90° phase-matched direct third-harmonic generation in LiIO_3

摘要

Phase-matching properties for harmonic generation via second- and third-order nonlinearities have been investigated in LiIO_3 using the Nd:YAG laser and its harmonic pumped parametric oscillator. It was found that this crystal is 90° phase-matchable for direct type-2 third-harmonic generation (THG) at 0.3568 μm at 20 ℃. In addition, the temperature acceptance bandwidths have been measured for second-order processes and were used for construction of the thermo-optic dispersion formula. The Sellmeier equations that correctly reproduce almost all of the experimental data in the whole transmission range are also presented.