Research On Error Analysis And System Optimization Of Aspheric Partial Compensatory Interferometric Testing Method

This dissertation mainly research on an aspheric partial compensatory testing method between null and nonnull. The method is general for aspheric testing because partial null lens(PNL) employed can partly compensate for aspherics with similar F-number. Based on system modeling, the reverse iterative optimization reconstruction technique(ROR) can reconstruct aspheric surface from the large aberration wavefront on the detector plane. It is possible to reach high precision by systematic error analysis and system optimization. The content of this dissertation include:After review of various applications and importance of aspheric testing, there is also a review over the current aspheric testing methods, especailly null and nonnull.The principle of partial null lens(PNL) compensating for aspherics is proposed in partial compensatory method. With series of partial null lens, normal aspherics can be tested universally. System modeling and omptization is present in optical software ZEMAX. Theory model of ROR technique is introduced which is convenient for analysis and processing of systematic error.Systematic error of aspheric partial compensatory testing system is analyzed and extracted. The influence of aligment error of PNL and aspheric such as tilt and decenter on aspheric reconstructed precision is simulated in ZEMAX, with conclusion that it is direct relationship between aligment error and aspheric reconstructed error and inverse relationship between aspheric F# and aspheric reconstructed error. Due to ignorable influence of PNL and obvious influence of aspheric, computer aid-aligment technique for aspheric aligment and Fiezau interference locating method for distance of PNL and aspheric are employed to meet system precision requirement. According to the result of error analysis and simulation, the method of ray trace based on system modeling and error storage is proposed to extract systematic error. Systematic error is categorized into two types, the error of testing path by ray trace in system modeling, and the rest from the interferometer excluding testing path by error storage.The validation experiment of aspheric partial compensatory testing system has been established and the testing experiment for paraboloid with F2.5 has been carried out. Comparison experiments show the aspheric surface reconstructed by ROR is good agreement with the result of autocollimation method and exact aspheric surface is obtained. In the experiment, the testing method of vertex radius of aspheric based on reverse optimization fuction is proposed, which can give an exact vertex radius with micron precision for high-precision surface testing.