IEEE Photonics Journal (Jan 2011)
Excitation of Surface Plasmons Using Tilted Planar-Waveguide Bragg Gratings
Abstract
We present a planar-integrated optical surface plasmon refractometer. The fabricated device operates by grating-matched coupling between a core waveguide mode and a set of hybrid plasmon-dielectric modes of a much wider integrated structure. The constructed device incorporates a 50-nm-thin gold layer that separates a tilted planar-waveguide Bragg grating and a liquid analyte. It is demonstrated that polarization-dependent plasmon anomalies occur in the transmission spectra of the device, which are understood using a numerical Cauchy integral mode solving approach. Sensitivities in this planar-integrated device are comparable with existing fiber-based plasmonic sensors but with the advantages of planar integration and microfluidic adaptation.
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