Optical encryption in single shot digital holography
Ching‐Yang Lin, Gu-Liang Chen, Ming-Kuei Kuo, Chi-Ching Chang, Hon-Fai Yau · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 2007
We propose a novel optical encryption approach using a lenticular lens array (LLA) as a deterministic phase modulator and the single-shot digital holographic scheme. In the proposed scheme, the input amplitude image is encrypted and interferes with the reference wave phase, which is modulated by a LLA, then recorded holographically by a digital CCD camera to form an encrypted hologram. A decryption key is obtained from the key hologram using numerical reconstruction. The image is decrypted using a digital holographic approach after which the encrypted hologram is multiplying the numerical reconstructed key for decryption. The experimental results show that only an encrypted hologram is needed. Moreover with this approach, the decryption procedure can be rapidly accomplished using a personal computer, presenting a decrypted image of satisfactory image quality. Finally the selective sensitivity of the key rotation is also investigated.