Dielectric response and electro-optical effects in suspensions of anisotropic particles

The dielectric properties of suspensions of microellipsoids may be controlled by reorientation of the particles in an applied electric field. We study this process and the resulting electro-optical effects for fields of arbitrary strength. The magnitude of these effects is determined by the concentration of the particles, their intrinsic dielectric anisotropy and their shape. The approach presented here provides an explicit link between the particle properties, their orientation distribution and the field-induced birefringence and electro-optical phase shift of the suspensions, taking into account the electrostatic interaction among the particles at moderate concentrations. It reproduces well published experimental observations and should therefore be useful for studying electro-optical properties as well as reorientation phenomena in these systems.