Research On Wavefront Reconstruction And Calibration Method Of Hybrid Modulation Shearing Interferometric

The quadriwave lateral shearing interferometry wavefront measurement technique based on amplitude and phase hybrid modulation has the characteristics of a compact system structure,strong anti-interference capability,and large dynamic range.Compared with the Shack-Hartmann wavefront measurement technique,it has higher spatial resolution and wide application prospects in high-power laser system beam quality diagnosis,optical processing,system installation and adjustment testing,industrial surface morphology detection,and quantitative phase imaging of live cells.With the increasing precision of optical manufacturing,higher requirements have been needing for wavefront measurement accuracy.According to the principle of shearing interferometry,wavefront reconstruction accuracy and shearing calibration accuracy are the main factors affecting the measurement accuracy of the hybrid modulation shearing interferometry wavefront.Traditional zonal wavefront reconstruction has the problem of accumulating noise error along the integration path,and traditional shearing calibration accuracy is limited by the detector’s pixel spatial resolution.Therefore,how to improve the accuracy of wavefront reconstruction and shearing calibration accuracy of hybrid modulation shearing interferometry is a technical problem that needs to be solved urgently.The main research contents of this thesis are as follows:1 、 The theory of quadriwave lateral shearing interferometry wavefront measurement based on hybrid modulation is explained in this.The simulation platform of hybrid modulation shearing quadriwave lateral shearing interference based on scalar diffraction theory is established.On this basis,the characteristics of several filtering window functions used in wavefront reconstruction methods are analyzed,and the influence of shearing on the dynamic range,sensitivity,and measurement accuracy of quadriwave lateral shearing interferometry wavefront measurement is analyzed.2、A wavefront reconstruction method based on the integration path guidance of quadriwave lateral shearing interferometry is proposed,and a deviation model of differential phase derivative is established to guide the wavefront reconstruction path,which prevents the propagation and accumulation of noise errors along the integration direction and provides the wavefront reconstruction algorithm.The proposed algorithm is theoretically simulated and analyzed,and an experimental verification device based on a pure phase-type liquid crystal spatial light modulator is designed and built.The proposed method and traditional methods are compared and analyzed,and the superiority of the proposed method is verified.3、The shear calculation models based on plane waves and spherical waves are theoretically derived,and the influence of wavefront curvature radius on shear under the spherical wave calibration mode is analyzed.On this basis,a shear calibration method based on spherical wave multi-step optimization is proposed,and the calibration algorithm is provided.The proposed algorithm is theoretically simulated and analyzed,and an experimental device is designed and built to verify the proposed calibration method.The results show that the shear calibration accuracy of the proposed method is better than 1.7 ?m,proving the effectiveness of the proposed method in this thesis.