Abstract

The nonlinear optical effects in nematic liquid crystals (NLCs) leads to nondiffractive beam propagation, called a spatial soliton. With an increase in light intensity the birefringence axis of liquid crystalline molecules changes its direction and as a consequence a gradient profile of the refraction index is induced. A spatial solitons in nematic liquid crystals (nematicons) are formed due to a balanced interplay between diffraction, which defocuses the beam, and optically-induced change in refractive index resulting in beam focusing [1,2]. Nematicons may be formed for relatively low optical powers, of the order of magnitude of several miliwatts, and have been demonstrated in all elementary LCs configurations including planar, twisted and chiral NLCs [2]. Perturbation in refractive index distribution caused by an intense light is strongly nonlocal and extends well beyond the beam profile. Such feature allows for long-range interactions of nematicons with either extra solitons or localized defects or both. Light guiding, coupling, routing and combining of two optical signals are essential to optical signal processing, and this crucial light manipulation leads to important development of optical communication systems.

© 2015 IEEE