy3+/Tb3+:YAP crystal, implying the existent energy migration between Dy3+ and Tb3+, as well as an effective deactivation of Tb3+ to Dy3+. The role of Tb3+ to reinforce Dy3+:F-4(9/2) H-6(13/2) emission in YAP host was established. On the basis of the derived results, both crystals could be recognized as competitive materials for polarized yellow lasers, especially the Dy3+ /Tb3+:YAP crystal.