title: Emergence of geometrical optical nonlinearities in photonic crystal fiber nanowires.
abstract: We demonstrate analytically and numerically that a subwavelength-core dielectric photonic nanowire embedded in a properly designed photonic crystal fiber cladding shows evidence of a previously unknown kind of nonlinearity (the magnitude of which is strongly dependent on the waveguide parameters) which acts on solitons so as to considerably reduce their Raman self-frequency shift. An explanation of the phenomenon in terms of indirect pulse negative chirping and broadening is given by using the moment method. Our conclusions are supported by detailed numerical simulations.
authors.affiliation: Max Planck Institute for the Science of Light, Günther-Scharowsky Strasse 1, Bau 26, 91058 Erlangen, Germany.
authors.forename: Fabio
authors.initials: F
authors.lastname: Biancalana
authors.forename: Truong X
authors.initials: TX
authors.lastname: Tran
authors.forename: Sebastian
authors.initials: S
authors.lastname: Stark
authors.forename: Markus A
authors.initials: MA
authors.lastname: Schmidt
authors.forename: Philip St J
authors.initials: PS
authors.lastname: Russell