Abstract

Materials with large and fast third-order nonlinearities and low losses have proven difficult to find and use in all-optical switching device configurations. Large nonlinear phase shifts, however, can be obtained in non-centrosymmetric materials relying on a cascaded second-order effect, i.e. up-conversion of a fundamental beam into its second-harmonic and the subsequent down-conversion for a phase-mismatched interaction.[1-2] Because of the recent development of efficient second harmonic generation in waveguides, it appears that phase shifts of order π can be reached over centimeter distances with peak powers of 10's of Watts or less in KTP or poled polymers, an improvement of orders of magnitude over the current capabilities of third order materials.

© 1992 Optical Society of America