Experiment and theory of beam smoothing using induced spatial incoherence with a lens array

The smoothing effect of induced spatial incoherence combined with a lens array on a large-bandwidth and short-coherence-time laser is reported. A theoretical model based on statistical optics is developed to describe the spatial and temporal characteristics of the focal spot. Theoretical simulation is consistent with the experimental results. A method was proposed to remove or reduce the residual interference fringes of the experimental focal spot, and both the simulation and analysis show that this method does not affect the smoothing speed of the focal spot. (C) 2020 Optical Society of America