The influence of topography and variations of optical properties on the near field scattered by an inhomogeneous sample is analyzed. A perturbative expression of the near field is derived and its range of validity is investigated. This expression shows quantitatively how dielectric contrast and topography modulate the near-field distribution close to a surface. It is shown that the near-field images, produced by conventional near-field optical devices, are sensitive to the integral of the dielectric contrast along the vertical direction across the sample. This point is illustrated by a numerical simulation of the near field scattered by surfaces exhibiting submicronic asperities and subsurface structures.
© 1995 Optical Society of America
Original Manuscript: April 6, 1995
Revised Manuscript: July 14, 1995
Manuscript Accepted: July 18, 1995
Published: December 1, 1995
Rémi Carminati and Jean-Jacques Greffet, "Influence of dielectric contrast and topography on the near field scattered by an inhomogeneous surface," J. Opt. Soc. Am. A 12, 2716-2725 (1995)