Design and fabrication of narrow-frequency sharp angular filters.

The theoretical deduction for the frequency variations of the defect mode and its dependence on the incident angle in one-dimensional defective photonic crystals is discussed. Filters with the dual function of narrow frequency passbands and sharp angular pass breadths in visible and near-infrared wave bands, in which both the defect mode and the periodic structure are layers of integral times of quarter-wavelengths, were designed. This kind of filter was fabricated with commonly used coating machines.