The fine tracking system is important to improve the performance of orbital angular momentum (OAM) space optical communication system. In order to improve the accuracy and stability of the centroid algorithm, this article proposes a modified algorithm to detect the center position of OAM light beam. The modified algorithm firstly takes a binary-conversion with the threshold based on the intensity profile of OAM beam, and then calculates the center position of the light spot using centroid algorithm. The threshold for binary-conversion of Laguerre-Gaussian (LG) beam is obtained by theoretical analysis and numerical calculation. The accuracy, stability and complexity of the modified algorithm are studied by numerical simulation. The results show that the new algorithm, compared with the centroid algorithm, has 2 orders of magnitude higher in computing accuracy and 3∼4 orders of magnitude higher in stability. However, the computing time has increased by about 1.5 times compared with the centroid algorithm.

Date Published: 5 January 2017
PDF: 6 pages
Proc. SPIE 10244, International Conference on Optoelectronics and Microelectronics Technology and Application, 1024409 (5 January 2017); doi: 10.1117/12.2264542

Published in SPIE Proceedings Vol. 10244:
International Conference on Optoelectronics and Microelectronics Technology and Application
Shaohua Yu; Jose Capmany; Yi Luo; Yikai Su; Songlin Zhuang; Yue Hao; Akihiko Yoshikawa; Chongjin Xie; Yoshiaki Nakano, Editor(s)