Combining lateral shear interferometry with digital holography for quantitative phase microscopy

By combining the concept of Lateral Shear Interferometry (LSI) with Digital Holography we demonstrate that quantitative phase microscopy (QPM) can be used for investigation in different field of applications. The proposed approach gives some important advantages compared to other methods used for QPM. The method is a true single image QPM approach. In fact by using the digital shear of the reconstructed phase map in the image plane the defocus aberration introduced by the microscope objective can efficiently removed. In addition in most cases the unwrapping procedure can be avoided greatly simplifying the phase-map recovery for quantitative measurement. Numerical lateral shear of the reconstructed wave front in the image plane makes it possible to retrieve the derivative of the wave front. In analogy with the standard procedure usually applied in optical testing by means of LSI, the wave front can be reconstructed.