Numerical Simulation and Experimental Confirmation on Reconstruction of Bessel Beam

The Bessel beam has the characteristics of non-diffraction and reconstruction, and has important application value in the fields such as optical tweezers and biological imaging. Based on the angular spectrum theory, the reconstruction behavior of the Bessel beam blocked by obstacles is analyzed, and the cross-correlation coefficient is used to characterize the similarity of the cross-section intensity distributions of the reconstructed Bessel beam and the original one, thus to determine the recovery distance in the simulation, and get the influence of different obstacles on Bessel beam reconstruction. The simulation results show that the relationship between the recovery distance and the obstacle size is not simply linear. The recovery distance will only increase when the obstacle blocks more sidelobes and the off-axis obstacle causes longer recovery distance than that of the on-axis obstacle. For on-axis obstacles, when their sizes are smaller than the hollow areas of the high-order Bessel beam, the high-order Bessel beam has a stronger self-healing ability. In the experiment, the spatial light modulator is used to generate a flexible Bessel beam to verify the simulation results. The experimental results are in good agreement with the simulation results, which indicates that the cross-correlation method based on the angular spectrum theory can accurately simulate the reconstruction characteristics of Bessel beam.