ABSTRACT
This chapter focuses on one of the simplest quantum mechanical systems. It considers the effect of the Polaroid from a quantum mechanical point of view. An immediate consequence of the fact that the passage of photons through the Polaroid is governed by the laws of probability is that only rarely will exactly half the photons pass through. The mean number of photons passing through will be half the incident number. The chapter considers the passage of photons through crystals that to a first approximation allow all the photons to pass through, but change the state of polarization of the photons. The photons polarized perpendicular to the optic axis is called the ordinary ray, and the photons polarized parallel to the optic axis are called the extraordinary ray. Consequently the polarization state of the photon when it emerges from the calcite will, in general, be different than its state of polarization on entering the calcite.
