We have observed that a light beam that passed through an optically active crystal of Bi12SiO20 and that was then reflected exactly back through it did not recover its initial polarization orientation. The nonreciprocal component of the rotation was of the order of 2 × 10−3 of the reciprocal, single-pass rotation. This nonreciprocity is unambiguous evidence of broken reversality of the light–matter interaction process.
© 1996 Optical Society of America
P. J. Bennett, S. Dhanjal, Yu. P. Svirko, and N. I. Zheludev, "Nonreciprocity of natural rotatory power," Opt. Lett. 21, 1955-1957 (1996)