Phase retrieval technology based on multi-angle tilt light modulation

The non-interferometric phase retrieval technique based on the transport-of-intensity equation (TIE) is employed to calculate the missing phase information from the intensity measurement. However, since the limiting effect of the lens aperture is existed in the actual imaging system, a certain effect on the resolution of the recovery phase is under consideration. A phase retrieval technology based on multi-angle tilt light modulation is proposed. Firstly, a spatial light modulator (SLM) is introduced in the original lens-based intensity acquisition system. Then the modulation function is displayed on the SLM to make the parallel illumination into tilted illumination with various incident angles. Lastly, the recorded intensity images are synthesized to compute the phase information. The experimental results show that the proposed method can improve the resolution of recovery phase without compromising the numerical error of the recovery results.