In this module the propagation of a monochromatic completely polarized plane wave of light and the effect of various optical elements on the corresponding electric field vector is simulated. The user chooses the amplitudes of the two components of the electric field and the phase difference between the two components. This electric field then propagates across the screen. The user can then insert linear polarizers or various types of retarders (waveplates) into the path of the light. The user can interactively change the position of each polarizer and the orientation of its transmission axis. Similarly, the user can interactively change the position of each waveplate, the orientation of its fast axis, and the number of waves of path length difference that is introduced by it.