Dual wavelength digital holography phase unwrapping by linear regression

Digital holography records the superposition of the object and reference waves. The subsequent reconstruction of both amplitude and phase of the optical field is done by numerically propagating the optical field along the direction perpendicular to the hologram plane in accordance with the laws of diffraction. Phase changes undergone by a light wave passing through or reflecting from objects can be converted to the optical thickness or height measurements, providing the three dimensional structural information about the object. Our dual wavelength phase imaging method allows three dimensional measurements of a wide variety of biological systems and microstructures.