title: Third-harmonic generation in quasi-phase-matched chi(2) media with missing second harmonic.
abstract: What we believe to be a conceptually novel scheme for third-harmonic generation in engineered quasi-phase-matched chi((2)) optical structures is proposed in which the fundamental-frequency field is directly converted into the third-harmonic field without the intermediate generation of the second-harmonic field. This counterintuitive scheme, which exploits the concept of adiabatic passage and the existence of a nonlinear dark state, bears a close connection to the "stimulated Raman adiabatic passage" technique of population transfer in atomic physics.
authors.affiliation: Dipartimento di Fisica and Istituto di Fotonica e Nanotecnologie del CNR, Politecnico di Milano, Piazza Leonardo da Vinci, 32, I-20133 Milano, Italy. longhi@fisi.polimi.it
authors.forename: Stefano
authors.initials: S
authors.lastname: Longhi