Phase retrieval and phase derivative determination in digital holography

With the advent of CCD camera and the rapid development of computer technology, digital holographic technique has recently attracted much attention from various research fields. This paper presents spatial phase retrieval techniques in digital holography. In the spatial domain, a novel method using the concept of complex phasor is proposed to determine the phase difference map in digital holography. A simple method based on finite difference is also proposed to compute high quality phase derivatives. Based on a deformation phase map obtained by the complex phasor method, slope, curvature and twist maps can be determined. Unwrapped derivative maps can be determined directly from a wrapped phase map without any phase unwrapping process. Simulation and experimental results demonstrate that the proposed method has high measurement accuracy and can effectively determine high resolution phase derivative with less computational effort. It is shown that the proposed techniques can effectively and accurately overcome theoretical and application problems in digital holography. 2014.