[en] Absorption, luminescence characteristics, and stimulated emission parameters of Nd³⁺ ions in the wide temperature region of a full concentration series of (La/sub 1-x/Nd/sub x/)₃Ga₅SiO₁₄ single crystals are studied. Luminescence intensity characteristics are analyzed and transition cross-section at the laser wavelengths of two ⁴F/sub 3/2/ → ⁴I/sub 11/2/ and ⁴F/sub 3/2/ → ⁴I/sub 13/2/ generation channels of activator are determined. Registered induced transitions are identified. Electromechanical characteristics of La₃Ga₅SiO₁₄, specifically, elastic, dielectric, and piezoelectric modules and constants are investigated. A comparison of the properties between La₃Ga₅SiO₁₄ crystals and crystalline SiO₂ is carried out. (author)