Design and simulation of compact plasmonic decoder with high contrast ratio to propagate graphene surface plasmon polaritons

In this research, by using graphene nano-ribbons on silicon dioxide, a plasmonic channel with high confinement has been designed to guide surface plasmon polaritons. By adjusting the chemical potential of graphene, the transmission of the channel can be controlled. The simulation results show that by applying voltages of 1.5 and 8.3 V to graphene nano-ribbons, chemical potentials of 0.1 and 0.5 eV can be obtained and the channel loss can be changed from 88.23 to 0.91 dB/μm. Based on this, two logical zero and one states and switching operation can be realized. The figure-of-merit of 975.43 shows that there is a good ratio between the confinement of surface plasmons and their propagation loss. The coupling length of 99.1 μm shows that the power leakage to the adjacent channel can be controlled and the small size of the proposed decoder which is equal to 1.92 μm2 shows the importance of power leakage control. The contrast ratio of the decoder is 45.73 dB, which shows the ability of the device to distinguish logical levels of one and zero. Comparing the structure obtained from this research with other works confirms that the proposed design has been able to improve the performance of the optical decoder.