title: Coherent Visible-Light-Generation Enhancement in Silicon-Based Nanoplasmonic Waveguides via Third-Harmonic Conversion.
abstract: We report visible third-harmonic conversion at λ=517 nm in subwavelength silicon-based nanoplasmonic waveguides at an unprecedented conversion efficiency of 2.3×10^{-5}. This marks both the highest third-harmonic conversion efficiency in a silicon-based or nanoplasmonic structure and the smallest silicon waveguide structure demonstrated to date. The high conversion efficiency is attributed to tight electric field confinement and strong light-matter coupling arising from surface plasmon modes in the nanoplasmonic waveguide, enabling efficient nonlinear optical mixing over micrometer length scales. The nonresonant geometry of the waveguide enables the entire λ=1550 nm femtosecond pulse spectrum to be converted to its third harmonic, which may be easily extended to the entire visible spectrum. We envisage that third-harmonic generation in silicon-based nanoplasmonic waveguides could provide a platform for integrated, broadband visible light sources and entangled triplet photons on future hybrid electronic-silicon photonic chips.
authors.affiliation: Ultrafast Optics and Nanophotonics Research Laboratory, University of Alberta, Edmonton, Alberta T6G 2V4, Canada.
authors.forename: S
authors.initials: S
authors.lastname: Sederberg
authors.affiliation: Ultrafast Optics and Nanophotonics Research Laboratory, University of Alberta, Edmonton, Alberta T6G 2V4, Canada.
authors.forename: A Y
authors.initials: AY
authors.lastname: Elezzabi