Multilayer optical coatings which heated and defogged the substrate, provided permeation barriers to water and air, and controlled emittance have been developed. All coatings were deposited by reactive de and rf magnetron sputtering, and the polymer multilayer process being developed at Pacific Northwest National Laboratory. The three coatings discussed in this article were applied to flexible and rigid substrates with diameters up to 28 cm. Fourteen-layers SiO2/Si3N4/TiO2/Ag coatings were applied to surveillance camera lenses to reject at least two laser wavelengths, defog the lens, and provide a high transmission notch at the operating wavelengths. The coatings were able to heat the substrates at a rate of 16 degrees C/min at relatively modest power inputs of 2 W/cm(2). The second coating had eight Cr/Si3N4 layers, and absorbed strongly at the 1.06 mu m laser wavelength and emitted strongly in the 3-5 mu m wavelength band. This coating was used in infrared displays. The last coating was a 15-layer polymer Al2O3 permeation barrier to water and air on a flexible polyethylene substrate. The coating was transparent. The permeation rates for oxygen were less than 2.55E-6 cm(3)/cm/day, and were less than 1.55E-6 g/cm(2)/day for water. The permeation test results provided further evidence for a synergistic relationship between polymer and oxide layers to prevent surface and solution diffusion of gases and water.