LAUSR

Talbot effect in a metallic groove array is observed numerically based on finite element method (FEM) and verified theoretically based on non-paraxial approximation. Grooves in the metallic layer are separated from backside with a narrow gap that is smaller than surface plasmon (SP) penetration depth in metal. At certain circumstances, SPs tunnel through the gap and constructively interfere beneath the metallic layer. In propagation pattern, called Talbot carpet, self-images at certain distances in a periodic row parallel the metallic layer are formed. The distance, called Talbot distance, is coincident with non-paraxial approximation result. To evaluate the periodicity of revivals, new parameters such as R-square, contrast, and image size are introduced. Afterwards, influence of the structural parameters such as groove size, period, and gap thickness on the light intensity is analyzed and proper values for near-infrared wavelength range is determined. We anticipate that our finding reveals better understanding of SP tunneling and paves a way toward utilization of this effect in Talbot effect attributed applications, particularly image processing.