Polarization encoding for optical encryption using twisted nematic liquid crystal spatial light modulators
We propose and demonstrate a polarization-encoded encryption system based on a doubly exclusive OR logic (XOR) operation using cascaded twisted nematic liquid crystal spatial light modulators. The transfer characteristic of the encryption system is analyzed by the Jones matrix method to yield the suitable polarization modulation for optical realization. An experimental demonstration reveals that the binary image encryption/decryption is achieved with fair image quality by selecting the orientation of polarization and the modulation conditions. Both analytical and experimental results are presented and discussed.