In the field of electrical engineering, analysis can be divided into two broad categories that are related by Fourier transforms,
namely, analysis in the time domain and analysis in the frequency domain. If phenomena are known in one domain, those in the
other domain can be found by means of an appropriate transformation.
Similarly, in the field of optics, analysis can be carried out either in the space domain or in the spatial frequency domain. By knowing one, the other can be found by using a Fourier transform relationship. Previous chapters have dealt with problem
solving in optics from the space domain viewpoint. In this chapter, treatment in the spatial frequency domain is introduced.