Design and performance of a pulsed THz diffuse reflectance system

Diffuse reflectance spectroscopy in the visible and NIR is widely used to measure complex dielectric constants of highly scattering opaque materials. Compared with specular reflectance measurements, it has the advantages of low sensitivity to sample position and surface preparation, and improved accuracy in the determination of optical constants. We extend this technique to the THz range, describing the design and performance of a THz diffuse reflectance system.