Guest-host-interaction-induced enhancement of optical nonlinearity of liquids

Summary form only given.Guest-host interaction has received a great deal of attention in the field of liquid crystals because of its potential. applications to displays and other optoelectronic devices. In one case, it was found that the unusually strong optical nonlinearity of nematic liquid crystals (LCs) can be further enhanced dramatically by a small amount of dye dissolved in the host. It was suggested that the enhancement is caused by optical excitation of dye molecules and dye-LC interaction. An important question unanswered is whether this effect is specific to liquid crystalline host material or it may have a more generic perspective. In this work, we show that the same guest-host effect also exists in the isotropic phase of liquid crystals, and more generally, in ordinary liquids without a mesomorphic phase. We demonstrate that by using 1-amino-anthroquinone dye as guest material and alkylcyanobiphenyls CN(C/sub 6/H/sub 4/)/sub 2/C/sub n/H/sub 2n+1/ as host materials, and performing optical Kerr effect measurement on such guest-host systems. To understand this guest-host effect on a microscopic level, we use a model based on the selective excitation of dye molecules and the change of guest-host interaction upon excitation.