The Application Of Hartmann-Shack Wavefront Sensor In Testing Of Laser Wavefront And Laser Beam Quality

The application of Hartmann-Shack wavefront sensor in testing of laser wavefront and laser beam quality is presented in the theses. The algorithms of fitting wavefront and laser power distribution are provided and the accuracy is theoretically analyzed. The application of Hartmann-Shack wavefront sensor in Adaptive Optics is used for reference. By selecting a normative plane wave as a benchmark for relative test, the influence of system error and random error such as machining error of optical components, background noise is in some extent eliminated, therefore the accuracy and the degree of automatic processing can be promoted. In the measurement of wavefront slope, a sub-pixel method is used to increase the accuracy of locating the light spot mass centers which are formed at a CCD sensing surface when a testing light wave passes through the Hartmann-Shack sensor. In the wavefront reconstruction, a modal wavefront estimation method (i.e. wavefront fitting with Zernike polynomials) is used, therefore the aberration types of wavefront can be well understood and the high accuracy can be obtained. In fitting the laser power distribution, Double Cubic B Spline Function is used for surface fitting of the distribution. The surface patches are naturally linked and the whole distribution surface is smooth. Laser wavefront testing is successfully performed by using Hartmann-Shack wavefront sensor and laser beam quality parameters are obtained at the same time. A simple and feasible method of wavefront and laser beam quality test with high accuracy, high sensitivity is provided.