Tunable terahertz optical bistability and multistability in photonic metamaterial multilayers containing nonlinear dielectric slab and graphene sheet

In this study, optical bistability and multistability phenomena are numerically investigated in the terahertz frequency domain based on the quasiperiodic photonic metamaterial multilayers, in which both the regular positive index and special negative index materials are artificially arranged, according to the interesting Fibonacci sequence structure. In order to obtain the tunable bistability and multibistability behaviors, the Kerr-type nonlinear dielectric layer and graphene sheet are sandwiched between two Fibonacci quasiperiodic one-dimensional photonic crystals. Results show that the intensity-dependent hysteresis curves including bistability and multistability are thoroughly discussed by judiciously changing the systematical parameters such as the frequency of incident wave, thickness of each layer, incident angle, as well as the chemical potential of graphene which can produce strong influences on the switch-up/down threshold values and widths of hysteresis loops.