Structure peculiarities and disorderness of trigonal Ca3Ga2Ge4O14 and Sr3Ga2Ge4O14 crystals are considered. Absorption and luminescence characteristics and stimulated emission parameters of Nd3+ ions in said compounds are investigated. The luminescence intensity parameters of the activator are analyzed and the cross‐sections of its induced transitions at the wavelengths of the two lasing 4F3/2 → 4I11/2 and 4F3/2 → 4I13/2 channels are determined. All registered induced transitions are identified. The electromechanical properties of Ca3Ga2Ge4O14 and Sr3Ga2Ge4O14 crystals, including elastic, dielectric, and piezoelectric modulus and constants are studied.

No abstract

New germanates with the NdAlGe2O7‐type structure are synthesized. The Czochralski method is used to grow LaGaGe2O7: Nd3+ single crystals and the full concentration series of Gd1−xNdxGaGe2O7 crystals. The GdGaGe2O7 crystal structure is refined. The absorption–luminescence properties of the grown crystals have been studied. The main intensity parameters of luminescence are determined. The stimulated emission of the crystals including that of self‐activated NdGaGe2O7, are excited for two lasing 4F3/2 → 4I11/2 and 4F3/2 → 4I13/2 channels, using the conventional lamppumping technique at 300 K. All the observed induced transitions are identified.

Complex spectral investigations are made on new Nd3+‐ and Pr3+‐doped and pure nonlinear‐laser trigonal LaBGeO5 crystals. Raman spectra and nonlinear optical properties are studied including second harmonic generation, absorption, and luminescence spectra, which allow to determine the energy of Stark levels of the activator ions, luminescence‐intensity characteristics, and pulse stimulated‐emission parameters of Nd3+ ions at two intermanifold 4F3/2 → 4I11/2 and 4F3/2 →4I13/2 channels as well as of Pr3+ ions at the visible 3P0 → 3H6 transition. A preliminary theoretical analysis is made of the crystal field at activator ions using a new many‐electron semiempirical method. All registered induced transitions are identified. LaBGeO5:Nd3+ is shown as a promising material for self‐frequency doubled laser.