Das Bhargab, Joseph Joby, Singh Kehar
Photonics Group, Physics Department, Indian Institute of Technology Delhi, New Delhi, 16, India.
Appl Opt. 2010 Feb 10;49(5):781-9. doi: 10.1364/AO.49.000781.
We investigate for suitable methods that enable reliable content-addressable data search in a defocused volume holographic data storage system. Two techniques have been introduced and are shown to overcome the shortcomings of the known methods used to perform content searching in defocused holographic recording geometry. In effect, we remove the deterministic errors that result because of the presence of nonmatching database records, producing almost the same correlation scores as the true targeted correlation scores. Such deterministic errors give rise to erroneous search outcomes and reduce the speed advantage of the parallel holographic data search. We present experimental results and discuss the improvements offered by the two introduced methods in terms of storage density and measured correlation scores. Both the methods of modified-balanced and 25% sparse modulation coded data pages are found to produce good results, negating the undesired correlation characteristics.
我们研究了适用于在散焦体全息数据存储系统中实现可靠的内容可寻址数据搜索的方法。已经引入了两种技术，并且已证明它们克服了用于在散焦全息记录几何结构中执行内容搜索的已知方法的缺点。实际上，我们消除了由于存在不匹配的数据库记录而导致的确定性误差，产生了几乎与真正的目标相关分数相同的相关分数。这种确定性误差会导致错误的搜索结果，并降低并行全息数据搜索的速度优势。我们展示了实验结果，并讨论了这两种引入的方法在存储密度和测量的相关分数方面所带来的改进。发现修改平衡和25%稀疏调制编码数据页这两种方法都产生了良好的结果，消除了不期望的相关特性。
