Enhanced dipolar transport in one-dimensional waveguide arrays

We study the transport properties of fundamental and dipolar (first-excited) modes on one-dimensional coupled waveguide arrays. By modulating an optical beam, we are able to generate fundamental and dipolar modes to study discrete diffraction (single-site excitation) and gaussian beam propagation (multi-site excitation \& phase gradient). We find that dipolar modes experience a coupling constant more than two times larger than the one for fundamental modes. This implies an enhanced transport of energy for dipoles in a tight-binding lattice. Additionally, we study disordered systems and find that while fundamental modes are already trapped in a weakly disorder array, dipoles still diffract across the lattice.