The coupling interaction between an individual optical emitter and the propagating surface plasmon polaritons in a graphene microribbon(GMR) waveguide is investigated by numerical calculations, where the emitter is situated above the GMR or in the same plane of the GMR. The results reveal a multimode coupling mechanism for the strong interaction between the emitter and the propagating plasmonic waves in graphene. When the emitter is situated in the same plane of the GMR, the decay rate from the emitter to the surface plasmon polaritons increases more than 10 times compared with that in the case with the emitter above the GMR.
Rare-earth(RE)doping can greatly enhance the voltage gradient of ZnO-based varistors,and their nonlinear coefficient,leakage current,energy absorption capability,through-current capability and residual voltage can also be improved to certain extent.In this review,the progress on RE-doped ZnO-based varistor materials in recent years was summarized.The mechanism of RE doping on the electrical performance of ZnO varistors was analyzed.The issues in exploring new ZnO-based varistor materials by RE doping were indicated,and the development trends in this area were proposed.
