摘要：

A three layer composite optical structure wherein a first layer is a substrate having surface variations holographically formed therein that contain phase information of a light pattern or object desired to be reconstructed from the element by reflection, a thin substantially uniform layer of material coated over that surface variation, and a third layer that overcoats the thin layer in order to form a substantially uniform thickness composite structure. The indices of refraction of the overcoating and the substrate are made substantially the same so that light transmitted through the element is neither diffracted nor refracted. The thin intermediate layer is disclosed to be either reflective metal or a substantially transparent layer having an index of refraction substantially different from that of the other two layers. Such an element has applications in sunglasses or as an addition to car or other windows.

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