Kong Shuai, Peng Junjie, Fu Youyi, Wei Xinyu
Appl Opt. 2017 Dec 10;56(35):9620-9628. doi: 10.1364/AO.56.009620.
Optical computing has advantages over electronic computing because it can carry much more information and process more data bits. Providing that carry-look-ahead is applied in optical computing in the same way electronic computing accomplishes addition calculation, it will be more inefficient because of the delay caused by a large number of serial carries. On the basis of the research on relations among the augend, addend, results, and the redundancy of modified signed-digit (MSD) number, the implementation method of carry-free one-step MSD addition is presented. Meanwhile, the corresponding logical light path scheme is designed in this paper. Extensive experimental results show that the proposed implementation method of one-step addition is correct, and the designed light path scheme is reasonable.
光学计算相对于电子计算具有优势，因为它可以承载更多信息并处理更多数据位。如果在光学计算中像电子计算完成加法运算那样应用先行进位，由于大量串行进位导致的延迟，它将效率更低。基于对被加数、加数、结果以及修正符号数（MSD）的冗余之间关系的研究，提出了无进位一步MSD加法的实现方法。同时，本文设计了相应的逻辑光路方案。大量实验结果表明，所提出的一步加法实现方法是正确的，并且所设计的光路方案是合理的。
