Patterned photonic crystals for hiding information
Coding technique is not only a popular strategy for information recording and communication, but also an efficient strategy for information protection. Many species in nature, such as chameleon and peacock, demonstrate brilliant colorful appearance for camouflage, courtship or communication. The unique optical property that originates from the light interaction with the periodic nanostructure on their surface, known as photonic crystal (PC), provides an attractive candidate for coding and anti-counterfeiting. Here we present a prototype design for hiding information in photonic crystals by building the coding and encryption relationship between optical stopbands and information units. The hiding messages are protected by three different defense strategies: characteristic optical stopband, algorithm encryption and angle dependent encryption, which could dramatically improve the security level of the hiding information. Combining with the large coding capacity, inherent optical stability and robust fabrication process, this PC coding system has great potential for secure information storage and communication, anti-counterfeiting and massively parallelized sensors.