Measuring complex refractive indices

In the preceding paragraphs, we have discussed the theoretical and general properties of the complex refractive index, the scarcity of bibliographic sources for obtaining it, and the influence of sample shaping and manufacture on optical constants. We now turn to data acquisition and the methods used to characterize real samples, whether they are as pure and perfect as possible, or as ordinary as possible.

The most commonly used term for the reflection or transmission indicator surface of a given material surface is BRDF/BTDF (Bidirectional Reflectance/Transmittance Distribution Function). When used as an emission indicator for a real light source, it's referred to as a photometric solid. This expression refers to the spatial and spectral dimension of the radiation pattern of a real light source. These notions of BRDF and BTDF are widely used in radiative transfer...