Loading...

Analysis of High-Tc Superconducting Plasmonic Waveguides

Vahedi, Zeinab | 2018

1367 Viewed
  1. Type of Document: M.Sc. Thesis
  2. Language: Farsi
  3. Document No: 50787 (05)
  4. University: Sharif University of Technology
  5. Department: Electrical Engineering
  6. Advisor(s): Rejaei, Behzad; Fardmanesh, Mahdi
  7. Abstract:
  8. Surface plasmons are the result of a resonant interaction between the waves and the mobile electrons at the interface between negative and positive permittivity materials stimulated by incident light. Due to their specific quantum mechanical nature and zero electrical resistance, superconductors are capable of supporting low-loss plasma waves with extremely large propagation length. In this study, palsmon confinement in some superconducting waveguide structures has been measured by computing the effective index parameter. Superconductors are classified in to high-Tc an low-Tc categories. It is not possible for plasma waves to propagate in low-Tc superconductors, because the plasma energy exceeds the superconducting gap and causes transition to normal state; however due to their layered uniaxial anisotropic structure constituted from the CuO2 planes, the high-Tc superconductors make it feasible for plasma waves to propagate in the superconducting phase in the vicinity of the c-axis plasma frequency. In this study the dispersion plots of a half space and a superconducting film are derived using analytic computation based on Maxwell’s equations below and above the c-axis plasma frequency; then the effective index of a rectangular high-Tc waveguide is obtained by using Marcatili’s method and EIM as approximate methods and also green’s function method (GFM) in homogeneous and layered medium as a numerical method equations below the c-axis plasma frequency. At last, the high-Tc based grating structure has been investigated and the electric field profile has been obtained by using GFM and the resonance frequencies has been computed by COMSOL software. The relation between these resonance frequencies and the dispersion plot of a superconducting slab has also been detected. All of the results are perfectly matched with the ones obtained by COMSOL. This investigation shows that above the c-axis plasma frequency and below the gap frequency the high-Tc superconductor becomes a hyperbolic medium with a high effective index which provides the optimum circumstances for the plasma waves to propagate
  9. Keywords:
  10. Resonance ; Gratings ; Waveguides ; Green Function ; High Temperature Superconductor ; Surface Plasmon ; Plasmonic Waveguides

 Digital Object List

 Bookmark

...see more