Experimental results of phase retrieval with reduced noise using inline digital holography and an iterative method

Digital holographic microscopy is a method used to retrieve microscopic phase objects. However, the limited CCD bandwidth, used to record the hologram, and the aberrations of imaging lens add some noise into the retrieval process. In this context, the use of referenceless on axis digital holography is highly convenient due to the simplification of the required optical setup. However, the amount of noise, due to the conjugate and zero-order terms in the holograms tend to increase, because these hologram terms are overlapped with the signal term. We propose to enclose the object in a pupil and use this information to obtain an approximation of the object phase. This approximation is used in an iterative method, where the recovered field is cleaned from the conjugate and zero order hologram terms. Moreover, we show that the distortion introduced by loss of high frequency information, in the retrieval process, can be compensated with the iterative method. The simulation of this method had been proved with good results and they present a fast convergence of the algorithm. In this work we present the first experimental results applying this method.