This tutorial shows you how SPRAY can be used to compute spectra of light scattering systems like powders, paints or colloidal suspensions. As an example we compute diffuse reflectance spectra in the infrared. The sample system is a collection of glass spheres (with and without a thin surrounding water film) in a metallic cup. Since the focus of this section is on the computation of scattering and absorption effects we use very simplified illumination and detection conditions. Much more realistic experimental setups for recording diffuse reflectance could be simulated in SPRAY as well, of course.

In the first section, we will import all required optical constants from the database and define the interfaces that will be used later on. Then the scattering and absorption properties of single (coated and uncoated) spheres are determined. After the definition of the sample geometry some diffuse reflectance spectra are computed for a number of configurations.