EFFECT OF AN ELECTROSTATIC-FIELD ON THE OPTICAL-PROPERTIES OF A CLOUDOF DIELECTRIC PARTICLES

The optical properties of a cloud of anisotropic dielectric particles when the orientational distribution is made nonrandom by interaction w ith an electrostatic field are studied. Since the interaction energy i s determined by the polarizability of the particles, a general express ion for the polarizability of nonspherical particles is worked out. In particular, we investigated the response to the electrostatic field o f two different dispersions whose component particles are built as clu sters of four identical spheres. Although in one cloud the clusters we re shaped as linear chains, and in the other cloud the clusters were s haped as the optical. properties of both dispersions as a function of the static field are rather There are, however, noticeable ranges of s ize within which the optical response of the two kinds of particles is substantially different.