title: Roughness induced backscattering in optical silicon waveguides.
abstract: We report on the direct observation of backscattering induced by sidewall roughness in high-index-contrast optical waveguides based on total internal reflection. Our results demonstrate that backscattering is one of the most severe limiting factors in state-of-the art silicon on insulator nanowires employed in densely integrated photonics. We also derive the general relationship between backscattering and geometrical and optical parameters of the waveguide. Further, the role of roughness in polarization rotation and coupling with higher-order modes is pointed out.
authors.affiliation: Policom-DEI, Politecnico di Milano, Via Colombo 81, 20133 Milano, Italy. morichetti@elet.polimi.it
authors.forename: Francesco
authors.initials: F
authors.lastname: Morichetti
authors.forename: Antonio
authors.initials: A
authors.lastname: Canciamilla
authors.forename: Carlo
authors.initials: C
authors.lastname: Ferrari
authors.forename: Matteo
authors.initials: M
authors.lastname: Torregiani
authors.forename: Andrea
authors.initials: A
authors.lastname: Melloni
authors.forename: Mario
authors.initials: M
authors.lastname: Martinelli