Near-field optical contrasts in the Fresnel evanescent wave

The surface waves generated by total internal reflection at the surface of a transparent material may be viewed as quasi-two-dimensional, because they decay exponentially in the direction normal to the sample surface. These waves are appropriate to analyze polarization effects associated with light confinement phenomena in near-field optics. In this paper we derive four useful analytical relations governing the near-field contrast around dielectric nanometer-sized particles versus a limited number of external parameters. In the p-polarized mode, unlike to what happens with the electric near field, we show that the magnitude of the magnetic near-field contrast can be adjusted by increasing the incident angle beyond the critical angle.