Soto Juan M, Rodrigo José A, Alieva Tatiana
Appl Opt. 2018 Jan 1;57(1):A205-A214. doi: 10.1364/AO.57.00A205.
Quantitative label-free imaging is an important tool for the study of living microorganisms that, during the last decade, has attracted wide attention from the optical community. Optical diffraction tomography (ODT) is probably the most relevant technique for quantitative label-free 3D imaging applied in wide-field microscopy in the visible range. The ODT is usually performed using spatially coherent light illumination and specially designed holographic microscopes. Nevertheless, the ODT is also compatible with partially coherent illumination and can be realized in conventional wide-field microscopes by applying refocusing techniques, as it has been recently demonstrated. Here, we compare these two ODT modalities, underlining their pros and cons and discussing the optical setups for their implementation. In particular, we pay special attention to a system that is compatible with a conventional wide-field microscope that can be used for both ODT modalities. It consists of two easily attachable modules: the first for sample illumination engineering based on digital light processing technology; the other for focus scanning by using an electrically driven tunable lens. This hardware allows for a programmable selection of the wavelength and the illumination design, and provides fast data acquisition as well. Its performance is experimentally demonstrated in the case of ODT with partially coherent illumination providing speckle-free 3D quantitative imaging.
定量无标记成像作为研究活微生物的一种重要工具，在过去十年中受到了光学领域的广泛关注。光学衍射层析成像（ODT）可能是应用于可见光范围内宽视场显微镜的定量无标记三维成像最相关的技术。ODT通常使用空间相干光照明和专门设计的全息显微镜来进行。然而，ODT也与部分相干照明兼容，并且正如最近所证明的那样，通过应用重聚焦技术可以在传统宽视场显微镜中实现。在这里，我们比较这两种ODT模式，强调它们的优缺点，并讨论其实现的光学设置。特别地，我们特别关注一种与传统宽视场显微镜兼容的系统，该系统可用于两种ODT模式。它由两个易于连接的模块组成：第一个基于数字光处理技术用于样品照明工程；另一个使用电驱动可调谐透镜进行焦点扫描。这种硬件允许对波长和照明设计进行可编程选择，并且还提供快速数据采集。在部分相干照明的ODT情况下，其实验性能得到了证明，可提供无散斑的三维定量成像。
