Electro-optic routing of spatial solitons in Nematic Liquid Crystals

The great interest arisen in the past decades in optical spatial solitons, i.e. self-confined waves supported by the balance between diffraction and nonlinear self-focusing, stems from their character of light-induced waveguides, thus allowing versatile and reconfigurable schemes for optical signal handling and processing [1]. Nematic Liquid Crystals (NLC) are excellent materials for the generation, propagation and the control of spatial solitons, also known as Nematicons [2]: NLC exhibit large birefringence and transparency, coupled with a high reorientational nonlinearity owing to (mean) molecular rotation induced by quasi-static and/or optical frequency electric fields. In addition, the high nonlocal character of their response stabilizes two-dimensional selfconfinement of beams into solitons [3,4]. Hereby we illustrate planar NLC cell configurations whereby nematicons can be electrically routed by propagating in a non-uniform dielectric with transverse and longitudinal variations of the refractive index and/or the orientation of the optic axis, i.e. by undergoing voltage-driven modulation of linear and nonlinear properties. The numerical models and numerical results are in excellent agreement with the experimental data.