This paper describes a study made on several mirror coatings for near and far infrared applications at room and cryogenic temperatures. Three materials (Al, Ag and Au) have been tested at two angles of incidence. Absolute measurements at 10.6 μm were obtained with a power stabilized CO2 laser. Bidirectional reflectance distribution function (BRDF) and total integrated scattering (TIS) are given for three wave-lengths at 0° and 45° angles of incidence.
"Infrared Mirror Coatings For Room And Cryogenic Temperatures", Proc. SPIE 1157, Infrared Technology XV, (8 January 1990); doi: 10.1117/12.978580; https://doi.org/10.1117/12.978580