“…), as well as several dopants simultaneously. [1,[7][8][9] The introduction of two dopants into a crystal in a different concentration ratio is of practical interest, since the combination of dopants provides new possibilities of controlling the optical properties of crystals. [1,7,[10][11][12] Doping LN crystals with such photorefractive additives as magnesium and zinc leads to a decrease in the value of the coercive field (up to 4.6 and 1.4 kV mm À1 in LiNbO 3 :Mg and LiNbO 3 :Zn crystals) and a significant increase in the optical resistance of crystals to laser radiation.…”