The ALPHA R Module is designed for measurements in diffuse reflection. When Mid Infrared light shines on a rough or a matte surface, two types of reflection occur: specular reflection (i.e. the light reflects directly off the surface) and the diffuse reflection (the IR light penetrates the sample surface and is partly reflected, i.e. reflected over all angles, due to the rough surface). The optics of a diffuse reflection accessory is designed in such a way that detection of diffusely reflected light is optimized, and the detection of specular reflected light is minimized. DRIFTS (diffuse reflectance infrared fourier transform spectroscopy) is an analyzing technique in FTIR spectroscopy that makes use of the phenomenon of diffuse reflection. The main advantages of these techniques are they enable the analysis of strongly scattering and absorbing samples and they have high signal intensity unlike transmission measurements.
