Theoretical investigation of a multi-functional logic device based on plasmonic Mach-Zehnder interferometer waveguides

Abstract

Optical logic device is an essential part of the all-optical signal processing system. A multi-functional logic device is proposed in this paper, it consists of plasmonic Mach–Zehnder Interferometer (MZI) waveguides and a couple of identical hexagonal resonators with swiveling ellipses embedded in them. The input boolean value is defined by the rotation angle of rotatable ellipses. The output boolean values are distinguished by monitoring the transmissions of the output port and setting the appropriate thresholds. The finite-difference time-domain (FDTD) method is used to simulate the proposed structure. Ultimately, four logical functions: NOR, AND, OR and NOT could be accomplished simultaneously. Furthermore, the contrast ratios of the four logic gates are obtained by calculating the structure simulated results. Compared with the same type of logic devices, the proposed logic device has better performance in contrast ratio. Therefore, the structure has excellent application prospects in optical communications and photonic integrated devices.