研究单层石墨烯的三阶非线性和光双稳态效应。通过理论分析和数值模拟,改变单层三阶非线性石墨烯的费米能级、弛豫时间、双光子吸收系数及温度条件,调制单层三阶非线性石墨烯光双稳态的阈值大小。单层三阶非线性石墨烯的费米能级越大,温度越高,则光双稳态的阈值越大;双光子吸收系数越大,双稳态的低阈值越大;弛豫时间和双光子吸收系数会明显地改变石墨烯结构的光透射率,而光透射率则对石墨烯材料自身温度不敏感。该结论可为设计各类微纳结构的光子器件如光开关和光传感等提供理论依据。

In this study, the third-order nonlinearity and optical bistability effect of mono-layer graphene was investigated. Using theoretical analysis and numerical simulation, the threshold value of the optical bistability of mono-layer third-order nonlinearity graphene can be tuned by changing its Fermi energy, relaxation time, two-photon absorption coefficient, and temperature. We demonstrate that the larger Fermi energy level,the higher temperature and the larger threshold value of the optical bistability. Further, a higher two-photon absorption coefficient corresponds to a higher low threshold of the bistability. Moreover, the relaxation time and two-photon absorption coefficient can significantly alter the light transmissivity of the graphene structure, although the light transmissivity is insensitive to the temperature of the graphene material. Results offer a theoretical basis for designing nanophotonic devices with micro-nano structure such as optical switches and optical sensors.