Liquid Crystals and the Optical Theorem

The "optical theorem" is the calculation of plane electromagnetic wave propagation through a transparent dielectric slab, that views the slab as a uniformly distributed collection of point scatterers in a vacuum. The theorem shows that the apparent index of refraction of the slab is the result of the interference of the net forward scattered light with the incident beam. We are exploring this effect for the case where the slab is a nematic liquid crystal, probing in particular the effect of the strong scattering by director fluctuations on refractive index, and thus on phase fluctuations in the outgoing radiation.