title: Tailoring the spectral response of liquid waveguide diagnostic platforms.
abstract: Liquid filled waveguides that form the basis for on-chip biophotonics diagnostic platforms have primarily found application in fluorescence and Raman spectroscopy experiments that require sensitive discrimination between weak analyte signals and a variety of background signals. Primary sources of background signal can include light from excitation sources (strong, narrow frequency band) and photoluminescence generated in waveguide cladding layers (weak, wide frequency band). Here we review both solid and liquid core filtering structures which are based on anti-resonant reflection that can be integrated with waveguides for attenuating undesirable optical bands. Important criteria to consider for an optimized biosensor include cladding layer materials that minimize broad-spectrum photoluminescence and optimize layer thicknesses for creating a desired spectral response in both solid and liquid guiding layers, and a microfabrication process capable of producing regions with variable spectral response. New results describing how spurious fluorescence can be minimized by optimized thermal growth conditions and how liquid-core filter discrimination can be tuned with liquid core waveguide length are presented.
authors.affiliation: ECE Department, Brigham Young University, 459 Clyde Building, Provo, UT 84602, USA.
authors.forename: Yue
authors.initials: Y
authors.lastname: Zhao
authors.forename: Brian
authors.initials: B
authors.lastname: Phillips
authors.forename: Damla
authors.initials: D
authors.lastname: Ozcelik
authors.forename: Joshua
authors.initials: J
authors.lastname: Parks
authors.forename: Philip
authors.initials: P
authors.lastname: Measor
authors.forename: David
authors.initials: D
authors.lastname: Gulbransen
authors.forename: Holger
authors.initials: H
authors.lastname: Schmidt
authors.forename: Aaron R
authors.initials: AR
authors.lastname: Hawkins
mesh_terms: D049449:Luminescence; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation*; D055096:Optical Devices; D013057:Spectrum Analysis