Pure and Nd3+-doped Ca3Ga2Ge4O14 and Sr3Ga2Ge4O14 single crystals, their structure, optical, spectral luminescence, electromechanical properties, and stimulated emission

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.