Hefyene, NasserGrandjean, Nicolas2017-08-112017-08-112017-08-112017https://infoscience.epfl.ch/handle/20.500.14299/139619A method for marking a product (1) with a photoluminescent mark, said mark comprising a photoluminescent portion (10) which is transparent under normal light conditions and revealed by photoluminescence under UV illumination, said mark further comprising a non photoluminescent portion (9) which is transparent under normal light conditions as well as under UV illumination, said method comprising: deposing on said product a stack, said stack comprising alternatively layers (2, 4), such as AlN, with a thickness of less than 1 micron and layers (3) of a second material, such as GaN, with a thickness of less than 10nm; raising the transparency of said non photoluminescent portion (10) with a deposition of transparent material (6) or incorporation of ions into said non photoluminescent portions.patentKR102595036US11298968CN108699672US2020369069US10752043JP6622910JP2019501035CN108699672EP3380642US2018257421KR20180085712TWI596226TW201718919WO201708985754884092