The results concerning propagation characteristics of plasmonic metal stripe waveguide using FEM analysis are presented. The metal stripe waveguide consists of a layer of gold (Au) which is 55nm thick and 1μm wide on a glass substrate with air at the interface excited at 800nm wavelength. Various characteristics like modal confinement, propagation length, and dispersion were investigated. Finite Element analysis (FEM) for hybrid modes is used to solve for various bound modes. These bound modes could be either symmetric or asymmetric in nature. The symmetric modes can be characterized by electric field maxima inside the metal. As a result these modes die down very fast and propagate distances of few micrometers. The asymmetric modes can be characterized by electric field maxima at the interface and can propagate distances of tens of micrometers. For lower width of metal, propagation length of 100μm or more can also be observed. It was also observed that with increase in metal width higher order bound modes get characterized. There exists a definite relation between number of such modes and width of the metal stripe for a given excitation wavelength. Such modes tend asymptotically towards the characteristic of surface Plasmon wave similar to that energized at a metal-air interface. Based on all these parameters various characteristics of metal stripe waveguide are analyzed.

Date Published: 23 August 2011
PDF: 7 pages
Proc. SPIE 8173, Photonics 2010: Tenth International Conference on Fiber Optics and Photonics, 81731L (23 August 2011); doi: 10.1117/12.897855

Published in SPIE Proceedings Vol. 8173:
Photonics 2010: Tenth International Conference on Fiber Optics and Photonics
Sunil K. Khijwania; Banshi D. Gupta; Bishnu P. Pal; Anurag Sharma, Editor(s)