A scheme to excite transverse electric graphene plasmon polariton with positive value of imaginary part of conductivity

We proposed a scheme to generate a transverse electric graphene plasmon polariton in which the imaginary part of conductivity need not be negative. In a three-dimensional periodic structure with graphene ribbons embedded in a medium, at a suitable frequency and wavelength, the periodic modification factor is not a real number but a purely imaginary one, which makes dispersion relations possibly satisfied, that is, a transverse electric graphene plasmon polariton can be excited in this case. The spectrum of the plasmon polariton is broadband. Furthermore, the coupling between the plasmon polariton and electromagnetic wave was enhanced and the enhancement is beneficial to design high efficiency optoelectronic devices.