Study of growth and optical homogeneity of 45-degree $LiNbO_3$ crystals for infrared parametric oscillators

Various problems associated with the growth of 45degree $LiNbO_3$crystals of high optical quality are studied. Results are given of an experimental investigation of the optical homogeneity of $LiNbO_3$, crystals grown under different technological conditions. Data on parametric light generation in these crystals, when pumped by fundamental-frequency radiation from a YAG laser, are presented.