This paper discusses some of the general considerations relating to the use in optical instruments of polarization elements, with particular emphasis being given to partial polarizers of the dichroic type. A functional classification is provided for optical instruments which employ polarized light. Also provided is a functional classification for polarization elements, which classification involves four categories: polarizers, phase shifters, polarizing beam splitters, and depolarizers. The various methods of modulating light are discussed. A qualitative description of partial dichroic polarizers is included, and this is followed by the derivation of some of the basic mathematical relations which hold among the parameters which can be used to describe quantitatively the properties of partial dichroic polarizers.
C. D. WEST and R. CLARK JONES, "On the Properties of Polarization Elements as Used in Optical Instruments. I. Fundamental Considerations," J. Opt. Soc. Am. 41, 976-980 (1951)