Depolarization of a randomly distributed plasmonic meander metasurface characterized by Mueller matrix spectroscopic ellipsometry.

Metallic nanostructures offer efficient solutions in polarization control with a very low thickness. In this report, we investigate the optical properties of a nano-fabricated plasmonic pseudo-depolarizer using Mueller matrix spectroscopic ellipsometry in transmission configuration. The depolarizer is composed of 256 square cells, each containing a periodically corrugated metallic film with random orientation. The full Mueller matrix was analyzed as a function of incident angle in a range between 0 and 20° and over the whole rotation angle range. Depolarization could be achieved in two visible wavelength regions around the short-range and long-range surface plasmon polariton frequencies, respectively. Furthermore, depolarization for circularly polarized light was 2.5 times stronger than that for linearly polarized light. Our results could work as a guidance for realizing a broadband high efficiency dielectric metasurface depolarizers.