  This report is concerns with optical nano-antennas in their various forms
such as metallic nano-rods, cross-shaped nano-particles and apertures, periodic
meta-surfaces such hole arrays and bullseye structures. Their applications in
wavelength division multiplexing/demultiplexing, shaping the radiation pattern
and the state of polarization of the transmitted light, refractive index based
sensing, enhancement to the radiative decay rate of nearby quantum emitters and
novel approach in achieving such effects are presented.
