Multiple-Wavelength Phase Retrieval With Digital Holographic Microscopy

The phase of an image is very important because it is the phase, not the amplitude, that carries most of the information in an image. A traditional bright-field microscope only captures the amplitude information from a sample, and are therefore not of great use in applications where the sample is partially or totally transparent. Digital Holographic Microscopy (DHM) provides a phase retrieval technique that can obtain both the amplitude and phase of a sample. In this thesis, an iterative phase retrieval method for DHM using two illumination wavelengths is proposed which exhibits high immunity to noise and yields wrap-free phase images of biological samples when the image is reconstructed. Experimental results of human cheek cells, human blood smear, and neurons are presented to demonstrate the approach