Effect of film absorption on a film-substrate reflection polarizer

Abstract

An analysis is made of the effect of film absorption on the characteristics of a reflection polarizer of a thin film on an absorbing metal substrate. Monochromatic polarized light is obtained component of polarization is extinguished by means of interference. A method of analysis is developed determining the angle of incidence and the film thickness for which polarization occurs. Numerical results are presented for polarizers having a silver substrate and films with different degrees Very weakly absorbing or transparent films may give rise to excessive sensitivity of the extinguished component to departures from the polarizing angle and from the optimum film thickness, particularly substrate is highly reflecting (e.g., silver). The use of properly selected absorbing films can degree of sensitivity for the extinguished component and still yield adequately high reflectances unextinguished component.