Abstract

It was commonly believed that polarization plane rotation in a non-magnetic, optically active media is reciprocal. Here we report, what is to the best of our knowledge, the first observation of nonreciprocal polarization plane rotation in an optically active, nonmagnetic crystal. We saw that a light wave which passed through the crystal, B₁₂SO₂₀, and which was then reflected exactly back through it, did not recover its initial polarization azimuth. The nonreciprocal component of rotation was of the order of 7×10^-3 of the reciprocal rotation. The effect is unambiguous evidence of broken reversality of the light-matter interaction process. Our interest in this research was motivated by the fundamental importance of the topic, and because time non-reversal effects may be exploited in unidirectional valves for electromagnetic radiation.

© 1996 Optical Society of America