Atomic force microscopy is modeled in the time-frequency phase space.
In this phase space it is equivalent to a succession of temporal lense
s and free spaces which includes a temporal fractional Fourier device.
Then, the Wigner transform and its second order moments are introduce
d to model the atomic forte microscopy as a detector of ultrafast elec
trical signals. (C) 1997 Elsevier Science B.V.