Inhibition of light tunneling in waveguide arrays

TL;DR

This paper demonstrates how harmonic modulation of refractive index in waveguide arrays can nearly completely inhibit light tunneling, enabling long-distance light trapping and tunable localization thresholds.

Contribution

It introduces a method to achieve near-perfect light tunneling inhibition in waveguide arrays through band collapse induced by harmonic modulation.

Findings

Light tunneling can be almost completely suppressed.

Light can be trapped in a single waveguide over long distances.

The localization threshold power can be tuned.

Abstract

We report the observation of almost perfect light tunneling inhibition at the edge and inside laser-written waveguide arrays due to band collapse. When the refractive index of the guiding channels is harmonically modulated along the propagation direction and out-of-phase in adjacent guides, light is trapped in the excited waveguide over a long distance due to resonances. The phenomenon can be used for tuning the localization threshold power.