We perform a theoretical study of enhancement of magnetooptical rotation on reflection of light from a periodic system with a defect. Using calculations based on a coupled mode approach and the transfer matrix method we demonstrate that an asymmetric placing of a single defect allows arbitrary Kerr rotations with better than 99% reflectivity from very short devices.
M. J. Steel, M. Levy, and R. M. Osgood, "Large Magnetooptical Kerr Rotation with High Reflectivity from Photonic Bandgap Structures with Defects," J. Lightwave Technol. 18, 1289- (2000)