Optical filed enhancement by surface-plasmon resonance: theory and application to miro-bioelectronics

The optical field enhancement from plasmon resonance at spheroids is studied by solving the Maxwell's equations using spheroidal vector wave functions. The theory is applied to silver and gold. The enhancement is shown to be substantial under resonance conditions. Optical capture of fluorescent molecules to the enhancement region is discussed. Attractive as well as repulsive forces are possible depending on the wavelength. Applications for a lab-on-a-chip technology are envisaged.