Impedance conjugate matching of plasmonic nanoantenna in optical nanocircuits

Optical antennas are a state-of-the-art concept in modern plasmonics. Nanoantennas can be advantageously used to localize, enhance and detect radiation in nanoscale volumes. These abilities unlock an enormous potential applications ranging from optoelectronics engineering and integrated optical nanocircuitry to nanoscale optical microscopy and ultra-sensing. The coupling efficiency between nanoantenna and other elements in integrated optical nanocircuit strongly depends on its properties where the impedance matching plays a crucial role. We investigate the dependence of impedance of the T-shaped optical nanoantenna on its geometrical parameters. We show that several parameters - an arm length of the T-shaped nanoantenna, nanoantenna width and a width of the front facet of the connector - can influence on the impedance conjugate matching which gives flexibility in impedance tuning for coupling of antenna to the nano-waveguides.