title: Modal coupling in fiber tapers decorated with metallic surface gratings.
abstract: An interference-based scheme for fabricating periodic metal gratings on one side of the uniform waist of optical fiber tapers has been developed. Optical characterization of a 5 mm long, 511 nm period gold grating fiber taper with a 10 microm diameter reveals backward coupling to both guided and radiation modes that is explained by using an analytical mode-coupling analysis. A refractometer based on this grating taper has a high and constant sensitivity over a large refractive index operating range of 1 to 1.41.
authors.affiliation: Department of Physics, University of Bath, Claverton Down, Bath, UK. pypwd@bath.ac.uk
authors.forename: W
authors.initials: W
authors.lastname: Ding
authors.forename: S R
authors.initials: SR
authors.lastname: Andrews
authors.forename: T A
authors.initials: TA
authors.lastname: Birks
authors.forename: S A
authors.initials: SA
authors.lastname: Maier