Abstract
In this work, we excite SPP by four-wave mixing (FWM) and find the optimum angle of incidence using finite-difference time domain method. Besides, we propose and design mode converters in a plasmonic nanocircuit by controlling the phase of surface plasmon polaritons on two-wire transmission lines (TWTLs) with the length difference between the two wires. Our samples are fabricated by focused ion beam milling of a gold flake deposited on a cover glass. In the experimental process, we use our home-made confocal microscope focusing the spot at the end of TWTL and CCD camera is used to observe the emission spot. Finally, we can observe the excitation spots are sufficiently displaced from the mode detector. The mode conversion transforms successfully between transverse electric(TE) mode and transverse magnetic(TM) mode by the length difference between the two wires.