INTERFERENCE PATTERNS UNDER OBLIQUE-INCIDENCE IN BIREFRINGENT OPTICALLY-ACTIVE PLANE-PARALLEL PLATES

We have studied the interference patterns of multiple reflections from a uni-axial, optically active and non-absorbing plane-parallel plate under oblique incidence. Due to birefringence, a beam of polarized lig ht splits into an ordinary and an extraordinary component. During cros sing of the plate the phase difference between beams is increased by f ixed amounts. The calculations show that the interference pattern of t he transmitted light is more complex than that of an isotropic plane-p arallel plate. Strong singlets are followed by weak fringes which exhi bit splitting in the form of doublets. The intensity ratio of the stro ng to the nearest neighbour doublet fringe and the splitting of the fr inges depend on reflectivity and are increased at oblique incidence. T he interference pattern is determined by the birefringence and is inse nsitive to the optical activity except in some extreme cases. Investig ation of these extreme cases allows the separation of the effect of op tical activity from the much stronger birefringence effect. The transm ission signal generated by the optical activity is weak, which creates serious difficulties for its practical utilization.