Tunable terahertz bistability with temperature in photonic crystals containing an InSb layer and coupled nonlinear defects

Abstract

In this paper, we investigate the terahertz bistability behavior in a photonic crystal doped with an InSb layer and coupled nonlinear defects by employing the modified transfer matrix method. It is demonstrated that the switch-up threshold for bistability can be strongly controlled by ambient temperature without changing the structure of photonic multilayer. The switch-up threshold increases with increasing temperature to a certain value. No dramatic changes are observed in switch-down threshold with increasing the ambient temperature. Further increase of temperature from 309 K to 311 K leads to the strong reduction of switch-up threshold. Our results reveal that the switch-up threshold for the case T = 311 K is approximately 3000 times lower than that of the case T = 309 K. This sensitivity to temperature can have potential applications in terahertz devices. When temperature increases from 309 K, both switch-up and switch-down threshold increase. However, the switch-down threshold indicates much smaller changes compared to the switch-up threshold. Furthermore, we investigate the effect of incident angle on the bistability behavior. It is shown that the temperature at which the lowest value of switching powers is achieved depends on the incident angle.