Tunneling escape in optical waveguide arrays with a boundary defect.

Tuning of the decay law of light in an array of tunneling-coupled optical waveguides with a defect is theoretically demonstrated. An analytical form for the decay law in terms of a Neumann series is obtained in case of a semi-infinite array with a boundary defect waveguide. Different decay regimes, ranging from a near-exponential decay to an oscillatory or nonoscillatory power-law decay, are found in the parameter range where the boundary defect waveguide does not support localized modes.