Gervasi Herranz. Invited talk at the META 2019, the 10th International Conference on Metamaterials, Photonic Crystals and Plasmonics: “Nonreciprocal magnetoplasmonic gratings”, (Session SP5. “Magneto-plasmonics”) Instituto Superior Técnico, Lisbon, Portugal, July 23, 2019 – July 26, 2019