Theoretical analysis of third-harmonic generation via direct third-order and cascaded second-order processes in CsLiB6O10 crystals

Abstract

Third-harmonic generation using a single medium receives theoretical analysis and the results are applied to CsLiB6O10 crystals. From the solutions for a full set of coupled-amplitude equations, comprehensive expression of overall-effective third-order nonlinear optical susceptibility is derived, including the contributions of direct third-order and cascaded second-order processes. The overall-effective third-order nonlinear optical susceptibility shows peculiar behaviors, such as oscillatory dependence on propagation distance and dependence on azimuthal and polarization angles with inversion symmetry. The optimum conditions for efficient third-harmonic generation are predicted at the phase-matching angles of second-harmonic generation, sum-frequency generation, and third-harmonic generation.