Influence of iron and neodymium impurities on second harmonic generation in a lithium niobate crystal

An investigation was made of the influence of Fe and Nd impurities (for different stoichiometric coefficients R of the mixture) on the 90° phase-matching temperature T_m and the width of the phasematching temperature range ΔT of lithium niobate crystals. It was established that the dependence of T_m on R and the type of impurity observed for doped crystals was quite different from that of pure crystals. It was found that the temperature T_m for lithium niobate crystals can be controlled by adding suitable impurities.