Investigation of localized electromagnetic field in a subwave-length metallic slit

Electromagnetic field localization in a subwavelength metallic slit by a thermo-elastic optical indicator microscope (TEOIM) was investigated. As an indicator for the TEOIM system a slide glass with sizes of $20\times20\times0.5 (mm)$ was used, on the surface of which an Al film of $20~nm$ thickness was vaporized using the vacuum evaporation technique, with various slit width ($10-50~µm$). Strongly localized electromagnetic field has been exited in the slits by $50~ GHz$ generator and was visualized by a TEOIM. The waveguide properties of the system were characterized by COMSOL Multiphysics$^\circledR$ additionally. The simulation results are in good agreement with the visualization data set.