A combination of electrically tunable lens with a microscope objective lens (MO) for multifocal plane imaging capability is proposed. The method aims at extending the depth of focus of the MO by changing its axial range and field of view. The combination is implemented in a common path off-axis digital holographic microscopy configuration experimentally and it achieves an axial scanning range of 363.5 μm. It utilizes image plane holography to obtain in-focus images throughout the axial range. The proposed method demonstrates its application in quantitative phase imaging of the USAF 1951 test chart and flowing red blood cells at different axial depths. An axial depth variation of 0.76 μm–0.81 μm is obtained between two consecutive focused planes. The results validate and postulate the advantage of the proposed method over traditional extended depth-of-focus algorithms. The quantitative and qualitative results exploit the possibility of using the proposed method further for localization and tracking of flowing microscopic samples.

提出了将电可调透镜与显微镜物镜（MO）结合使用以实现多焦平面成像的功能。该方法旨在通过更改MO的轴向范围和视场来扩展其焦深。该组合在共同的路径中实现离轴数字全息显微结构实验和它达到的363.5的轴向扫描范围μ米。它利用图像平面全息术来获得整个轴向范围内的对焦图像。所提出的方法证明了其在USAF 1951测试图定量相成像以及在不同轴向深度流动的红细胞中的应用。0.76的轴向深度变化μ M-0.81 μ在两个连续的聚焦平面之间获得m。结果证实并假设了所提出的方法相对于传统的扩展焦深算法的优势。定量和定性结果充分利用了所提出的方法对流动的微观样品进行定位和跟踪的可能性。