Nonlinear Optical Propagation and Self-Limiting Effect in Liquid-CrystallineFibers

摘要

The nonlinear optical properties of the isotropic phase of liquid crystalsinduced by nanosecond laser pulses are analyzed in the context of nonlinear multi-mode propagation in a liquid-crystal-cored fiber. The negative thermal density nonlinearity of the core gives rise to an intensity-dependent loss in the core-guided transmission and optical action. Experiments conducted with such liquid-crystal-cored fibers show that the optical limiting threshold for nanosecond laser pulses can be as low as O.O9J/cm2, which is one of the lowest among known nonlinear optical materials and structures, including bulk liquid-crystal films. (MM).