Research On Wavefront Sensing Technology With Computational Light Field Imaging

Coherent optical communication has attracted widespread attention due to its high detection sensitivity,multiple modulation methods and high security.Due to the randomness of the atmospheric turbulence,the wavefront of the signal beam propagating along through the atmospheric turbulence is distorted,and the mixing efficiency of the coherent communication system is reduced.Adaptive optics is considered as an effective way to compensate the wavefront aberrations of the signal beam,which can stabilize the communication link.Computational light field imaging can simultaneously record the position and direction of signal at the same time,and computational light field imaging is applied to the field of adaptive optical wavefront sensing,the wavefront distortion information can be calculated by light field data.Therefore,it is of great practical significance to carry out research on the wavefront sensing technology with computational light field imaging.In this thesis,the perfornance of the wavefront sensing with the computational light field imaging is studied and verified by relevant experiments.The main contributions are listed as follows:1.According to the system composition of the computational light field imaging,the optical effects of optical components in wavefront sensing process are described in detail.Under the influence of the interference effect between the lenslets,a theoretical model of the wavefront sensing with computational light field imaging based on phase mask is established.2.Taking the wavefront aberration simulated by Zernike polynomial as the research object,the ability of the wavefront sensing technology with computational light field imaging to recover the wavefront phase is simulated and analyzed.The effects of spatial resolution and aberration size on its recovery accuracy are discussed.3.An experimental system for the wavefront sensing technology with computational light field imaging is established.The source of the experimental error is analyzed and the method of reducing errors is proposed.Using the experimental system to realize an experimental study on wavefront phase recovery for wavefront aberrations.Several experimental results prove the correctness and effectiveness of the theoretical analysis.The research results show that the wavefront sensing technology with computational light field imaging can effectively recover the wavefront aberration.The recovery accuracy of the wavefront sensing technology with computational optical field imaging is easily affected by spatial resolution and spatial frequency resolution.For the determined phase plane,there is an optimal spatial resolution and spatial frequency resolution to maximize the recovery accuracy.For higher-order aberrations,increasing spatial resolution and spatial frequency resolution can effectively improve recovery accuracy.