Optics Lab Polarization, Birefringence, and Retardance Polarization is the property that describes the orientation, i.e., time-varying direction and amplitude, of an electromagnetic wave. States of polarization are described in terms of the figures traced as a function of time by the projection of the extremity of a representation of the electric vector onto a fixed plane in space, which plane is perpendicular to the direction of propagation. In general, polarization, is elliptical and is traced in a clockwise or counterclockwise sense, as viewed in the direction of propagation. If the major and minor axes of the ellipse are equal, the polarization is said to be circular . If the minor axis of the ellipse is zero, the polarization is said to be linear.
Birefringence is the dependence of light refraction on light polarization.
The refractive index is related to the speed of light. This phenomenon is the origin of the terms Birefringence and also Double Refraction. Many materials, such as glasses or plastics become birefringent when subjected to mechanical strain. Inc. All rights reserved.