Resonance tunnelling of photons through multiple-well structures in two- dimensional photonic crystals with various well-media

Resonant transmission of light through multiple well structures is investigated by the R-matrix algorithm. The structure consists of the two-dimensional photonic crystal barrier series with homogeneous transparent media in between. We find that the transmission probability displays a typical pattern in the propagation forbidden band, which shows n-fold peak splitting in an n-well system. A higher permittivity value of the transparent well-medium results in denser resonance peaks with frequencies shifted towards the red and furthermore the number of peaks can be greatly suppressed when the normal well-medium is replaced by left-handed materials. We observe a new distortion of resonance-peak splitting with alternately placing the normal and the left-handed media in two wells completely different from the distortion induced by the asymmetry of well-width with the same kind of well-media in both wells. Based on analytical calculation of the transmission probability in one-dimensional photonic-crystal wells the new observation is understood as a result of destructive interference in the left-handed and normal well-media. Since the numerical calculations are carried out for the two-dimensional crystal system with practical photonic-crystal parameters, it is expected that the predictions can be verified by experiments.