Optical non-linearity in liquid crystals using surface plasmon-polaritons

Abstract

The authors present a detailed report of the observation of a strong, thermally induced optical non-linearity in a system comprised of a silver film and a nematic liquid crystal, in which the surface plasmon-polariton (SPP) mode may be excited. Various measurements of the reflected intensity from the experimental system as a function of the incident angle, including a novel 'AC-on-DC' probe technique, reveal that the observed sharp optical switching is due to warming of liquid crystal, close to the metal/liquid crystal interface, into the isotropic phase through loss of energy of SPPS in Joule heating of the silver film. The many factors contributing to the observed reflectances are investigated and lead to a detailed model of the non-linearity for which a computer model is constructed. Conclusions drawn from the results of this work have serious implications for the use of SPPS in non-linear optics.