Electromagnetic theory of Talbot imaging

Abstract

Electromagnetic diffraction theory is applied to investigate self-imaging of optical fields transmitted by lamellar diffraction gratings. We consider both conventional and fractional Talbot imaging of metallic Ronchi rulings and dielectric surface-relief gratings. Our rigorous approach takes fully into account diffraction inside the modulated grating structure as well as non-paraxial propagation of the electromagnetic field into the observation plane, and it is valid for any grating period. We also show that, for certain grating periods, the transmitted electromagnetic field self-images exactly, regardless of the grating profile.