Shirakashi Zen, Goto Taichi, Takagi Hiroyuki, Nakamura Yuichi, Lim Pang Boey, Uchida Hironaga, Inoue Mitsuteru
Toyohashi University of Technology, 1-1 Hibarigaoka, Tempaku, Toyohashi, Aichi, 441-8580, Japan.
JST, PRESTO, 4-1-8 Honcho, Kawaguchi, Saitama, 332-0012, Japan.
Sci Rep. 2017 Oct 9;7(1):12835. doi: 10.1038/s41598-017-12442-z.
Hologram memory is expected to be the next-generation of optical data storage technology. Bismuth-substituted yttrium iron garnet is typically used for rewritable magnetic hologram media. The diffraction efficiency of magnetic holography depends on the Faraday rotation angle, but the experimental diffraction efficiency is not as high as that expected from calculations. This difference could be caused by incomplete magnetization reversal at the recorded region. In this study, we investigated the effects of magnetic assist (MA) recording through numerical simulation and experiment to improve the diffraction efficiency and the resulting reconstructed images. The improvement of diffraction efficiency was more effective in garnet films thinner than the width of a fringe, and a suitable value of the assist magnetic field was identified for the improvement. In addition, MA recording improved the intensity of reconstructed images and broadened the non-error recording conditions to the low energy region. This technique shows promise in improving the reconstructed quality of magnetic hologram data.
全息存储有望成为下一代光学数据存储技术。铋取代钇铁石榴石通常用于可重写磁全息介质。磁全息术的衍射效率取决于法拉第旋转角，但实验衍射效率不如计算预期的高。这种差异可能是由记录区域的磁化反转不完全引起的。在本研究中，我们通过数值模拟和实验研究了磁辅助（MA）记录对提高衍射效率和由此产生的重建图像的影响。对于比条纹宽度更薄的石榴石薄膜，衍射效率的提高更为有效，并确定了用于改善的辅助磁场的合适值。此外，MA记录提高了重建图像的强度，并将无误记录条件扩展到低能量区域。该技术在提高磁全息数据的重建质量方面显示出前景。
