Optical coatings are one means of controlling heat in lighting applications such as film projectors and microscope illumination systems. Unfortunately, suppliers of multilayer dielectric coatings have primarily emphasized spectral performance, except when designing coatings for laser optics. This has limited coatings' use in commercial illumination applications, in which thermomechanical properties and the ability to economically coat highly curved parts and/or large surfaces are as important as spectral performance.
Recent innovations in coating technology have increased the temperature-handling capability and applicability of thin-film coatings to larger, curved surfaces. This has, in turn, enabled some interesting, new high-intensity lighting applications.