Profile of a parametric luminescence line emitted by lithium niobate crystals

The results are given of an experimental investigation of the line profile in one-dimensional parametric luminescence excited in several samples of LiNbO₃. The difference between the experimental and calculated results is attributed to optical inhomogeneities in real crystals. Consideration is given to the possibility of using the experimentally determined line profile in the evaluation of the quality of lithium niobate crystals. The influence of thermal self-interaction of the fundamental radiation on the parametric luminescence is pointed out.