Incoherent interaction of nematicons in bias-free liquid-crystal cells

TL;DR

This study investigates how incoherent nematicons propagate and interact in bias-free liquid crystal cells, revealing power-dependent behaviors and long-range nonlocal effects in different geometries.

Contribution

It provides the first comparison of copropagating and counterpropagating nematicon interactions in bias-free liquid crystals, highlighting the influence of input power and nonlocal nonlinearity.

Findings

Counterpropagating nematicons require higher power for attraction.

Long-range nonlocal nonlinearity affects soliton interactions.

Interaction dynamics differ between copropagating and counterpropagating geometries.

Abstract

We study experimentally the propagation dynamics and interaction of a pair of mutually incoherent nematicons: spatial optical solitons in nematic liquid crystals. In contrast to earlier studies, we consider a bias-free liquid-crystal cell and compare the soliton interaction in copropagating and counterpropagating geometries. We analyze the dependence of nematicon interaction on input power and observe a direct manifestation of a long-range nonlocal nonlinearity. Attraction of counterpropagating solitons requires higher powers and longer relaxation times than that of copropagating nematicons due to losses-induced power asymmetry of counterpropagating nematicons.