Significance: Differential phase contrast (DPC) is a well-known imaging technique for phase imaging. However, simultaneously acquiring multidepth DPC images is a non-trivial task. We propose simultaneous multiplane DPC imaging using volume holographic microscopy (VHM). Aim: To design and implement a new configuration of DPC-VHM for multiplane imaging. Approach: The angularly multiplexed volume holographic gratings (AMVHGs) and the wavelength-coded volume holographic gratings (WC-VHGs) are used for this purpose. To obtain asymmetric illumination for DPC images, a dynamic illumination system is designed by modifying the regular Köhler illumination using a thin film transistor panel (TFT-panel). Results: Multidepth DPC images of standard resolution chart and biosamples were used to compare imaging performance with the corresponding bright-field images. An average contrast enhancement of around three times is observed for target resolution chart by DPC-VHM. Imaging performance of our system is studied by modulation transfer function analysis, which suggests that DPC-VHM not only suppresses the DC component but also enhances high-frequency information. Conclusions: Proposed DPC-VHM can acquire multidepth-resolved DPC images without axial scanning. The illumination part of the system is adjustable so that the system can be adapted to bright-field mode, phase contrast mode, and DPC mode by controlling the pattern on the TFT-panel.

中文翻译：

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在体全息显微镜中使用不对称照明的多平面微分相衬成像


意义：微分相衬（DPC）是一种众所周知的相位成像技术。然而，同时获取多深度 DPC 图像并不是一项简单的任务。我们建议使用体积全息显微镜 (VHM) 进行同步多平面 DPC 成像。目的：设计并实现用于多平面成像的 DPC-VHM 新配置。方法：角度复用体全息光栅（AMVHG）和波长编码体全息光栅（WC-VHG）用于此目的。为了获得 DPC 图像的不对称照明，通过使用薄膜晶体管面板（TFT 面板）修改常规科勒照明来设计动态照明系统。结果：使用标准分辨率图表和生物样本的多深度 DPC 图像来将成像性能与相应的明场图像进行比较。通过 DPC-VHM 观察到目标分辨率图平均对比度增强约三倍。通过调制传递函数分析研究了我们系统的成像性能，这表明DPC-VHM不仅抑制了直流分量，而且增强了高频信息。结论：所提出的 DPC-VHM 无需轴向扫描即可获取多深度分辨 DPC 图像。系统的照明部分可调，通过控制TFT面板上的图案，系统可以适应明场模式、相衬模式和DPC模式。