Holographic, traceable, and switchable anti-counterfeiting using temperature-tolerant relief gratings on polyimide substrate

Holographic images based on surface relief gratings are widely used in anti-counterfeiting labels for their high image resolution, full-color display and durability. However, traditional polymer-based holographic anti-counterfeiting labels are faced with the risk of being counterfeited due to the simple grating structures, and cannot provide further verification information except for dynamic optical effects. Moreover, in extreme environments, such as high / low temperatures, polymer-based holographic anti-counterfeiting labels may lose their encrypted information due to thermal / cold deformation. Therefore, developing one smart holographic label that is easy to read, difficult to replicate, and durable is a challenge. Herein, we propose a strategy of reconstructing quick response (QR) code on polyimide films through holographic relief gratings. And by utilizing the structural characteristics of QR code and multiplexing technology, we have achieved the integration of multiple authentication information access entrances without crosstalk at the same location. The applicability and superiority of switchable holographic QR codes that combine anti-counterfeiting and information traceability in encryption applications are discussed. This strategy for integrating encryption information based on surface relief grating provides an effective alternative for the manufacture of temperature-tolerant polymer-based smart holographic anti-counterfeiting labels.