Wave-front Test By Sub-aperture Stitching Technique Based On Shack-Hartmann Wave-front Sensor

As one of the key technical specifications, excellent image quality is the goal of the design and construction of great ground-based telescope. The need to study fainter and further objects has naturally led to telescopes of ever large diameter. some advantage technologies, such as active optics and adaptive optics, have played an important role in great ground-based telescope. These change and technologies bring challenges for the image quality test of traditional telescope. At the same time, the development of science and technology leads to advanced test devices and methods, which work quicker, give more sensitive and more accurate test results. In this situation, it needs to take modified or brand new devices and methods to test the image quality of modern great telescopes.This thesis gives a summary about the image quality test methods and devices for telescopes, advantages and disadvantages of each method are summarized. The ground-based telescope is traditionally test by autocollimation against a flat mirror. As the aperture of telescope goes larger, this can not be performed any more because of the more severe limitation of unstable environment and impracticably flat mirror. The solution of testing wave-front by sub-aperture stitching technique based on Shack-Hartmann wave-front sensor is introduced. This solution is broken into two relative parts. The topic of the first part is the design and constructing Shack-Hartmann wave-front sensor, including the way of choosing hardware component, the design of relay optics, wave-front reconstruction algorithm and software; In the second part, Sub-aperture test are studied when Shack-Hartmann sensor is used as wave-front test device, the detail including the method to locate sub-aperture, wave front testing and sub-aperture stitching algorithm. Moreover, A 32 units Shack-Hartmann wave-front sensor is used for testing a optical system 1.8 times larger than sub-aperture and the sub-aperture test results are stitched by two different ways. These research and experiment lays a foundation for optical shop test of image quality of great telescopes.