Application of FFT transformation for correlation analysis of near field microscopy measurements

The near field microscopy has been a dynamically developing diagnostic method for the last two decades. The number of measurement modes and data it delivers, sometimes make it difficult for interpreting. Thereby one needs sophisticated methods of extraction to get some specific information from the obtained results. Increasing complexity of the instruments as well as a software allows to acquire several signals simultaneously and to process them in a specific way in order to receive a particular result. Two dimensional Fast Fourier Transformation (2D FFT) is one of the most important tools in the picture analysis in near field microscopy. Such tools as finding specific spatial frequencies or noise filtering are very efficient. In the article we present some results of different modes of AFM measurements, where additional signals were acquired during measurements and by performing 2D FFT with the comparison approach, specific results and information were obtained.