
DIFFRACTION 243
TABLE 8.1
Variables in Fraunhofer Diffraction
Spatial Frequency Pupil Location Direction Cosines
Spatial frequency x
1
= λzf
x
u = f
x
λ
y
1
= λzf
y
v = f
y
λ
Pupil location f
x
=
x
1
λz
u =
x
1
z
f
y
=
y
1
λz
v =
y
1
z
Direction cosines f
x
=
u
λ
x
1
= uz
f
y
=
v
λ
y
1
= vz
Angle u = sin θ cos ζ
v = sin θ sin ζ
Note: The relationships among spatial frequency, location in the pupil,
and direction cosines are shown.
The best way to handle the exponent depends on the problem to be solved. For problems
where the integrand may have relatively large phase variations, it is best to leave it in this form
as we will see in the study of Fresnel diffraction. For other problems, it is convenient ...