Talbot effect beyond the paraxial limit at optical frequencies

This paper reports the experimental and theoretical investigation of the Talbot effect beyond the paraxial limit at optical frequencies. Au hole array films with periodicity a₀ comparable to the wavelength of coherent illumination λ were used to study the non-paraxial Talbot effect. Significant differences from the paraxial (classical) Talbot effect were observed. Depending on the ratio of a₀ /λ , the interference pattern in the direction perpendicular to the hole array was not necessarily periodic, and the selfimage distances deviated from the paraxial Talbot distances. Defects within the hole array film or above the film were healed in the self-images as the light propagated from the surface.