Figure 1
Scheme of the angular spectrum propagation method for a circularly symmetric optical wavefield, [{\bf E}(r,0)]. The angular spectrum of the initial wavefield, [\hat{{\bf E}}(\,f_{r}\semi0)], is calculated by a Hankel transform. Then, the propagated wavefield at a distance z, [{\bf E}(r,z)], is obtained by multiplying [\hat{{\bf E}}(\,f_{r}\semi0)] by the free-space propagator [\exp[i(2\pi/\lambda)z]\exp(-i\pi\lambda f_r^{\,2}z)] and applying a second Hankel transform.  [article HTML]