Cascaded second-order effects in N-(4-nitrophenyl)-L-prolinol, in a molecular single crystal

Abstract

An investigation of cascaded second-order optical effects resulting in effective third-order interactions, temporal and spatial self-action, are presented for N-(4-nitrophenyl)-l-prolinol (NPP) a molecular single crystal with one of the largest phase-matchable second-order nonlinear coefficients known in the visible and near-infrared portions of the spectrum. We emphasize the effects of temporal and spatial walk-off in the nonlinear-optical propagation in NPP and discuss their consequences for cascaded second-order nonlinear applications. Walk-off effects play a detrimental role in cascaded all-optical switching. Whereas in standard second-harmonic generation walk-off reduces the efficiency but does not prevent the generation, in the case of cascading backconversation is required and more-deleterious effects occur: a portion of the field is lost in that the overlap between fundamental and second-harmonic wavelengths is reduced.