Process for fabricating stable holograms
AssigneeHughes Aircraft Company
InventorsJohn E. Wreede, Andrejs Graube
Life of this patent
Estimating the term…
Abstract
An improved method for fabricating a light weight dichromated gelatin hologram package on plastic or glass substrates is provided. The prior art cover plate protecting the gelatin layer is eliminated by depositing on the gelatin a material providing a barrier to atmospheric moisture and possessing abrasion-resistant properties. In one embodiment, the photosensitive gelatin layer is deposited on a plastic substrate employing at least one subbing layer which provides a barrier to atmospheric moisture. Protection of the gelatin layer is provided by a plasma deposited silicon nitride film thereon.
Claims16
In a process for fabricating a hologram which comprises:
- (a) forming a layer of a hydrophilic, photosensitive material on at least a portion of a substrate;
- (b) exposing the photosensitive layer to an actinic interference pattern to record a latent image thereon;
- (c) developing the photosensitive layer to obtain the recorded latent image;
- and
- (d) forming a protective layer on at least a portion of the photosensitive layer, the improvement which comprises depositing on the layer of photosensitive material a protective cover layer including:
- (a) a moisture barrier layer less than about 5 .mu.m thick which provides a barrier against diffusion of water vapor such that over the lifetime of the hologram, no more than about 2.times.10.sup.-6 g H.sub.2 O/cm.sup.2 is transmitted therethrough;
- and
- (b) a hard, abrasion-resistant layer.
Dependencies are inferred from the claim text.