Chapter 8: Nematicons in Light Valves
INLN, Université de Nice-Sophia Antipolis, CNRS, Valbonne, France
Nonlinear Optics and OptoElectronics Lab, University ROMA TRE and CNISM, Rome, Italy
Solitons are ubiquitous in nature  and appear in such different fields as fluid dynamics, plasma physics, acoustics, magnetohydrodynamics, quantum electrodynamics, and Bose–Einstein condensates, just to cite a few. In optics, bright spatial solitons have been identified as nonlinear solutions of the propagation equation when light travels in materials with a dielectric constant increasing with the intensity of light . Optical spatial solitons are self-trapped beams able to create their own dielectric waveguide and propagate in it without diffractive spreading. A wealth of theoretical and experimental work has been devoted to optical solitons, not only for their fundamental interest  but also for their potential applications in photonics, waveguiding, and communications .
Nowadays, the ability to optically control soliton dynamics, their paths and trajectories, has attracted considerable attention in the perspective of implementing all-optical and parallel architectures in optical interconnects. This chapter discusses optical spatial solitons in liquid crystal (LC) light valves. In these systems, optical spatial solitons arise because of the molecular reorientational ...