title: Vertical plasmonic Mach-Zehnder interferometer for sensitive optical sensing.
abstract: Vertical plasmonic Mach-Zehnder Interferometers are investigated theoretically and experimentally, and their potential for ultra-sensitive optical sensing is discussed. Plasmonic interferences arise from coherently coupled pairs of subwavelength slits, illuminated by a broadband optical source, and this interference modulates the intensity of the far-field scattering spectrum. Experimental results, obtained using a simple experimental setup, are presented to validate theoretically predicted interferences introduced by the surface plasmon modes on top and bottom surfaces of a metal film. By observing the wavelength shift of the peaks or valleys of the interference pattern, this highly compact device has the potential to achieve a very high sensitivity relative to other nanoplasmonic architectures reported.
authors.affiliation: Center for Optical Technologies, Electrical and Computer Engineering Department Lehigh University, Bethlehem, PA 18015, USA. qig206@lehigh.edu
authors.forename: Qiaoqiang
authors.initials: Q
authors.lastname: Gan
authors.forename: Yongkang
authors.initials: Y
authors.lastname: Gao
authors.forename: Filbert J
authors.initials: FJ
authors.lastname: Bartoli
mesh_terms: D015374:Biosensing Techniques; D007368:Interferometry / Q000295:instrumentation* / Q000379:methods; D008670:Metals / Q000737:chemistry; D015233:Models, Statistical; D049329:Nanostructures / Q000737:chemistry; D036103:Nanotechnology / Q000379:methods; D055095:Optics and Photonics; D009991:Oscillometry / Q000379:methods; D012031:Refractometry / Q000295:instrumentation* / Q000379:methods; D012542:Scattering, Radiation; D020349:Surface Plasmon Resonance; D013499:Surface Properties
chemical_list: D008670:Metals