Unnikrishnan G, Joseph J, Singh K
Appl Opt. 2001 Jan 10;40(2):299-306. doi: 10.1364/ao.40.000299.
We propose and demonstrate a fractional Fourier domain encrypted holographic memory using an anamorphic optical system. The encryption is done by use of two statistically independent random-phase codes in the fractional Fourier domain. If the two random-phase codes are statistically independent white sequences, the encrypted data are stationary white noise. We exploit the capability of an optical system to process information in two dimensions by using two different sets of parameters along the two orthogonal axes to encode the data. The fractional Fourier transform parameters along with the random-phase codes constitute the key to the encrypted data. The knowledge of the key is essential to the successful decryption of data. The decoding of the encoded data is done by use of phase conjugation. We present a few experimental results.
我们提出并演示了一种使用变形光学系统的分数傅里叶域加密全息存储器。加密是通过在分数傅里叶域中使用两个统计独立的随机相位码来完成的。如果这两个随机相位码是统计独立的白色序列,那么加密数据就是平稳白噪声。我们利用光学系统沿两个正交轴使用两组不同参数来处理二维信息的能力对数据进行编码。分数傅里叶变换参数与随机相位码一起构成了加密数据的密钥。密钥的知晓对于成功解密数据至关重要。编码数据的解码是通过相位共轭来完成的。我们展示了一些实验结果。