  Ellipsometry is a powerful and well-established optical technique used in the
characterisation of materials. It works by combining the components of
elliptically polarized light in order to draw information about the optical
system. We propose an ellipsometric experimental set up to study polarization
interference in the total internal reflection regime for Gaussian laser beams.
The relative phase between orthogonal states can be measured as a power
oscillation of the optical beam transmitted through a dielectric block and
whose orthogonal components are then mixed by a polarizer. We show under which
conditions the plane wave analysis is valid and when the power oscillation can
be optimized to reproduce a full pattern of oscillation and to simulate quarter
and half wave plates.
