Ahmad Azeem, Kumar Anand, Dubey Vishesh, Butola Ankit, Ahluwalia Balpreet Singh, Mehta Dalip Singh
Opt Express. 2019 Feb 18;27(4):4572-4589. doi: 10.1364/OE.27.004572.
Multi-spectral quantitative phase imaging (QPI) is an emerging imaging modality for wavelength dependent studies of several biological and industrial specimens. Simultaneous multi-spectral QPI is generally performed with color CCD cameras. Here, we present a new approach for accurately measuring the color crosstalk of 2D area detectors, without needing prior information about camera specifications. Color crosstalk is systematically studied and compared using compact interference microscopy on two different cameras commonly used in QPI, single chip CCD (1-CCD) and three chip CCD (3-CCD). The influence of color crosstalk on the fringe width and the visibility of the monochromatic constituents corresponding to three color channels of white light interferogram are studied both through simulations and experiments. It is observed that presence of color crosstalk changes the fringe width and visibility over the imaging field of view. This leads to an unwanted non-uniform background error in the multi-spectral phase imaging of the specimens. The color crosstalk of the detector is observed to be the limiting factor for phase measurement accuracy of simultaneous multi-spectral QPI systems.
多光谱定量相位成像（QPI）是一种新兴的成像方式，用于对多种生物和工业样本进行波长相关研究。同步多光谱QPI通常使用彩色CCD相机进行。在此，我们提出一种新方法，无需相机规格的先验信息就能准确测量二维面积探测器的颜色串扰。使用紧凑干涉显微镜对QPI中常用的两种不同相机，即单芯片CCD（1-CCD）和三芯片CCD（3-CCD），系统地研究并比较了颜色串扰。通过模拟和实验研究了颜色串扰对与白光干涉图的三个颜色通道对应的单色成分的条纹宽度和可见度的影响。观察到颜色串扰的存在会改变成像视场中的条纹宽度和可见度。这在样本的多光谱相位成像中导致了不必要的非均匀背景误差。观察到探测器的颜色串扰是同步多光谱QPI系统相位测量精度的限制因素。
