Investigation of statistical properties of electromagnetic beams modulated by surface plasmon polaritons.

We report a controlled manipulation of the polarization characteristics of an electromagnetic beam generated by a Gaussian Schell model source using the surface plasmon polaritons (SPPs) excited in a metallic double-slit. To date, investigations of SPP-mediated effects have treated coherence and polarization properties separately, and such control using unification of these two properties has not been addressed. By employing a metallic (gold) double-slit interferometer, we demonstrate experimentally that the excitation of SPPs enables modulation of the statistical properties of light at subwavelength scales, well supported by the theoretical analysis. The interplay between coherence and polarization mediated by SPPs provides a flexible means of tailoring the statistical properties, with potential impact on imaging, sensing, and plasmonic device applications.