Open AccessTheoretical analysis of scanning near‐field optical microscopy
Author(s) -
Girard C.
Publication year - 1994
Publication title -
scanning
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.359
H-Index - 47
eISSN - 1932-8745
pISSN - 0161-0457
DOI - 10.1002/sca.4950160604
Subject(s) - optics , near field scanning optical microscope , field (mathematics) , discretization , detector , optical microscope , near and far field , dielectric , optical phenomena , physics , characterization (materials science) , materials science , computational physics , mathematics , optoelectronics , mathematical analysis , scanning electron microscope , pure mathematics
The near‐field optical (NFO) interaction between a pointed detector and dielectric or metallic substrates can be exploited to perform both nanometer scale topographies or spectroscopies of surfaces in the real space. The correlation of optical signals recorded with such detectors with other properties of the object (shape, index variation, … ) provides a wealth of new opportunities for characterization of small objects which has not yet been completely assessed. In fact, this new field represents a challenge to theoretical optics since NFO effects often are beyond the scope of classical theories. We present in this contribution a detailed study of both tip‐sample interactions and optical energy transfer occurring in scanning near‐field optical microscopy (SNOM). The treatment is based on the field‐susceptibility method applied in the real space. In this description, all multiple interactions including reflections with a substrate of arbitrary profile are accounted for by the usual self‐consistent equations. An original numerical scheme, based on a discretization procedure in the real space, is used to compute the field inside SNOM devices. This contribution reports the results of the numerical applications of this method to various NFO effects including, image‐object relation, nearfield spectroscopy of metallic aggregates, light‐induced forces, and nonlinear effects in confined geometry.