title: Multistep cascading in periodically poled directional couplers.
abstract: We suggest a novel scheme for multistep cascaded parametric processes based on a periodically poled nonlinear directional coupler and derive the conditions for simultaneous phase matching of the second-harmonic generation and sum-frequency mixing processes. We predict an efficient wavelength conversion by the cascaded third-harmonic generation from the third optical communication window (1.53-1.56 microm) to visible in a LiNbO3 poled waveguide coupler.
authors.affiliation: Faculty of Physics, University of Sofia, 5 J. Bourchier Boulevard, 1164-Sofia, Bulgaria.
authors.forename: Kaloyan
authors.initials: K
authors.lastname: Koynov
authors.forename: Solomon M
authors.initials: SM
authors.lastname: Saltiel
authors.forename: Yuri S
authors.initials: YS
authors.lastname: Kivshar