Successive evaporation of two correctly chosen elements now make possible highly efficient X—UV mirrors. However, good results depend on two points: First we must know the manufacturing tolerances; these depend strongly on the spectral range and the refractive index of materials used for the coating. The other important parameter is the roughness of each interface, which can result in significant losses in the reflectivity of the mirrors. This paper examines both points. Specular reflectance measurements at 0.159 nm are very sensitive to the roughness of each layer. To demonstrate this sensitivity we develop a method of calculation of this reflectance taking into account the roughness of each interface of the multilayer.
© 1984 Optical Society of America
B. Vidal and P. Vincent, "Metallic multilayers for x rays using classical thin-film theory," Appl. Opt. 23, 1794-1801 (1984)