Statistical measurement of power spectrum density of large aperture optical component

According to the requirement of ICF, a method based on statistical theory has been proposed to measure the power spectrum density(PSD) of large aperture optical components. The method breaks the large-aperture wavefront into small regions, and obtains the PSD of the large-aperture wavefront by weighted averaging of the PSDs of the regions, where the weight factor is each region’s area. Simulation and experiment demonstrate the effectiveness of the proposed method. They also show that, the obtained PSDs of the large-aperture wavefront by statistical method and sub-aperture stitching method fit well, when the number of small regions is no less than 8×8. The statistical method is not sensitive to translation stage’s errors and environment instabilities, thus it is appropriate for PSD measu