Application Of Differential Scanning Pentaprism In Wavefront Detection

With the development of science and technology, high precision large apertureoptical system has been widely used and development in the field of space optics,the detection and identification of foundation of space target and so on. However, thehigh precise wavefront test of large-aperture optical system has been restricted bythe large-scale and expensive testing instruments and the high machining precisionof part of the detection accessories. It has become the current focus of research thatthe detection of large aperture optical system with the methods of lower cost,without accessories, more flexible and more stable.The method of differential scanning pentaprism wavefront detection is proposedin this paper. There are many characteristics such as low cost, convenient operation,simple manufacturing process, without accessories, high precise wavefront test,stable Measurement results and so on. This method is the optimization of scanningpentaprism detection. The wavefront is divided into several sub-wavefront byscanning pentaprism. Firstly, the information of wavefront curvature is obtained bymeasuring wavefront slope change to reconstruct the wavefront. The system errorchanging the slope is decreased at the expenses of twice the number of samplingpoint. The wavefront error instructed by inaccurate center of mass calibration in thismethod is eliminated simultaneously. Then, the differential scanning pentaprism wavefront detection system isestablished to verify the feasibility of this method. Lastly, the error analysis is given.The system has been used for different aperture optical system wavefront detection.The wavefront detection accuracy could reach10nm and the repeat accuracy couldbe achieved within1/250λ through comparative analysis with the measurementresults of ZYGO interferometer and reproducibility tests under laboratory conditions.Finally, detailed measurements and theoretical analysis is given. In this paper, awavefront detection method of high precision and low cost is provided. And anavailable real-time wavefront detection instrument has been developed.