High resolution test for large optics with sub-pixel phase retrieval method

摘要

For large mirror test, there is growing need to increase the spatial resolution of the test instrument, when testing large optics. A novel test method is introduced to achieve high spatial resolution based on phase retrieval method that splits each pixel of CCD into sub-pixels by numeric processing. Because the more images are captured, the more information of wave front is gathered to confirm the state of each sub-pixel, the sub-pixel phase retrieval needs multi-images and also more calculation power to process these images. Numerical experiments shows that more than 4 times of resolution of traditional phase retrieval method can be achieved by this method .