  We elucidate the physical mechanisms by which electromagnetic excitations in
planar chiral waveguides exhibit broken time reversal and parity symmetries as
recently observed in metallic nanostructures (Phys. Rev. Lett. 91, 247404
(2003)). Furthermore, we show that concomitant with these broken symmetries the
electromagnetic excitations can acquire fractional winding numbers, revealing
analogies between light scattering from planar nanostructures and anyon matter.
