Reduction of thermal-stress-induced birefringence in a Faraday rotator based on a crystal with a negative optical anisotropy parameter

Abstract

Thermally induced polarization distortions in a Faraday rotator based on a crystal with a negative value of the optical anisotropy parameter was investigated in experiments. A terbium-containing cubic zirconia crystal was taken as a magneto-active medium. A crystal was cut in the orientation in which the axes of thermal-stress-induced birefringence are oriented in one direction. It was demonstrated that the distortions in such a Faraday rotator were reduced by an order of magnitude compared to the minimum possible depolarization arising with the use of a magneto-optical element with the standard [001] orientation, but were still higher than the calculated values. It was shown that for successful development of Faraday isolators based on crystals with a negative optical anisotropy parameter, the theoretical model describing thermal-stress-induced birefringence needs improvement.