Increased surface plasmon resonance sensitivity with the use of double Fourier harmonic gratings

Nicolas Bonod (1) , E. Popov (1) , Ross Mc Phedran (2)

1 FRESNEL - Institut FRESNEL
2 CUDOS - Centre for ultrahigh bandwidth devices for optical systems

A biomolecular sensor consisting of a thin metallic grating deposited on a glass prism is studied in the formalism of poles and zeros of the scattering matrix. Surface plasmon resonance is used to increase the sensitivity of the device with respect to a variation of the refractive index of the substrate. It is shown that a direct coupling between counter propagating surface plasmons using double-harmonic Fourier gratings leads to an enhancement of the sensitivity. The result of the stronger coupling is the transfer of the working point from the lower to the upper edge of the band gap in the dispersion diagram.

Mots clés: Surface Plasmons; Sensors; Diffraction gratings

Domaines: Optique / photonique

Nicolas Bonod, E. Popov, Ross Mc Phedran. Increased surface plasmon resonance sensitivity with the use of double Fourier harmonic gratings. Optics Express, 2008, 16 (16), pp.11691-11702. ⟨hal-00316011⟩