REFLECTION FROM A FLUID IN A UNIFORM ELECTRIC-FIELD

A fluid polarized by an electrostatic field E may exhibit reflection e ffects linear in E that cannot be observed in either transmission or l ight scattering. Fresnel reflection amplitudes are derived by means of a multipole theory, to the order of electric quadrupoles and magnetic dipoles, for light incident at a vacuum-fluid interface when the appl ied field E is either normal to the boundary or parallel to it. These Fresnel amplitudes are expressed in terms of the angle of incidence an d the properties of the fluid which are induced both by the electrosta tic field and the light wave fields. Experiments based on the differen tial reflection of orthogonal polarizations of the incident light beam are described for measuring the induced property linear in E for a fl uid.