Efficient generation of the second harmonic of the CW YAG:Nd-laser radiation in lithium metaniobate crystals

An experimental investigation was made of the efficient generation of the second harmonic of the radiation emitted by the YAG:Nd laser. This conversion was achieved in nonstoichiometric LiNbO₃ crystals. The second-harmonic power was 140 mW for the TEM₀₀ mode when the optimal output power of the fundamental radiation was 900 mW in the same mode. Possibilities of optimization of the conversion coefficient are considered.