Spectral barcode based on one-dimensional photonic crystal with continuous refractive index modulation

This paper demonstrates an example of optical information encoding using the spectral response of a photonic crystal. The spectral dependence of the reflection coefficient of a one-dimensional photonic crystal reproduces the sequence of the EAN-13 standard barcode. An algorithm for building the structure of a photonic crystal based on a given encoded sequence of 12 digits was developed. This structure was experimentally implemented, its spectral response allows to decode the original encoded sequence.