Polarization And Polarization-optical Information Encryption Selection Feature

Polarization state is an important parameter of light. It has drawn a lot of attention all these years in generation of specific2-D polarization distribution、 polarization-selection and polarization-selection grating. There are many applications based on the polarization of light, such as optical information encryption, polarization-selection elements, etc.With the analysis of Stokes and Jones theorem, we study an optical multiple encryption scheme:using a2D polarizer-array to realize Mueller-Stokes formalism. The simulation experiment results show that this formalism can encrypt images efficiently and turn out to be resistant against brute force attack. During the experiments we find that a high dynamic range for the key-amplitude image can provide a better encryption performance and the security against brute force attacks is enhanced.The polarization properties of liquid-crystal are studied in this paper. We use the gray-level parameter of TN-LC spatial light modulator (TN-LCSLM) to describe its polarization modulation capacity and successfully generate a2-D polarization distribution in a light beam, so different output information with different polarization states could be obtained. Based on two LCSLMs, a polarization-selective diffraction system is designed to realize polarization-selection of the diffractive field. Lastly this system is simplified and its polarization-selective diffraction capacity is consistent with the original system.Finally to achieve the generation of polarization-selection grating, we study the optical properties of blazed grating. By using two blazed gratings which can separately generate+1and-1diffraction spectrums, a new polarization-selection grating is realized based on the polarization property of LCSLM, and the experiment results demonstrate that this kind of grating can generate spectrums with different polarization states.