OPTICAL-PROPERTIES OF MAGNETICALLY DOPED CHOLESTERICS

We have computed the optical diffraction pattern for linearly polarize d light incident normal to the twist axis (phase grating mode) of a ma gnetically doped cholesteric (ferrocholesteric). The intrinsic Faraday rotation of the magnetic grains results in extra orders of diffractio n. Also we find diffraction for any azimuth of the incident vibration. Further, using the Jones N matrices we have worked out the optical pr operties for light propagation along the twist axis on the very low wa velength side of the reflection band. We find that the medium behaves very differently from a normal cholesteric.