Consider a graded index medium characterized by the following refractive indexdistribution...

Consider a graded index medium characterized by the following refractive index

distribution

      (100)

Substitute in Eq.(32) and integrate to obtain

    (101)

Notice that the periodic length

is independent of the launching angle (see Fig. 3.32) and all rays rigorously take the same amount of time in propagating through a distance zp in the z – direction.

Fig 3.40