Laser manipulation and characterization of liquid crystal droplets

We demonstrate laser manipulation of different nematic and smectic liquid crystal droplets in heavy water. Peculiarities of laser trapping and manipulation depending on the molecular structure of liquid crystal are discussed. Possibility of molecular reordering inside the tweezed droplet is demonstrated. This phenomenon can be used to induce the birefringence and to manipulate droplets, which have a small birefringence, e.g., a radial droplet of negligible birefringence can be turned into a birefringent one at high laser trapping power. This is a demonstration of the optical nonlinear effect being responsible for a micro-mechanical phenomenon such as spinning of the droplet in a circularly polarized laser tweezers. Three-photon absorption of MBAPB dye at 1064 nm wavelength is demonstrated inside the liquid crystal droplet at comparatively low similar to 60 MW/cm(2) intensity.