Research Of Laser Small-scale Distorted Wavefront Sensing Accuracy And Error Analysis

The control of laser beam quality is one of important basis which ensure the circulating security of the laser system and enhancing power effectively in the field of high power laser system, in which the diagnosis and control of small-scale distorted wavefront is a key issue. In this paper, the laser small-scale distorted wavefront sensing accuracy and measurement error are theoretically analyzed and experimentally researched, using the Fresnel zone plate arrays as wavefront sensor. The main research contents and innovative results can be summarized as follows:1. According to the principle of Hartmann- Shack wavefront sensor (HS WS), we put forward the Fresnel zone plate arrays as wavefront sensor. Also, We discuss the sensitivity and dynamic range of the HSWS and analyze the focus characteristic of the Fresnel zone plate array by experiment.2. We analyze the influence of the random noise of light source and the structure of Fresnel zone plate arrays on the wavefront reconstruction, and this study will offer reference in optimizing design of the system and practical operation in the measurement and control of small-scale distorted wavefront.3. According to analyzing the five kinds of inhibiting noise methods, the two nonlinear filtering algorithms are showed to be the optimal selection. Also, we apply Bi-cubic interpretation to light spot image in order to improve accuracy of centriod algorithm.4. We propose another new centriod algorithm based on optimizing detecting window in order to improve the centroid detecting precision and raise the wavefrontreconstruction accuracy.5. We build an adaptive optical system for the measurement of distorted wavefront of the long-focus lens and plane crystal glasses. The elementary experimental results prove the validity and stability of the new centroid algorithms based on optimizing detecting window and Bi-cubic interpretation presented in the paper.Our research results provide valuable reference to the real project in enhancement of the detecting accuracy in the laser small-scale distorted wavefront measurement.