Research On Large Field-of-view Wavefront Measurement Technology Based On Light Field Segmentation

During the observation of stars in the sky by telescopes,high-altitude atmospheric turbulence can drastically change the refractive index of the air during the transmission of light waves,which will cause blurred imaging and seriously affect the observation results.Adaptive optical system is one of the most effective methods to overcome the effects of atmospheric turbulence at the current stage.However,its problems such as non-equal halo and small field of view make it powerless to expand the target,so researchers have proposed multiple layers.Conjugate Adaptive Optics(MCAO)aim at these problems.Because MCAO uses multiple wavefront detectors to simultaneously detect multiple fields of view,this greatly increases the complexity of the system and is expensive,which makes it difficult to promote it in practical applications.The light field camera is a new type of wavefront sensor.Its special optical structure makes it have natural large field of view wavefront detection characteristics.It can obtain wavefront distortion information in multiple directions of sight through a single exposure.The front detection field has good application prospects.In this paper,the large-field wavefront detection capability of the light-field camera wavefront sensor is studied in-depth theoretically and verified in experiments.The main tasks are as follows:1.Based on the research status of wavefront detection in adaptive technology,the current challenges and limitations in traditional wavefront detection are proposed.The domestic and foreign research status of the light field camera as a new type of wavefront sensor is introduced.It can obtain wavefront distortion information in multiple field directions through a single exposure.This advantage fully demonstrates that The field of large-field wavefront detection has good application prospects.2.The mathematical theoretical model of the light field camera wavefront sensor is derived using wave optics theory.By comparing the detection principle of the light field camera wavefront sensor with the traditional Shaker-Hartman wavefront sensor,the light field camera wave is summarized.The advantage of the front sensor is that the field of view of the wavefront detection is large,and the advantage of the traditional Shack-Hartmann wavefront sensor is that the wavefront restoration accuracy is high.Subsequently,the large-field wavefront detection capability of the light-field camera wavefront sensor was studied theoretically,and the wavefront reduction capability was qualitatively analyzed from the main aspects such as dynamic range and sensitivity.3.Relying on the derived mathematical theoretical model and combining MATLAB with numerical simulation of light field camera wavefront sensors.Numerical simulations are performed for single-order Zernike mode wavefront aberrations,multi-order Zernike mode wavefront aberrations,and multi-field Zernike mode wavefront aberrations.Simulation results show that the light field camera wavefront sensor can accurately Restore the incident wavefront information.In order to verify the correctness of the theoretical derivation,a light-field camera wavefront sensor was designed and the initial calibration of the light-field camera wavefront sensor was completed.Then,a wavefront detection system was established,and the lightfield camera wavefront sensor was used to detect wavefronts in multiple fields of view at the same time.The results show that the lightfield camera wavefront sensor can effectively detect large field of view wavefronts.