Event Details
Long Range Surface Plasmons on an Asymmetric Suspended Waveguide Geometry
Presenter: Min Qiao ( John )
Supervisor: Dr. Reuven Gordon
Date: Thu, May 20, 2010
Time: 15:30:00 - 16:30:00
Place: EOW 430
ABSTRACT
Abstract:
Long range surface plasmons (LRSP) was theoretically achieved in a 1D asymmetric insulator-metal-insulator-insulator thin film structure, which is particularly useful for constructing suspended membrane waveguides. The optimum film thickness was analytically derived by restoring the effective index symmetry, which also gives the optimum LRSP effective index and the attenuation. The investigation on leaky modes was made for SiO2 and Si3N4 matching layers which shows structures with a smaller refractive index matching layer have the better LRSP performance and that the choice of the metal thickness is limited by metal loss and by the onset of leaky modes. These analytic results show a quantitative agreement with the transmission matrix method, and provide physical insights on the asymmetric geometry LRSP, which are promising for aqueous solution sensors that would otherwise suffer from the requirement of a low refractive index matched substrate to achieve the LRSP guiding.