The teaching of Fourier optics is greatly facilitated by the introduction of certain key tools -- conceptual and analytical -- and by a suitable sequencing of topics. Points addressed in this paper include the following: (1) Students of electrical engineering easily relate to an analysis of wave field propagation based on the angular spectrum concept, which can be exact but also leads in simple approximations to Fresnel regime expressions. (2) The notion of inverse propagation, where the wave field is in effect propagated backwards in time (possibly to a virtual or effective source distribution), can be an extremely useful tool in certain optical system analysis problems. (3) The preferable canonical systems for examining the Fourier transform property of a lens have the lens imaging a point source and the object in either the converging or diverging beam; the FT appears in the plane conjugate to the source point. (4) Coherent imaging systems are often analyzed incorrectly in Fourier optics courses, and adequate attention is rarely given to systems of a general nature. These deficiencies can be overcome by proper sequencing of systems analyzed and by including the analysis of a general system characterized by entrance and exit pupils.
William T. Rhodes, William T. Rhodes,
"Keys to structuring a Fourier optics course", Proc. SPIE 3190, Fifth International Topical Meeting on Education and Training in Optics, (8 December 1997); doi: 10.1117/12.294369; https://doi.org/10.1117/12.294369