| abstract |
A multi layer interference coating comprising at least one multi layer stack deposited on anreflective layer, wherein each multi layer stack comprises a first dielectric layer, a layer ofnabsorbing material and a second layer of dielectric material arranged in series and having anreflectance spectrum in the infrared region comprising at least one maximum. The dielectricnlayers are of equal optical thickness and typically are of the same material. The multi layernstructure of the coating is such that incident electromagnetic radiation, for which odd multiplesnof half wavelengths correspond to the optical thickness of the multi layer coating at the incidentnwavelength, do not propagate within the coating and reflection at these wavelengths isnsuppressed. Coatings may therefore be designed to have a near saturated colour in the visiblenwavelength spectrum. The reflective layer may be a metal or a conducting oxide, a conductingnnitride, a conducting silicide or a conducting sulphide. By using conducting oxides as absorbingnlayers the coatings may be designed to have strong reflectance characteristics in the infrarednwavelength region and may also be designed to have temperature dependent reflectancencharacteristics. Substoichiometric metal oxides, such as TiO x may also be used as the absorbingnmaterial. |