Pretransitional enhancement of the optical nonlinearity of thin dye-doped liquid crystals in the nematic phase

Abstract

We report a critical enhancement of the nonlinear optical response of dye-doped liquid crystals obtained by approaching the clearing point in the nematic phase. The enhancement of the nonlinear diffraction efficiency has been measured in the range 0.2-0.3 deg below the nematic-isotropic transition temperature. It allows reaching a nonlinear refractive index higher than 40 cm2 W in all the tested cells. © 2005 American Institute of Physics.