Goncharsky Alexander, Goncharsky Anton, Melnik Dmitry, Durlevich Svyatoslav
Research Computer Center, M.V. Lomonosov Moscow State University, Leninskiye Gory, 1, Building 4, Moscow, Russia, 119991.
Computer Holography Centre Ltd, Str.2, Proezd 4922, Zelenograd, Moscow, Russia, 124460.
Sci Rep. 2021 Jan 28;11(1):2426. doi: 10.1038/s41598-021-81950-w.
This paper focuses on the development of flat diffractive optical elements (DOEs) for protecting banknotes, documents, plastic cards, and securities against counterfeiting. A DOE is a flat diffractive element whose microrelief, when illuminated by white light, forms a visual image consisting of several symbols (digits or letters), which move across the optical element when tilted. The images formed by these elements are asymmetric with respect to the zero order. To form these images, the microrelief of a DOE must itself be asymmetric. The microrelief has a depth of ~ 0.3 microns and is shaped with an accuracy of ~ 10-15 nm using electron-beam lithography. The DOEs developed in this work are securely protected against counterfeiting and can be replicated hundreds of millions of times using standard equipment meant for the mass production of relief holograms.
本文着重于开发用于保护纸币、文件、塑料卡和证券不被伪造的平面衍射光学元件（DOE）。DOE是一种平面衍射元件，其微浮雕在白光照射下会形成由几个符号（数字或字母）组成的视觉图像，当倾斜时这些符号会在光学元件上移动。这些元件形成的图像相对于零级是不对称的。为了形成这些图像，DOE的微浮雕本身必须是不对称的。微浮雕的深度约为0.3微米，并使用电子束光刻技术以约10 - 15纳米的精度进行成型。这项工作中开发的DOE具有可靠的防伪性能，并且可以使用用于批量生产浮雕全息图的标准设备进行数亿次复制。
