High-precision phase extraction of biological tissues based on lateral shear with zig-zag scanning in off-axis digital holography.

We propose a method combining off-axis digital holography (DH) with one-dimensional (1D) lateral shear based on Zig-zag scanning to extract high-precision phase distribution of biological tissues. Firstly, object wavefront is reconstructed using the numerical reconstruction algorithm from digital hologram. Secondly, Zig-zag scanning is introduced to reorder the object wavefront from matrix to 1D vector, allowing the retrieved phase value to change smoothly without value saltation. Then, 1D lateral shear process is performed to acquire the shear vector, from which the phase difference vector is extracted by arctangent calculation. Given the small amount of shear, the phase difference vector is extracted without unwrapping process. Afterwards, the phase vector is obtained through numerical accumulation. Finally, the real phase distribution matrix is retrieved by inverse Zig-zag scanning. The proposed method has high precision in phase extraction of biological tissues. The simulated and experimental results demonstrate the feasibility and precision superiority of the proposed method. [ABSTRACT FROM AUTHOR]