Long-range surface plasmon-induced tunable ultralow threshold optical bistability using graphene sheets at terahertz frequency.

A proposal on optical bistability at ultralow switching threshold and lower Fermi-level of graphene around 2 THz is implemented analytically through the proposed long-range surface plasmon resonance configuration by employing local field enhancement effects owing to the excitation of a graphene symmetric mode within graphene sheets. Reported threshold intensity for the optical bistability to date is 1.6  kW/cm within the terahertz region and 1.83  MW/cm at near-IR range. Whereas the proposed scheme explores the possibility of reducing this threshold down to 143.68  W/cm, this technique proffers potential applications in nanoillumination, optical memory, and all-optical switching at an ultra-low threshold.