The Boundary Condition at the Surface for the Optically Active Medium

Condon's formalism of the optical activity suggests the presence of a sort of surface current at the boundary of the optically active medium. In this paper is discussed the origin of this surface current in terms of the general conductivity tensor. The expression of the surface current for the arbitrary medium consists of two parts; one is expressed with the bulk conductivity tensor and corresponds to the magnetization current in Condon's formalism, while the other is related to the surface charge and reflects the surface property. The reflectivity calculated for a lossless isotropic medium shows that the normally incident linearly polarized light does not undergo optical rotation by reflection as is pointed out by some authors.