Growth, spectroscopic and laser properties of crystals in the K5Bi1−xNdx(MoO4)4 system

Abstract

Complex spectral and laser properties are studied for crystals of the K5Bi1−xNdx(MoO4)4 system, grown by the Czochralski technique, in the whole concentration region of x = 0 to 1. By the analysis of absorption and luminescence spectra the crystal field splitting scheme of the lowest 4F3/2 and 4I9/2−15/2 manifolds and their Stark components are established. Weak concentration quenching of luminescence is observed. The luminescence lifetime of the metastable 4F3/2 state, the luminescence linewidth, probability, and cross-section of the most intensive transition are determined. From the radiative decay time of the 4F3/2 metastable state of dilute crystals (low x) and the transition probability of the resonance channel 4I9/2 ↔ 4I3/2 x = 1, the parameter of spectroscopic quality X is calculated. Using X, intermanifold luminescence bracnching ratios are determined. Stimulated emission of K5Bi1−xNdx(MoO4)4 crystals with x = 0.1 is excited in the pulse regime, using optical broad-band pumping by Xe flash-tube, and of “self-activated” crystals with x = 1, using laser excitation by a Raman laser, operating at λ = 0.745 and 0.805 μm.