Low-temperature optical bistability and multistability in superconducting photonic multilayers with graphene

Optical bistability and multistability are numerically investigated based on periodic superconducting photonic multilayers with graphene in cryogenic environments. Bandgap edge resonances are sensitive to circumstance temperature and can localize the electric field greatly, which is utilized to enhance the nonlinearity of graphene. Consequently, low threshold optical bistability and double-bistability are realized. Optical multistability subsequently arises by increasing the value of circumstance temperature as well. The thresholds of bistability and multistability lower further by decreasing the chemical potential of graphene or promoting the period number of photonic multilayers. The thresholds can be decreased as low as several hundred MW/cm2. The complex structure has a great potential for the development of two- and multiple-valued all-optical switches in low-temperature condition.