Optical nano-antennae as compact and efficient couplers from free-space to waveguide modes

Optical nano-antennae are one of the possible solutions for coupling free-space radiation into subwavelength waveguides. Other possibilities include, among others, grating couplers and end-fire end couplers. Our efforts were concentrated on nano-antennae used for coupling IR light in the telecom range from an optical fibre to a plasmonic slot waveguide. This type of coupling is still difficult to achieve and finding an efficient way in obtaining it would advance the use of plasmonic waveguides for optical interconnects.