Xie Zhongye, Tang Yan, Feng Jinhua, Liu Junbo, Hu Song
Opt Express. 2019 Apr 15;27(8):11721-11733. doi: 10.1364/OE.27.011721.
A differential optical sectioning microscopy with structured-illumination (DOSM-SI) with enhanced axial precision is explored in this paper for three-dimensional (3D) measurement. As the segment of data on the linear region of the contrast depth response curve (CDR) is very sensitive to variation of the height information, the DOSM-SI introduces a new CDR2 with an axial shift to intersect the linear region of the CDR1, which is achieved by using two charge-coupled detectors (CCDs) in the optical path. The CCD1 is located on the imaging plane and the CCD2 is displaced from the imaging plane. The difference between the CDR1 and CDR2 for each pixel is defined as the differential depth response curve (DCDR). Further, the zero-crossing point of the DCDR for each pixel is accurately extracted using the line-fitting technique, and finally, the sample surface can be reconstructed with a high resolution and precision. Since the slope around the zero-crossing point of the DCDR is apparently larger than that of near the focal position, an enhanced resolution and precision can be realized in DOSM-SI. The experiments and theoretical analysis are elaborated to demonstrate the feasibility of DOSM-SI.
本文探索了一种具有增强轴向精度的结构照明差分光学切片显微镜（DOSM-SI）用于三维（3D）测量。由于对比度深度响应曲线（CDR）线性区域的数据段对高度信息的变化非常敏感，DOSM-SI引入了一个具有轴向偏移的新CDR2，使其与CDR1的线性区域相交，这是通过在光路中使用两个电荷耦合探测器（CCD）来实现的。CCD1位于成像平面上，而CCD2偏离成像平面。每个像素的CDR1和CDR2之间的差异定义为差分深度响应曲线（DCDR）。此外，使用直线拟合技术精确提取每个像素的DCDR的过零点，最后，可以以高分辨率和高精度重建样品表面。由于DCDR过零点周围的斜率明显大于焦点位置附近的斜率，因此在DOSM-SI中可以实现增强的分辨率和精度。阐述了实验和理论分析以证明DOSM-SI的可行性。
