Photoisomerization manipulation for security covert photonic barcodes
Kun Ge, Juan Kang, Li Yi, Le Wang · Chinese Optics Letters · 2025
Microscale covert photonic barcodes demonstrate exceptional potential in anti-counterfeiting and information security applications due to their advanced security characteristics.However, the current methods suffer from spectral overlap and low concealment of security, restricting encoding capacity and requiring a high security level.These inherent drawbacks significantly restrict both the encoding capacity and the achievable security level.Here, we proposed a strategy to construct the high-security photonic barcodes via photomerization manipulation based on an excited-state intramolecular proton transfer (ESIPT) process in dye-doped whispering gallery mode (WGM) microcavities.The WGM microcavity is composed of highly polarized organic intramolecular charge-transfer (ICT) dye molecules, which have two cooperative gain states.Moreover, the light-manipulated covert photonic barcodes have further been obtained through an ESIPT energy-level process between the trans-excited state and cis-excited state.The WGM lasing spectrum constitutes the fingerprint of the corresponding microsphere, which can be modulated through tuning the dimensions of the microspheres.These results offer a promising route for exploring the light-manipulated security platform for advanced information anticounterfeiting.