Enhanced coupling between waveguides through randomness

The concept of amorphous lattices exhibiting a band gap was introduced in optics, and demonstrated using a liquid-like arrangement of waveguides. In this paper, the authors demonstrated an isolated defect state residing deep inside the gap. But how do defect states interact with one another? What is the nature of this interaction? Can defect states interact over great distances? To answer these questions, the authors present a comprehensive experimental and theoretical study on coupled defect states in an amorphous band-gap lattice, and find an enhancement of coupling arising from the random environment surrounding the defects.