ALL OPTICAL LOGIC GATES USING PLASMONIC RING RESONTORS

Abstract

Electronic integrated circuit scaling, predicted by Moore, has been the driving force of the developments in semiconductor industry. But in the recent years, the rate predicted by Moore’s law has deteriorated but the ever-increasing demand for energy-efficient and high-performance computing is still on the rise. Novel structures of transistors have already been developed to sustain the rate dictated by Moore’s law. The current issues in the state-of-the-art CMOS technology are the interconnect bottleneck and heat management, which can be solved to an extent by employing light in the bottom layers of the circuit. To enable this, optical waveguides and devices must be scaled beyond the diffraction limit of light and it is enabled by plasmonics which provide subwavelength-scale confinement of light. In plasmonics, surface plasmon polaritons (SPPs) is a key area for wave computing applications. SPPs are electromagnetic waves coupled to electron oscillations, supported by a metal-dielectric interface. The dispersion relation for SPPs yields the subwavelength-scale confinement. The electric field amplitude of the SPP wave decays exponentially perpendicular to the direction of propagation i.e, Transverse Magnetic mode is supported. This decay depends on the material in which the SPP wave resides and this results in a tradeoff between propagation length and confinement. So different waveguide topologies are suited for specific applications. This works shows the theoretical details of surface plasmon polaritons and micro ring resonators in the point od view of employing them to realize all optical logic computing. A basic SOI ring resonator is implemented using 3-D FDTD in Lumerical FDTD Solver and various fields, on and off resonance were plotted. Further a Silver-Air-Silver Metal-Insulator-Metal waveguide is used to design an all optical NOT logic and various fields were observed using 2-D FDTD when input is enabled and disabled. Perfectly Matched Boundary Conditions were applied in both cases.