Surface marking method for e.g. document, involves determining image representing information, and marking surface with polarized laser beam to form oriented nanostructures representing image on surface

摘要

The method involves determining an image representing information, and marking a surface with a polarized laser beam to form oriented nanostructures representing the image on the surface, where the information is representative of data relative to an object or a document comprising the surface. A laser source and a polarization unit are implemented during marking the surface, where the polarization unit polarizes light along a variable polarization axis depending on a signal received by the polarization unit, and the surface is made of paper, plastic material or cardboard. Independent claims are also included for the following: (1) a device for marking a surface (2) a method for reading an image marked on a surface (3) device for reading an image marked on a surface.