METHOD OF MAKING MICRO-BARCODE ON SURFACES USING PULSE LASER TECHNIQUE TO IDENTIFY THE AUTHENTICITY OF PRECIOUS METALS

Abstract

This invention discloses a method for making micro-barcodes on precious metal surfaces using a femtosecond pulse laser. The method as in this invention consists of a code modification and conversion process using a computer program, a collimator, the position of the precious metal with a 200× objective lens, scanning speed, determining the barcode size below 1 mm and the barcode position, then laser irradiation and engraving techniques. The laser used in accordance with this invention is a Ti: Sapphire pulse laser with a laser pulse specification of 100-200 femtoseconds; a laser wavelength of 500-1000 nm; a laser power of 1-2.5 watts; and a grafting speed of 100-200 mm / second. In making micro-barcodes, the laser light is focused on the precious metal surface using a 200× magnification objective lens with a metal-to-lens distance of 27 millimeters.Micro-barcode on a precious metal surface by pulse laser irradiation generated by the method according to claim 1, wherein the laser engraving can be authenticated using a barcode reader or smartphone.