• Asymmetric transport of light in linearly arrayed metallic nano-particles

      Aroua, Walid; Horchani, R.; AbdelMalek, Fathi; Haxha, Shyqyri; Kamli, Ali A.; National Institute of Applied Science and Technology, Tunisia; Dhofar University; University of Bedfordshire; Jazan University, Saudi Arabia (Springer, 2016-09-15)
      A strong asymmetric light transport in a linear chain of spherical and equidistantly spaced silver metal nano-particles (MNPs) located near a substrate is reported. The contrast ratio of the proposed structure is above 0.95. We have studied the propagation of light in the array with respect to the metal and the size of the last nano-particle of the chain and the nature of the substrate. It is shown also that the presence of a copper or gold substrate enhance the guiding properties of the array. This structure opens the possibility to design various optical devices such as broadband antennae and optical diodes.
    • Light-switching-light optical transistor based on metallic nanoparticle cross-chains geometry incorporating Kerr nonlinearity

      AbdelMalek, Fathi; Aroua, Walid; Haxha, Shyqyri; Flint, Ian; National Institute of Applied Science and Technology, Tunisia; University of Bedfordshire; 3Selex ES Ltd, Luton (Wiley-VCH Verlag, 2016-06-13)
      In this research work, we propose all-optical transistor based on metallic nanoparticle cross-chains geometry. The geometry of the proposed device consists of two silver nanoparticle chains arranged along the x- and z-axis. The x-chain contains a Kerr nonlinearity, the source beam is set at the left side of the later, while the control beam is located at the top side of the z-chain. The control beam can turn ON and OFF the light transmission of an incoming light. We report a theoretical model of a very small all-optical transistor proof-of-conceptmade of optical ‘light switching light’concept. We show that the transmission efficiency strongly depends on the control beam and polarization of the incoming light. We investigate the influence of a perfect reflector and reflecting substrate on the transmission of the optical signal when the control beam is turned ON and OFF. These new findings make our unique design a potential candidate for future highly-integrated optical information processing chips.