Multilayer designs of antireflective (AR) coatings over high-index substrates are compared to double-layer coatings. Equireflectance contours are computed and presented for double-layer coatings of Si, Ge, CdTe, and ZnSe substrates. It is argued that the large theoretical improvement in the performance of AR coatings when going from double-layer to multilayer design is greatly reduced in practice due to fabrication errors. The contours given here for specific substrates can be used for the design and evaluation of double-layer AR coatings.
"Practical Design Of Double-Layer Antireflective Coatings For High-Index Substrates," Optical Engineering 22(6), 226753 (1 December 1983). https://doi.org/10.1117/12.7973234