CASCADING NONLINEARITIES IN AN ORGANIC SINGLE-CRYSTAL CORE FIBER - THE CERENKOV REGIME

The large nonlinear phase shifts imparted to the fundamental beam duri ng Cerenkov second harmonic generation (SHG) in a DAN, 4-(N,N-dimethyl amino)-3-acetamidonitrobenzene, single crystal core fiber are explaine d and modelled numerically. Cascading upconversion and downconversion processes leads to nonlinear phase shifts produced by the second order nonlinear coupling of the guided fundamental mode and the component o f the Cerenkov second harmonic field trapped in the fiber cladding.