A customizable digital holographic microscope

We propose a low-cost, compact, and portable holographic microscope designed for the characterization of micrometric particles suspended in a liquid.
This system is built around a commercial optical microscope by substituting its illumination source (a light-emitting diode) with a collimated laser beam. Similarly, a quartz flow cell replaces the microscope glass slide using 3D-printed custom mounting.
With the hardware presented in this paper, the holographic imaging of the electromagnetic fields emitted by the objects that intercept the laser beam achieves a resolution close to that achieved with optical microscopes, but with a much larger depth of field.
Once a hologram is recorded, a variety of morphological and optical features, including particle projected section, aspect ratio, and extinction cross-section can be extracted.
Additionally, we introduce a remote system control that enables users to process the acquired holograms to a remote computational device.
This work encompasses a comprehensive description of the methodology of the image processing in holographic microscopy, and a series of validation measurements conducted using calibrated particles. This technique is suitable for the characterization of airborne particles found in snow, firn and ice; here we report experimental results obtained from Alpine ice cores.

We include the 3d printer design files, the Holography tutorial in jupyter, and the files to control remotely the camera, the Pycamera project in python

本项研究提出了一种低成本、紧凑便携的全息显微镜，旨在对悬浮于液体中的微米级颗粒进行表征。该系统基于商用光学显微镜构建，通过替换其照明光源（发光二极管）为平行激光束，并使用3D打印定制的安装支架替换显微镜载玻片。本论文中展示的硬件，通过全息成像技术捕捉拦截激光束的物体所发出的电磁场，其分辨率接近光学显微镜，但具有更大的景深。一旦记录全息图，即可提取多种形态和光学特征，包括颗粒投影截面、形状比和消光截面。此外，我们引入了一种远程系统控制，使用户能够将获取的全息图处理到远程计算设备。本研究全面阐述了全息显微镜图像处理的方法论，并使用校准颗粒进行了一系列验证测量。该技术适用于对雪、积雪和冰中发现的空气颗粒进行表征；在此，我们报告了从阿尔卑斯山冰芯获得的实验结果。我们还包含了3D打印机设计文件、Jupyter中的全息术教程以及控制远程相机的文件，以及Python中的Pycamera项目。