Complex field-stabilised nematic defect structures in Laguerre–Gaussian optical tweezers

Abstract

Novel optical field-stabilised defect structures are presented in nematic liquid crystals as produced by Laguerre–Gaussian optical beams. Our modelling study is based on the phenomenological free energy approach. To mimic generic experiments, Laguerre–Gaussian optical beams of various helical indices are applied to a nematic cell. The symmetry of these field-stabilised nematic structures is directly determined by the beam indices. We show that the structures can also be tuned by the beam intensity and the strength of the nematic elastic constant. Finally, local intensity-induced control of the nematic order via absorption of the beam is demonstrated as a complementary mechanism for producing and tuning the nematic field-stabilised structures.