Crystal growth and spectroscopic characterization of Yb3+:LiTaO3

Spectroscopic properties are presented for Yb3+ incorporated into single crystals of LiTaO3 grown by the top-seeded solution growth method. From an analysis of the absorption and fluorescence spectra, we are able to determine the Stark-level components of the 2F7/2 (the ground-state multiplet manifold) and the 2F5/2 (the excited-state multiplet manifold of Yb3+ (4f13)). The room-temperature fluorescence lifetime of 2F5/2 is 678 μs as measured on a thin sample to reduce possibilities for reabsorption. Spectral comparisons of Yb3+-doped LiTaO3 and LiNbO3 are drawn. The crystal-field splitting of Yb3+(4f13) in both crystal hosts is modeled using a set of crystal-field splitting parameters, Bnm, determined from a recent spectroscopic analysis of Er3+(4f11) in LiNbO3. Without adjustment of the Bnm parameters, the model predicts the Stark-level energy and the symmetry label for each level in reasonable agreement with the experimental values. Less photorefractive than its niobate cousin, LiTaO3 has potential for use in numerous integrated electro-optical circuits and devices.