Adiabatic propagation in nematic liquid crystals with competing nonlinearities

Abstract We theoretically investigate the influence of the variation of the nonlocal degree of the molecular orientation effect σ 1 and the nonlocal degree of the thermal effect σ 2 on beam propagation in nonlocal media with competing nonlinearities. According to the model proposed by JUNG P S, we find that variations in σ 1 and σ 2 have completely different effects on beam propagation in the medium. When σ 1 increases, the beam tends to broaden, whereas when σ 2 increases, the beam tends to compress. Numerical calculations, conducted using the split-step Fourier method, show that changes in σ 2 have a smaller effect on propagation compared to σ 1 . Adiabatic propagation of the beam in nematic liquid crystals can be achieved if σ 1 changes gradually, but not if σ 1 changes abruptly. In contrast, adiabatic propagation can be realized with σ 2 whether it changes abruptly or gradually. The variational results are well confirmed by numerical simulations.