Holotomography merges holography and tomography to solve the challenge of recovering light phase shifts to generate image contrast in Quantitative Phase Imaging. HT illuminates a cell with very low power visible light at various illumination angles and measures the phase delay of the transmitted light. Holotomography’s advantages lie in its capability to provide non-invasive, label-free 3D images of live cells, allowing real-time studies while the measurement of RI tomogram also allows quantitative analysis. Its data acquisition speed surpasses traditional methods, making it invaluable for quick results in medical diagnostics and drug research.