Research On Aberration Correction Of Imaging System Based On Computational Adaptive Technology

In traditional optical imaging,the simplification and high imaging quality of the imaging system are often contradictory.In this paper,the correction of imaging system aberrations in simple optical systems is studied.This study is based on computational adaptive optics.The direct image of the optical system is used as the intermediate image,and the image after the aberration correction is the final image,which improves the imaging quality indirectly.This study is expected to reduce the difficulty of optical system design.Based on the diffraction transmission theory and the phase retrieval algorithm,a model solving the pupil function of the optical system is established.The feasibility of the model is verified by gradient descent algorithm,Fletcher-Reeves(FR)conjugate gradient algorithm and stochastic parallel gradient descent algorithm.Comparing these three algorithms,the result shows that the stochastic parallel gradient descent method has the best convergence.Based on solving the system pupil function,a model of the system aberration correction filter under the condition of coherent illumination is established.The feasibility that system aberration can be corrected by aberration correction filter in small field-of-view imaging is verified by simulation.Then,the effect of using aberration correction filter to correct aberrations of defocused imags is analyzed.The result proves that within a certain range of the axial defocus,the aberration correction filter still can correct the image.Furthermore,the effect of distance error on aberration correction in experiments is studied by simulation.This distance error is caused by the inability to accurately locate the focus position of lens in experiments.The result shows that when the distance error is within 0.1 mm,aberrations in images can be effectively corrected.A small field-of-view optical system is built to image a test target.First the wavefront function of the exit pupil is solved.The system aberration correction filter is established.Then correct the image of the test target.The resolution of the corrected image is significantly improved.It proves that the aberration correction method proposed in this paper can be used to correct the aberrations of the imaging system.