Multiplane differential phase contrast imaging using asymmetric illumination in volume holographic microscopy

• Published in: Journal of biomedical optics Vol. 25; no. 12; p. 123704
• Main Authors: Chia, Yu-Hsin, Vyas, Sunil, Tsai, Jui-Chang, Huang, Yi-You, Yeh, J. Andrew, Luo, Yuan
• Format: Journal Article
• Language: English
• Published: United States Society of Photo-Optical Instrumentation Engineers 01.12.2020; S P I E - International Society for
• Subjects: Asymmetry; Charts; Diagnostic Tests, Routine; Fourier transforms; Function analysis; Holography; Illumination; Image acquisition; Image contrast; Image enhancement; Imaging techniques; Lighting; Methods; Microscopy; Microscopy, Phase-Contrast; Modulation transfer function; Phase contrast; Semiconductor devices; Special Series on Biomedical Imaging and Sensing; Thin film transistors; Thin films; volume gratings; holography; microscopy; imaging systems; diffraction gratings; illumination design
• ISSN: 1083-3668; 1560-2281; 1560-2281
• DOI: 10.1117/1.JBO.25.12.123704

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.