Moving grating‐based laser heterodyne digital holographic microscopy system for measuring dynamic phase of living cell attachment

Abstract

We propose a laser heterodyne digital holography microscopy system based on a moving grating, which uses the Doppler principle between a moving grating and beam to achieve a low‐frequency bias between the diffracted beams, abandoning traditional heterodyne digital holography that requires multiple acousto‐optic modulators. The dynamic phase distribution obtained using the laser heterodyne digital holography phase‐reconstruction algorithm was more realistic and analyzable than the results of the angular spectrum algorithm. The structure and algorithm were used to capture the shape characteristics of mouse fibroblasts after ~2 h of incubation (37°C, 5% CO2), and the dynamic phase distribution of the cells was monitored in real‐time during the attachment process. The system proposed in this study, with its high spatial resolution and high‐precision phase measurement capability, is suitable for both static and live cells.