Polarization rotation enhancement and gyrotropic photonic bandgaps in birefringent magneto-photonic crystals

We present a study of polarization rotation enhancement in birefringent magneto-optic photonic crystal waveguides and provide theoretical and experimental support for a novel type of photonic bandgap. The coupling between counter-propagating elliptically birefringent local normal modes of different order results in the formation of partially overlapping bandgaps and selective suppression of Bloch state propagation near the band edges. We use a bilayer unit cell stack model with an alternating system of birefringent states in adjacent layers. A magnetically tunable and large polarization rotation of the allowed Bloch modes near the band edges is computed theoretically and observed experimentally