Diagnosing the evolution of laser-generated high energy density (HED) systems is fundamental to develop a correct understanding of the behavior of matter under extreme conditions. Talbot–Lau interferometry constitutes a promising tool, since it permits simultaneous single-shot X-ray radiography and phase-contrast imaging of dense plasmas. We present the results of an experiment at OMEGA EP that aims to probe the ablation front of a laser-irradiated foil using a Talbot–Lau X-ray interferometer. A polystyrene (CH) foil was irradiated by a laser of 133 J, 1 ns and probed with 8 keV laser-produced backlighter radiation from Cu foils driven by a short-pulse laser (153 J, 11 ps). The ablation front interferograms were processed in combination with a set of reference images obtained ex situ using phase-stepping. We managed to obtain attenuation and phase-shift images of a laser-irradiated foil for electron densities above ${10}^{22}\;{\mathrm{cm}}^{-3}$ . These results showcase the capabilities of Talbot–Lau X-ray diagnostic methods to diagnose HED laser-generated plasmas through high-resolution imaging.

在显微成像领域中，高成像质量图像的获取与良好的照明方式息息相关。传统显微镜使用聚光透镜来提供均匀强度的照明，调节聚光透镜的光阑匹配不同放大倍率的物镜。然而无色生物细胞的光学吸收系数低，在传统显微镜下难以观测到其细节信息。为了突破传统显微镜的成像功能，本文设计了一种可调控的显微镜聚光镜模块，通过将小型扭曲液晶器件嵌入聚光透镜的后焦面处，调控液晶器件的对光的透过效果可以实现明场成像以及差分相衬成像。系统由一款商用显微镜改装而成，液晶器件尺寸为22 mm×18 mm，实现了系统的高度集成化。通过实验验证了系统的成像性能，实现了对微凸透镜样品的定量相位重建，实验与理论曲线的互相关系数达到0.994 9，并且通过胚胎干细胞的重建展示了系统在实际应用中的效果。

The most recent discoveries in the biochemical field are highlighting the increasingly important role of lipid droplets (LDs) in several regulatory mechanisms in living cells. LDs are dynamic organelles and therefore their complete characterization in terms of number, size, spatial positioning and relative distribution in the cell volume can shed light on the roles played by LDs. Until now, fluorescence microscopy and transmission electron microscopy are assessed as the gold standard methods for identifying LDs due to their high sensitivity and specificity. However, such methods generally only provide 2D assays and partial measurements. Furthermore, both can be destructive and with low productivity, thus limiting analysis of large cell numbers in a sample. Here we demonstrate for the first time the capability of 3D visualization and the full LD characterization in high-throughput with a tomographic phase-contrast flow-cytometer, by using ovarian cancer cells and monocyte cell lines as models. A strategy for retrieving significant parameters on spatial correlations and LD 3D positioning inside each cell volume is reported. The information gathered by this new method could allow more in depth understanding and lead to new discoveries on how LDs are correlated to cellular functions.The most recent discoveries in the biochemical field are highlighting the increasingly important role of lipid droplets (LDs) in several regulatory mechanisms in living cells. LDs are dynamic organelles and therefore their complete characterization in terms of number, size, spatial positioning and relative distribution in the cell volume can shed light on the roles played by LDs. Until now, fluorescence microscopy and transmission electron microscopy are assessed as the gold standard methods for identifying LDs due to their high sensitivity and specificity. However, such methods generally only provide 2D assays and partial measurements. Furthermore, both can be destructive and with low productivity, thus limiting analysis of large cell numbers in a sample. Here we demonstrate for the first time the capability of 3D visualization and the full LD characterization in high-throughput with a tomographic phase-contrast flow-cytometer, by using ovarian cancer cells and monocyte cell lines as models. A strategy for retrieving significant parameters on spatial correlations and LD 3D positioning inside each cell volume is reported. The information gathered by this new method could allow more in depth understanding and lead to new discoveries on how LDs are correlated to cellular functions.

目前针对双相位光栅干涉仪灵敏度的分析存在着灵敏度模型不合理、理论结果不完整等问题，制约着系统灵敏度的提高。对此，提出了新的灵敏度模型，即物体所产生的条纹移动与光源位置变化产生的条纹移动是等效的。该灵敏度模型将物体对X射线的折射作用转化成了光源的移动，同时巧妙地利用了系统的劳条件将光源移动与成像条纹移动联系起来。利用新的灵敏度模型，成功获取了双相位光栅干涉仪和Talbot-Lau干涉仪的灵敏度，为优化系统灵敏度提供了理论指导。

Non-interferometric X-ray quantitative phase imaging (XQPI), much simpler than the interferometric scheme, has provided high-resolution and reliable phase-contrast images. We report on implementing the volumetric XQPI images using concurrent-bidirectional scanning of the orthogonal plane on the optical axis of the Foucault differential filter; we then extracted data in conjunction with the transport-intensity equation. The volumetric image of the laminate microstructure of the gills of a fish was successfully reconstructed to demonstrate our XQPI method. The method can perform 3D rendering without any rotational motion for laterally extended objects by manipulating incoherent X-rays using the pinhole array.

Applying an ultrafast vortex laser as the pump, optical parametric amplification can be used for spiral phase-contrast imaging with high gain, wide spatial bandwidth, and high imaging contrast. Our experiments show that this design has realized the 1064 nm spiral phase-contrast idler imaging of biological tissues (frog egg cells and onion epidermis) with a spatial resolution at several microns level and a superior imaging contrast to both the traditional bright- or dark-field imaging under a weak illumination of 7nW/cm2. This work provides a powerful way for biological tissue imaging in the second near-infrared region.

限制自适应光学（Adaptive Optics, AO）系统表现的一个关键因素是由波前传感器所在路径和科学成像路径之间差异引起的非共光路像差（Non-Common Path Aberration,NCPA），同时AO系统共光路部分也会不可避免地引入静态像差。为此，本文提出了一种基于焦面点扩散函数（Point Spread Function,PSF）复制的技术，用于校正AO系统中的静态像差。此技术利用点光源产生的PSF图像作为参考图像，通过迭代优化算法控制可变形镜改变其面型，将参考PSF图像复制到AO系统科学成像路径。实验结果表明，校正后的斯特列尔比（Strehl Ratio，SR）从初始的0.312提高到0.995。此技术可以稳定、快速地获得全局校正结果，特别是在系统具有较大的初始静态像差时。