Type of Diffraction: Fresnal and Fraunhoffer Diffraction
The phenomenon of diffraction can be clarified into two categories:
(i) Fresnal diffraction: In this category, the sources and the screen are situated near the obstacle producing diffraction. The beam approaching or going away from the obstacle is not modified by means of a lens or mirror. The wavefronts in this case, are spherical or cylindrical wavefronts.
(ii) Fraunhoffer diffraction: In this case, both source and screen are at effective distance from the diffracting device and pattern is the image of source modified by diffraction effects.
