Energy exchange between orthogonally polarized waves by cascaded quasi-phase-matched processes

Abstract

By identifying appropriate quasi-phase-matching (QPM) conditions in z-cut congruent lithium niobata, we demonstrate simultaneous QPM of type-I (ooe) and higher order type-0 (eee) second-harmonic-generation, which share a common second harmonic wave. We demonstrate this experimentally at 1064nm, and show that cascading between these processes occurs. The cascading can result in energy exchange between the cross-polarized fundamentals, indicative of an equivalent 3rd order process. The nonlinear phase shifts and transfer functions resulting from this cascading are explored numerically.