Anomalous refraction in disordered one-dimensional photonic lattices

We study the light refraction behavior at the entrance surface of the width-disordered one-dimensional waveguide array. As compared to the case in a uniform periodic waveguide array, anomalous refraction behavior is observed for the eigenmodes in the first band of the disordered waveguide array. The transverse propagation velocities of the eigenmodes in the first band are dramatically suppressed and the light is tightly confined around and propagates along the initially exciting waveguides. This may provide an effective method for beam coupling and collimation in the disordered photonic lattices. (C) 2013 Optical Society of America