Generalized Spatial Talbot Effect based on All-dielectric Metasurfaces

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.