傅里叶叠层显微术的照明光强校正研究

Intensity Correction Research for Fourier Ptychographic Microscopy

傅里叶叠层显微术(FPM)是一种新型的计算显微成像技术,FPM与传统显微术照明方式不同,常采用可编程LED阵列进行不同角度照明,而LED灯珠发射光强与角度有关,随角度增大光强迅速减弱,不同角度照明光强不能保证一致,导致重建图像质量下降。因此,在进行相位迭代反演计算过程中,需要对不同角度照明拍摄的图像进行光强校正。介绍了不同角度照明光强不均一的原因,通过数值模拟,探讨了对不同角度照明光强进行校正的必要性,最后给出了物理上光强校正的实验结果。

Fourier ptychographic microscopy （FPM） is a recently developed computational microscopy. Different from the conventional microscopy, the FPM generally employs a programmable LED array as an illumination source for angular illuminations. The intensity of LED illumination is corresponding to the emitting angle. The luminous intensity decreases rapidly with the increasing of emitting angle. The illumination intensity of different angles cannot be consistent, which leads to the decline of the reconstructed image quality. Consequently, the intensity correction of low-resolution raw images is consequently needed before the iterative phase retrieval process. The reasons of the different angles of illumination intensity inhomogeneity are introduced. Numerical simulations demonstrate the necessity of the intensity correction. Finally, the experimental results of physical intensity correction are given.