  A generalized spatial Talbot effect is proposed where the period of the input
aperture is scaled by a non-integer real value, as opposed to the integer-only
factor in a conventional Talbot effect. This is achieved by allowing and
engineering the phase discontinuity distributions in space using metasurfaces,
in conjunction with free-space propagation. The introduction of such abrupt
phase discontinuities thereby enables non-integer scalings of the aperture
periodicities. Specific implementations using Huygens' metasurfaces are
proposed and their operation to achieve non-integer scaling of the input
aperture period is demonstrated using numerical results based on Fourier
propagation.
