Simulation analysis of iterative wavefront reconstruction algorithm for center-offset radial shearing interference

In the measurement of radial shearing interference, the center-offset between beam expansion and beam shrinkage situation is a frequent event. In the case, the traditional wavefront reconstruction algorithms will introduce large reconstruction errors, and their applications are also challenged. The iterative wavefront reconstruction algorithm for center-offset radial shearing interference was derived. Through theoretical simulation, the influences of combined aberration, single-order Zernike aberrations, center offset and its calculation errors on reconstruction algorithms were analyzed. The results show that the proposed algorithm can accurately reconstruct the wavefront phase in the case of center offset between shearing beams, and its reconstruction accuracy is significantly better than that of traditional algorithm. Under the simulation conditions, the root mean square (RMS) value of wavefront error of the proposed reconstruction algorithm is not higher than 0.05 λ with the increase of center offset. However, the reconstruction error of traditional algorithm reaches 1.6 λ (RMS value) and is approximately linearly related to the center offset.