Quantitative Phase Contrast Digital Holographic Microscopy in Biophotonics

Label-free, non-contact, non-destructive, on-line (video repetition rate), high resolution, full field (no scanning), quantitative analysis of morphology and dynamic processes in living cells are required features in life science research and medical diagnostics. Digital Holography combined with microscopic imaging provides these features simultaneously. The modular integration of digital holographic microscopy (DHM) into commercial microscopes yields an axial resolution with interferometric resolution while the lateral resolution is diffraction limited. As amplitude and phase are available by numerical reconstruction from a single digital hologram subsequent automated focus correction is enabled. The evaluation of quantitative digital holographic phase contrast images permits also an effective detection of lateral object movements. Thus, 3D tracking is achieved. The applicability of DHM techniques for dynamic live cell analysis is demonstrated by results from tumor cells and human erythrocytes.