2ND-HARMONIC GENERATION AND SUM-FREQUENCY MIXING OF DOUBLE-WAVELENGTH NDYALO3 LASER TO 413.7-NM VIOLET COHERENT RADIATION IN LIIO3 CRYSTAL

A new method to get 413.7-nm violet coherent radiation by using second-harmonic generation and sum-frequency mixing of radiation from a 1341.4- and 1079.5-nm dual-wavelength Nd:YALO3 laser in a LiIO3 crystal is reported in this communication. First, the 670.7-nm red coherent radiation is obtained by second-harmonic generation of 1341.4-nm radiations in a LiIO3 crystal, and then the 670.7- and 1079.5-nm radiations are mixed again in a second LiIO3 crystal to get 413.7-nm radiation. The phase-matching angles are obtained for both nonlinear optical processes. The experimental results agree well with calculated results.