Baumeister P
Appl Opt. 1996 Sep 1;35(25):4978-81. doi: 10.1364/AO.35.004978.
Explicit equations are presented for the refractive indices of all-dielectric multilayers that reflect at a longer wavelength and transmit over a broad range of shorter wavelengths. Equations are given for the refractive indices of the layers of a simulated rugate reflector.