National technical systems (NTS) applied research has been successful in fabricating super high efficiency holographic reflection coatings with optical density of a 6 for specific bandwidths in visible portion of the spectrum. In addition NTS was able to extend these holographic coatings into the near IR region of the spectrum. The holographic coatings are 20 micrometers thick and have extremely small absorption. Electron micrographs have shown the index of refraction variation with film depth to be sinusoidal. Several filter band widths can be imprinted in the same hologram, i.e., a natural rugate filter. These holographic coatings have reflective properties that exceed the best dielectric stacks at a projected cost of fabrication that is an order of magnitude less than dielectric mirrors and are larger in area and more inexpensive . Thus, the possibility of using these holographic coatings as a light weight mirror in bandwidths of the visible and near IR regions suggests itself. The ability to reflect narrow band regions (delta lambda 20nm) has been demonstrated by impingement with low power lasers. Since these holographic coatings are fabricated with a laser beam, the only limitation to fabricating large areas (m2 ), is the ability to diverge the laser beam so that it is still uniform and coherent over the surface of TeSe hologram.
