▎ 摘　　要

In this paper, we propose a multilogic gate (MLG) by utilizing a dielectric-loaded graphene-based plasmonic waveguide (DLGPW) in the mid-infrared spectral region. The proposed MLG is composed of DLGPW-based switches and multimode interference (MMI) splitters and supports three logical operations-AND, XNOR, and NOR-simultaneously. First, by proper control of the graphene surface conductivity, a graphene plasmonic on-off switch is presented, and then a 3 dB MMI splitter based on a DLGPW for a wavelength of 7.8 mu m is designed and investigated. Our studies show that electro-optical logic gates based on DLGPWs have not been reported to date. The structure of the presented MLG is very simple and CMOS-compatible. The calculated minimum extinction ratios (ER) for AND, XNOR, and NOR logic gates are 17.53 dB, 53.43 dB, and 17.53 dB, respectively. Also, by some modifications, this structure can act as a NAND logic gate with an ER of 55.22 dB. Compact footprint, high ER, and easiness of on-chip implementation are some advantages of the presented MLG. (C) 2018 Optical Society of America