On the Properties of Polarization Elements as Used in Optical Instruments II Sinusoidal Modulators*

Abstract

The paper begins with a general formulation of the problem of the optimum polarizer. It is suggested that the problem must be investigated by studying separately each of the classes of applications of polarizers, and the rest of the paper is addressed to the derivation of the optimum polarizer for use in a sinusoidal modulator, defined as two polarizers rotating at substantially constant relative angular velocity. The optimum polarizer is defined as the one which yields a sinusoidal modulator whose operation upon a given beam of light yields a maximum signal-to-noise ratio in the transmitted light. An expression is derived for said signal-to-noise ratio, and from this a specific combination of polarizer parameters is obtained which is to be maximized. Explicit expressions are obtained for the values of the various parameters which provide the optimum polarizer; the results are exhibited graphically in Figs. 4 and 5 .