High-Q filters based on one-dimensional photonic crystals using epsilon-negative materials

A new type of filter based on one-dimensional photonic crystals is presented. A photonic crystal consists of a periodic repetition of air layers and epsilon-negative (ENG) material layers. This type of filter has high-Q values without defects. The Q values and the filtering frequency can be precisely adjusted by modulating the thicknesses of the ENG material layers and the air layers, respectively. A method of deciding the position of the transmission band for the photonic crystals is presented. The effect of absorption of ENG materials on the filter is also considered.