Imagine that you have a cosine grating (i.e., a transparency whose amplitude transmission profile is cosinusoidal varying between 0 and 1) with a spatial period of 0.01 mm. The grating is illuminated by quasimonochromatic plane waves of λ = 500 nm, and the setup is the same as that of Fig. 13.36, where the focal lengths of the transform and imaging lenses are 2.0 m and 1.0 m, respectively.

a) Discuss the resulting pattern and design a filter that will pass only the first-order terms. Describe it in detail.

b) What will the image look like on Σ_i with that filter in place?

c) How might you pass only the DC term, and what would the image look like then?

Fig. 13.36

Transcribed Image Text:

Plane wave Object plane Transform plane Image plane (a) (b) (d)