Optical diode based on a highly anisotropic layer of a helical periodic medium subjected to a magnetic field

The effect of an applied magnetic field on the optical properties of a layer of a helical periodic medium is studied in view of magnetooptic activity. The case when the radiation is normally incident on the layer and the magnetic field is aligned with the axis of the medium is considered. Irreversibility (nonreciprocity) effects in such a system are discussed. The situations with weak and high anisotropy are investigated. It is shown that the system can function as an optical shutter, optical diode, or one-side reflector. Reasons for the high irreversibility of transmission (reflection) are found.