  Diffraction is a manifestation of light at edge due to its wavelike nature.
The well-known diffraction phenomena are Fresnel and Fraunhofer, they find
variety of applications individually. But the synergy of two phenomena is not
studied and understood, which is important to understand the compound optical
instruments. This research studies and demonstrates the synergic patterns of
Fresnel and Fraunhofer diffractions. The combined diffraction resulted in the
patterns similar to Hermite-Gaussian Beam intensity distribution in both
simulated and experimental results. Further, the combined phenomena is
implemented in speckle lithography to fabricate wide area micro grating
patterns which are better than simple speckle diffraction grating patterns.
This work may contribute to the deeper understanding of complex diffraction in
optical instruments and also shows the way for robust fabrication of micro
gratings.
