Characterization and calibration of a variable-angle absolute reflectometer

The instrument described is a newly designed reflectometer. Measurements are made with a polarized light beam as a function of wavelength and angle of incidence. Calibration tests have outlined the possibility of using the instrument for reflectance measurements on mirrors with good reproducibility (0.2%) and accuracy (better than 1%). This has been obtained by the alignment system of the sample and the absolute method used for the determination of its reflectance.