In applications where a mirror coating is required to be non-conductive and/or non-absorbing, a metal cannot be used. In such cases, an all-dielectric mirror coating can be applied to an optic. This type of mirror can provide very high reflection over a narrow wavelength region as shown in the design graph.
This is dependent on the number of layers in the multi-layer stack and the width of the wavelength region.
Adhesion, severe abrasion, and humidity as per the following (where applicable): MIL-C-675, MIL-M-13508, MIL-M-14806, MIL-C-48497, MIL-F-48616, MIL-STD-810F