绿光空间光干涉显微镜技术

Spatial-Light Interference Microscope Technology Using Green-Light

首先从理论上推导准相干或宽带光照明下空间光干涉光场的分布,由此可得准相干或宽带光照明下的四步相移法。其次,通过搭建绿光空间光干涉显微镜(SLIM)系统,以直径为6μm的聚苯乙烯微球分散于显微镜物镜用油模拟细胞的微环境。最后,利用4幅SLIM图像成功重建出油浸微球的相位分布,平均半径相对误差为6.5%,光程差体积相对误差为8.4%。由于相干光的四步相移法和宽带光的四步相移法重建结果相差较小,因此,在追求成像速度的场合且细胞厚度较小时,可不对四步相移法进行修正,以加快相位重建的速度。

In this study,we first derive the light field distribution for the spatial interference with quasi-coherent or broadband light illumination,so as to obtain a four-step phase shift corrected method for such an illumination.Second,we construct a spatial interference microscope system that uses green light and diluted 6-μm polystyrene microsphere into the microscopic objective oil to simulate microenvironment of a cell.Finally,using four of the spatial-interference images,we reconstruct the phase distribution of the oil-immersed microspheres.The relative error in the microsphere radius is 6.5%,and the relative error of optical path difference volume of the oil-immersed microsphere is 8.4%.By comparing these results with those achieved by the traditional four-step phase shift method,the improvement can be neglected.Therefore,in situations where the imaging speed is important and the observed cell is sufficiently thin,it is not necessary to use the corrected four-step phase-shift method to increase the imaging speed.