Application of fourier algorithm to near field optical images: Local resolution estimation

Abstract

In Near Field Optics, the lateral resolution is better than the limit given by the Rayleigh criterion, but this fact was usually demonstrated by using test samples. In this study we apply local Fourier algorithms to near field optical experimental images, using a noise consideration to define resolution criterion. These algorithms are able to estimate the resolution automatically and thus can lead to simple image processing. We investigate the local resolution in scanning lines and we introduce the apparatus characterization. In the first part we discuss on the problem of resolution in near field optics. © Les Éditions de Physique 1997.