Interference effects in single wave plates

Although the presence of interference effects related to wave plate retarders has been known for some time, their overall polarimetric properties are generally not fully appreciated. The effects of interference within a simple wave plate is explored by extension of the Airy formulation describing multiple-beam interference within a parallel plate. It is first demonstrated that phase delay does not grow linearly with plate thickness as expected from the standard simple formula appearing in optical texts. The wavelength dependences of the phase delay, polarizance and transmittance of simple quarter- and half-wave plates are presented to highlight the effects that internal interference has on the operation of these devices.