Long-range surface plasmon-polariton waveguide sensors with a Bragg grating in the asymmetric double-electrode structure

We propose a Bragg grating resonance sensor based on long-range surface plasmon-polaritons (LRSPP) excited on an asymmetric double-electrode waveguide structure. The proposed LRSPP waveguide sensor utilizes spectral resonance of the asymmetric double-electrode structure by adding a Bragg grating layer on the top surface of the metal slab. We have numerically estimated the bulk index resolution and thickness detection limit of a target biomolecule layer under 30 dB total propagation loss. The sub-mu m fluidic channel between the two metal layers always experiences a highly confined LRSPP mode excited by end-fire coupling with optical fibers, therefore the proposed LRSPP sensor platform can be applied to a variety of integrated sensor-chip scenarios. (C) 2009 Optical Society of AmericaThis work supported by the IT R&D program [2008-F-022-01] of the MKE/IITA, Korea and the Research fund of HYU (HYU-2008-T) and the Korea Science and Engineering Foundation(KOSEF) grant funded by the Korea government(MEST) [R01-2008-000-1185202008] and the Seoul Science Fellowship