An experimental study of the plasmonic Talbot effect.

The Talbot effect of the surface plasmon polaritons (SPPs) using SPP launching gratings is studied experimentally. Talbot carpets are obtained and the Talbot distance is given when the paraxial approximation is not satisfied. Multi-layer and multi-level-phase launching gratings are designed to enhance the intensities of the amplitude-modulated revivals. Effective focusing of SPPs with multiple focal spots and a subwavelength full width at half maximum is obtained by using a three-layer four-level-phase launching grating.