Abstract

In the nonlinear optics of Liquid Crystals (LC) a new chapter has been opened by the recent discovery that the addition of a small amount of organic dyes, less than 1%w/w, can greatly enhance the LC optical response. In the presence of the dye dopant, the optical torque exerted by light on LC molecules, which is responsible for the nonlinear behaviour, is magnified by a factor η, depending on the dye-LC mixture, on the dye concentration and on the wavelength. This factor may be up to 100 and both positive and negative in sign, leading to both focusing and defocusing nonlinearities¹. This property can be attractive in designing nonlinear optical waveguides, at least for the realisation of quasi-static devices, for which no care is due to the time response. We developed a general model to describe both the light propagation inside the waveguide and the LC response to the guided light, in the plane wave approximation².

© 1996 Optical Society of America