Electrical Tuning of Optoelastic Interaction in Nematic Colloids

We discuss the effect of electric field on the optoelastic trapping occurring when a micron size particle is dispersed in a nematic liquid crystal. It is shown that in case of homeotropic sample with dielectric positive anisotropy and radial anchoring of the director on the particle surface the applied voltage is able to control the strength and range of interaction. Excellent fit of experimental data is obtained by a theoretical model that considers the interaction due to the overlapping of the orientational distortion around the particle with the one in the focal spot