The Faraday effect of an antiferromagnetic photonic crystal with a defect layer

A theoretical calculation of the Faraday optical rotation effect of an antiferromagnetic (AF) photonic crystal is presented. This crystal is composed of AF and dielectric (D) layers and contains an AF defect layer. From the theoretical results for the FeF2-SiO2 crystal, we see a defect mode with high transmission and a high Faraday rotation angle in the optical stop band for omega/2 pi c < 105 cm(-1). The Faraday rotation of the mode is about 28 degrees mm(-1) and 15 times that of the single AF film. Another more striking property is that the rotation in the vicinity of the zero-field AF resonance frequency is even larger than that of the defect mode: about 250 times. The Faraday rotation can be tuned by changing the strength of the external static magnetic field.