Magnetically controllable intra-Brillouin-zone band gaps in one-dimensional helicoidal magnetophotonic crystals

Abstract

Interleaving magnetophotonic garnet layers with layers of a structurally chiral material (SCM) leads to a one-dimensional helicoidal magnetophotonic crystal, the interaction of whose overall period and the helicoidal period of the SCM layers leads to intra-Brillouin-zone photonic band gaps which depend on the structural handedness of the SCM layers and whose gap widths are magnetically controllable. Even as the overall period grows very large, one photonic band gap remains unaffected as it is due to the helicoidal period. Also, the gap widths can be magnetically decreased by turning up the magnitude of the externally impressed dc magnetic field.