Broadband optical diode and giant nonreciprocal tunable light localization

Some new properties of optical diodes were investigated, as well as compared with the known ones for the following three systems: 1) an isotropic magnetoactive layer, 2) a magnetophotonic crystal layer, and 3) a photonic crystal with a helical structure, assuming that these systems are in an external magnetic field and have giant parameters of magneto-optical activity. It is shown that these systems can be used as broadband ideal optical diodes. At giant values of the magneto-optical activity in the long-wavelength region of the spectrum, there appears a new photonic band gap (PBG) for helically structured photonic crystals. Accordingly, two PBGs and a transparent window between them appear in the whole spectral region. When magneto-optical activity parameter increases, this new (the second) PBG occupies the entire spectrum. Furthermore, the light localization at the edge modes is investigated. It is shown that an unusually strong light localization takes place at some modes. The trapped total light energy and the energy density peculiarities are investigated, too. [Display omitted] •Diode properties of isotropic magneto-active layer in the external magnetic field was investigated.•Diode properties of magnetophotonic crystal layer was investigated.•Diode properties of chiral structured photonic crystal being in external magnetic field was investigated.•Light localization peculiarities was investigated.