Accelerated optical solitons in reorientational media with transverse invariance and longitudinally modulated birefringence

We demonstrate that reorientational spatial solitons can curve when propagating in a medium with engineered walk-off along the direction of propagation. In this regard, we employ nematic liquid crystals with molecular anchoring defined by electron-beam lithography and optic axis distribution modulated in the longitudinal direction only, keeping the transverse orientation constant. The experimental results are in remarkably good agreement with a simple modulation theory based on momentum conservation

Nonlinear Optics: A Vibrant Field

We present here a brief history and an editorial perception of nonlinear optics. © 2009 Photonics Society of Poland

Quasi two-dimensional astigmatic solitons in soft chiral metastructures

We investigate a non-homogeneous layered structure encompassing dual spatial dispersion: continuous diffraction in one transverse dimension and discrete diffraction in the orthogonal one. Such dual diffraction can be balanced out by one and the same nonlinear response, giving rise to light self-confinement into astigmatic spatial solitons: self-focusing can compensate for the spreading of a bell-shaped beam, leading to quasi-2D solitary wavepackets which result from 1D transverse self-localization combined with a discrete soliton. We demonstrate such intensity-dependent beam trapping in chiral soft matter, exhibiting one-dimensional discrete diffraction along the helical axis and one-dimensional continuous diffraction in the orthogonal plane. In nematic liquid crystals with suitable birefringence and chiral arrangement, the reorientational nonlinearity is shown to support bell-shaped solitary waves with simple astigmatism dependent on the medium birefringence as well as on the dual diffraction of the input wavepacket. The observations are in agreement with a nonlinear nonlocal model for the all-optical response.publishedVersionPeer reviewe

Optothermal vortex-solitons in liquid crystals

We report on vortex-solitons generated in dye-doped nematic liquid crystals by a purely optothermal nonlocal nonlinearity. This response not only supports stable doughnut-shaped ordinary-wave beams with orbital angular momentum, but also provides self-confined solitary waves with excellent trajectory and profile stability over time. Using an interferometric technique, we also investigate the role of nonlocal nonlinearity in the non-illuminated axial region

Electro-optic quenching of nematicon fluctuations

Employing a low-frequency external electric field bias in nematic liquid crystals with negative dielectric anisotropy, we demonstrate that the trajectory fluctuations of reorientational spatial solitons can be substantially reduced, improving confinement and polarization purity of the output beams

Thermo-optic soliton routing in nematic liquid crystals

We demonstrate thermo-optic control on the propagation of optical spatial solitons in nematic liquid crystals. By varying the sample temperature, both linear and nonlinear optical properties of the reorientational material are modulated by acting on the refractive indices, the birefringence, and the elastic response. As a result, both the trajectory and transverse confinement of spatial solitons can be adjusted, demonstrating an effective means to tune and readdress self-induced optical waveguides