All-Optical switching in metal nanoparticles plasmonic waveguide using EIT phenomenon

In this work an all-optical switch based on array of metal nanoparticles (MNP), imbedded in a medium which shows Electromagnetically Induced Transparency (EIT), has been proposed. By implementing EIT in the host medium of MNP plasmonic waveguide, we can induce a transparency and alter the refractive index, by applying reasonable values of optical pumps. Using Finite-Difference Time-Domain (FDTD) simulation, it is found that the proposed all-optical switching exhibits femtosecond-scale feedback time. Results show that the response time of signal light switching up and down are about 100 fs. The proposed switch has a signal transmission of about 14% for a chain of 20 silver MNPs with a length of about 3 pm. It shows losses about 7.75 dB/mu m. The proposed nanoscale plasmonic switch has optical properties that cannot be achieved in any other ways at the nanometer scale, such as overcoming diffraction limit. (C) 2016 Elsevier GmbH. All rights reserved.