The narrow transmission peaks and field confinement produced by defects in a multilayered microsphere

Abstract: We study numerically the frequency spectrum of light propagating through a multilayered micro-sphere coated by an alternating sub-wavelength photonic bandgap stack with an embedded defect. We found the formation of an extremely narrow resonant peak with nearly complete transmission in the area of the band gap. The spectral evolution of such a resonance at the change of a defect layer is investigated in details. It is found the confinement of the defect photon mode that results in the formation of strong field oscillations in the vicinity of the defect layer. The influence of a random deviation in the width of the spherical layers is also discussed. [Copyright &y& Elsevier]