Polarization transformation of a wave field propagating in an anisotropic medium

The momentous experimental discovery of the Faraday (1846) effect is sketched from a historical perspective, through the eyes of several well-known scientists. This effect and its generalization can be explained theoretically by using the dispersion theory for waves propagating in an anisotropic medium. A wave of arbitrary initial polarization will have its wave polarization transformed continuously as it propagates. It is convenient to represent this continuous polarization transformation by a locus in the polarization-ratio plane. In a lossless medium, when both characteristic waves are propagating, this locus is a circle. Five cases in a magneto-ionic medium have been investigated for different propagation angles. The results are discussed and illustrated.