Jacek Piłka
supervisor: Mirosław Karpierz
Nematic liquid crystals, due to their unique properties, are reliable materials in optics, allowing easy manipulation of light beams, which has gained them nonfading attention of researchers. Especially, due to their birefringence and the ability to reorientate molecules via electric field, liquid crystals make an exceptional medium for observing formation of optical beams via nonlinear effects.
This work will cover the case of co-propagation of linearly polarized high-power optical vortex and a low-power gaussian beam in nematic liquid crystal. The first beam is characterized by its phase’s rotation around propagation axis resulting with achieving unique donut-shaped profile with point of zero intensity in the centre and carrying orbital angular momentum. Due to high nonlinearity of the medium, such beam creates a waveguide in which the second one can propagate. However, the results show not only a profile change of the low power gaussian beam, but also a phase rotation, indicating the transfer of the orbital angular momentum between the two beams. Such effect is not dependent on the wavelengths of each participated beam, making the results the first step towards the new type of broad spectral range light manipulator designed for optical vortices generation in various experimental and industrial applications.