Explain the difference between Fresnel diffraction and Fraunhofer diffraction. Comment on the behavior of fields and how they interfere in each zone, and explain if there is a sudden or smooth transition from the Fresnel zone to the Fraunhofer zone? (3 marks) Describe how you would write Python code that could model the far-field diffraction pattern of a rectangular aperture source. Note: Precise syntax is not required, just a description of the steps to be taken in the code. (4 marks) Consider the Python code, required in part (b) above, to model the far-field pattern of a rectangular aperture source. Explain if this same theory and code could be used to model the near-field radiation patterns? For a given wavelength of light, and source dimensions a and b, define the typical *cut-off propagation distance z, below which the far-field approximations should not be used. (3 marks)