Inhibition of light tunneling for multichannel excitations in longitudinally modulated waveguide arrays

TL;DR

This paper investigates how specific longitudinal modulations in waveguide arrays can inhibit light tunneling, preserving multichannel excitation structures and revealing symmetry-dependent robustness and nonlinear effects.

Contribution

It demonstrates that phase-specific modulation can selectively inhibit tunneling while maintaining excitation structure, highlighting the role of symmetry and nonlinearity.

Findings

Resonant tunneling inhibition depends on modulation symmetry.

Antisymmetric excitations are more robust than symmetric ones.

Nonlinearity causes delocalization at higher amplitudes.

Abstract

We consider evolution of multichannel excitations in longitudinally modulated waveguide arrays where refractive index either oscillates out-of-phase in all neighboring waveguides or when it is modulated in phase in several central waveguides surrounded by out-of-phase oscillating neighbors. Both types of modulations allow resonant inhibition of light tunneling, but only the modulation of latter type conserves the internal structure of multichannel excitations. We show that parameter regions where light tunneling inhibition is possible depend on the symmetry and structure of multichannel excitations. Antisymmetric multichannel excitations are more robust than their symmetric counterparts and experience nonlinearity-induced delocalization at higher amplitudes.