Calculated reflectance of aluminum in the vacuum ultraviolet

Abstract
A calculation of the absorptance A of aluminum in the vacuum ultraviolet (vuv) indicates that the lowest values measured to date, A=0.08−0.10 for h/ω=3−12 eV, are very near the intrinsic limit. Operating at low temperature, purifying the metal, or improving the surface are not expected to decrease A by more than ∼0.02, and metallic reflectors better than aluminum are not likely to be found. Thus, values of A<0.06 for metals without reflection−enhancing coatings are not likely to be attained in the vuv, and lasers with such reflectors will continue to be limited by the performance of the reflectors.