Chinese Optics Letters, Vol. 17, Issue 12, 121101 (2019)
Piston sensing via a dispersed fringe sensor with a merit-function-based active scanning algorithm at low light levels
Yongfeng Zhang1,2,3, and Hao Xian1,2,*
- 1Key Laboratory on Adaptive Optics, Chinese Academy of Sciences, Chengdu 610209, China
- 2Institute of Optics and Electronics, Chinese Academy of Sciences, Chengdu 610209, China
- 3University of Chinese Academy of Sciences, Beijing 100049, China
Dispersed fringe sensors are a promising approach for sensing the large-scale physical step between adjacent segments with acceptable accuracy. However, the nature of dispersion in a dispersed fringe sensor leads to the ideal dispersed fringe pattern becoming vulnerable to noise, particularly at low light levels. A reliable merit-function-based algorithm with an active actuation is introduced here. The feasibility of our algorithm is numerically demonstrated, and Monte Carlo experiments for different signal-to-noise ratios are conducted to assess its robustness. The results show that the method is valid even when the signal-to-noise ratio is as low as 1.