Tunable filters based on Thue-Morse quasicrystals composed of single-negative materials

Tunable filters have been proposed and demonstrated. It is seen that a Thue-Morse aperiod structure composed of single-negative materials can act as a tunable filter, which is insensitive to the incident angle and polarization of light, and is an omnidirectional filter, and the bandwidth and frequency of the filter can be changed by adjusting the layer thicknesses and plasma frequency, respectively.