Periodic dielectric multifilm stack with symmetrical period having films of three different refractive indices: use as a heat reflecting mirror

Results of the theoretical computations of reflectance and transmittance values of periodic dielectric multi-film stacks with symmetrical periods, each consisting of films of three different refractive indices, are reported. The analysis yields good estimates of the bandwidths of the low reflectance and high reflectance zones for different compositions of the periodic structures, and one of the structures offers the possibility of use as a heat reflecting mirror. This particular structure when combined with a previously published design gives a heat reflecting mirror design with good spectral characteristics and seems to be relatively easy to fabricate, while the earlier design, which exhibits somewhat superior spectral characteristics, appears to be extremely difficult to fabricate.