Nobukawa Teruyoshi, Nomura Takanori
Graduate School of Systems Engineering, Wakayama University, 930 Sakaedani, Wakayama 640-8510, Japan.
Faculty of Systems Engineering, Wakayama University, 930 Sakaedani, Wakayama 640-8510, Japan.
Polymers (Basel). 2017 Aug 18;9(8):375. doi: 10.3390/polym9080375.
Holographic recording media can store the amplitude and the phase, or the complex amplitude, of a beam on the basis of holography. Owing to this characteristic, digital data can be encoded onto the complex amplitude of a signal beam in holographic data storage. However, most of conventional holographic storage systems encode digital data onto the amplitude alone because there are difficulties for modulating and detecting the phase. To solve the difficulties, a holographic storage system using digital holographic techniques has been proposed. With the help of digital holographic techniques, it is possible to modulate and detect the complex amplitude of a signal beam. Moreover, the proposed system can modulate the complex amplitude of a reference beam. In this paper, by making use of the capability, a correlation-based multiplexing with uncorrelated reference beams is demonstrated in the proposed system. Multiple holograms can be recorded in the same volume of a recording medium with no need for mechanical movements. Experimental results show that the proposed system with a correlation-based multiplexing can improve the storage capacity and can utilize the full potential of a recording medium without crosstalk noise stem from the optical setup.
全息记录介质能够基于全息术存储光束的振幅、相位或复振幅。基于这一特性，数字数据可在全息数据存储中编码到信号光束的复振幅上。然而，大多数传统全息存储系统仅将数字数据编码到振幅上，因为相位调制和检测存在困难。为了解决这些困难，已提出一种使用数字全息技术的全息存储系统。借助数字全息技术，可以调制和检测信号光束的复振幅。此外，所提出的系统还可以调制参考光束的复振幅。在本文中，利用这一能力，在所提出的系统中演示了基于相关性的非相关参考光束复用。多个全息图可以记录在记录介质的同一体积中，无需机械移动。实验结果表明，所提出的基于相关性复用的系统可以提高存储容量，并能充分利用记录介质的潜力，而不会产生源于光学设置的串扰噪声。
