Digital holographic microscopy (DHM) is a technique that has high potential for analyzing biological samples and has been successfully applied to the study of cells and cell lines providing information about important parameters such as refractive index, morphology, and dry mass, among others; it has also found applicability to study the effects of therapeutic treatments. Finding the size and shape of cells is important since they tend to change in the presence of some pathologies. In this research work, we obtain the morphology thickness and refractive index of the A375 melanoma cell line through a slight tilting of the cell in a DHM setup. Further, the development of a novel mathematical expression based on this tilt and in the optical phase difference is presented. We show images of melanoma cells with the refractive index information included, and their morphology thickness as rendered from the holographic phase maps recorded with DHM.

Today digital holographic interferometry (DHI) is considered a modern full-field non-destructive technique that allows generating 3D quantitative data of a wide variety of specimens. There are diverse optical setups for DHI that enable the study of specimens in static and dynamic conditions: it is a viable alternative to characterize a wide diversity of parameters in the micro and macro world by conducting repeatable, reliable and accurate measurements that render specimen data, e.g., displacements, shape, spatial dimensions, physiological conditions, refractive indices, and vibration responses. This paper presents a review and progress on the most significant topics, contributions and applications involving DHI for the study of different specimens such as: cells, bio tissues, grains, insects, and nano-structures. For most of the research work involving macro and micro specimens the wave-like source used in the measurements were photons from a laser, while the studies carried out in the nano regime used the wave-like nature of the electron.

Many models and methods commonly used in colorimetry have been incorporated to the study and knowledge of the colorimetric properties in the reflection color holograms; these methods have reported the possibilities of color reproduction in holograms. One method is based in calculating the color differences between the CIE-L*a*b* coordinates of the original object compared to the same values obtained for the reconstructed hologram; these values are calculated through the measurement of the spectral composition of the light in the reproduced hologram which are made with spectrometers. Other methods are based in the use of cameras for the color measurement, although, they are not commonly used for that ending in holography. This work presents the results of a comparative study between the use of spectrometers and RGB digital cameras for the color measurement in holograms. The diffraction efficiency of the holograms for a GretagMacbeth Colorchecker samples is measured through a spectrometer and their CIE-L*a*b* coordinates are calculated; the color differences are also calculated by taking as theoretical values the coordinates of the original object. A similar procedure is made by capturing the reconstructed images of the hologram through a CMOS-RGB camera, which requires a linearizing and characterizing procedure. The RGB coordinates of the original object are compared with the RGB coordinates of the reproduced hologram too.

No abstract