Design, fabrication and characterization of plasmonic waveguides

Properties of long range surface plasmon polaritons (LRSPP) are studied in lossy silver waveguides at lambda0=633 nm using a tool developed in MATLAB as well as finite element method (FEM) and finite-difference time domain (FDTD) simulation software. Designs for vertically coupled LRSPP waveguides with coupling lengths as short as 22lambda0 are proposed using FEM and FDTD. Simulations show that losses can be reduced below 1 dB using vertical coupler configurations. In-house proficiency is developed for the fabrication of plasmon devices using silver and PMMA. Silver films as thin as 10 nm are deposited using electron-beam evaporation and patterned using photolithography and wet etching. Surface properties of silver are studied through atomic force microscopy and scanning electron microscopy. Silver waveguides and couplers are fabricated. Device characterization of these structures is performed using an end-fire coupling setup and a HeNe laser and the results are compared to simulation values.