Optically Variable Identification Element FUSE-ID
A composite security feature with identification information about the document holder. FUSE-ID was developed by Giesecke&Devrient company. It is printed with optically variable ink (OVI) and laser engraved afterwards. The element is produced by a laser beam which moves sequentially over the image background area and leaves the image outline untouched. The laser energy discolors optically variable ink by changing its surface nanorelief and optical features. The image contrasts with the brightened background and looks darker. The image color is determined by interference effect which appears on the layered structure of ink pigments.
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Fig. 1. Latvia. Passport:
а — data page, FUSE-ID element location; b — document holder's portrait viewed at a right angle under front illumination; c — the same image viewed at an acute angle of illumination and observation; d — scheme of image formation by laser engraving the background