Complex field-induced nematic defect structures in Laguerre-Gaussian optical tweezers

Complex optical field-induced defect structures are presented in nematic and chiral nematic liquid crystals, as imprinted by Laguerre-Gaussian (LG) laser beams. Our modeling study is based on the phenomenological free energy approach, which dielectrically couples the nematic optical axis with the polarization of the LG beams. The symmetry of the presented structures proves to be conditioned by the beam helical indices. The beam intensity, strength of the nematic elastic constant, and local intensity-induced control of the nematic order via absorption of the light are demonstrated as possible mechanisms for producing, imprinting, and tuning of the field-induced complex defect structures in achiral and chiral nematics.