One-way optical waveguides for perfectly matched non-reciprocal nano-antennas with dynamic beam tuning. (arXiv:1109.1148v1 [physics.optics])

One-way optical waveguides for perfectly matched non-reciprocal nano-antennas with dynamic beam tuning. (arXiv:1109.1148v1 [physics.optics]):
An optical signal that propagates along a conventional waveguide is back
reflected at waveguide terminations. If the waveguide permits only one-way
propagation, this back reflection cannot take place; the optical signal
undergoes a nearly 100% conversion to radiation modes. Hence, a terminated
one-way waveguide may serve as a matched nano-antenna with a natural guiding
and feeding mechanism. We examine the termination effect in a recently
suggested nano-scale one-way plasmonic waveguide, and its properties as a
matched nano antenna are shown. Since one-way structures are inherently
non-reciprocal, our antenna possesses different transmitting and receiving
patterns, and a dynamic beam-forming functionality. These unique properties may
be used in applications requiring dynamic directional selectivity that differ
in transmit and receive operations.