New needs to measure soft matter at micro-/nanoscale: a new possibility thanks to digital holography

The digital holography method has been implemented to several industrial systems with the aim of improving new products by quantitative measurement. Nowadays, digital holography (DH) has been considered an important measurement tool, owing to the abilities of non-contact, label-free, quantitative, high-resolution and real-time. The inherent characteristics of DH makes it a powerful tool for visualization and testing of soft matter, as well as in-situ and real-time characterization of bottom-up fabrication processes. Herein, we report the most useful applications of soft matter, where the capabilities offered by DH, such as three-dimensional (3D) imaging, extended focus, 3D tracking, full-field analysis, high sensitivity, and wide measurement's range, permit completely non-invasive characterizations on a full-scale. Taking the advantages of DH measurement, the possibility of numerically managing the complex wavefront scattered or transmitted by the sample under investigation allows the extraction of all information through a full-digital modality. Meanwhile, the numerical diffraction propagation process allows object imaging well-in-focus during dynamic process. This also creates the possibility to retrieve phase-contrast maps that enable quantitative measurements of the sample in full-field mode and 3D. Moreover, DH measurement has good ability to manage and remove aberrations in the optical system using simple and flexible methods, thus simplifying the optical apparatus and measurement operations. Owing to these unique features of DH, we have possibility to better study the world of soft-matter.