Abstract

The admittance diagram is a useful device for visualizing performance of dielectric and metal-dielectric structures with small or negligible losses. Admittance can readily be converted into reflectance by a set of isoreflectance circles that is a function of the admittance of the incident medium. Difficulties are caused by the variation of admittance with angle of incidence because the isoreflectance circles are not constant but vary both with angle of incidence and plane of polarization. A simple scheme of admittances in which the incident medium is normalized to be constant at its normal incidence value is straightforward and permits the isoreflectance circles to remain constant. The scheme involves multiplying the normal p-admittance and dividing the s-admittance by cosθ₀ where θ₀ is the angle of incidence in the incident medium. This normalization does not affect either reflectance, absorbance, transmittance, or phase changes. Resonances such as those associated with coupling to a surface plasmon become straightforward to visualize including some involving metal-dielectric multilayers.

© 1985 Optical Society of America