The absorptance characteristics of bare silver aluminum, gold, copper, and molybdenum mirrors at angles of incidence from 0 to 89° are presented. The angle-dependent absorptance measurements are performed using a photoacoustic calorimetry technique. Absolute absorptance is determined using a laser energy ratiometer. Data are obtained for both s- and p-polarization light at two wavelengths,0.5145 and 10.6 µm. It is found that the Fresnel theory for bare metal surfaces does not always reliably predict the measured absorptance at high angles of incidence.
© 1986 Optical Society of America
Wayne D. Kimura and Dennis H. Ford, "Absorptance measurements of metal mirrors at glancing incidence," Appl. Opt. 25, 3740-3750 (1986)