Using finite difference time domain (FDTD) method, we numerically investigate onedimensional photonic crystals (1D PCs) with (AB) m C(BA) m structure, where A and B stand for different dielectric materials, and C the graded-index (GRIN) material. The transmission properties of the multilayer structure have been studied, and the results show that a tunable narrow band-pass filter (BPF) can be obtained by changing gradient coefficients of the GRIN defect layer. For an increasing incident angle, although the transmittance becomes smaller, positions of the resonant peak remain the same, which can act as the angle-insensitive filter.

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In this paper, polystyrene (PS) opals template, opal with a closed-packed face centered cubic (fcc) lattice, was prepared using vertical deposition method. The template provided void space for infiltration of Nb2O5 etc. PS colloidal nanospheres was face-centered-cubic (FCC) structure with its (111) planes parallel to the substrate. Finally, the transfer matrix method (TMM) was used to calculate photonic band-gap of PS opal and Nb2O5 inverse opal structure. The calculation results show that the photonic band-gap of Nb2O5 with inverse opal structure is wider than that of PS opals.