Numerical analysis of spin-filter effect of optical tornados and chiral edge states in two-dimensional photonic crystal waveguides

We numerically analyze the wave propagation of optical tornados in a waveguide, a part of which is made of an inversion-asymmetric photonic crystal. Frequency-sensitive anisotropic propagation patterns are demonstrated, and we discuss about this phenomenon in terms of the Berry phase engineering, and interpret it as an effect similar to the electronic spin-filter effect. In addition to this time-reversal invariant system, we also study the characteristics of rotatory modes in a magnetic photonic crystal superlattice, where there appear photonic chiral interface modes.