High Kerr optical nonlinearity observed in a liquid crystal by Z-scan technique

Abstract

In this paper we present the preliminary experimental results about the measuring of Kerr optical nonlinearity in a 5CB liquid crystal sample doped with methyl-yellow at 1 %. These results are obtenided througth Z-scan tecnhique using a simple low power He-Ne laser in CW operation. We observe a great negative Kerr nonlinearity in the sample obtained in the regime temperature of nematic phase. For upper temperature, we observe a notable decreasing of the optical nonlinearity due to sample change to isotropic phase. In adition, we observe the presence of a nonlinear absorption contribution.