223
3.3. Diffraction
F
6 L
6 D
Figure 3.16: Wave front aberration.
The aperture plane is labeled A in the figure. In the absence of
aberrations and in the limit of geometrical optics, an ideal point
image I is formed from a point object O. The magnification M is
defined as the ratio of the respective image and object heights.
It is easy to verify by similar triangles in the figure that this is
identical with the ratio −f 2 /f 1 of the respective lens focal lengths,
where the minus sign accounts for the inversion of the image.
Each ray emanating from the object O intersects the aperture
plane A at a unique transverse position (x A , y A ). Each point
(x A , y A ) in turn maps to a unique ray slope (x I
� , y I
� ) where the ray
intersects the Gaussian image plane. The wave front aberration
3.3. Diffraction
F
6 L
6 D
Figure 3.16: Wave front aberration.
The aperture plane is labeled A in the figure. In the absence of
aberrations and in the limit of geometrical optics, an ideal point
image I is formed from a point object O. The magnification M is
defined as the ratio of the respective image and object heights.
It is easy to verify by similar triangles in the figure that this is
identical with the ratio −f 2 /f 1 of the respective lens focal lengths,
where the minus sign accounts for the inversion of the image.
Each ray emanating from the object O intersects the aperture
plane A at a unique transverse position (x A , y A ). Each point
(x A , y A ) in turn maps to a unique ray slope (x I
� , y I
� ) where the ray
intersects the Gaussian image plane. The wave front aberration