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Updated: Nov 5, 2025
Hyperspectral Imaging as a Tool to Study Optical Anisotropy in Lanthanide-Based Molecular Single Crystals
Published on: April 14, 2020
Vibrational and optical studies of a nonlinear optical crystal, Cs2Bi2O(Ge2O7)
Aneta Ciupa-Litwa1, Jan Albert Zienkiewicz1, Mariusz Stefanski1
1Institute of Low Temperature and Structure Research, Polish Academy of Sciences, Okólna 2, 50-422 Wrocław, Poland.
Abstract:
Single crystals of a non-centrosymmetric and polar Cs2Bi2O(Ge2O7) compound were grown from melt. This material was characterized by polarized Raman scattering at room temperature. The comparison to the polycrystalline IR and Raman spectra has been made and assignment of all observed modes to the respective vibrations and their symmetry has been proposed. Our results show that this crystal is promising SRS-active nonlinear optical material for up- and down-Raman laser-frequency converters with the most intense lasing line at 481 cm-1. Optical studies show that Cs2Bi2O(Ge2O7) exhibits intense absorption bands with peaks maxima at 260 and 293 nm (77 K) typical for 1S0→1,3P1 transitions of Bi3+ ions, which are parity-allowed due to spin-orbit coupling as well as unexpected band centered at 360 nm that was assigned to intervalence charge transfer transition.
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