Diffraction pattern study of gratings with radial symmetry and local modified periods

A theoretical study of gratings with radial symmetry and variable periods with sinusoidal profile, modulated for amplitude are shown. The behavior of the diffraction pattern and their symmetry degree of gratings were observed. Grating period can be modulated by external factor as spatial orientation effects per propagation, as inclination perspective of image projections that can produce local modified periods; this modulation kind causes changes in the diffracted pattern orders.