Temporal division for time-varying phenomena observation using off-axis digital holography

Off-axis digital holography can allow quantitative and visual measurement of time-varying phenomena using commercial camera. However, phase unwrapping or high-speed acquisition has to be employed to remove the static phase and carrier phase from the observed phase maps during the phase retrieval, resulting in high computational expense, high cost and/or low spatial resolution. Here, a temporal division method is developed to realize the retrieval without the help of phase unwrapping and/or high-speed acquisition. Due to the temporal division, the static phase and carrier phase can be removed before executing the arctangent operation to retrieve the observed phase maps. As a result, both the computational expense and the acquisition rate can be relieved. Some experiments are demonstrated that our approach can enable significant improvement of the retrieval speed and quality, and perform high impact application such as observing phenomena with large dynamic range and complex flow.