▎ 摘　　要

Fast and compact optoelectronic devices are highly sought after for applications in high-speed signal processing in optical communication networks. One approach to realizing such devices is through all-optical digital logic circuits. One of the main building blocks of such circuits is a decoder. In this work, we present a novel design for a tunable optoelectronic 2-to-4 binary decoder. The presented structure is realized by utilizing three photonic crystal (PhC) ring resonators. Each PhC ring resonator is formed by silicon rods encircled by silica (SiO2) rods coated with graphene nanoshells (GNSs). By adjusting the chemical potential of GNS with a proper gate voltage, we can tune the desired PhC resonant mode. The fundamental PhC microstructure's photonic band structure is analyzed by using the plane wave expansion method. Furthermore, the finite-difference time-domain technique is used to solve Maxwell's equations and analyze the light propagation within the structure. Our numerical results reveal that 0.8 ps and 0.3 ps are the maximum rise and fall times for the final structure, respectively and the total size of this device is 850 mu m(2). Due to the short rise and fall times and its size which are among very important features in high-speed systems, the proposed design could be utilized for high-speed signal processing systems in miniaturized optical communication network devices.