可见光域多波长叠层衍射成像的实验研究

运用模拟实验和光学实验研究了叠层衍射成像中波长数量和噪声对复原结果的影响. 模拟结果表明, 在多波长叠层衍射成像中, 复原质量随波长数量的增加而不断提高并最终达到一定极限. 光学实验以不同样品进行实验验证, 进一步研究了增加波长与随之引入噪声及系统复杂度间的制约关系. 研究发现, 并非波长越多成像效果越好, 而可能存在一个最优的成像条件. 利用所建实验装置, 在双波长照明条件下取得了相对最优的成像效果. 本结论对提高叠层衍射成像的质量具有现实意义.

Experimental study on multi-wavelength ptychographic imaging in visible light band

We perform a series of computer simulations and optical experiments for multiple-wavelength ptychographic imaging to analyze the relationship between the imaging quality and the magnitude of wavelength. Two kinds of samples including the grating-like and the biological sample are tested. Our experimental results are highly consistent with simulations, demonstrating the feasibility and effectiveness of the multiple-wavelength ptychography. Compared with the single-wavelength ptychographic imaging, it can achieve very good imaging quality with a fast speed of iterative convergence and a high robustness to the noises in the case of multiple-wavelengh ptychography. In addition, optical experiments also reveal that with the magnitude of wavelength increasing, the complexity of the ptychographic system is grown up within increased noises and errors, which causes the imaging quality to keep no enhancement or even to get worse. For our concrete configuration in this paper, with a simple digital procedure for noise depressing, the best results may be obtained for the case of dual-wavelength. Furthermore, it implies that there is an optimized condition for multiple-wavelength ptychography. We find that it requires mainly analyzing the balance between the multiple-wavelength-benefited noise-resistance and the systematic complexity for the optimized condition, which may be really important and meaningful for the practical utilizing of multiple-wavelength ptychography.