Spectroscopic properties and stimulated emission in the4F3/2 →4I11/2 and4F3/2 →4I13/2 transitions of Nd3+ ions from cubic Bi4Ge3O12 crystals

Abstract

Detailed complex investigations of the spectral and physical characteristics for cubic Bi4Ge3O12–Nd3+ crystals were made. An analysis of absorption, luminescence, and stimulated emission spectra for 4F3/2 → 4I11/2 and 4F3/2 → 4I13/2 transitions were carried out. The luminescence lifetime of the metastable state, inter-multiplet and “Stark” luminescence branching coefficients, luminescence quantum efficiency, luminescence line width, spontaneous transition probabilities and stimulated-emission transition cross-sections were determined. The temperature dependence of the stimulated-emission (4F3/2 → 4I11/2) excitation threshold was investigated and interpreted. Preliminary conclusions on the activator centre structure of Nd3+ ions in Bi4Ge3O12 were made, and informations on the extent of the vibronic spectra of Bi4Ge3O12 crystals were obtained. [Russian Text Ignored].