A new narrowband multilayer DWDM optical filter in the order of defected Fibonacci sequence

The self-similar narrow stop-bands in the reflectivity spectrum of the structures in the order of generalized Fibonacci sequence are utilized in this study. A multilayer structure in the order of generalized Fibonacci sequence is defected by a proper layer to get narrow stop-bands identical to channels of dense wavelength division multiplexing (DWDM) filter with ITU-T standard (100 GHz grid). The index profile of the defected structure is apodized and index-matched to eliminate the sidelobes between the stop-bands. After these modifications, a thin, new DWDM filter is designed having significantly suppressed sidelobes.