Holographic data memory for use as safety label on object, has retro-reflecting element arranged below memory layer arrangement for reflecting light penetrating in memory layer arrangement anti-parallel to direction of arrival

摘要

The memory has a memory layer arrangement (1) in which a hologram i.e. computer-generated hologram, is written by an energy application and is read in reflection. A retro-reflecting element (2) is arranged below the memory layer arrangement. The retro-reflecting element reflects light penetrating in the memory layer arrangement anti-parallel to a direction of arrival. A distance between the retro-reflecting element and the hologram written in the memory layer arrangement is smaller than 4 micrometers.