title: Visible-band dispersion by a tapered air-core Bragg waveguide.
abstract: We describe out-coupling of visible band light from a tapered hollow waveguide with TiO(2)/SiO(2) Bragg cladding mirrors. The mirrors exhibit an omnidirectional band for TE-polarized modes in the ~490 to 570 nm wavelength range, resulting in near-vertical radiation at mode cutoff positions. Since cutoff is wavelength-dependent, white light is spatially dispersed by the taper. Resolution on the order of 2 nm is predicted and corroborated by experimental results. These tapers can potentially form the basis for compact micro-spectrometers in lab-on-a-chip and optofluidic micro-systems.
authors.affiliation: ECE Department, University of Alberta, 2nd Floor, 9107-116 St. NW, Edmonton, AB, T6G 2V4 Canada.
authors.forename: B
authors.initials: B
authors.lastname: Drobot
authors.forename: A
authors.initials: A
authors.lastname: Melnyk
authors.forename: M
authors.initials: M
authors.lastname: Zhang
authors.forename: T W
authors.initials: TW
authors.lastname: Allen
authors.forename: R G
authors.initials: RG
authors.lastname: DeCorby
mesh_terms: D004867:Equipment Design; D019544:Equipment Failure Analysis; D007909:Lenses; D012031:Refractometry / Q000295:instrumentation*; D020349:Surface Plasmon Resonance / Q000295:instrumentation*