卤素灯照明光栅衍射共路数字全息显微定量相位成像

Halogen-Light Quantitative Phase Imaging with Common-Path Digital Holographic Microscopy Based on Grating Diffraction

数字全息显微术是数字全息术和光学显微术相结合的定量相位成像技术。为克服高相干光源(激光)照明产生的散斑噪声和寄生条纹噪声,以及参物光路分离系统结构的不稳定性(易受外界震动干扰),实现了白光照明(卤素灯照明)的基于光栅衍射的共路离轴数字全息显微定量相位成像。首先基于理论分析和计算,得出系统可采用的光学元件参数和系统结构参数;然后建立了一套卤素灯照明的光栅衍射共路数字全息显微成像系统;最后对系统的成像准确度和时空噪声进行了测量。实验结果表明,该系统具有高准确度的成像性能,并具有非常高的时空敏感性(空间噪声为0.6nm,时间噪声为0.04nm)。

In order to eliminate a large amount of speckle noise and parasitic interference fringes noise caused by high coherence light source（laser）,as well as the effects from the mechanical vibrations and air fluctuations which typically affect any uncommon-path interferometric system,we design and establish a white-light（halogen-light）common-path digital holographic microscope based on the grating diffraction.First,the parameters of the selected optical elements and the optical system are derived by theoretical analysis and calculation.Then,a common-path offaxis digital holographic microscope based on grating diffraction,which uses a halogen lamp as the illumination light source,is constructed.At last,the imaging accuracy and the spatiotemporal noise of the system are measured.Experimental results demonstrate that the established digital holographic microscope has a very high accurate imaging performance and spatiotemporal sensitivity with the spatial noise of 0.6 nm and the temporal noise of0.04 nm.