Phase compensation for asynchronous sampling in digital off-axis holography

We present a new method based on Fourier transform to correct the frequency shift and compensate the phase in off-axis holography. First, we show detailed theoretical analysis about the frequency shift error caused by asynchronous sampling, and then the further errors in reconstructed phase associated with the frequency shift error are demonstrated. We use the artificial neural network algorithm to perform surface fitting with the discrete spectrum value, calculate the frequency shift error, and do the phase compensation. The necessity and validity of the phase compensation have been verified by both theoretical deduction and representative simulations. (C) 2015 Elsevier GmbH. All rights reserved.