强激光与粒子束2011，Vol.23Issue(6)：1492-1496,5.DOI:10.3788/HPLPB20112306.1492
利用Cramér-Rao理论研究相位差法的最佳离焦量
Optimum defocus diversity in phase diversity wave-front sensing using Cramér-Rao theorem
李斐 1饶长辉2
作者信息
- 1. 中国科学院光电技术研究所,成都610209
- 2. 中国科学院自适应光学重点实验室,成都610209
- 折叠
摘要
Abstract
Phase diversity wave-front sensing(PDWFS) is a method for estimating wave-front aberrations from two (or more) images whose pupil phases differ from one another with a known diversity phase. It can be used to estimate wave-front for point source as well as extended source. The accuracy of the estimate is relied on the diversity phase and is always given quantitatively in Cramer-Rao theorem. With defocus is used as the diversity mode, the effect of the object and the aberration on the optimum defocus is studied using Cramer-Rao theorem in this paper when the photons is enough. The results show that the optimum defocus does not depend on the peak-to-valley value or the spatial frequency of the aberration observably in the case of point source. For extended source, although the optimum defocus does not depend on the spatial frequency of the aberration, it increases as the aberration increases. Besides, the optimum defocus depends on the structure of the object instead of the extent. In the imaging process, when the crosstalk of each point of the object increases, the optimum defocus should be larger.关键词
波前传感技术/最佳离焦量/Cramér-Rao下限/相位差法Key words
wave-front sensing/optimum defocus/Cramer-Rao lower band/phase diversity分类
数理科学引用本文复制引用
李斐,饶长辉..利用Cramér-Rao理论研究相位差法的最佳离焦量[J].强激光与粒子束,2011,23(6):1492-1496,5.
