Diffractive patterns correlation with shape and structure of imprint objects

Analysis of optical diffractive pattern of natural or virtual objects is an actually problem which has important applications. We realized the correlation between diffractive patterns from imprinted objects with different shapes, structures and sizes. An iterative algorithm based on Fourier transform for far field written in MATLAB is used to design computer generated hologram (CGH) in a different number of equidistant phase-levels patterns, which produces the desired image in far field. Spatial light modulators (SLM), two-dimensional electrically addressable devices, are used in experimental setup in order to modulate the phase of a wave front from a monochromatic plane wave. Through the diffractive pattern obtained experimentally with CGH and SLM, we show that the shape of the objects is of less importance than the structure. The shape is modified by different geometrical figures, and the structure is periodical, with or without defects. We use this method to study different imprint objects. By correlation profile we remark the distinction in the shape and structure of different sample.