A compact realization of Feynman Reversible and NOR logic gate using Plasmonic waveguide based MZI for all-optical signal processing

The reversible logic function becomes a potential solution in the regime of optical switching and computing. The one-to-one mapping between inputs and outputs in a reversible gate is a key advantage, that prevents information loss. The reversible logic gates have shown potential applications in low-power complementary metal-oxide semiconductors and in quantum computing. Therefore, to utilize these benefits of reversible functions, we have proposed an all-optical compact circuit to realize the functioning of Feynman reversible and NOR logic gates. The proposed all-optical circuit is modeled within the footprints of 87 mu m by using a plasmonic metal-insulator-metal (MIM) waveguide-based Mach-Zehnder interferometer (MZI). The numerical investigation of the MZI is done by evaluating the power imbalance and extinction ratio. The results show that the optical signal propagating in a single MZI with an extinction ratio of 15.1 dB for the power difference of 0.001 W/mu m (similar to 0.1 dB) and 0.0012 W/mu m (similar to 0.79 dB) for logic '0' and logic '1', respectively. The logic '0' and '1' is represented by low (0.028 W/mu m) and high (0.038 W/mu m) power signals. At logic '0' the optical signal propagates in linear arms of MZI with 'pi' phase variation, which causes constructive interference (CI) and thrives the signal at the cross-port. For logic '1' the optical signal experiences '0' phase variation in linear arms of MZI, and due to destructive interference reaches its through-port. The investigated results of the proposed circuit are attained by using the finite difference time domain (FDTD) method.