Demonstration of a Novel Surface Plasmon Based Interferometer with COMSOL

Excerpt from the Proceedings of the COMSOL Conference 2010 Boston


^{Interferometry, Surface Plasmons, SPR, FEM, COMSOL}

Department of Electrical and Computer Engineering, Université de Sherbrooke

Dominic Carrier and Jan J. Dubowski Sherbrooke, Québec, J1K 2R1, Canada, E-mail: dominic.carrier@usherbrooke.ca

Abstract: A novel method was developed to increase sensitivity of classical surface plasmon resonance (SPR) setup. This method consists in integrating to the SPR structure a self-referenced surface plasmon interferometer, where a change of refractive index will induce a shift of the resonance point but will also modulate the output response due to the optical path length difference of the SP modes in the interferometer structures. We conceptually demonstrate this integrated SP interferometer and its properties with the help of COMSOL Multiphysics^{®, a finite element method (FEM) simulation commercial software. We also highlight how the multiplexing of SP resonance signal to the interferometer modulation allows for greater accuracy of measurement. Keywords:}

Simulation architectures (not to scale). Results were produced at normal incidence, sweeping in incident energy. A) Infinite grating architecture; the light source is described by equations {2}. B) Finite grating architecture. C) Cavity / integrated interferometer architecture