Xiu P, Liu Q, Zhou X, Xu Y, Kuang C, Liu X
State Key Laboratory of Modern Optical Instrumentations, College of Optical Science and Engineering, Zhejiang University, Hangzhou, 310027, China.
Key Laboratory of Biomedical Engineering of Ministry of Education, Department of Biomedical Engineering, Zhejiang Provincial Key Laboratory of Cardio-Cerebral Vascular Detection Technology and Medicinal Effectiveness Appraisal, Zhejiang University, Hangzhou, 310027, China.
J Microsc. 2018 May;270(2):235-243. doi: 10.1111/jmi.12677. Epub 2018 Jan 11.
The refractive index (RI) of a sample as an endogenous contrast agent plays an important role in transparent live cell imaging. In tomographic phase microscopy (TPM), 3D quantitative RI maps can be reconstructed based on the measured projections of the RI in multiple directions. The resolution of the RI maps not only depends on the numerical aperture of the employed objective lens, but also is determined by the accuracy of the quantitative phase of the sample measured at multiple scanning illumination angles. This paper reports an analogous on-axis interference TPM, where the interference angle between the sample and reference beams is kept constant for projections in multiple directions to improve the accuracy of the phase maps and the resolution of RI tomograms. The system has been validated with both silica beads and red blood cells. Compared with conventional TPM, the proposed system acquires quantitative RI maps with higher resolution (420 nm @λ = 633 nm) and signal-to-noise ratio that can be beneficial for live cell imaging in biomedical applications.
样品的折射率（RI）作为一种内源性造影剂，在透明活细胞成像中起着重要作用。在层析相显微镜（TPM）中，可以基于在多个方向上测量的RI投影来重建三维定量RI图。RI图的分辨率不仅取决于所使用物镜的数值孔径，还由在多个扫描照明角度下测量的样品定量相位的精度决定。本文报道了一种类似的同轴干涉TPM，其中样品光束和参考光束之间的干涉角在多个方向的投影中保持恒定，以提高相位图的精度和RI断层图的分辨率。该系统已通过二氧化硅珠和红细胞进行了验证。与传统TPM相比，所提出的系统能够获取具有更高分辨率（在λ = 633 nm时为420 nm）和信噪比的定量RI图，这对于生物医学应用中的活细胞成像可能是有益的。
