Effects of defects and disorder in light propagation in one-dimensional photonic bandgap structures

Abstract

The light localization due to defects and disorder and its effects on light propagation in one-dimensional (1D) photonic band gap (PBG) structures is studied numerically with transfer matrix method. For a defect layer embedded at the center of a I D PBG structure, the simulation results indicated that, the photons will be trapped in the defect region. For a disordered I D PBG structure, a mechanism for extension of the transmission band gap is illustrated with combining the effects of Bragg reflection and Anderson localization. We propose that, analog to disordered semiconductors, there may exist two band gaps in disordered PBG structure: transmission gap and mode-density gap.