Advancements in Digital Holography for Crystalline Material Characterization: A Review (Invited)

As an interferometric imaging method, digital holography has shown its unique potential in many fields, especially in the mature and diverse fields of crystallography. Compared to early microscopy imaging and X-ray diffraction approach, this technique captures and accurately reproduces the three-dimensional information of the crystal in real time. It offers advantages such as fast imaging, nondestructive testing, and optimized data processing. This review discusses the progress of digital holography in crystallography, covering crystallization, mineral imaging, and microstructure analysis of two-dimensional materials. The reconstruction of copper sulfate pentahydrate and sodium chloride crystallization serves as an example to demonstrate its powerful ability. Particular emphasis is placed on the advancement of optical instruments and the development of image reconstruction approaches. Regarding the solutions to problems such as dataset processing and field of view limitations, this paper summarizes the research results of combining digital holography with deep learning algorithm models and the free field of view method. In addition, the operating principle of the technology is expounded and the future development direction is also prospected.