Antireflection coatings for both visible and far-infrared spectral regions.

Two methods are described for the design of antireflection coatings that act in two widely separated spectral regions. Design results are presented for coatings on ZnS, ZnSe, and Ge substrates that reduce the reflectance in a broad region at approximately 10 microm, as well as in a band of wavelengths in the visible or near-infrared part of the spectrum. Experimental results are given for one system.