Modeling of the scanning surface plasmon microscope.

We propose a family of exact solutions of Maxwell's equations to model some aspects of the imaging process involved in the scanning surface plasmon microscope (SSPM). More precisely, we compute the SSPM response of a spherical nanoparticle immobilized close to a thin gold layer and illuminated by a tightly focused spot. We discuss the influence of parameters such as the defocus and the width of the gold layer on the image contrast. We show that this microscopy combines a subwavelength spatial resolution together with high sensitivity to small changes in dielectric properties on the nanoparticle.