A Wavefront Restoration Method Based on Shack-Hartmann Wavefront Sensor

Abstract

The invention discloses a wavefront restoration method based on a Shack-Hartmann wavefront sensor. The method takes the correlation function of the theoretical far-field light intensity distribution and the measured far-field light intensity distribution as the objective function, and modulates the optimized random The parallel gradient descent method recovers the wavefront. The invention takes the far-field spot intensity distribution as the input of the algorithm, makes full use of the information in the sub-aperture, effectively reduces the dependence of the Shack-Hartmann wavefront sensor on the high-density sub-aperture, improves the wavefront restoration accuracy, and modulates the The factor modulates the Zernike coefficient disturbance in space and time, which can avoid the algorithm from falling into local optimum and speed up the algorithm convergence speed. Compared with the traditional Shack-Hartmann wavefront sensing algorithm, the present invention can restore the wavefront with higher accuracy under the same sub-aperture condition, and complete the wavefront restoration with a smaller number of sub-apertures under the same restoration accuracy, which is: Low-light, high-precision wavefront detection and other fields provide a new technical approach.

Description

technical field [0001] The invention belongs to the technical field of wavefront detection, in particular to a wavefront restoration method based on a Shack-Hartmann wavefront sensor. Background technique [0002] Phase measurement has always been one of the research hotspots in the optical field, and it is involved in many fields such as astronomical observation, optical detection, medical imaging, adaptive optics and so on. The existing mainstream phase measurement methods are mainly divided into three categories: interferometry, direct measurement and indirect measurement based on intensity distribution. Each type of method has its own unique advantages and is used in different occasions. Among them, the Shack-Hartmann wavefront sensor based on slope measurement has been widely used in various fields due to its advantages of fast measurement speed and high precision. [0003] The Shack-Hartmann wavefront sensor mainly divides and samples the wavefront through a microlens...

AI Technical Summary

Problems solved by technology

However, the wavefront information extracted by this method is limited, and there is an inherent contradiction between the measurement accuracy of the Shack-Hartmann wavefront sensor and the spatial sampling rate, which limits the measurement performance of the Shack-Hartmann wavefront sensor

[0004] How to improve the detection performance of the Shack-Hartmann wavefront sensor under low spatial sampling has always been one of the research hotspots. Some researchers have proposed to use GS algorithm, phase difference method and other methods to restore the wavefront according to the spot intensity distribution, and improve the The accuracy of wavefront restoration and the order of Zernike mode aberration reduce the number of sub-apertures, but this kind of algorithm is easy to fall into the local optimal solution, and it is difficult to effectively restore the wavefront when the incident wavefront distortion is large and the signal-to-noise ratio of the detection signal is low. forward

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