ABSTRACT
In Chapter 7, Fresnel’s equations for reflection and transmission of waves at an air-dielectric interface were cast in the form of Mueller matrices. In this chapter, we use these results to derive the Mueller matrices for dielectric plates. The study of dielectric plates is important because all materials of any practical importance are of finite thickness and so at least have upper and lower surfaces. Furthermore, dielectric plates always change the polarization state of a beam that is reflected or transmitted. This property can therefore be exploited to manipulate polarized and unpolarized light. For example, one application is that of a polarizer design using dielectric plates for the thermal infrared region of the spectrum. Wire grid polarizers of excellent quality are now available for this spectral region (see Chapter 23), but this was not always the case. There are no polarizer materials corresponding to calcite in the thermal infrared region, but materials such as germanium and silicon, as well as others, do transmit very well in the infrared region. By making thin plates of these materials and then constructing a “pile of plates,” it is possible to create highly polarized light in the infrared. This arrangement therefore requires that the Mueller matrices for transmission play a more prominent role than the Mueller matrices for reflection.
