Design and fabrication of narrowband multichannel filters

Three proposed approaches are used to obtain narrowband multichannel filters . The first approach is using multiple heterostructures inserted with defects mode. The enlargement of the forbidden band and the realization of multiple channeled filtering can be reached simultaneously by using this method. The second approach is using guided -mode resonance Brewster filters with multiple channels. For this method, narrowband filters with multiple channels can not only be obtained by using single layer structure, but also be obtained by using double layer structure with equal refractive index. The third approach is integrated optical filter arrays using the combinatorial etching technique. Single and double chamber narrowband filter arrays can be both obtained by using this method. Narrowband multichannel filters obtained by using these three methods are potentially useful in many optical applications.