All-optical diode action with quasiperiodic photonic crystals

We theoretically investigate the possibility of realizing a nonlinear all-optical diode by using the unique features of quasiperiodic one-dimensional photonic crystals. The interplay between the intrinsic spatial asymmetry in odd-order Thue–Morse lattices and Kerr nonlinearity, combined with the unconventional field localization properties of this class of quasiperiodic sequences, gives rise to sharp resonances that can be used to give a polarization-insensitive nonreciprocal propagation with a contrast close to unity for low optical intensities.