提出了一种用于长工作距离下显微成像的数字全息合成孔径方法。首先, 在不同斜入射照明条件下记录多幅包含不同物光频谱范围的数字全息图。然后, 利用每一幅全息图通过数字方法重构并放大物体强度像。最后, 通过非相干叠加这些强度像得到分辨力提高且散斑噪声减小的合成物体强度像。理论分析和实验结果表明, 此方法可应用于长工作距离下的原位显微观测。

A high-resolution and long working distance digital holographic microscopy is proposed based on synthetic aperture method. A series of digital holograms are successively recorded, which cover different spatial frequency ranges scattered from the object, with different tilted object illuminations. Subsequently, the intensity image is numerically reconstructed and magnified for each digital hologram. Finally, a synthetic image with the resolution improved and speckle noise suppressed is obtained by synthesizing the reconstructed images. The theory and experimental results show that the proposed method can be easily used in in-situ microscopy at a long working distance.