针对空间光干涉望远镜提出了一种基于四棱锥波前传感器的相位平移误差检测与闭环校正方法.该方法依次在三种不同波长条件下, 用四棱锥传感器检测两两子镜间的平移误差, 并依据实时测量结果控制子镜产生相应的校正平移量, 直到将平移误差校正到所用半波长的整数倍, 而后根据已知的波长数据和子镜平移量数据计算得到真实的平移误差, 进而对平移误差进行闭环校正.以两个子镜构成的空间望远镜为研究对象, 对该检测与闭环校正方法进行了仿真验证.仿真结果表明, 该方法可在500 μm范围内对相位平移误差进行准确闭环校正, 具有纳米级的精度与良好的重复性.

For the Fizeau optical interferometric telescope system, the co-phasing detection of piston errors between subapertures plays an important role in realizing the high resolution of system. In this paper, the relationship between piston error and the main peak displacement of monochromatic interferogram of two sub-aperture system is analyzed based on physical principles, then the piston error detecting method is developed and clarified based on their linear relationship in the range of one wavelength. Furthermore, an innovative co-phasing detecting method based on grating dispersed interferogram with bandwidth light source is proposed, and its feasibility, detecting precision and dynamic range are analyzed in theory and studied in simulation. The results prove that with this method, the piston error between the two sub-apertures of the system can be soundly detected and its measuring error is less than 20 nm while the piston error is not more than 50 μm. In addition, the novel method solves the problems of 2π ambiguity and direction determination that might exist within some other detecting methods. Besides its millimeter level dynamic range, this new co-phasing detecting method provides a new way and an effective reference for in-depth research of co-phasing detecting techniques.

用Z-扫描技术研究了各向同性手性介质(聚酯酰亚胺吡啶溶液)对于左、右圆偏振光的非线性圆双折射,得到在低光强下非线性旋光角的变化规律,验证了非线性圆双折射与非线性旋光的关系。